Anticardiolipin antibodies and their associations with cerebrovascular risk factors.

OBJECTIVE: To investigate associations between cerebrovascular risk factors and anticardiolipin (aCL) immunoreactivity. BACKGROUND: High titers of aCL immunoreactivity, mainly the immunoglobulin (Ig) G isotype, were shown to predict aCL-related thrombo-occlusive complications. METHODS: aCL antibodies, and IgG and IgM isotypes were measured by a validated assay in a single laboratory, run in duplicate, in 749 individuals with first ischemic stroke (n = 300) and patients with other CNS disease or undergoing diagnostic procedures. RESULTS: Age varied according to aCL categories, with a mean of 61.8 years among patients with negative aCL (< 10 IgG phospholipid units [GPL]) to 62.3, 64.9, and 69.9 years in patients with immunoreactivity 10 to 20, 20 to 40, and >40 GPL respectively (p = 0.02). History of atrial fibrillation, congestive heart failure, or valvular heart disease was associated with significantly higher rates of positive IgG aCL (>10 GPL) and with higher immunoreactivity. IgG aCL immunoreactivity increased significantly, in a dose-response manner, as a function of the number of cerebrovascular risk factors present. In patients with first ischemic stroke, rates of 10 to 20, 20 to 40, and >40 GPL were 14%, 7%, and 0% among those with no risk factors versus 20%, 12%, and 12% respectively among patients with four or more risk factors (p = 0.007). No significant associations were identified, however, between IgM isotype aCL and any of the risk factors or increasing number of risk factors. CONCLUSION: The presence of multiple cerebrovascular risk factors is associated with substantially higher rates of positive IgG isotype aCL, and with higher immunoreactivity. These findings should caution against overdiagnosis of the antiphospholipid syndrome, and consequent changes in management among patients with multiple cerebrovascular risk factors.

Specificity, isotype, and titer distribution of anticardiolipin antibodies in CNS diseases.

BACKGROUND AND PURPOSE: There is an association between anticardiolipin antibodies (aCL) and ischemic stroke. There are, however, also occasional reports linking aCL with other CNS diseases (OND), particularly with multiple sclerosis (MS). Hence, we studied the specificity of aCL for ischemic stroke. METHODS: Prospective, consecutively identified patients evaluated for aCL (immunoglobulin G [IgG] and immunoglobulin M [IgM] isotypes) were divided into two groups: ischemic stroke (first ever) and OND (stroke-free subjects affected by OND). RESULTS: The ischemic stroke group (n = 300) and the OND (n = 149) differed in the following risk factors: age (64 +/- 14 versus 58 +/- 15 years; p < 0.001) and proportions of African Americans (67% versus 29%; p < 0.001); current cigarette smoker (26% versus 17%; p = 0.028); hypertensive (69% versus 34%; p < 0.001); diabetic (18% versus 7%; p = 0.001); history of angina (16% versus 8%; p = 0.015) or myocardial infarction (15% versus 3%; p < 0.001). There were higher rates of aCL positivity (26% versus 17%; p = 0.050), IgG-aCL > 10 GPL (23% versus 11%; p = 0.003) or IgG aCL > 20 GPL (12% versus 4%; p = 0.012) among the stroke group than among the OND group. No differences in IgG-aCL positivity were found between the MS group and the rest of the OND group but the MS patients had a higher rate of IgM-aCL positivity than the other OND patients. CONCLUSION: IgG-aCL positivity does not appear to be a marker for CNS disease generally but of ischemic stroke.

IgG anticardiolipin antibody titer > 40 GPL and the risk of subsequent thrombo-occlusive events and death. A prospective cohort study.

BACKGROUND: Anticardiolipin antibodies (aCL) have been associated with an increased risk of stroke and thrombo-occlusive events. Little is known about the influence of aCL on recurrent thrombo-occlusive events. METHODS: Consecutively identified patients (n = 132) with focal cerebral ischemia [stroke = 112, transient ischemic attack (TIA) = 20] harboring aCL of at least 10 GPL units at the time of their index event were prospectively followed to estimate the effect of aCL titer on time to and risk of subsequent thrombo-occlusive events (stroke, TIA, deep venous thrombosis, pulmonary embolism, myocardial infarction) and death. On the basis of prior literature, we divided patients into those with aCL < or = 40 GPL (n = 111; mean age, 63 +/- 14 years; mean follow-up, 1.95 years) and those with aCL > 40 GPL (n = 21; mean age, 54 +/- 20 years; mean follow-up, 1.50 years). RESULTS: There was no difference between groups for prevalence of hypertension, diabetes mellitus, cigarette smoking, atrial fibrillation, prior TIA, or sex. The GPL > 40 group was younger (54 +/- 20 versus 63 +/- 14 years; P = .055), had more prior strokes [9/21 (48%) versus 27/111 (20%); P = .030], more frequent subsequent thrombo-occlusive events and death [15/21 (71%) versus 51/111 (48%); P = .030], and a shorter median time (years) to event (0.15 versus 0.61, log rank P = .005). The risk ratio for recurrent event and death with GPL > 40 obtained from Cox proportional hazards models, adjusted for prior strokes, prior TIAs, hypertension, diabetes mellitus, atrial fibrillation, and cigarette smoking was 1.9 (95% confidence interval, 1.0 to 3.5; P = .051). CONCLUSIONS: Our data suggest that subsequent thrombo-occlusive events and death after focal cerebral ischemia associated with IgG aCL may occur sooner and more frequently with GPL > 40.

Recurrent stroke and thrombo-occlusive events in the antiphospholipid syndrome.

We prospectively studied 81 consecutively identified patients with antiphospholipid antibodies (aPLs) who developed focal cerebral ischemia over a 7-year period. The mean age of this cohort was approximately a decade younger than the average atherothromboembolic stroke victim and women were more commonly involved than men. The frequency of conventional stroke risk factors was lowest in the group of stroke patients with the highest levels of IgG cardiolipin immunoreactivity. Other serological abnormalities associated with aPL (false-positive Venereal Disease Research Laboratory test, thrombocytopenia, prolonged activated partial thromboplastin time [aPTT]) were more common in the group with over 100 GPL units (high positive). Patients with the highest IgG anticardiolipin titers had the shortest times to subsequent thrombo-occlusive events. The most common recurrent event was cerebral infarction, often occurring within the first year of follow-up during a mean prospective follow-up of 3 years. Over one-half of the cohort had at least one recurrent thrombo-occlusive event during follow-up. This distinct syndrome of cerebral ischemia should be recognized for its younger age at onset, predominance of women, high risk of recurrent thrombo-occlusive events, and the possible use of the IgG anticardiolipin antibody titer for prognosis.

Postangiography headache.

In order to study the frequency and characteristics of post-angiography headache, we interviewed 45 consecutive patients (mean age +/- SD = 57 +/- 15 years; M/F = 15/30) who underwent transfemoral cerebral angiography for: ischemic cerebrovascular disease (n = 33); suspected arteriovenous malformations (n = 4; one confirmed); suspected cerebral aneurysm (n = 5; two confirmed); and arterial dissection (n = 3; one confirmed and one was a follow-up study of a previously demonstrated dissection). Postangiography headache developed in 15 (33%) patients, 125 +/- 99 min after the completion of the study. It was unilateral in nine (60%) patients, homolateral to the usual side of migraine headache in two or three migraineurs, and pulsating in six (40%). Nausea, vomiting, photophobia, and phonophobia accompanied postangiography headache in 20%, 7%, 33%, and 20% respectively. Postangiography headache fulfilled the International Headache Society criteria for migraine without aura (except for the number of attacks) in 27% of patients. Patients with and those without postangiography headache were comparable in mean age, sex, and indication for angiography. Fifty-three percent (8/15) of patients with postangiography headache and 23% (7/30) of the non postangiography headache group reported prior recurrent headaches (P = 0.047, likelihood ratio chi-square). Postangiography headache has the characteristics of delayed arterial pain which may be related to a catheter-induced or contrast dye-induced release of vasoactive substances, notably nitric oxide and serotonin.

Factors associated with early presentation of acute stroke.

BACKGROUND AND PURPOSE: Patients with stroke symptoms commonly delay many hours before seeking medical attention. We sought to explore the factors associated with early presentation of stroke patients to physicians. METHODS: We prospectively studied 100 consecutive acute stroke patients presenting to three large, urban medical centers. Using a standardized, structured interview and chart review, we assessed patient education about stroke, risk factors, clinical features of the stroke, source of stroke recognition, and timing of presentation. We did not study the distance from the site of stroke onset to the site of physician contact. RESULTS: Stroke onset time was known in 96 of the patients. Mean patient age was 71.3 years, 79% had at least one stroke risk factor, 26% had prior transient ischemic attack, 19% had prior stroke, 74% had some high school education, and 86% had regular physicians. Only 8% had been previously educated about stroke symptoms. Eighty one percent of strokes were ischemic. The mean time to physician contact was 13.4 +/- 2.3 hours (median, 4.0 hours) and to neurologist contact was 21.2 +/- 2.9 hours. A skewed distribution of presentation times accounts for the mean-median differences. A small number of patients presenting very late could have an effect on the correlations between presentation time and the variables studied. Early presentation time was associated with increased age, the sudden onset of a stable deficit, and recognition that the symptoms signified stroke. Only the sudden onset of a stable deficit correlated independently with early presentation time (P = .0048). There was no correlation between presentation time and prior transient ischemic attack or stroke, headache, vomiting, loss of consciousness or seizures at onset, or stroke subtype, but a type II error could not be excluded. CONCLUSIONS: Despite their education level, regular health care, and risk factors, especially prior stroke and transient ischemic attack, these patients were not knowledgeable about stroke and delayed many hours before contacting physicians. The course of symptoms and recognition that they signified stroke were associated with earlier presentation. Patient education focused on groups at risk may hasten the presentation and treatment of acute stroke.

Human focal cerebral ischemia: evaluation of brain pH and energy metabolism with P-31 NMR spectroscopy.

The authors investigated early human focal ischemia with phosphorus-31 nuclear magnetic resonance spectroscopy at 1.89 T to characterize the temporal evolution and relationship of brain pH and phosphate energy metabolism. Data from 65 symptomatic patients were prospectively studied; none of the patients had had ischemic stroke in the internal carotid artery territory before. Twenty-eight neurologically normal individuals served as control subjects. Serial ischemic brain pH levels indicated a progression from early acidosis to subacute alkalosis. When acidosis was present there was a significant elevation in the relative signal intensity of inorganic phosphate (Pi) and significant reductions in signal intensities of alpha-adenosine triphosphate (ATP) and gamma-ATP compared with those of control subjects. Ischemic brain pH values directly correlated with the relative signal intensity of phosphocreatine (PCr) and the PCr index and inversely correlated with the signal intensity of Pi. There was a general lack of correlation between either ischemic brain pH or phosphate energy metabolism and the initial clinical stroke severity. The data suggest a link between high-energy phosphate metabolism and brain pH, especially during the period of ischemic brain acidosis, and the authors propose that effective acute stroke therapy should be instituted during this period.