Preservation of the lesser occipital nerve during microvascular decompression for hemifacial spasm

The authors report on their technique for preserving the lesser occipital nerve (LON) during lateral suboccipital craniotomy. In their technique, the LON, which runs along the surface of or just beneath the sternocleidomastoid muscle, is identified and preserved. Lesser occipital nerve preservation using their technique was attempted in 25 patients who underwent microvascular decompression for hemifacial spasm. The LON was successfully preserved in 16 of these patients, was impossible to preserve in two patients, and could not be identified in seven patients. Among the patients in whom LON preservation was successful, 87.5% were free of sensory disturbance 6 months after surgery, whereas both patients in whom the LON could not be preserved complained of sensory disturbances in the occipital area and the posterior part of the auricula. Fifty-seven percent of the patients whose LON could not be identified complained of sensory disturbance. Thus, this technique for preserving the LON reduces the incidence of sensory disturbance in the occipital region after suboccipital craniotomy for microvascular decompression for hemifacial spasm.