Neurologic deficits after enucleation of schwannoma are not rare. To evaluate the neurologic deficits after surgical enucleation of schwannoma in the upper extremity, we performed a retrospective review of patients with surgically treated schwannoma over a 14-year period at a single institution.

Between March 2001 and September 2014, 103 patients underwent surgical enucleation for schwannomas; 36 patients of them had lesions in the upper extremity, and 2 out of 36 patients had multiple schwannomas. Each operation was performed by a single surgeon under loupe magnification. The postoperative neurological deficits were graded as major and minor in both immediate postoperatively and at last follow-up. The major deficit was defined as anesthesia or marked hypoesthesia, motor weakness of grade 3 or less and neuropathic pain. Minor deficit was defined as mild symptoms of mild hypoesthesia, paresthesia and motor weakness of grade 4 or more.

There were 2 major (2 mixed nerve) and 12 minor (4 motor, 7 sensory, 1 mixed nerve) neurologic deficits after surgery. At the last follow-up, one major mixed neurologic deficit remained as major motor and minor sensory, and other major ones changed to mixed minor. And all minor deficits except 1 sensory deficit were recovered spontaneously.

Even though high incidence rate of neurologic deficit after enucleation of schwannoma in the upper extremity (38.9%), about three fourths of them were recovered spontaneously. There were 3 permanent neurologic deficits, and one of them was major one. In some cases, surgeon cannot avoid to encounter a neurological deficit. So we recommend more delicate microscopic surgical procedure and preoperative planning and counseling. And surgery is indicated for only symptomatic lesions.