Excision of Giant Perineural Cyst Over the T1 Nerve Root With Neural Reconstruction: 2-Dimensional Operative Video

Among perineural cysts, there is wide variability of incidence ranging from 0.38% to 17.7% with sacral cysts predominating.(1) The mean pooled sagittal diameter is about 11.86 mm and presentation is typically asymptomatic.(1) We report a unique case of a T1 left-sided perineurial cyst measuring 2.5 cm transverse, 2.2 cm anteroposterior, and 3.4 cm craniocaudal in an 83 year-old female, who presented 1-day post accidental biopsy with headache, nausea, and vomiting. Originally admitted for chest pain thought to be secondary to heart failure, the patient had an incidentally discovered apical pleural mass at the T1-T2 junction on thoracic myelogram. Following interventional radiology biopsy of the benign cystic lesion, she experienced positional headache, nausea, and vomiting and was diagnosed with pneumocephalus and scant subarachnoid hemorrhage. Conservative management options were either unsuccessful or contraindicated due to patient cardiac history.(2) Baseline neurological exam was normal. Computed tomography myelogram strongly suggested a posterior T1 perineural cerebrospinal fluid leak. Alternative treatments were considered, and the patient consented to operative intervention. After exposure and using neuromodulation, the distal cyst was disconnected from its proximal attachment to the dural sleeve while leaving enough material around the nerve to reconstruct the nerve root sleeve using a dural cuff. One month postoperatively, visual analog scale pain scores averaged about 1 and extremity strength was 5/5. Three months postoperatively, visual analog scale pain scores averaged close to 0. In summary, the patient experienced immediate pain relief, normal hand motion, and headache cessation 1-day post operation and was discharged 3-days postoperatively. Follow up was discontinued at 4 months.