Non-atheromatous causes of cerebral infarction.

The 600-fold increase in the incidence of stroke with advancing age, from 10 per 100,000 below 35 years of age to 6,000 per 100,000 over 75 years (Kurtzke, 1976), is related in the main to the creeping peril of atherosclerosis. However, only a minority of strokes before middle-age can be ascribed to atheroma and in every age-group non-atheromatous causes of cerebral infarction account for a small but significant proportion of vascular lesions. Two fascinating reports, presented in this issue of the Postgraduate Medical Journal by Salanova and Taubner and by Monton et al., provide a reminder that extraordinary and preventable aetiological factors may precipitate sudden hemiplegia. The diversity of aetiologies of cerebral infarction reflects the changing patterns of modern civilization: our life-style includes many hazardous occupations and leisure pursuits, the excesses of society range from drug abuse to fitness fanaticism, and medical survival is achieved at the cost of occasional but unanticipated side effects ofyet more potent therapeutic agents (Chambers et al., 1981). One result has been an increase in the incidence of non-fatal strokes in the decade 1970-9 (Lindstrom, Soderstrom and Mettinger, 1982).