Vascular compression of cranial nerves: II: Pathophysiology

The pathophysiology of trigeminal neuralgia, hemifacial spasm and other dis orders that can be cured by microvascular decompression of cranial nerves, is reviewed and different hypotheses about its pathophysiology are discusse d. It is found that the pathophysiology of these disorders is complex and o ther factors than vascular compression are necessary to cause symptoms. Whi le the efficacy of the microvascular decompression (MVD) operation is indis putable, it is questionable if the symptoms and signs of these disorders ar e caused by abnormal neural activity in the respective cranial nerves that result from the compression from a blood vessel. Instead, studies point to hyperactivity and hyperexcitability of the respective nuclei as a cause of the symptoms and signs of these disorders. Results of several studies indic ate that irritation of the cranial nerve in question from close contact wit h a blood vessel may promote such development, and it seems necessary that other factors in addition to the vascular contact must be present in order that such a condition develops.