Transient ischaemic attacks in young patients: a thromboembolic or migrainous manifestation? A 10 year follow up study of 46 patients

Forty six patients aged 18-39 years with transient ischaemic attacks (TIA) were studied; two thirds were women. Twenty five patients had attacks accompanied by headache, and seven gave a history of common migraine. Only four of 27 angiograms were abnormal; no operable carotid lesion was demonstrated. Over a mean follow up period of 10 years stroke or myocardial infarction (AMI) occurred in all four patients who presented major cerebrovascular risk factors, but in only two of the remaining 42 patients. Thus irrespective of age thromboembolic TIA is a harbinger of stroke or AMI. However, most TIAs under the age of 40 years are caused by a non-embolic benign vascular disorder. The clinical characteristics, long-term prognosis, and possible pathogenesis, for such attacks are often indistinguishable from those of classical migraine. In the absence of cardiovascular risk factors, arteriography does not provide much diagnostic and prognostic information.

Long-term prognosis and quality of life after reversible cerebral ischemic attacks

The long-term prognosis and quality of life of 201 patients admitted to hospital with reversible ischemic attacks (RIA) were estimated in a prospective study. The median follow-up time was 58 months. Further RIAs were reported by 91 patients (45%) and 48 (24%) suffered a stroke. The risk of stroke was markedly higher in the first 6 months after RIA, after which the annual stroke rate was rather constant with an average of 4.8%, about 8 times higher than expected. The average annual mortality rate for the RIA patients was 5.9%, which is significantly higher than expected. Cardiovascular deaths accounted for more than half of all deaths, stroke for one fourth. Life-table analysis of subgroups disclosed a much more favorable prognosis for women under 60 years. High systolic blood pressure, diabetes, and previous myocardial infarction were identified as risk factors. The occurrence of RIA had significantly influenced the quality of life and occupational status for the majority of the patients, even for those who did not suffer a subsequent stroke. Decreased working capacity, general asthenia and fatigue and impaired memory were the most common complaints. We conclude that RIA may be a more serious vascular event than generally believed. Apart from carrying a substantial risk of stroke and death, even a single RIA can cause permanent psychological dysfunction influencing the quality of life.

Amaurosis fugax in a Danish community: a prospective study

A prospective study of amaurosis fugax was carried out in a Danish community (population 481,000); case ascertainment was based on the collaboration of practicing ophthalmologists and general practitioners. Over a 3-year period we registered 131 cases; the annual incidence of "first amaurosis fugax episodes coming to medical attention" was 8.6 and 6.2 per 100,000 population for men and women, respectively. On the basis of a comparison of the age-incidence curves for cerebral and retinal ischemic attacks, the "true" incidence of amaurosis fugax is estimated to be approximately 14/100,000/yr, or 25-30% of the reported incidence of transient ischemic attacks. Clinical and/or radiologic signs of a carotid lesion on the appropriate side were present in 56% of the patients, and an additional 27% had symptoms or signs of other organic cardiovascular disorders. Forty-three (68%) of the 63 patients who underwent arteriography had an atheromatous lesion apparently amenable to carotid endarterectomy. In spite of the case-finding procedures employed in the study, cases of amaurosis fugax suitable for carotid surgery were thus ascertained at a rate of only 3/100,000/yr. This suggests that surgical treatment of patients with retinal ischemic attacks is of minor importance as a preventive measure against stroke in the community.

The prognosis of transient global amnesia. Results of a multicenter study

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.

Myocardial infarction and cerebral infarction in a Danish suburban community

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.

Acetylsalicylic acid in the prevention of stroke in patients with reversible cerebral ischemic attacks. A Danish cooperative study

Two hundred and three patients, 148 males and 55 females, who during the last month before admission had experienced at least one reversible cerebral ischemic attack of less than 72 hours duration, were randomly assigned to treatment with either acetylsalicylic acid (ASA) 1000 mg daily (101 patients) or placebo (102 patients). The average follow-up period was 25 months. The two treatment groups were comparable with respect to age, sex, associated diseases, risk factors, number and duration of cerebral ischemic attacks. No statistically significant differences were found between the treatment groups as to the primary end point: stroke or death (ASA group 20.8%, placebo group 16.7%). Occurrence of transient ischemic attacks during the treatment period was not reduced by ASA treatment, whereas there was a trend suggesting fewer myocardial infarctions in the ASA group (5.9%) than in the placebo group (13.7%). The difference, however, was not statistically significant (p = 0.10). We were thus unable to demonstrate any favorable influence of ASA 1000 mg daily in patients with reversible ischemic attacks. This study does not, of course, prove that ASA treatment is ineffective in stroke prevention.

Prognostic value of in vitro measurements of platelet aggregability and fibrinolytic activity in patients with reversible cerebral ischemic attacks

Platelet aggregability and fibrinolytic activity were studied repeatedly in 83 patients with reversible cerebral ischemic attacks over a median follow-up period of 26 months. Platelet hyperaggregability, defined as in vitro secondary aggregation obtained by adenosine diphosphate concentration less than or equal to 1 mumol/l, was demonstrated in 36.1% or the patients examined 5-8 days after the attack, but only in 6% of age- and sex-matched blood donors (p less than 0.001). Fibrinolytic activity was reduced in 57.8% of the patients, as compared with 20.5% of the controls. At the time of follow-up only 8% of the survivors showed platelet hyperaggregability, whereas the fibrinolytic activity was still reduced in 44.4%. Over the observation period 21.7% of the patients had a stroke or died. No significant correlation was found between abnormalities of platelet aggregability or of fibrinolytic activity, when observed 5-8 days after the ischemic episode, and the subsequent risk of stroke or death. It is concluded that in patients with recent cerebral ischemic attacks the demonstration of platelet hyperaggregability or reduced fibrinolytic activity appears to be without prognostic significance.

Long-term prognosis after transient ischemic attacks

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.

Cerebrovascular disease in the community: results of a WHO collaborative study

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.

Incidence of stroke in Frederiksberg, Denmark

Since 1971, stroke registers in several countries have been cooperating in a study of stroke epidemiology, initiated by WHO. One of the registers covers the population of Frederiksberg, Copenhagen. During the first two years of registration strokes were recorded in 556 Frederiksberg citizens. A certain diagnosis of cerebral hemorrhage--verified by angiography, spinal fluid examination, or autopsy--was made in 10% of the patients; subarachnoid hemorrhage was demonstrated in only 2%; most of the remaining patients probably had cerebral infarction. The overall annual incidence of stroke, when adjusted for age for the Danish population, was 1.9 per 1,000 for males, and 1.6 per 1,000 for females. For every type of stroke, except subarachnoid hemorrhage, the incidence increased markedly with age. The age-specific stroke incidence rates found in the present investigation are much lower than those demonstrated by Aho in a community-based study in Finland. In view of the strict comparability of the two studies, real differences in the risk of stroke may exist between the two communities.

Controlled trial of intravenous aminophylline in acute cerebral infarction

In a double-blind trial intravenous aminophylline was compared with placebo in 79 patients with acute cerebral infarction. Immediate improvement in the neurological evaluation score was significantly more frequent in patients receiving aminophylline (38 per cent) than in those on placebo (15 per cent); only patients with mild or moderately severe strokes responded to the injection. After 3 weeks, however, the treated patients did not fare significantly better than the controls in terms of neurological score and residual disability. Survival rate, length of stay in hospital, and social readaptation were similar in the two groups. It is concluded that intravenous aminophylline in patients with ischaemic strokes can bring about an immediate symptomatic relief, but without appreciably influencing the ultimate recovery.