Neurovascular Cross-Compression of the Eighth Cranial Nerve in Patients With Vertigo and Tinnitus

Abstract

The eighth (stato-acoustic) cranial nerve, like the trigeminal, facial, and glossopharyngeal nerves, is subject to symptoms of disordered hyperactivity which may be gradually accompanied by progressive loss of function. The hyperactive symptoms in this special sensory nerve which carries hearing (cochlear nerve) and balance (superior and inferior vestibular nerves) functions consist of a caricature of these normal functions of the nerve, just as the hyperactive symptoms in a somatic sensory nerve include pain (i.e. trigeminal neuralgia, N V) and in a somatic motor nerve, abnormal muscular movements or twitching (hemifacial spasm — N VII). Patients may first have symptoms of cochlear and/or vestibular nerve involvement. Symptoms which may include tinnitus, hyperacusis, diplacusis, hearing loss and vertigo, may vary in time and intensity. Symptoms may develop in one branch of the eighth cranial nerve and then gradually involve the other. Operative treatment over the years has generally consisted of peripheral denervation. This has indeed been the best available treatment for patients with intractable symptoms. The results regarding quality of life have not been excellent. Replacing one symptom with another has not proven to be a superior method of treatment.