Neurol India Home 

Year : 2021  |  Volume : 69  |  Issue : 2  |  Page : 522--523

Idiopathic Spinal Accessory Neuropathy: A Case Report

Dimitrios Tsiptsios1, Christoph Mueller2, Konstantinos Tsamakis2,  
1 Department of Neurophysiology, South Tyneside and Sunderland NHS Foundation Trust, Sunderland, United Kingdom
2 King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom

Correspondence Address:
Dimitrios Tsiptsios
Sunderland Royal Hospital, South Tyneside & Sunderland NHS Foundation Trust, Sunderland, SR47TP
United Kingdom

How to cite this article:
Tsiptsios D, Mueller C, Tsamakis K. Idiopathic Spinal Accessory Neuropathy: A Case Report.Neurol India 2021;69:522-523

How to cite this URL:
Tsiptsios D, Mueller C, Tsamakis K. Idiopathic Spinal Accessory Neuropathy: A Case Report. Neurol India [serial online] 2021 [cited 2021 Jun 14 ];69:522-523
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Full Text


Isolated spinal accessory neuropathy (SAN) is an uncommon motor neuropathy most often related to local surgical procedures at the posterior cervical triangle, such as lymph node biopsy or tumor excision. Rare causes, such as nerve injury during carotid endarterectomy or catheterization of the internal jugular vein, after acromioclavicular or sternoclavicular dislocations, or penetrating injury due to trauma are also mentioned.[1] In the case of unknown etiology, the term idiopathic SAN is used.[1],[2]

A 74-year-old man was reviewed due to 4-month history of right shoulder weakness and deep scapular pain. As shown in [Figure 1], ipsilateral droopy shoulder, prominent levator scapulae muscle, scapular winging accentuated by shoulder abduction and head-tilt to the contralateral side were evident. Moreover, the right genioglossus muscle was unaffected; thus Collet-Sicard syndrome was excluded.[3] Furthermore, Ear, Nose and Throat evaluation consisting of oral examination and laryngoscopy revealed normal palatal and vocal fold mobility excluding Schmidt syndrome.[4]{Figure 1}

Electromyography (EMG) sampling exhibited active chronic neurogenic changes (a. fibrillations, positive sharp waves +3, b. motor unit action potentials [MUAPs] of moderately increased amplitude and duration and normal or increased number of phases and c. severely reduced recruitment of MUAPs) from the right trapezius and sternocleidomastoid muscles. EMG findings from the ipsilateral genioglossus, serratus anterior, rhomboid major, infraspinatus, deltoid, biceps brachii, triceps brachii and 1st dorsal interosseous muscles were unremarkable.

Cervical spine, neck, brain and skull base MRIs with and without contrast could not identify underlying structural pathology that could explain the patient's symptoms. Cerebrospinal fluid and extensive blood testing, including full blood count, erythrocyte sedimentation rate, C-reactive protein, immunoelectrophoresis and immunofixation, were also normal. Neither trauma nor history of related surgical procedures or infection was mentioned. Thus the diagnosis of idiopathic SAN was confirmed.

Idiopathic SAN is an exceedingly rare motor mononeuropathy. To our knowledge, only a few cases are reported in the literature.[1],[2] In contrast to the cases reported by Sergides et al.[1] and Gürsoy et al.[2] where the trapezius muscle was only involved, in our case both trapezius and sternocleidomastoid muscles were wasted.

Idiopathic SAN diagnosis is based on the combination of clinical, electrophysiological, blood and MRI testing.[2] Management is nonoperative involving analgesia and physiotherapy to strengthen trapezius and build up adjacent shoulder stabilizing muscles. Prognosis is unclear, though full recovery is possible.[1]


We would like to thank the patient and his family for providing full consent to publish this case.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


1Sergides NN, Nikolopoulos DD, Polyzois IG. Idiopathic spinal accessory nerve palsy. A case report. Orthop Traumatol Surg Res 2010;96:589-92.
2Gürsoy AE, Babacan-Yildiz G, Kolukisa M, Celebi A. Idiopathic spinal accessory nerve palsy: A case report and review of the literature. Neurol India 2013;61:82-3.
3Barbiero FJ, Baehring JM, Fulbright RK, Becker KP. MRI findings in Collet-Sicard syndrome. Neurology 2017;88:811.
4Kayamori R, Orii K. Schmidt syndrome due to idiopathic accessory nerve paralysis. Electromyogr Clin Neurophysiol 1991;31:199-201.