Residual Symptoms after Microvascular Decompression for Trigeminal Neuralgia Previously Treated by Percutaneous Nerve Blocking

Thirty-seven patients with trigeminal neuralgia and prior treatment by percutaneous nerve blocking underwent microvascular decompression between June, 1985 and September, 1986. On admission, hypesthesia in the affected branch of the trigeminal nerve was recognized in 29 of the 37 patients. Thirteen had dysesthesia and one had paresthesia. Microvascular decompression was carried out via suboccipital craniotomy, and a piece of muscle was inserted between the trigeminal nerve and the offending vessel. Postoperatively, dysesthesia increased in three cases and paresthesia in one case. The degree of hypesthesia was unchanged postoperatively in all 29 patients with this symptom. However, pain relief was experienced by all 37 patients. The incidence of residual sensory disturbance was unrelated to the site of the previous nerve blocks, the anesthetic agents administered, or the number of blocking procedures performed. The nerves showed neither degenerative changes due to blocking nor trauma as a result of the surgical procedure.