Decompression of the facial nerve in cases of hemifacial spasm.

a ) Primary hemifacial spasm, by some authors termed "cryptogenic", "idiopathic" or "autonomous". In reviewing 106 cases Ehni and Woltm a n 5 gave the fo l lowing characteristics of this group: (1) the spasms are of an intermittent, twitching nature, ( 2 ) the eyel ids on the ipsilateral side are almost always involved, ( 3 ) the spasms are usually unilateral and when bilateral they are not synchronous or equal in extent or severity, (4 ) the spasms may persist in sleep, (5 ) the patient does not feel any compulsion to make the movement, (6 ) the patient is unable to stop the movement by exercise of the will , ( 7 ) the patient cannot reproduce the movement voluntarily, (8 ) psychic upsets of any sort, fatigue and voluntary movements of the face, make the condition worse, (9 ) children do not have hemifacial spasm and (10 ) the spasms are limited to muscles innervated by the facial nerve.