Microvascular Decompression of Parastem Segments of the V, VII and IX Craniocerebral Nerves: Experience of Treatment of 175 Patients

E.V. Onopchenko, Yu.A. Grigoryan

(Federal Center of Pain Neurosurgery, State Medical Center of the Russian Ministry of Public Health, Moscow)

The results of treatment of patients with trigeminal neuralgia, hemifacial spasm and vasoglossopharyngeal neuralgia are analyzed. Microvascular decompression of the trigeminal nerve root, facial nerve, glossopharyngeal and vagus nerves was performed in 145, 24 and 6 cases respectively. The most frequent cause of compression of the trigeminal nerve was the superior cerebellar artery. Sometimes it was caused by the inferior anterior cerebellar and basilar arteries and venous trunks. Neuralgic pain disappeared in the nearest period in 98% of patients with trigeminal neuralgia. Preservation of pain syndromes in 2 cases was conditioned by inadequate decompression and slide of a placed pad. Fatal outcomes due to ischemic strokes, thromboembolism of the pulmonary artery and cerebellar hematoma were watched in 2.7% of cases. Neurologic complications were as follows: hearing disorders (6%), which were accompanied by transitory paresis of the facial nerve in 4.4% of cases. Relapses of trigeminal neuralgia in a remote postoperative period were observed in 6.6% of patients.

Transcutaneous radio frequency trigeminal rhizotomy was used as an alternative method in aged and senile patients (n=107), suffering from trigeminal neuralgia. Partial destruction of fibers of the trigeminal root was performed up to the moment of creating analgesia zones with minor hypesthesia in the area of branches of the trigeminal nerves, involved in pain syndrome. Intraoperative rentgenologic and electrophysiologic monitoring was carried out. Complete elimination of trigeminal neuralgia syndrome in the nearest postoperative period was achieved in 95% of cases. Preservation of good results in a remote period was watched in 68% of cases. The main cause of compression of the facial nerve root was the inferior cerebellar artery. Sometimes it was vertebral, basilar and posterior inferior cerebellar arteries. Excellent results were typical of the nearest and remote periods in 92% of cases. Diminished hearing, as a complication of the procedure, was observed in 2-3 patients. The most spread cause of compression of the IX-X nerves was the posterior inferior cerebellar artery. Compression, caused by the vertebral artery, was a less frequent phenomenon. An excellent postoperative result was present in 5 out of 6 cases with vasoglossopharyngeal neuralgia. In spite of reduction of pain syndrome, a result was considered to be bad in 1 patient. Treatment was complicated by transitory paresis of the soft palate and vocal ligament in 2 cases.

Selecting the most adequate methods for neurosurgical treatment of "hyperfunctional" syndromes of cranial nerves (microvascular decompression, puncture rhizotomy, radiosurgery) is a sophisticated problem, whose solution strongly depends on diagnostic findings, accompanying pathology. Besides, a patient is to be acquainted in detail with all existing alternative ways of treatment.

Microvascular decompression is a hi-tech operation, demanding profound microsurgical experience. Though it is characterized by the best postoperative results, it cannot be regarded as an ideal method of treatment because of different complications.