Isolated accessory nerve palsy of unusual cause

@article{Magoni2006IsolatedAN,
  title={Isolated accessory nerve palsy of unusual cause},
  author={Marzia Magoni and V. Scipione and Gian Paolo Anzola},
  journal={The Italian Journal of Neurological Sciences},
  year={2006},
  volume={15},
  pages={239-243}
}
We report the case of a 23 year old male patient who presented for an isolated left accessory nerve palsy which had appeared one year before. Neuroradiological investigations showed that the causative pathology was a giant saccular aneurism of the intracranial left vertebral artery. Three months after diagnosis, signs of bulbar palsy rapidly developed. An emergency intra-arterial embolization was then attempted, which led to complete recovery except for the accessory nerve palsy which remained… 
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References

SHOWING 1-2 OF 2 REFERENCES
Isolated accessory nerve palsy of spontaneous origin. A clinical and electromyographic study.
TLDR
Four cases of unilateral accessory nerve palsy occurring without any definitive cause are described and electromyography demonstrated slowing of the accessory nerve conduction and evidence of denervation of the trapezius and sternomastoid muscles.
Accessory nerve palsy: a review of 23 cases.
TLDR
The prognosis was better following blunt trauma, stretch injuries and after a spontaneous onset, and the anatomical relationships of the accessory nerve and aspects of the clinical picture and management are discussed.