Skip to content

Patients › General-Health

Mga Nerve Test at Conduction Study

What nerve conduction studies and EMG are, why they are done for carpal tunnel and other nerve problems, what to expect, and how accurate they are.

Updated Oct 2026
Isang nerve conduction study: isang probe sa bisig na may mga electrode lead sa kamay.
Sinusukat ng mga nerve conduction study kung gaano kahusay nagdadala ng mga signal ang mga nerve, na tumutulong sa pag-diagnose ng carpal tunnel at iba pang problema sa nerve. Kieran Hirpara 4.0

Ang pahinang ito ay isinalin ng makina at hindi pa nasusuri ng isang doktor. Ang bersyong Ingles ang siyang opisyal.

Ano ito

Sinusukat ng mga nerve test kung gaano kahusay nagdadala ng mga electrical signal ang iyong mga nerve. May dalawang electrical na paraan upang suriin ang paggana ng nerve, at kapwa napatunayang kapaki-pakinabang ang mga ito sa praktika [1]. Ang pangunahing test ay tinatawag na nerve conduction study. Nagpapadala ang isang maliit na device ng napakaliit na pulse sa iyong nerve at itinatala kung gaano kabilis dumadaloy ang signal. Kung naiipit o napinsala ang isang nerve, bumabagal o humihina ang signal.

Pinakamadalas gamitin ang mga test na ito para sa carpal tunnel syndrome, kung saan nasa ilalim ng pressure ang nerve sa harapan ng iyong pulso. Itinuturing ang mga ito na isang hindi maaaring mawalang bahagi ng pagsusuri bago ang operasyon para sa kondisyong iyon [2]. Karamihan sa mga doktor ay hindi mag-oopera nang walang ganitong kumpirmasyon [3]. Makatutulong din ang mga test sa iba pang problema sa nerve, gaya ng pressure sa nerve sa siko (cubital tunnel syndrome) [4].

Karaniwang magkakaroon ka ng pangalawang test sa parehong pagbisita. Para rito, inilalagay ang isang pinong karayom sa ilang kalamnan. Sinusuri nito kung gaano kahusay tumutugon ang mga kalamnan sa nerve na nagsusuplay sa kanila. Kapag pinagsama, tinatawag ang mga ito na electrodiagnostic studies, na ang ibig sabihin lamang ay mga test na gumagamit ng kuryente upang pag-aralan ang mga nerve at kalamnan.

Gumagana ang mga test dahil nagdadala ng mga signal ang mga nerve gaya ng pagdadala ng kuryente ng mga kawad. Ang naiipit na nerve ay kumikilos na parang naipit na kable, kaya naaantala o humihina ang signal sa kahabaan nito. Nagbibigay ang mga resulta ng sukat kung gaano kapinsala ang nerve, at ito ang pinakamahusay na makukuhang palatandaan ng pangkalahatang kalubhaan ng sakit [5]. Ang halaga ng mga test na ito ay nasa pagkuha ng tamang diagnosis at sa pagtasa kung gaano ito kalala, hindi sa paghula kung ano ang mararamdaman mo pagkatapos ng operasyon [6].

Isang puntong mabuting malaman: hindi inaalis ng normal na test ang posibilidad ng carpal tunnel syndrome, dahil maaaring dumating at umalis ang pagkaipit ng nerve.

Gumagana ba ito?

Ang tapat na sagot ay mahusay ang mga test na ito sa ilang trabaho at limitado sa iba. Kapaki-pakinabang na karagdagan ang mga ito kapag sinusuri ang carpal tunnel syndrome, lalo na kapag normal ang lumabas sa mga karaniwang test [7]. Natuklasan ng isang pag-aaral ng isang espesyal na nerve test na natukoy nito ang kondisyon sa 69% ng mga kaso, at tama ang bawat positibong resulta. Nang pagsamahin ang test na iyon at ang isa pang paraan ng pagsukat ng pakiramdam, natukoy nito ang 84% ng mga kaso [8].

Tumutulong din ang mga test na kumpirmahin ang diagnosis bago ang operasyon. Kapag tumuturo ang iyong mga senyales at sintomas sa banayad hanggang katamtamang pressure sa nerve at isinasaalang-alang ang operasyon, maaaring pataasin ng karagdagang pagsusuri ang tsansa na nakatutok ang operasyon sa isang tunay at nagagamot na problema [9]. Natuklasan ng isang pag-aaral ang malaking agwat sa pagitan ng bilang ng mga taong na-diagnose batay sa sintomas lamang (73%) at ng bilang na nakumpirma ng mga test na ito at ng ultrasound (51%) [10]. Ang agwat na iyon mismo ang dahilan kung bakit mahalaga ang pagsusuri: inaalam nito kung sino talaga ang may problema sa nerve na matutulungan ng operasyon.

May mga limitasyon. Iba-iba ang kalidad ng mga test na ito sa pagitan ng mga provider, at mas detalyado ang ilang ulat kaysa sa iba [11]. Kailangan ding mas malinaw na tukuyin ang mga pamantayan sa pagbasa sa mga ito, upang tumpak ang mga diagnosis at hindi magsagawa ng operasyon kapag hindi ito kailangan [12]. At hindi kayang sabihin sa iyo ng mga test ang lahat. Sinusukat nila ang nerve, hindi ang iyong mga sintomas.

Magkakahalo ang ilang natuklasan. Hindi naging makabuluhan sa loob ng dalawang taon ang mga pagbabago sa mga resulta ng test pagkatapos ng steroid injection [13]. Sa kabilang banda, ang magandang tugon sa isang iniksyon ay isang kapaki-pakinabang na senyales kung paano maaaring maging resulta ng operasyon [14]. Ang isang sukat mula sa mga test, na tinatawag na distal motor latency, na ang ibig sabihin lamang ay kung gaano katagal bago umabot ang signal sa isang kalamnan, ay may kaunting halaga sa paghula kung ano ang magiging lagay mo pagkatapos ng operasyon [15].

Kaya mahusay na gumagana ang mga test bilang kasangkapan sa pag-diagnose. Hindi sila gaanong maaasahan bilang bolang kristal para sa iyong paggaling.

Ano ang mga panganib?

Ligtas ang mga nerve test, ngunit dapat mong malaman kung ano ang aasahan. Ang pinakakaraniwang epekto ay hindi komportableng pakiramdam habang isinasagawa ang test mismo. Ang mga electrical pulse ay parang maliliit na tapik o kirot. Kung maglalagay ng pinong karayom sa isang kalamnan, makararamdam ka ng maikling hapdi, at maaaring mangalay ang kalamnan nang isa o dalawang araw pagkatapos. Mabilis ang bersyon ng test sa palasingsingan at napakaliit ng pagod na idinudulot nito sa iyo [16].

Walang pangmatagalang epekto sa iyong balat o tissue ang mga electrical pulse. Maliliit ang mga pulse, at dumadaan ang mga ito sa balat nang hindi ito pinipinsala. Kung magkakaroon ka ng needle test, maaaring bahagyang masakit kapag hinawakan ang mga lugar na tinusukan ng karayom, at maaaring lumitaw ang maliit na pasa. Kusang humuhupa ang mga ito.

Hindi inilalarawan ng ebidensya ang mga epekto sa iba pang bahagi ng iyong katawan, at hindi nito inilalarawan ang mga bihira ngunit malubhang komplikasyon mula sa mga test na ito. Mabuting sabihin iyon nang tahasan: ang mga pag-aaral sa likod ng pahinang ito ay nag-uulat kung gaano kahusay nagda-diagnose at humuhula ang mga test, hindi tungkol sa mga pinsala, kaya limitado ang impormasyon dito tungkol sa malulubhang panganib.

Ang isang panganib ay hindi pisikal. Maaaring magkakaiba ang pagbasa ng iba't ibang provider sa mga test, at mas detalyado ang ilang ulat kaysa sa iba [11]. Ang isang ulat na naglilista ng maliliit na abnormalidad nang hindi ipinapaliwanag ang mga ito ay maaaring humantong sa maling konklusyon [17]. Kailangan ding mas malinaw na tukuyin ang mga pamantayan sa pagbasa sa mga test, upang tumpak ang mga diagnosis at hindi magsagawa ng operasyon kapag hindi ito kailangan [12]. Ito ang pangunahing bagay na maaaring magkamali: hindi ang test mismo, kundi isang diagnosis na nakabatay sa isang hindi kumpleto o hindi malinaw na ulat.

Kung nagkaroon ka ng steroid injection para sa carpal tunnel syndrome, hindi naging makabuluhan sa loob ng dalawang taon ang mga pagbabago sa mga resulta ng test pagkatapos ng iniksyong iyon [13]. Ibig sabihin, mukhang hindi binabago ng iniksyon ang ipinapakita ng mga test sa mas mahabang panahon, kaya dapat pa ring magbigay ng patas na larawan ng iyong nerve ang isang inulit na test pagkatapos ng iniksyon.

Hilingin sa iyong doktor o sa taong gumagawa ng test na ipaliwanag sa iyo ang ulat. Ang malinaw na paglalarawan kung ano ang natuklasan ng test, at kung ano ang ibig sabihin nito, ay bahagi ng isang mabuting resulta.

Tama ba ito para sa iyo?

Kung tumuturo ang iyong mga sintomas sa carpal tunnel syndrome at pinag-iisipan ang operasyon, karaniwang bahagi ng plano ang mga test na ito. Karamihan sa mga doktor ay hindi mag-oopera nang walang ganitong kumpirmasyon [3]. Maaaring pataasin ng karagdagang pagsusuri ang tsansa na nakatutok ang operasyon sa isang tunay at nagagamot na problema sa nerve [9]. Mahalaga iyon, dahil nakukuha ng mga test ang tamang diagnosis at ipinapakita kung gaano kalala ang pressure sa iyong nerve [6].

Maaaring hindi gaanong kapaki-pakinabang ang mga ito kung malabo ang iyong mga sintomas o dumarating at umaalis. Maaaring hindi matukoy ang pagkaipit ng nerve sa araw ng test. Hindi inaalis ng normal na resulta ang posibilidad ng carpal tunnel syndrome. Hindi rin kayang hulaan ng mga test kung ano ang mararamdaman mo pagkatapos ng operasyon, kaya kasangkapan ang mga ito sa diagnosis, hindi pangako tungkol sa iyong paggaling [6].

Ang pangunahing alternatibo ay ultrasound, na maaari ring sumuri kung may pressure sa nerve [9]. Maaaring imungkahi ng iyong doktor ang isa o pareho. Bawat isa ay may kanya-kanyang kalakasan, at nakadepende ang tamang pagpili sa iyong mga sintomas at pagsusuri.

Dapat itong maging pinagsamang desisyon ninyo ng iyong doktor. Itanong kung ano ang inaasahang ipakita ng test, at kung ano ang mangyayari kung normal ang resulta. Kung may mga tanong ka tungkol sa mga panganib ng test mismo, basahin ang seksyon sa itaas tungkol sa mga panganib.

Ang pinaka-importanteng punto

Kung isinasaalang-alang ang operasyon para sa carpal tunnel syndrome, sulit gawin ang mga test na ito. Kinukumpirma nila kung totoo ang pressure sa iyong nerve at ipinapakita kung gaano ito kalala [6]. Maaaring pataasin ng karagdagang pagsusuri ang tsansa na nakatutok ang operasyon sa isang tunay at nagagamot na problema [9]. Pumasok nang may makatotohanang inaasahan: mahusay ang mga test sa diagnosis, ngunit hindi nila kayang hulaan kung ano ang mararamdaman mo pagkatapos ng operasyon [6]. Ang pinakamahalagang paalala ay hindi inaalis ng normal na resulta ang posibilidad ng carpal tunnel syndrome, dahil maaaring dumating at umalis ang pagkaipit ng nerve. Humingi ng malinaw na paliwanag sa iyong ulat bago gumawa ng anumang desisyon.

Mga Sanggunian

[1] Sensory threshold and conductance testing in nerve injuries. The Journal of Hand Surgery: Journal of the British Society for Surgery of the Hand. 1986. DOI: 10.1016/0266-7681(86)90252-4

[2] Correlation of Clinical Signs with Nerve Conduction Tests in the Diagnosis of Carpal Tunnel Syndrome. Journal of Hand Surgery. 1994. DOI: 10.1016/0266-7681(94)90244-5

[3] Current Practice in the Use of Nerve Conduction Studies in Carpal Tunnel Syndrome by Surgeons in the Netherlands. Journal of Hand Surgery (European Volume). 2007. DOI: 10.1016/j.jhse.2007.09.007

[4] Diagnosis of Ulnar Neuropathy at the Elbow Using Ultrasound — A Comparison to Electrophysiologic Studies. The Journal of Hand Surgery. 2023. DOI: 10.1016/j.jhsa.2023.08.014

[5] Use of nerve conduction studies in carpal tunnel syndrome. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231191685

[6] Electrical studies as a prognostic factor in the surgical treatment of carpal tunnel syndrome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80384-4

[7] Provocative motor nerve conduction testing in presumptive carpal tunnel syndrome unconfirmed by traditional electrodiagnostic testing. The Journal of Hand Surgery. 1997. DOI: 10.1016/s0363-5023(97)80045-7

[8] The utility of portable nerve conduction testing for patients with carpal tunnel syndrome: A prospective clinical study. The Journal of Hand Surgery. 1992. DOI: 10.1016/0363-5023(92)90117-8

[9] Diagnosis of Mild-to-moderate Idiopathic Median Neuropathy at the Carpal Tunnel Based on Signs and Symptoms is Discordant From Diagnosis Based on Electrodiagnostic Studies and Ultrasound. Clinical Orthopaedics & Related Research. 2023. DOI: 10.1097/corr.0000000000002751

[10] CORR Insights®: Diagnosis of Mild-to-moderate Idiopathic Median Neuropathy at the Carpal Tunnel Based on Signs and Symptoms is Discordant From Diagnosis Based on Electrodiagnostic Studies and Ultrasound. Clinical Orthopaedics & Related Research. 2023. DOI: 10.1097/corr.0000000000002822

[11] Electrodiagnostic reports of median neuropathy at the wrist. The Journal of Hand Surgery. 1998. DOI: 10.1016/s0363-5023(98)80089-0

[12] Electrodiagnostic testing and carpal tunnel release outcome. The Journal of Hand Surgery. 1997. DOI: 10.1016/s0363-5023(05)80209-6

[13] Nerve Conduction Studies after Treatment for Carpal Tunnel Syndrome. Journal of Hand Surgery. 1992. DOI: 10.1016/0266-7681(92)90191-4

[14] Diagnostic and therapeutic value of carpal tunnel injection. The Journal of Hand Surgery. 1984. DOI: 10.1016/s0363-5023(84)80065-9

[15] Carpal Tunnel Syndrome: Neurophysiological Results of Surgery Based on Preoperative Electrodiagnostic Testing. Journal of Hand Surgery. 1997. DOI: 10.1016/s0266-7681(97)80355-5

[16] Relative slowing of the median antidromic sensory nerve conduction velocity to the ring finger in screening for carpal tunnel syndrome. The Journal of Hand Surgery. 2004. DOI: 10.1016/j.jhsa.2004.04.026

[17] Electrodiagnostic testing in hand surgery. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80298-x


Evidence & references

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Overview

  • Nerve conduction studies serve as a measure of impaired nerve function and are the best available indicator of overall disease severity with some prognostic value for surgical outcome [1].
  • Nerve conduction studies are considered an indispensable part of the pre-operative evaluation for carpal tunnel syndrome [2].
  • Provocative nerve conduction testing is a useful and simple addition to the overall evaluation of patients with carpal tunnel syndrome, particularly those with otherwise normal findings on traditional electrodiagnostic studies [3].
  • The selection of an appropriate electrical screening test for peripheral nerve injury depends on the prevalence and seriousness of the target disease and the relative consequences of over- and underdiagnosis [4].
  • The absence of any real difference in nerve conduction time between a working group with symptoms and a group with diagnosed carpal tunnel syndrome indicates a high probability that many participants with symptoms would have had abnormal findings on standard electrodiagnostic tests [5].
  • The value of preoperative nerve conduction studies lies in obtaining the correct diagnosis and determining the severity of the median nerve disease, not in predicting postoperative outcome [6].
  • Electrodiagnostic criteria used in some referenced studies were inadequate and not the most sensitive available, potentially leading to the erroneous conclusion that electrodiagnostic studies offer no additional diagnostic power in carpal tunnel syndrome [7].
  • The value of electrodiagnostic testing is not negated by findings that it does not predict postoperative outcome [8].
  • When signs and symptoms suggest mild-to-moderate median neuropathy and surgery is being considered, patients and clinicians might consider additional testing, such as electrodiagnostic studies or ultrasound, to increase the probability of actual median neuropathy that can benefit from surgery [9].
  • Clinical, electrodiagnostic, and physical examination criteria need better definition to avoid inaccurate diagnoses and unnecessary surgeries [10].
  • Highly sensitive tests are required to assess or exclude the diagnosis in one quarter of cases of carpal tunnel syndrome [11].
  • Nerve conduction studies were more sensitive than sensibility testing in confirming the diagnosis of carpal tunnel syndrome [13].
  • The combination of nerve conduction studies and sensibility testing is more sensitive than either test alone in confirming the diagnosis of carpal tunnel syndrome [13].
  • Given specific clinical criteria for establishing the diagnosis of carpal tunnel syndrome, electrodiagnostic testing does not appear to correlate with improved final symptomatic outcome after carpal tunnel release [20].
  • Surgical intervention is advocated for patients with symptoms only, even when electrodiagnostic studies are normal, in the context of cubital tunnel syndrome [21].
  • The majority of neurosurgeons and orthopaedic surgeons seldom operate without electrodiagnostic confirmation in line with the Dutch consensus guideline on this subject [29].
  • When used together, Semmes-Weinstein monofilament mappings and sensory nerve conduction parameters present a clearer picture of the patient's sensory status than either test used alone [31].
  • Receiver operating characteristic curves showed distal sensory latency measurement to be a superior diagnostic test for carpal tunnel syndrome, with 3.3 ms as optimal upper limit of normal, giving a sensitivity of 74% and a specificity of 87% [45].

How It Works

Diagnostic Utility and Role

  • The clinical, electrodiagnostic, and physical examination criteria need better definition to avoid inaccurate diagnoses and unnecessary surgeries [10].
  • Electrodiagnostic studies are used as part of a clinical evaluation process and are considered a reasonable way to practice medicine [12].

Sensitivity and Specificity

  • Nerve conduction studies were more sensitive than sensibility testing in confirming the diagnosis of carpal tunnel syndrome, but the combination of the two studies is more sensitive than either test alone [13].
  • The sensitivity of the neurometer test alone was 69% and specificity was 100%, increasing to 84% sensitivity when combined with quantitative sensibility testing [28].
  • The relative slowing of the antidromic sensory conduction velocity of the median nerve to the ring finger is determined easily and efficiently and imposes minimal strain on the patient [34].

Prognostic Value and Outcomes

  • Compound muscle action potential amplitude, but not other conventional electrodiagnostic parameters, was predictive of functional outcomes after in situ decompression of the ulnar nerve [22].
  • Suprascapular nerve dysfunction, evidenced by reduced nerve amplitudes and supraspinatus muscle atrophy, significantly predicts poor functional outcomes following shoulder hemiarthroplasty, even when tuberosities are well healed [19].
  • This strength recovers gradually as the median nerve heals, but never returns to normal, indicating that this test can be extrapolated to the reinnervation of the abductor pollicies brevis [23].

Technical Considerations and Reporting

  • There is variability with respect to the thoroughness of electrodiagnostic studies and in the quality of information in the reports [16].
  • Electrodiagnostic reports should specifically indicate abnormalities of latency and conduction and present a clear description of the probable pathophysiologic processes rather than just compiling slight abnormalities [26].
  • The conduction velocity of the ulnar nerve after an anterior transposition is determined by both the position of the elbow and the location for the measurement of the skin distance [37].

Physiological Mechanisms and Intraoperative Findings

  • When in situ nerve strain reached 8.1 ± 0.5%, the compound muscle action potential was not evoked [33].
  • Intraoperative conduction latencies indicated a dramatic and immediate reduction in the conduction latency across the carpal canal in all but seven patients, two of whom had diabetes [36].
  • Electrodiagnostic studies revealed an acute median nerve lesion at the wrist with motor and/or sensory conduction blocks in 20/30 women with pregnancy-related carpal tunnel syndrome [18].

Comparative Modalities

  • Ultrasound is a valid alternative confirmatory test compared with electrodiagnostic studies in detecting ulnar neuropathy at the elbow [14].
  • The study confirms the high diagnostic value of the pre-operative antidromic sensory conduction velocity findings [25].

What the Evidence Shows

Diagnostic Role and Sensitivity

  • The absence of any real difference in nerve conduction time between the working group with symptoms and the group with diagnosed carpal tunnel syndrome indicates a high probability that many participants with symptoms would have had abnormal findings on standard electrodiagnostic tests [5].
  • There is a severe discordance between the estimated prevalence of mild-to-moderate carpal tunnel syndrome based on clinical signs and symptoms (73%) versus electrodiagnostic studies and ultrasound (51%) [27].
  • The authors argue that the electrodiagnostic criteria used in the referenced study were inadequate and not the most sensitive available, potentially leading to the erroneous conclusion that electrodiagnostic studies offer no additional diagnostic power in carpal tunnel syndrome [7].
  • Carpal tunnel injection is a reasonably accurate diagnostic test, as a good response to injection is an excellent diagnostic and prognostic sign for surgical treatment [42].

Prognostic Value and Outcomes

  • Upper arm motor nerve conduction velocity might be a useful predictor of poor surgical outcome in cubital tunnel syndrome [32].
  • Distal motor latency is a simple test with a predictive value of the postoperative neurophysiological and clinical outcome of carpal tunnel syndrome [39].
  • The changes in electrophysiological findings occurring spontaneously in carpal tunnel syndrome and after treatment by injection are not statistically significant at two years [38].

Clinical Application and Reporting

  • The author continues to use electrodiagnostic studies as part of a clinical evaluation process and considers this a reasonable way to practice medicine [12].
  • The author proposes that the clinical, electrodiagnostic, and physical examination criteria need better definition to avoid inaccurate diagnoses and unnecessary surgeries [10].
  • The study confirms the high diagnostic value of the pre-operative antidromic sensory conduction velocity findings in carpal tunnel syndrome [25].
  • Surgical intervention is advocated for patients with symptoms only, even when electrodiagnostic studies are normal, in cases of cubital tunnel syndrome [21].
  • The incidence of abnormal conduction times was not reliably correlated with either age or duration of paralysis in the paraplegic hand [24].
  • In primates, there is no significant difference in the conduction velocity of peripheral nerves repaired in adults and those repaired in early life [15].
  • Although there are essential differences between Semmes-Weinstein monofilament mappings and sensory nerve conduction parameters, when used together they present a clearer picture of the patient's sensory status than either test used alone [31].
  • The strength of the abductor pollicis brevis recovers gradually as the median nerve heals but never returns to normal, indicating that this test can be extrapolated to the reinnervation of the abductor pollicis brevis [23].
  • Chitosan phonophoresis demonstrated significant improvements in nerve conduction, pain reduction, and enhancement of hand function for mild to moderate cubital tunnel syndrome [17].
  • All patients had good clinical and electrophysiological recovery at 6 months following single-stage opponensplasty added at the time of release for severe carpal tunnel syndrome [41].
  • Three weeks after the operation, 77% of the patients in the tourniquet group had denervation in other than thenar muscles [46].

Practical Considerations

Diagnostic Interpretation and Utility

  • Nerve conduction studies serve as a measure of impaired nerve function and the best available indicator of overall disease severity, rather than a test that determines the diagnosis [1].
  • The value of preoperative nerve conduction studies lies in obtaining the correct diagnosis and determining the severity of median nerve disease, not in predicting postoperative outcome [6].
  • Electrodiagnostic testing does not appear to correlate with improved final symptomatic outcome after carpal tunnel release given specific clinical criteria for establishing the diagnosis [20].
  • When signs and symptoms suggest mild-to-moderate median neuropathy and surgery is being considered, patients and clinicians might consider additional testing, such as EDS or US, to increase the probability of actual median neuropathy that can benefit from surgery [9].
  • The authors argue that the electrodiagnostic criteria used in the referenced study were inadequate and not the most sensitive available, potentially leading to the erroneous conclusion that electrodiagnostic studies offer no additional diagnostic power in CTS [7].
  • This does not negate the value of electrodiagnostic testing [8].

Testing Variations and Screening

  • Provocative nerve conduction testing is a useful and simple addition to the overall evaluation of patients with CTS, particularly those with otherwise normal findings on traditional electrodiagnostic studies [3].
  • The absence of any real difference in nerve conduction time between the working group with symptoms and the group with diagnosed CTS indicates a high probability that many of the participants with symptoms would have had abnormal findings on standard electrodiagnostic tests [5].
  • There is a significant discrepancy between the practice recommended by the Danish Society of Neurophysiology of performing neurophysiological investigations in all cases of suspected CTS and what is actually done in most surgical departments [35].

Specific Clinical Scenarios

  • Upper arm motor nerve conduction velocity (MNCV) might be a useful predictor of poor surgical outcome in cubital tunnel syndrome [32].
  • Surgical intervention is advocated for patients with symptoms only, even when electrodiagnostic studies are normal, in cases of electrodiagnostic-negative cubital tunnel syndrome [21].
  • SSN dysfunction, evidenced by reduced nerve amplitudes and supraspinatus muscle atrophy, significantly predicts poor functional outcomes following shoulder hemiarthroplasty, even when tuberosities are well healed [19].
  • The incidence of abnormal conduction times in the paraplegic hand was not reliably correlated with either age or duration of paralysis [24].
  • Intraoperative electrodiagnosis may offer limited value in neonatal brachial plexus palsy surgery, but there is insufficient evidence to reach robust conclusions [44].
  • This underscores the need for surgeons to carefully evaluate suprascapular nerve integrity in cases of rotator cuff tear [40].

Methodological and Prognostic Notes

  • Only studies with randomization, blinding, and sham injection or sham surgery can address subjective symptoms and satisfaction reliably and accurately [30].

Key Evidence

  • [L5] Nerve conduction studies should be understood not as a test that determines the diagnosis but as a measure of impaired nerve function, serving as the best available indicator of overall disease severity with some prognostic value for surgical outcome. [1] (10.1177/17531934231191685)
  • [L3] We consider nerve conduction studies to be an indispensable part of the pre-operative evaluation. [2] (10.1016/0266-7681(94)90244-5)
  • [L2] Provocative nerve conduction testing is a useful and simple addition to the overall evaluation of patients with CTS, particularly those with otherwise normal findings on traditional electrodiagnostic studies. [3] (10.1016/s0363-5023(97)80045-7)
  • [L3] The selection of an appropriate electrical screening test for peripheral nerve injury, such as entrapment neuropathy, depends on the prevalence and seriousness of the target disease and the relative consequences of over- and underdiagnosis. [4] (10.1016/s0363-5023(96)80165-1)
  • [L3] The absence of any real difference in nerve conduction time between the working group with symptoms and the group with diagnosed CTS indicates a high probability that many of the participants with symptoms would have had abnormal findings on standard electrodiagnostic tests. [5] (10.1016/0363-5023(92)90116-7)
  • [L5] The value of preoperative nerve conduction studies lies in obtaining the correct diagnosis and determining the severity of the median nerve disease, not in predicting postoperative outcome. [6] (10.1016/s0363-5023(96)80384-4)
  • [L5] The authors argue that the electrodiagnostic criteria used in the referenced study were inadequate and not the most sensitive available, potentially leading to the erroneous conclusion that electrodiagnostic studies offer no additional diagnostic power in CTS. [7] (10.1067/jhsu.2000.jjhsu00025a1le01)
  • [L5] This does not negate the value of electrodiagnostic testing. [8] (10.1016/s0363-5023(96)80222-x)
  • [L3] When signs and symptoms suggest mild-to-moderate median neuropathy and surgery is being considered, patients and clinicians might consider additional testing, such as EDS or US, to increase the probability of actual median neuropathy that can benefit from surgery. [9] (10.1097/corr.0000000000002751)
  • [L5] The author proposes that the clinical, electrodiagnostic, and physical examination criteria need better definition to avoid inaccurate diagnoses and unnecessary surgeries. [10] (10.1016/s0363-5023(05)80209-6)
  • [L3] Highly sensitive tests are required to assess or exclude the diagnosis in one quarter of cases of carpal tunnel syndrome. [11] (10.1016/0266-7681(94)90245-3)
  • [L5] The author continues to use electrodiagnostic studies as part of a clinical evaluation process and considers this a reasonable way to practice medicine. [12] (10.1016/s0363-5023(96)80380-7)
  • [L4] The results indicate that nerve conduction studies were more sensitive than sensibility testing in confirming the diagnosis of carpal tunnel syndrome, but the combination of the two studies is more sensitive than either test alone. [13] (10.1016/s0363-5023(82)80176-7)
  • [L4] Ultrasound is a valid alternative confirmatory test compared with electrodiagnostic studies in detecting ulnar neuropathy at the elbow. [14] (10.1016/j.jhsa.2023.08.014)
  • [L3] The study demonstrates that in primates there is no significant difference in the conduction velocity of peripheral nerves repaired in adults and those repaired in early life. [15] (10.1016/s0363-5023(83)80199-3)
  • [L4] There is variability with respect to the thoroughness of electrodiagnostic studies and in the quality of information in the reports. [16] (10.1016/s0363-5023(98)80089-0)
  • [L1] This approach demonstrated significant improvements in nerve conduction, pain reduction, and enhancement of hand function. [17] (10.1016/j.jht.2024.02.006)
  • [L4] Electrodiagnostic studies revealed an acute median nerve lesion at the wrist with motor and/or sensory conduction blocks in 20/30 women. [18] (10.1016/s0266-7681(98)80232-5)
  • [L3] SSN dysfunction, evidenced by reduced nerve amplitudes and supraspinatus muscle atrophy, significantly predicts poor functional outcomes following SHA, even when tuberosities are well healed. [19] (10.1016/j.jse.2025.07.001)
  • [L3] Given specific clinical criteria for establishing the diagnosis of carpal tunnel syndrome, electrodiagnostic testing does not appear to correlate with improved final symptomatic outcome after carpal tunnel release. [20] (10.1016/s0363-5023(96)80164-x)
  • [L2] We advocate surgical intervention for patients with symptoms only, even when electrodiagnostic studies are normal. [21] (10.1053/jhsu.2001.26327)
  • [L2] Compound muscle action potential amplitude, but not other conventional electrodiagnostic parameters, was predictive of functional outcomes after in situ decompression of the ulnar nerve. [22] (10.1016/j.jhsa.2022.10.008)
  • [L5] This strength recovers gradually as the median nerve heals, but never returns to normal, indicating that this test can be extrapolated to the reinnervation of the abductor pollicies brevis. [23] (10.1016/s0266-7681(03)00022-6)
  • [L4] The incidence of abnormal conduction times was not reliably correlated with either age or duration of paralysis. [24] (10.1016/s0363-5023(88)80132-1)
  • [L4] The study confirms the high diagnostic value of the pre-operative antidromic sensory conduction velocity findings. [25] (10.1016/0266-7681(88)90161-1)
  • [L5] EDX reports should specifically indicate abnormalities of latency and conduction and present a clear description of the probable pathophysiologic processes rather than just compiling slight abnormalities. [26] (10.1016/s0363-5023(96)80298-x)
  • [L5] There is a severe discordance between the estimated prevalence of mild-to-moderate carpal tunnel syndrome based on clinical signs and symptoms (73%) versus electrodiagnostic studies and ultrasound (51%), calling into question whether clinicians can confidently diagnose patients with mild-to-moderate CTS. [27] (10.1097/corr.0000000000002822)
  • [L3] The sensitivity of the neurometer test alone was 69% and specificity was 100%, increasing to 84% sensitivity when combined with quantitative sensibility testing. [28] (10.1016/0363-5023(92)90117-8)
  • [L4] The majority of neurosurgeons and orthopaedic surgeons seldom operate without electrodiagnostic confirmation in line with the Dutch consensus guideline on this subject. [29] (10.1016/j.jhse.2007.09.007)
  • [L4] Although there are essential differences in these two tests, when used together they present a clearer picture of the patient's sensory status than either test used alone. [31] (10.1016/s0894-1130(87)80010-8)
  • [L3] Upper arm motor nerve conduction velocity (MNCV) might be a useful predictor of poor surgical outcome. [32] (10.1177/17585732241293360)
  • [Paper] The results showed that when the in situ nerve strain reached 8.1 ± 0.5%, the compound muscle action potential was not evoked. [33] (10.1016/s0736-0266(02)00080-3)
  • [L3] The relative slowing of the antidromic sensory conduction velocity of the median nerve to the ring finger is determined easily and efficiently and imposes minimal strain on the patient. [34] (10.1016/j.jhsa.2004.04.026)
  • [L4] There is a significant discrepancy between the practice recommended by the Danish Society of Neurophysiology of performing neurophysiological investigations (NI) in all cases of suspected CTS and what is actually done in most surgical departments. [35] (10.1016/s0266-7681(97)80443-3)
  • [L4] The results of intraoperative conduction latencies indicated a dramatic and immediate reduction in the conduction latency across the carpal canal in all but seven patients, two of whom had diabetes. [36] (10.1016/s0363-5023(78)80119-1)
  • [L4] The conduction velocity of the ulnar nerve after an anterior transposition is determined by both the position of the elbow and the location for the measurement of the skin distance. [37] (10.1016/s0363-5023(87)80051-5)
  • [L3] The changes in electrophysiological findings occurring spontaneously in carpal tunnel syndrome and after treatment by injection are not statistically significant at two years. [38] (10.1016/0266-7681(92)90191-4)
  • [L3] DML is a simple test with a predictive value of the postoperative neurophysiological and clinical outcome of carpal tunnel syndrome. [39] (10.1016/s0266-7681(97)80355-5)
  • [L5] This underscores the need for surgeons to carefully evaluate suprascapular nerve integrity in such cases. [40] (10.1186/s12891-025-09195-6)
  • [L3] All patients had good clinical and electrophysiological recovery at 6 months. [41] (10.1177/1558944716660555fx)
  • [L4] Results suggest that carpal tunnel injection is also a reasonably accurate diagnostic test, as a good response to injection is an excellent diagnostic and prognostic sign for surgical treatment. [42] (10.1016/s0363-5023(84)80065-9)
  • [L4] Intraoperative electrodiagnosis may offer limited value in neonatal brachial plexus palsy surgery, but there is insufficient evidence to reach robust conclusions. [44] (10.1177/17531934261478357)
  • [L3] Receiver operating characteristic curves showed distal sensory latency measurement to be a superior diagnostic test, with 3.3 ms as optimal upper limit of normal, giving a sensitivity of 74% and a specificity of 87%. [45] (10.1016/s0363-5023(96)80020-7)
  • [L1] Three weeks after the operation 77% of the patients in the tourniquet group had denervation in other than thenar muscles. [46] (10.1016/s0363-5023(89)80011-5)

References

[1] Use of nerve conduction studies in carpal tunnel syndrome. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231191685

[2] Correlation of Clinical Signs with Nerve Conduction Tests in the Diagnosis of Carpal Tunnel Syndrome. Journal of Hand Surgery. 1994. DOI: 10.1016/0266-7681(94)90244-5

[3] Provocative motor nerve conduction testing in presumptive carpal tunnel syndrome unconfirmed by traditional electrodiagnostic testing. The Journal of Hand Surgery. 1997. DOI: 10.1016/s0363-5023(97)80045-7

[4] A comparison of traditional electrodiagnostic studies, electroneurometry, and vibrometry in the diagnosis of carpal tunnel syndrome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80165-1

[5] Use of motor nerve conduction testing and vibration sensitivity testing as screening tools for carpal tunnel syndrome in industry. The Journal of Hand Surgery. 1992. DOI: 10.1016/0363-5023(92)90116-7

[6] Electrical studies as a prognostic factor in the surgical treatment of carpal tunnel syndrome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80384-4

[7] Diagnostic testing in carpal tunnel syndrome. The Journal of Hand Surgery. 2000. DOI: 10.1067/jhsu.2000.jjhsu00025a1le01

[8] Electrical studies as a prognostic factor in carpal tunnel syndrome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80222-x

[9] Diagnosis of Mild-to-moderate Idiopathic Median Neuropathy at the Carpal Tunnel Based on Signs and Symptoms is Discordant From Diagnosis Based on Electrodiagnostic Studies and Ultrasound. Clinical Orthopaedics & Related Research. 2023. DOI: 10.1097/corr.0000000000002751

[10] Electrodiagnostic testing and carpal tunnel release outcome. The Journal of Hand Surgery. 1997. DOI: 10.1016/s0363-5023(05)80209-6

[11] Sensitivity of the Various Tests for the Diagnosis of Carpal Tunnel Syndrome. Journal of Hand Surgery. 1994. DOI: 10.1016/0266-7681(94)90245-3

[12] Electrical studies as a prognostic factor in the surgical treatment of carpal tunnel syndrome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80380-7

[13] Nerve conduction studies and sensibility testing in carpal tunnel syndrome. The Journal of Hand Surgery. 1982. DOI: 10.1016/s0363-5023(82)80176-7

[14] Diagnosis of Ulnar Neuropathy at the Elbow Using Ultrasound — A Comparison to Electrophysiologic Studies. The Journal of Hand Surgery. 2023. DOI: 10.1016/j.jhsa.2023.08.014

[15] Nerve conduction velocity, microscopic, and electron microscopy studies comparing repaired adult and baby monkey median nerves. The Journal of Hand Surgery. 1983. DOI: 10.1016/s0363-5023(83)80199-3

[16] Electrodiagnostic reports of median neuropathy at the wrist. The Journal of Hand Surgery. 1998. DOI: 10.1016/s0363-5023(98)80089-0

[17] Effectiveness of chitosan phonophoresis on ulnar nerve conduction velocity, pain relief, and functional outcomes for mild to moderate cubital tunnel syndrome: A double-blind randomized controlled trial. Journal of Hand Therapy. 2024. DOI: 10.1016/j.jht.2024.02.006

[18] Pregnancy-Related Carpal Tunnel Syndrome. Journal of Hand Surgery. 1998. DOI: 10.1016/s0266-7681(98)80232-5

[19] Radiological and electrodiagnostic insights into suprascapular nerve dysfunction: a key predictor of poor functional outcomes in shoulder hemiarthroplasty. Journal of Shoulder and Elbow Surgery. 2026. DOI: 10.1016/j.jse.2025.07.001

[20] Electrodiagnostic testing and carpal tunnel release outcome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80164-x

[21] The rationale for and efficacy of surgical intervention for electrodiagnostic-negative cubital tunnel syndrome. The Journal of Hand Surgery. 2001. DOI: 10.1053/jhsu.2001.26327

[22] Electrodiagnostic Predictors of Outcomes After In Situ Decompression of the Ulnar Nerve. The Journal of Hand Surgery. 2023. DOI: 10.1016/j.jhsa.2022.10.008

[23] Re. Clinical value of electrodiagnostic testing following repair of peripheral nerve lesions: a prospective study. Th. H.J. Van de Kar, J.B. Jaquet, J. Meulstee, C.B.H. Molenaar, R.J. Schimsheimer, S.E.R. Hovius. Journal of Hand Surgery 2002: 27B(4): 345–349.. Journal of Hand Surgery. 2003. DOI: 10.1016/s0266-7681(03)00022-6

[24] The paraplegic hand: Electrodiagnostic studies and clinical findings. The Journal of Hand Surgery. 1988. DOI: 10.1016/s0363-5023(88)80132-1

[25] Assessment of sensory nerve conduction in carpal tunnel syndrome before, during and after operation. The Journal of Hand Surgery: Journal of the British Society for Surgery of the Hand. 1988. DOI: 10.1016/0266-7681(88)90161-1

[26] Electrodiagnostic testing in hand surgery. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80298-x

[27] CORR Insights®: Diagnosis of Mild-to-moderate Idiopathic Median Neuropathy at the Carpal Tunnel Based on Signs and Symptoms is Discordant From Diagnosis Based on Electrodiagnostic Studies and Ultrasound. Clinical Orthopaedics & Related Research. 2023. DOI: 10.1097/corr.0000000000002822

[28] The utility of portable nerve conduction testing for patients with carpal tunnel syndrome: A prospective clinical study. The Journal of Hand Surgery. 1992. DOI: 10.1016/0363-5023(92)90117-8

[29] Current Practice in the Use of Nerve Conduction Studies in Carpal Tunnel Syndrome by Surgeons in the Netherlands. Journal of Hand Surgery (European Volume). 2007. DOI: 10.1016/j.jhse.2007.09.007

[30] Probability_and_Pathophysiology_S0363502312002821. 2002.

[31] Correlating Semmes-Weinstein monofilament mappings with sensory nerve conduction parameters in Hansen's disease patients: An update. Journal of Hand Therapy. 1987. DOI: 10.1016/s0894-1130(87)80010-8

[32] Clinical significance of upper arm motor nerve conduction velocity in cubital tunnel syndrome. Shoulder & Elbow. 2024. DOI: 10.1177/17585732241293360

[33] In situ strain and stress of nerve conduction blocking in the brachial plexus. Journal of Orthopaedic Research. 2002. DOI: 10.1016/s0736-0266(02)00080-3

[34] Relative slowing of the median antidromic sensory nerve conduction velocity to the ring finger in screening for carpal tunnel syndrome. The Journal of Hand Surgery. 2004. DOI: 10.1016/j.jhsa.2004.04.026

[35] Operative Treatment of Carpal Tunnel Syndrome in Denmark. Journal of Hand Surgery. 1997. DOI: 10.1016/s0266-7681(97)80443-3

[36] Intraoperative changes in motor nerve conduction latency in carpal tunnel syndrome. The Journal of Hand Surgery. 1978. DOI: 10.1016/s0363-5023(78)80119-1

[37] Validity of nerve conduction velocity studies after anterior transposition of the ulnar nerve. The Journal of Hand Surgery. 1987. DOI: 10.1016/s0363-5023(87)80051-5

[38] Nerve Conduction Studies after Treatment for Carpal Tunnel Syndrome. Journal of Hand Surgery. 1992. DOI: 10.1016/0266-7681(92)90191-4

[39] Carpal Tunnel Syndrome: Neurophysiological Results of Surgery Based on Preoperative Electrodiagnostic Testing. Journal of Hand Surgery. 1997. DOI: 10.1016/s0266-7681(97)80355-5

[40] Electromyography does not show adequate effectiveness in diagnosis of suprascapular nerve lesions caused by rotator cuff tear in rat model. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-09195-6

[41] Should Single-Stage Opponensplasty Be Added at the Time of Release for Severe Carpal Tunnel Syndrome?. HAND. 2016. DOI: 10.1177/1558944716660555fx

[42] Diagnostic and therapeutic value of carpal tunnel injection. The Journal of Hand Surgery. 1984. DOI: 10.1016/s0363-5023(84)80065-9

[44] Intraoperative electrodiagnostic testing as a decision-making tool for neonatal brachial plexus palsy: a scoping review. Journal of Hand Surgery (European Volume). 2026. DOI: 10.1177/17531934261478357

[45] Evaluation of portable nerve conduction testing in the diagnosis of carpal tunnel syndrome. The Journal of Hand Surgery. 1996. DOI: 10.1016/s0363-5023(96)80020-7

[46] Upper extremity tourniquet effects in carpal tunnel release. The Journal of Hand Surgery. 1989. DOI: 10.1016/s0363-5023(89)80011-5

Creative Commons BY-NC 4.0

CC Creative Commons licence
BY Attribution — you must credit the source
NC NonCommercial — not for commercial use

Attribution-NonCommercial 4.0 International


Creative Commons Corporation ("Creative Commons") is not a law firm and does not provide legal services or legal advice. Distribution of Creative Commons public licenses does not create a lawyer-client or other relationship. Creative Commons makes its licenses and related information available on an "as-is" basis. Creative Commons gives no warranties regarding its licenses, any material licensed under their terms and conditions, or any related information. Creative Commons disclaims all liability for damages resulting from their use to the fullest extent possible.

Using Creative Commons Public Licenses

Creative Commons public licenses provide a standard set of terms and conditions that creators and other rights holders may use to share original works of authorship and other material subject to copyright and certain other rights specified in the public license below. The following considerations are for informational purposes only, are not exhaustive, and do not form part of our licenses.

Considerations for licensors: Our public licenses are intended for use by those authorized to give the public permission to use material in ways otherwise restricted by copyright and certain other rights. Our licenses are irrevocable. Licensors should read and understand the terms and conditions of the license they choose before applying it. Licensors should also secure all rights necessary before applying our licenses so that the public can reuse the material as expected. Licensors should clearly mark any material not subject to the license. This includes other CC- licensed material, or material used under an exception or limitation to copyright. More considerations for licensors: wiki.creativecommons.org/Considerations_for_licensors

Considerations for the public: By using one of our public licenses, a licensor grants the public permission to use the licensed material under specified terms and conditions. If the licensor's permission is not necessary for any reason--for example, because of any applicable exception or limitation to copyright--then that use is not regulated by the license. Our licenses grant only permissions under copyright and certain other rights that a licensor has authority to grant. Use of the licensed material may still be restricted for other reasons, including because others have copyright or other rights in the material. A licensor may make special requests, such as asking that all changes be marked or described. Although not required by our licenses, you are encouraged to respect those requests where reasonable. More considerations for the public: wiki.creativecommons.org/Considerations_for_licensees


Creative Commons Attribution-NonCommercial 4.0 International Public License

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution-NonCommercial 4.0 International Public License ("Public License"). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.

Section 1 -- Definitions.

a. Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

b. Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License.

c. Copyright and Similar Rights means copyright and/or similar rights closely related to copyright including, without limitation, performance, broadcast, sound recording, and Sui Generis Database Rights, without regard to how the rights are labeled or categorized. For purposes of this Public License, the rights specified in Section 2(b)(1)-(2) are not Copyright and Similar Rights.

d. Effective Technological Measures means those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

e. Exceptions and Limitations means fair use, fair dealing, and/or any other exception or limitation to Copyright and Similar Rights that applies to Your use of the Licensed Material.

f. Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License.

g. Licensed Rights means the rights granted to You subject to the terms and conditions of this Public License, which are limited to all Copyright and Similar Rights that apply to Your use of the Licensed Material and that the Licensor has authority to license.

h. Licensor means the individual(s) or entity(ies) granting rights under this Public License.

i. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

j. Share means to provide material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public including in ways that members of the public may access the material from a place and at a time individually chosen by them.

k. Sui Generis Database Rights means rights other than copyright resulting from Directive 96/9/EC of the European Parliament and of the Council of 11 March 1996 on the legal protection of databases, as amended and/or succeeded, as well as other essentially equivalent rights anywhere in the world.

l. You means the individual or entity exercising the Licensed Rights under this Public License. Your has a corresponding meaning.

Section 2 -- Scope.

a. License grant.

1. Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.


Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.