Microvascular decompression operations.

Moving a blood vessel off the intracranial portion of the auditory nerve can successfully cure some individuals with specific forms of subjective tinnitus. This operation, known as microvascular decompression (MVD) is in general use to treat other hyperactive disorders such as hemifacial spasm (HFS) and trigeminal neuralgia (TGN) where the operation has a success rate of approximately 85%. MVD for tinnitus has lower success rate. MVD operations have also been used to treat some forms of vestibular disorders, disabling positional vertigo (DPV). In a study of treatment of a selected group of 72 patients with severe tinnitus and signs of change in the conduction properties of the auditory nerve 13 (18.2%) had total relief from tinnitus after MVD, 16 (22.2%) had marked improvement, 8 slight improvement and 33 (45.8%) no improvement. Two patients became worse (2.8%). There were 40 men and 32 women in the study group and there was considerable difference in the success rate for men and women. Fifty-five percent of the women and 29% of men showed relief or improvement. The success of the operation depended on the length of time the participants in the study had had their tinnitus and it was best for those who had had tinnitus for less than 3 years. The success rate for bilateral tinnitus was much lower than for unilateral tinnitus.