Microsurgical Decompression in “Hyperfunctional” Syndromes of Roots of Cranial Nerves

Grigoryan Yu.

Pirogov National Medical Surgical Centre, Moscow, Russia;
Clinical Diagnostic Complex N3, Moscow, Russia


The research goal was analysis of intraoperative findings and estimation of results of microsurgical treatment of “hyperfunctional” syndromes of cranial nerve roots in a compression effect of vessels and tumors on an entrance/exit zone of nerve fibers.

Material and Methods. There were 191 cases with “hyperfunctional” syndromes. Trigeminal neuralgia (TN), vagoglossopharyngeal neuralgia (VN) and hemifacial spasm (HS) were watched in 170, 5 and 16 of them respectively. Vascular compression and tumor compression of parastem segments of nerve roots were causes of “hyperfucntional” syndrome in 180 and 11 patients respectively. Microsurgical intervention with performing a retromastoid approach was aimed at decompression of parastem segments of nerve fibers. It was achieved by microdissection with transposition of vascular structures and removal of tumors. Different protectors were placed between nerve roots, brain stem and vessels.

Results and Discussion. TN was a result of compression by the superior cerebellar artery and its branches, arterial and venous trunks; compression by the anterior inferior cerebellar and basilar arteries was less frequent. As for VN and HS, a leading etiologic factor was vertebral, anterior and posterior inferior cerebellar arteries. Compression by a tumor was revealed in 10 cases with TN and one patient with HS. Neurological symptoms disappeared in the nearest postoperative period in 99% of patients. Pain syndrome recurrence was watched in 5% of cases with TN. It was eliminated by repeated operations.

Conclusion. Microsurgical decompression, performed in “hyperfunctional” syndromes of roots of cranial nerves, is a highly effective method of treatment, characterized by preservation of functions of nervous structures and a low rate of relapses.