Trapezius muscle denervation in accessorius palsy due to a posterior fossa arachnoid cyst

Case contributed by Dr Roberto Schubert

Presentation

A young man noticed an asymmetry about his neck while shaving in front of the mirror. He went to see an orthopaedic surgeon, who referred him for an MRI of the neck.

Patient Data

Age: 19
Gender: Male

Marked atrophy and increased T2 signal of the right trapezius muscle. The other muscles, including sternocleidomastoideus are normal. On the coronal T2-weighted images, there is a liquid mass in the right posterior cranial fossa.

Cranial MRI performed a few days later.

Modality: MRI

There is a large cyst in the lateral cerebellomedullary cistern that extends from Luschka's foramen down to the jugular foramen and displaces the cranial nerves X and XI anteriorly.

Case Discussion

Cranial nerve palsies resulting from posterior fossa arachnoid cysts have been rarely described. In this case, typical signs of subacute muscle denervation are present, indicating the affected nerve.

PlayAdd to Share

Case Information

rID: 17130
Case created: 19th Mar 2012
Last edited: 20th Mar 2017
Inclusion in quiz mode: Included

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.