Microvascular decompression as a treatment for cranial nerve hyperactive dysfunction--a critical view.

Neurovascular compression has been postulated as a probable mechanism for a large number of cranial nerve syndromes, with trigeminal neuralgia (TGN) as the prime example. Microvascular decompression (MVD) is often cited as the procedure of choice for treatment of medically refractory TGN. Arguments against these assumptions are: MRA studies indicate that vascular contact with the trigeminal nerve is present in most healthy individuals. Treatment results of MVD in multiple sclerosis patients with TGN are almost as good (at least in the short term) as in idiopathic cases. MVD is reported to provide pain relief even in TGN patients without visible neurovascular contact . In other syndromes of cranial nerve'hyperactive dysfunction'--vertigo, tinnitus and neurogenic hypertension--the documentation is even weaker.