Since the causes of tic douloureux are unknown,1 any scraps of information tending to throw light on its source are worth collecting. I have recently encountered an instance of the familial occurrence of this malady, and last year Harris2 published a pedigree in which 9 cases occurred in three generations. Harris has encountered 9 instances of the occurrence of trigeminal neuralgia in a child and one parent and 2 of its occurrence in a child and one grandparent. The histories of these 12 families constituted 1 per cent of his series of cases. He found anticipation to be the rule, the age of onset in each succeeding generation being earlier than in the preceding one.
REPORT OF A CASE
A white man aged 32 who was convalescing from resection of the sensory root of the right fifth nerve and who had suffered from tic douloureux for ten years