Search

In a Danish multicenter study, 74 patients 20 to 75 years of age (mean age, 58.8 years) with transient global amnesia (TGA) without accompanying major neurological signs were studied. Over a follow-up period ranging from seven to 210 months (mean, 66.6 months) the observed rates of death and cerebrovascular morbidity were similar to those expected in the Danish population, matched for age and sex. Sixteen patients (22%) had further TGAs occurring one month to nine years after the original episode; the mean annual recurrence rate was 4.7%. We concluded that TGA without associated major neurological deficits is a benign clinical phenomenon, probably caused by a functional cerebral disturbance unrelated to cerebrovascular disease in general. Furthermore, the observed temporal pattern of recurrence suggests that, although TGA is in principle a recurrent disorder, the annual risk of recurrence is so low that most of the elderly patients are likely to experience only one attack.

A comparison was made of 485 cases of cerebral infarction (CI), registered prospectively in Frederiksberg, Copenhagen, with 495 cases of myocardial infarction (AMI), recorded retrospectively in the same population. The overall annual incidence of AMI was 6.5 per 1,000 population for males, 3.8 for females; the rates for CI were 2.4 and 2.5, respectively. The age-incidence curves, particularly those for AMI, were significantly steeper in the females than in the males. Correspondingly, the male predominance in the AMI-group subsided with age. Age-specific incidence-rates rose exponentially with advancing age; for each sex and diagnosis the relationship can thus be expressed as a simple mathematical formula, which may facilitate comparisons of incidence patterns in different communities. Theories explaining the similarities and differences of the age-incidence curves for AMI and CI are discussed.

A retrospective follow-up study of 243 patients with transient ischemic attacks (TIA) is reported. The long-term mortality of the patients was higher than that of the corresponding general population. It is demonstrated that the excess mortality over the whole period of observation, irrespective of the age and sex of the patients, can be characterized by a single figure expressing the slope of the curve obtained by semilogarithmic plotting of the ratios of observed to expected survival against time. The use of this numerical expression--in the present series -0.04--will thus facilitate comparisons of the survival of TIA patients drawn from different populations. Unfavourable prognostic factors were: carotid TIA, associated extracerebral disease, and a history of hypertension. Fatal strokes, being four times as frequent as expected according to published incidence figures, accounted for 20% of the deaths, heart disease 38%. Stroke deaths tended to occur earlier than cardiac deaths. The results support the concept that most TIAs, like strokes, are incidents in the progressive course of a generalized vascular disease. The finding of a constant excess mortality over the years following a TIA makes it difficult to recommend a discontinuation of prophylactic therapy at any particular time.

In a cooperative study coordinated by WHO, stroke was registered between 1971 and 1974 in 17 centres both in developing and developed countries. A common operating protocol was used to obtain comparable data. Age-adjusted incidence of stroke shows moderate geographical variations, cerebrovascular accidents being common in all the contrasting populations studied in various parts of the world. Data were also obtained on the types of management of stroke patients, their survival rates, and functional prognosis. Control of hypertension, although known to be effective in the prevention of stroke, seemed to be insufficient in most countries. It is concluded that stroke registers may be used as a source of information for the planning and implementation of stroke control programmes in the community.