Abstract
Peripherally-induced movement disorder (PIMD) is a group of conditions manifested by involuntary movements or other motor abnormalities that are induced by or emerge in the context of injury to the peripheral nervous system.
Peripheral nerve entrapment (PNE) in the upper extremities is common and their clinical signs are very well known by hand surgeons.
Only 3 cases of tremor with PNE have already been reported (one in 1986 and two very recently). The aim of this multicentric retrospective study is to report clinical cases of tremors caused by PNE and to analyze their clinical findings and treatment.
17 patients was referred to 5 hand centers for tremors of their hand after being examined by a neurologist clinically and electrophysiologically. The clinical examination showed simple, double or multiple crush nerve entrapment at the upper limb (elbow was involved for all of them except one). The treatment was conservative (myofascial manipulation and taping) for 8 patients and surgical (wide awake nerve release) for 9 others after failure of conservative treatments. The tremors disappeared for all of them.
Our study showed upper limb peripheral nerve entrapment can be a cause of tremor of the hand in rare but misdiagnosed situations.
We suggest that tremor induced by peripheral nerve entrapment can be a new type of tremor classified in the PIMD group.
Hand physiotherapist and surgeons must be questioned by medical doctors who take care of tremors (family doctors, neurologists …) and so, be awared of that etiology.
Keywords: Tremor, Hand, Surgery, Nerve, Entrapment
1. Introduction
There is a lot of types of tremors.1, 2, 3 Among all of these types, peripherally-induced movement disorder (PIMD) is a group of conditions manifested by involuntary movements or other motor abnormalities that are induced by or emerge in the context of injury to the peripheral nervous system.4 The spectrum of the phenomenology of PIMD is broad, encompassing both hyperkinetic and hypokinetic movement disorders.
Peripheral nerve entrapment (PNE) in the upper extremities, such as carpal tunnel syndrome, cubital tunnel syndrome, Guyon syndrome, radial tunnel syndrome or lacertus syndrome, is common and can cause a range of symptoms, including neuropathic pain, tingling, numbness, clumsiness, and weakness.5
In 1986, Little et al.6 reported a case of tremor caused by ulnar nerve compression in the cubital tunnel. In 2023, Tchiloemba et al.7 have reported 2 cases caused by ulnar nerve entrapment at the elbow and wrist for the first case and a lacertus syndrome for the second case.
The aim of this multicentric retrospective study is to report a series of clinical cases with tremors and PNE and therefore, to analyze clinical findings and treatments.
2. Material and method
17 adult or teenaged patients (mean age 34) was referred to 5 hand centers for unilateral tremors of their hand with PNE. All the patients gave their agreement to explore and publish their data for that retrospective study. This study has been approved by the Ethical committee of the first author.
Tremor of the hand was manifested by involuntary movements when trying to keep the hand immobilize. The hand was never painful and has never been operated before. Tremors occurred for only one hand for every patient.
The PNE was diagnosed with the triad of Hagert8: pain at the nerve entrapment, weakness of the muscle targeted by the nerve and a positive scratch collapse test confirmed by the cold spray test. The clinical examination showed simple, double or multiple crush nerve entrapment at the upper limb (Table 1). The median nerve was incriminated for 6 patients, ulnar nerve for patients 9 patients and radial nerve for 8 patients. The elbow is the most frequent location as it is concerned for 16 patients, far away from the wrist (4 patients).
Table 1.
patients’ data and treatments.
| Case | Age | Sex | Occupation/sport | Nerve compression(s) | Prior CRPS diagnosis | Treatment | Injury mechanism |
|---|---|---|---|---|---|---|---|
| 1 | 19 | F | Tennis | ulnar nerve at the elbow and wrist | NO | surgery | None |
| 2 | 24 | F | Student | radial nerve at the elbow | NO | therapy-taping | Wrist arthroscopy |
| 3 | 37 | M | Electrian | lacertus syndrome | NO | surgery | Fishing |
| 4 | 28 | F | Unemployed | lacertus syndrome | YES | surgery | None |
| 5 | 29 | F | Nurse | radial nerve at the elbow | NO | surgery | None |
| 6 | 31 | F | Nurse | radial nerve at the elbow | NO | therapy-taping | None |
| 7 | 48 | F | Office worker | ulnar nerve at the elbow and wrist | NO | surgery | None |
| 8 | 48 | F | Office worker | ulnar nerve at the elbow and wrist | NO | surgery | None |
| 9 | 94 | F | Retired | median nerve at the wrist | NO | therapy-taping | None |
| 10 | 15 | M | Student | radial ulnar and median nerves at the elbow | NO | surgery | Falling down |
| 11 | 16 | F | Student | radial ulnar and median nerves at the elbow | NO | surgery | Falling down |
| 12 | 17 | F | Student | Ulnar Nerve at the elbow | NO | therapy-taping | Basketball |
| 13 | 42 | F | Pediatric Speech Therapist | radial nerve at the elbow | NO | therapy-taping | Dorsal and volar ganglion open surgery |
| 14 | 31 | F | Occupational Therapist | Ulnar Nerve at the elbow | NO | therapy-taping | Skydiving |
| 15 | 34 | M | Veterinary technician | ulnar nerve at the elbow | YES | therapy-taping | Forearm puncture wounds |
| 16 | 36 | F | Store owner | radial nerve at the elbow | NO | therapy-taping | Elbow fracture |
| 17 | 31 | F | Cashier | radial ulnar and median nerves at the elbow | YES | therapy-taping | Elbow Fracture |
F: Female.
M: Male.
CRPS: Complex Regional Pain Syndrome.
3 patients with PNE at the elbow have been diagnosed complex regional pain syndrome (CRPS) before our clinical examination.
Electrophysiological and clinical examinations studies conducted by a neurologist were normal for all the patients which assessed there was no central neurologic signs and no static PNE but dynamic ones.
Imagery (CT scan or MRI) or ultrasonography have been asked for each patient without showing any tumor compressing a peripheral nerve.
All the patients have been followed for at least 6 months.
3. Results
Patients’ datas are in Table 1. The treatment was only conservative (myofascial manipulation and taping9,10) for 8 patients. The Taping test at the elbow was sometimes helpful as it decreased the oscillations induced by PNE at the elbow. The tremors disappeared of all of them after 3 months.
The treatment was surgical for 9 the other patients. All the procedures have been performed under wide awake local anesthesia and no tourniquet.11 The immediate recovery of the targeted muscles strength validated the complete release. The tremor of the hand which was still there under local anesthesia disappeared per operatively.
At the minimum follow up of 6 months, tremors have never been observed anymore for our 17 cases.
4. Discussion
The neurophysiological mechanisms underlying tremor in the context of peripheral nerve entrapment (PNE) remain incompletely understood. Tremors caused by peripheral neuropathies have been hypothesized to result from a hyperactivated stretch reflex triggered by subtle weakness or impaired reflex regulation.12,13 Progressive PNE may selectively involve large-diameter sensory axons, reducing afferent input to stretch reflex pathways while sparing some connections. This imbalance can increase synaptic excitability of the preserved afferents, thereby facilitating abnormal rhythmic discharges. In our series, repetitive compression of the ulnar and median nerves within the radial tunnel, cubital tunnel, Guyon's canal, or beneath the lacertus fibrosus appeared to generate intentional tremors.
Previous reports of tremor associated with peripheral nerve disorders are scarce. Most published cases have described polyneuropathies—diabetic, uremic, alcoholic, immune-mediated, or vasculitic neuropathies, as well as motor neuron disease.14 Only one case of tremor following cubital tunnel syndrome was reported in 1986,6 with two additional recent reports.7 Our observations therefore add to this limited literature by suggesting that focal PNE, not only diffuse neuropathies, may underlie tremor. Importantly, all alternative neurological causes, including essential tremor, Parkinson's disease, and dystonia, were excluded by experienced neurologists before PNE was considered.
Complex Regional Pain Syndrome (CRPS) illustrates the diagnostic challenges in this field. Approximately 25 % of CRPS patients develop movement disorders such as dystonia, myoclonus, or tremor.15 Munts et al.16 analyzed eight such cases and concluded that the characteristics of CRPS-related myoclonus differ from other forms. Based on our findings, we suggest that in some patients diagnosed with CRPS and tremor, unrecognized PNE may be a contributing factor, warranting reconsideration of the diagnosis.
The concept of multiple crush syndrome is also relevant, as concomitant entrapments at different levels of the upper limb are common.17 Clinicians—including hand surgeons and physiotherapists—should carefully examine entrapment-prone sites such as the elbow, wrist, and forearm. Techniques such as taping or myofascial manipulations may provide temporary relief,18 but persistent tremor in this context should raise suspicion for surgically correctable PNE.
Our study has several limitations. All patients were assessed and treated by the co-authors, without independent evaluation. The follow-up period was relatively short, and recurrence of tremor at the same or other sites remains possible. In addition, no radiological or electrophysiological gold standard currently exists to objectively confirm PNE-related tremor; diagnosis was therefore based on predefined positive clinical signs assessed by experienced clinicians, with resolution of symptoms after targeted treatment serving as confirmatory evidence. These limitations highlight the need for future prospective, blinded, and multicenter studies.
Despite these caveats, our findings suggest that upper limb PNE can occasionally manifest as hand tremor—a rare but likely underrecognized presentation. We propose that tremors induced by peripheral nerve entrapment represent a clinical subtype within the broader category of peripherally induced movement disorders (PIMDs). Awareness of this entity may improve diagnostic accuracy and guide effective treatment in carefully selected patients.
Informed consent
Written informed consent was obtained from all subjects before the study.
Ethical approval
Ethical approval for this study was obtained from the ETHICS COMMITTEE OF THE ULTRASOUND GUIDED HAND CENTER.
Contributorship
Not Applicable.
Trial registration
Not applicable.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Declaration of competing interest
Authors declares no conflict of interests.
Acknowledgment
authors want to thank all the patients and their family for their trust and agreement to explore and publish their data for that study.
Contributor Information
Thomas Apard, Email: thomasapard@yahoo.fr.
Jean-paul Brutus, Email: jpbrutus@gmail.com.
Benjamin Ferembach, Email: ben.ferembach@gmail.com.
Alison Tayor, Email: taylorssi@icloud.com.
Elisabet Hagert, Email: Elisabet.Hagert@aspetar.com.
References
- 1.Lenka A., Jankovic J. Tremor syndromes: an updated review. Front Neurol. 2021;12 [Google Scholar]
- 2.Bhatia K.P., Bain P., Bajaj N., et al. Consensus statement on the classification of tremors from the task force on tremor of the international parkinson and movement disorder society. Mov Disord. 2018;33:75–87. doi: 10.1002/mds.27121. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.van de Wardt J., van der Stouwe A.M.M., Dirkx M., et al. Systematic clinical approach for diagnosing upper limb tremor. J Neurol Neurosurg Psychiatry. 2020 Aug;91(8):822–830. doi: 10.1136/jnnp-2019-322676. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Lenka A., Jankovic J. Peripherally-induced movement disorders: an update. Tremor Other Hyperkin Move. 2023;13(1):1–16. doi: 10.5334/tohm.758. 8. [DOI] [Google Scholar]
- 5.Hagert E., Curtin C. Median and ulnar nerve compressions: simplifying diagnostics and surgery at the elbow and hand. Plast Reconstr Surg. 2023 Jul 1;152(1):155e–165e. doi: 10.1097/PRS.0000000000010268. [DOI] [PubMed] [Google Scholar]
- 6.Little J.W., Burchiel K., Nutter P. Tremor and peripheral nerve entrapment. Case report. J Neurosurg. 1986;64(1) [Google Scholar]
- 7.Tchiloemba B., Chang M.C., Ferembach B., Hagert E., Brutus J.P. Vol. 5. August 25, 2023. (Tremor Induced by Focal Peripheral Nerve Entrapment: A Case Series Journal of Hand Surgery Global Online). 6pp.841–842 Published online. [Google Scholar]
- 8.Hagert E., Lalonde D. In: Plastic Surgery Vol 6: Hand and Upper Limb. fourth ed. Chang J., Neligan P.C., editors. Elsevier; Canada: 2018. Nerve entrapment syndromes; pp. 525–548. [Google Scholar]
- 9.Basson A., Olivier B., Ellis R., Coppieters M., Stewart A., Mudzi W. The effectiveness of neural mobilization for neuromusculoskeletal conditions: a systematic review and meta-analysis. Jour of Ortho & Sports PT. 2017;593–615:A1–A6. [Google Scholar]
- 10.Walsh M.T. Upper limb neural tension testing and mobilization fact, fiction, and a practical approach. J Hand Ther. 2005:241–258. doi: 10.1197/j.jht.2005.02.010. [DOI] [PubMed] [Google Scholar]
- 11.Lalonde D.H. Conceptual origins, current practice, and views of wide awake hand surgery. J Hand Surg Eur Vol. 2017 Nov;42(9):886–895. doi: 10.1177/1753193417728427. Epub 2017 Sep. 8. [DOI] [PubMed] [Google Scholar]
- 12.Said G., Bathien N., Cesaro P. Peripheral neuropathies and tremor. Neurology. 1982;32(5) [Google Scholar]
- 13.Ure R.J., Dhanju S., Lang A.E., Fasano A.J. Unusual tremor syndromes: know in order to recognise. Neurol Neurosurg Psychiatry. 2016 Nov;87(11):1191–1203. doi: 10.1136/jnnp-2015-311693. [DOI] [Google Scholar]
- 14.Gallego R., Kuno M., Núñez R., Snider W.D. Disuse enhances synaptic efficacy in spinal motoneurons. J Physiol. 1979;291 [Google Scholar]
- 15.Van Hilten J.J. Movement disorders in complex regional pain syndrome. Pain Med. 2010;11:1274–1277. doi: 10.1111/j.1526-4637.2010.00916. [DOI] [PubMed] [Google Scholar]
- 16.Munts A.G., Van Rootselaar A.-F., Van Der Meer J.N., et al. Clinical and neurophysiological characterization of myoclonus in complex regional pain syndrome. Mov Disord. 2008;23:581–587. doi: 10.1002/mds.21910. [DOI] [PubMed] [Google Scholar]
- 17.Kong G., Brutus J.P., Vo T.T., Hagert E. The prevalence of Double- and multiple crush syndromes in patients surgically treated for peripheral nerve compression in the upper limb. Hand Surg Rehabil. 2023 Sep;13 doi: 10.1016/j.hansur.2023.09.002. S2468-1229(23)00170-6. [DOI] [Google Scholar]
- 18.Martinel V., Apard T. The lacertus antagonist test: a predictive test for strength recovery after surgery for lacertus syndrome. Plast Reconstr Surg Glob Open. 2023 Oct 11;11(10) doi: 10.1097/GOX.0000000000005309. [DOI] [Google Scholar]