Biomedical subjects

T Isack

Publications and source records attributed to T Isack.

5 recordsLinked to original sources

PubMed1990

Transient ischemic attacks: their frequency in the Lehigh Valley.

The incidence of transient ischemic attacks (TIAs) in the Lehigh Valley was analyzed using the Lehigh Valley Stroke Register based on data collected between July 1, 1982, and June 30, 1986. The overall average annual incidence rate was 22.9 per 100,000 population, and 23.2 and 22.5 per 100,000 population in men and women, respectively. Men had a statistically significant higher age-specific rate of TIAs than women. Our incidence appears to be lower than that reported in earlier studies but, because of methodologic differences, only continued observations in our population and in similar populations using a standardized methodology will resolve the question of whether TIA frequency is, in fact, declining.

Adult↗

PubMed1989

Stroke in the Lehigh Valley: combined risk factors for recurrent ischemic stroke.

We used the Lehigh Valley Stroke Register and a logistic regression model for the odds ratio to study the relative contribution of several factors, considered jointly, to the risk of recurrent ischemic stroke. The factors were hypertension (HT), transient ischemic attack (TIA), myocardial infarction (MI), other heart diseases (OHD), diabetes mellitus (DM), age, and sex. Among these factors MI, OHD, and TIA constituted significantly greater risk than HTN, DM, age, or sex for ischemic stroke recurrence.

Cerebrovascular Disorders↗

PubMed1989

Stroke in the Lehigh Valley: racial/ethnic differences.

We investigated black/white differences in stroke rate (standardized morbidity), severity, and subtype, and the relative frequencies of 5 primary risk factors (hypertension, diabetes, myocardial infarction, other heart diseases, and transient ischemic attack [TIA]) using the Lehigh Valley Stroke Register. Blacks had a statistically significant higher, age-adjusted rate of stroke than whites. We found no differences in stroke severity using our measures but blacks had a statistically higher proportion of lacunar stroke, while whites had a higher proportion of embolic stroke. There were no differences in proportions of thrombotic stroke or intracerebral hemorrhage. The relative frequencies of hypertension, myocardial infarction, other heart diseases, and diabetes were higher for blacks, while the relative frequency of TIA was higher for whites. These observations are consistent with other reports that blacks have a higher frequency of stroke and tend to have more small-vessel cerebrovascular pathology than whites.

Age Factors↗

PubMedDate not supplied

Stroke in the Lehigh Valley: seasonal variation in incidence rates.

We investigated the seasonal pattern of stroke using the Lehigh Valley Stroke Register. This register includes all patients hospitalized with stroke or transient ischemic attack (TIA) from among the 600,000 Lehigh Valley residents. Meterological data were obtained from the National Oceanic and Atmospheric Administration. The study, which uses 18 months of data, included 1,944 cases. Using single harmonic regression analysis, the seasonal pattern of TIA and infarction, but not hemorrhage, fit a sine-cosine wavefunction with a 12-month period (R2 = 41% and 36%, respectively). For infarction, the strongest seasonal pattern was exhibited for women of all ages and for both sexes in the age groups 65-74 and 75-84, but only the sine component was significant. The peak months for TIA were June-August, while the peak months for infarcts were February-April. Correlations between ambient temperature and each type of stroke were computed. A significant positive correlation for TIA was found (r = 0.57, p = 0.01). After adjusting for a 2-month lag between the low for infarction and the peak for temperature, a significant negative correlation was found (r = -0.64, p = 0.01). No significant correlation was found for hemorrhage. Possible reasons for the opposite relations of TIA and infarct are discussed.

Age Factors↗

PubMedDate not supplied

Acute stroke, hematocrit, and blood pressure.

A population-based study of the relation between hematocrit and stroke subtype was carried out among 2,077 individuals using the Lehigh Valley Stroke Register. This register identifies all stroke patients admitted to the 8 acute care hospitals serving the Lehigh Valley area of eastern Pennsylvania-western New Jersey. The mean hematocrit was higher in patients with lacunes than with thrombotic or embolic strokes (p = 0.02). However, when blood pressure was also considered the increase in hematocrit in patients with lacunar stroke was significant only when systolic hypertension (greater than or equal to 150 mm Hg) was also present (p = 0.029); no significant difference in hematocrit was found between stroke subtypes in normotensive individuals. Therefore, we cannot exclude the possibility that hypertension interacts with hematocrit in accounting for the observed association with lacunar infarcts. There was no trend for increased in-hospital mortality for stroke patients in either the low (less than or equal to 30, 30-36%) or high (greater than or equal to 47%) hematocrit groups.

Acute Disease↗