Biomedical subjects

R F Macko

Publications and source records attributed to R F Macko.

At least 19 recordsLinked to original sources

PubMed2002

The impact of angiotensin II receptor blockade and the DASH diet on markers of endogenous fibrinolysis.

Hypertension is associated with impaired fibrinolysis. Both angiotensin receptor blockers (ARB) and the DASH (Dietary Approaches to Stop Hypertension) diet effectively lower blood pressure in hypertensive patients. Some evidence suggests that treatment with ARBs could increase fibrinolysis, however, data is conflicting. The impact of the DASH diet on fibrinolytic parameters is not known. Fifty-five hypertensive participants (35 African-American, 20 white) were randomly assigned to receive 8 weeks of either a control diet or the DASH diet. The diets did not differ in sodium content (approximately 3 g/day). Within each diet, individuals were randomly assigned to receive losartan or placebo for 4 weeks in double-blind, cross-over fashion. Tissue plasminogen activator (t-PA) antigen, t-PA activity, plasminogen activator inhibitor-1 (PAI-1) activity and plasma renin activity (PRA) were measured at the end of a 2-week run-in period on the control diet and after each treatment period. The DASH diet did not affect markers of fibrinolysis. Losartan significantly lowered t-PA antigen levels (-1.8 ng/mL, P = 0.045), but had no effect on t-PA or PAI-1 activities. This effect was more pronounced in whites (-4.1 ng/mL (P = 0.003)) compared with African-Americans (-0.3 ng/mL (P = 0.7), P-interaction = 0.03). Results were not materially affected by adjustment for basline values or changes in blood pressure. This study demonstrates that losartan reduces t-PA antigen levels in white, but not African-American hypertensive individuals. In contrast, the DASH diet had no significant effect on markers of fibrinolysis in whites or African-Americans.

Angiotensin II↗

PubMed2001

Treadmill training improves fitness reserve in chronic stroke patients.

OBJECTIVE: To investigate the hypothesis that treadmill training will improve peak fitness, while lowering the energy cost of hemiparetic gait in chronic stroke patients. DESIGN: Noncontrolled exercise intervention study with repeated-measures analysis. SETTING: Hospital-based senior exercise research center. PARTICIPANTS: Twenty-three patients (mean age +/- standard deviation [SD] 67 +/- 8 yr) with chronic hemiparetic gait after remote (>6 mo) ischemic stroke. INTERVENTION: Three 40-minute sessions of treadmill exercise weekly for 6 months. MAIN OUTCOME MEASURES: Peak exercise capacity (VO2peak) and rate of oxygen consumption during submaximal effort treadmill walking (economy of gait) by open circuit spirometry and ambulatory workload capacity before and after 3 and 6 months of training. RESULTS: Patients who completed 3 months of training (n = 21) increased their VO2peak +/- SD from 15.4 +/- 2.9 mL x kg(-1) x min(-1) to 17.0 +/- 4.4 mL x kg(-1) x min(-1) (p <.02) and lowered their oxygen demands of submaximal effort ambulation from 9.3 +/- 2 mL x kg(-1) x min(-1) to 7.9 +/- 1.5 mL x kg(-1) x min(-1) (p =.002), which enabled them to perform the same constant-load treadmill task using 20% less of their peak exercise capacity (62.3% +/- 17.2% vs 49.9% +/- 19.3%, p <.002). Gains in VO2peak and economy of gait plateaued by 3 months, while peak ambulatory workload capacity progressively increased by 39% (p <.001) over 6 months. CONCLUSIONS: Treadmill training improves physiologic fitness reserve in chronic stroke patients by increasing VO2peak while lowering the energy cost of hemiparetic gait, and increases peak ambulatory workload capacity. These improvements may enhance functional mobility in chronic stroke patients.

Aged↗

PubMed2001

Fibrinolytic response to acute exercise in patients with peripheral arterial disease.

PURPOSE: Elevations in tissue plasminogen activator (tPA) are postulated to protect against atherothrombotic events during exercise. However, fibrinolytic response to repetitive bouts of symptom-limited exercise is unknown in peripheral arterial disease (PAD) patients, a population with impaired fibrinolysis and increased risk for ischemic events. The purpose of the present study was to evaluate the fibrinolytic response to repetitive bouts of symptom-limited exercise in PAD patients. METHODS: Nine (8 male, 1 female) patients with Fontaine State II PAD were studied. Fasting blood samples for determination of tPA and plasminogen activator inhibitor (PAI-1) were obtained into an acidified citrate solution via an indwelling venous catheter before, immediately after, 30 min after, and 60 min after submaximal treadmill walking. Patients walked intermittently at 65% of maximal intensity achieved on a previous graded exercise test until 30 min of exercise was achieved. RESULTS: Exercise increased tPA activity by 180% (0.5 +/- 0.16 IU.mL(-1) baseline, 1.4 +/- 1.2 IU.mL(-1) postexercise), and decreased PAI-1 activity by 40% (20.6 +/- 5.5 AU.mL(-1) baseline, 11.8 +/- 6.2 AU.mL(-1) postexercise), without changing tPA or PAI-1 antigen. Notably, plasma tPA activity levels 1 h after exercise remained elevated by 80%, whereas PAI-1 activity remained decreased by 49%. The decrease in PAI-1 significantly (P < 0.05) correlated with oxygen uptake (VO(2)) during submaximal exercise (r = -0.77). CONCLUSION: These findings demonstrate that repetitive bouts of symptom-limited exercise produce a substantial improvement in the fibrinolytic profile of PAD patients, which persists at least 1 h after exercise cessation.

Aged↗

PubMed2001

Alcohol intake, type of beverage, and the risk of cerebral infarction in young women.

BACKGROUND AND PURPOSE: The relationship between alcohol consumption and cerebral infarction remains uncertain, and few studies have investigated whether the relationship varies by alcohol type or is present in young adults. We examined the relationship between alcohol consumption, beverage type, and ischemic stroke in the Stroke Prevention in Young Women Study. METHODS: All 59 hospitals in the greater Baltimore-Washington area participated in a population-based case-control study of stroke in young women. Case patients (n=224) were aged 15 to 44 years with a first cerebral infarction, and control subjects (n=392), identified by random-digit dialing, were frequency matched by age and region of residence. The interview assessed lifetime alcohol consumption and consumption and beverage type in the previous year, week, and day. ORs were obtained from logistic regression models controlling for age, race, education, and smoking status, with never drinkers as the referent. RESULTS: Alcohol consumption, up to 24 g/d, in the past year was associated with fewer ischemic strokes (<12 g/d: OR 0.57, 95% CI 0. 38 to 0.86; 12 to 24 g/d: OR 0.38, 95% CI 0.17 to 0.86; >24 g/d: OR 0.95, 95% CI 0.43 to 2.10) in comparison to never drinking. Analyses of beverage type (beer, wine, liquor) indicated a protective effect for wine consumption in the previous year (<12 g/wk: OR 0.58, 95% CI 0.35 to 0.97; 12 g/wk to <12 g/d: OR 0.55, 95% CI 0.28 to 1.10; >/=12 g/d: OR 0.92, 95% CI 0.23 to 3.64). CONCLUSIONS: Light to moderate alcohol consumption appears to be associated with a reduced risk of ischemic stroke in young women.

Adolescent↗

PubMed2001

Hemiparetic gait parameters in overground versus treadmill walking.

OBJECTIVE: Hemiparetic gait is characterized by high stride-cycle variability, diminished stance time, single-limb stance time, and stance/swing ratio in the paretic limb. Recent studies suggest treadmill (TM) training may improve the motor control underlying these variables, but supporting evidence is sparse. METHODS: This study compared gait patterns of untrained chronic hemiparetic stroke patients (n = 18; mean, 39.5 months poststroke) during overground (OG) and TM walking at matched velocities. Variables included relative stance time, relative single-limb stance time, stance/swing ratio, peak force, and impulse. Within-subject variability of these measures (CV) was used to assess gait pattern stability. RESULTS: OG and TM cycle durations were similar, but CVs differed (TM < OG, p < 0.05). In the paretic limb, differences were seen in relative stance time, relative single-limb stance time, and stance/swing ratio, respectively (TM > OG, p < 0.05). These variables decreased in the nonparetic limb during TM walking (p < 0.05 for all). Improved interlimb symmetry and coordination were evidenced by decreased between-limb differences and improved relative temporal phasing, respectively, in the TM condition (p < 0.05). CONCLUSIONS: Collectively, these results demonstrate that the TM induces an immediate alteration toward a more consistent and symmetric gait pattern. Further investigation is needed to determine whether TM training leads to motor relearning and neuroplasticity in chronic hemiparetic subjects.

Chronic Disease↗

PubMed2000

Lipoprotein (a) and the risk of ischemic stroke in young women.

BACKGROUND AND PURPOSE: lipoprotein (a) (lp (a)) is a lipid-containing particle similar to LDL which has been found in atherosclerotic plaque. The role of lp (a) in ischemic stroke remains controversial, but some studies suggest lp (a) is particularly important as a risk factor for stroke in young adults. We investigated the role of lp (a) as a risk factor for stroke in young women enrolled in the Stroke Prevention in Young Women Study. METHODS: subjects were participants in a population-based, case-control study of risk factors for ischemic stroke in young women. Cases were derived from surveillance of 59 regional hospitals in the central Maryland, Washington DC, Pennsylvania and Delaware area. Lp (a) was measured in 110 cases and 216 age-matched controls. Demographics, risk factors, and stroke subtype were determined by interview and review of medical records. RESULTS: lp (a) values were higher in blacks than whites, but within racial groups, the distribution of lp (a) values was similar between cases and controls. After adjustment for age, race, hypertension, diabetes, cigarette smoking, coronary artery disease, total cholesterol and HDL cholesterol, the odds ratio for an association of lp (a) and stroke was 1.36 (95% CI 0.80-2.29). There was no dose-response relationship between lp (a) quintile and stroke risk. Among stroke subtypes, only lacunar stroke patients had significantly elevated lp (a) values compared to controls. CONCLUSIONS: we found no association of lp (a) with stroke in a population of young women with ischemic stroke. Small numbers of patients limit conclusions regarding risk in ischemic stroke subtypes, but we could not confirm previous suggestions of an association of lp (a) with atherosclerotic stroke in young adults.

Adolescent↗

PubMed2000

Repetitive bilateral arm training with rhythmic auditory cueing improves motor function in chronic hemiparetic stroke.

BACKGROUND AND PURPOSE: Chronic upper extremity hemiparesis is a leading cause of functional disability after stroke. We investigated the hypothesis that bilateral arm training with rhythmic auditory cueing (BATRAC) will improve motor function in the hemiparetic arm of stroke patients. METHODS: In this single group pilot study we determined the effects of 6 weeks of BATRAC on 14 patients with chronic hemiparetic stroke (median time after stroke, 30 months) immediately after training and at 2 months after training. Four 5-minute periods per session (3 times per week) of BATRAC were performed with the use of a custom-designed arm training machine. RESULTS: The patients showed significant and potentially durable increases in the following: Fugl-Meyer Upper Extremity Motor Performance Test of impairment (P<0.0004), Wolf Motor Function Test (performance time measure, P<0.02), and University of Maryland Arm Questionnaire for Stroke measuring daily use of the hemiparetic arm (P<0.002). Isometric strength improved in elbow flexion (P<0.05) and wrist flexion (P<0.02) for the paretic arm and in elbow flexion (P<0.02) and wrist extension (P<0.02) for the nonparetic arm. Active range of motion improved for paretic-side shoulder extension (P<0.01), wrist flexion (P<0.004), and thumb opposition (P<0.002), and passive range of motion improved for paretic wrist flexion (P<0.03). CONCLUSIONS: -Six weeks of BATRAC improves functional motor performance of the paretic upper extremity as well as a few changes in isometric strength and range of motion. These benefits are largely sustained at 8 weeks after training cessation.

Acoustic Stimulation↗

PubMed2000

Effects of aerobic treadmill training on gait velocity, cadence, and gait symmetry in chronic hemiparetic stroke: a preliminary report.

It is widely assumed that only limited improvement in functional mobility is possible beyond the subacute period following ischemic stroke. Contrary to this notion, we studied "neurologically plateaued" stroke patients with chronic hemiparesis to assess whether a "task-oriented" treadmill-training regimen would improve walking speed, cadence, and gait cycle symmetry on a modified "Get-Up and Go" task. Five male patients with a mean age of 60.4 +/- 2.7 years (mean +/- S.D.) status post ischemic stroke (> 6 months prior) participated in this nonrandomized low-intensity treadmill exercise pilot study three times/week for 3 months. All patients had mild to moderate gait asymmetries due to residual hemiparesis. Patients were videotaped before and after 3 months of treadmill aerobic exercise (AEX) while performing a functional task consisting of arising from a chair, walking 3.1 m without an assistive device as fast as safely possible, and returning to sit. Gait events were timed using a 2-D Peak Motus video analysis system. After 3 months AEX training, times for the overall "get-up and return-to-sit" (GURS) task and the "straight-away walk" (SAW) segment decreased from 8.2 +/- 1.4 sec to 6.5 +/- 0.8 sec (mean +/- SEM) (p < 0.05), and from 3.7 +/- 1 sec to 2.8 +/- 0.7 sec (p < 0.05), respectively. These data represent improvements of 21% and 24% for the GURS and SAW segments, respectively. Mean velocity increased from 0.9 +/- 0.2 to 1.2 +/- 0.21 m/sec, a 33% improvement (p < 0.01). Mean cadence (steps/min) increased from 89 +/- 9 to 97 +/- 8, a 9% increase (p < 0.05). Mean stance and swing duration diminished for both paretic (P) and nonparetic (NP) limbs, and the intralimb stance/swing ratio values moved toward normal for both the paretic and nonparetic limbs. However, these latter changes reached significance only for the P limb. Interlimb stance symmetry was unchanged. The more impaired subjects experienced the greatest gains in gait velocity and temporal measures. Collectively, these findings indicate that treadmill exercise improves functional overground mobility in individuals with chronic, stable hemiparesis.

Aged↗

PubMed1999

Distribution and correlates of elevated total homocyst(e)ine: the Stroke Prevention in Young Women Study.

PURPOSE: To determine the distribution and correlates of elevated total homocyst(e)ine (tHcy) concentration in a population of premenopausal black and white women. METHODS: Data from the Stroke Prevention in Young Women Study (N = 304), a population-based study of risk factors for stroke in women aged 15-44 years of age, were used to determine the distribution and correlates of elevated tHcy in black (N = 103) and white women (N = 201). RESULTS: The mean tHcy level for the population was 6.58 micromol/L (range 2.89-26.5 micromol/L). Mean tHcy levels increased with age, cholesterol level, alcohol intake, and number of cigarettes smoked (all: p < 0.05). There were no race differences (mean tHcy 6.72 micromol/L among blacks and 6.51 micromol/L among whites; p = 0.4346). Regular use of multivitamins and increasing education was associated with significant reductions in tHcy concentration. Approximately 13% of the sample had elevated tHcy levels, defined as a tHcy concentration > or = 10.0 micromol/L. Multivariate-adjusted correlates of elevated tHcy included education > 12 vs. < or = 12 (odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.2-0.8); smoking > or = 20 cigarettes/day vs. nonsmokers (OR = 2.8, 95% CI = 1.1-7.3); and the regular use of multivitamins (OR = 0.4, 95% CI = 0.2-0.9). CONCLUSIONS: These results suggest that a substantial proportion of healthy young premenopausal women have tHcy levels that increase their risk for vascular disease. A number of potentially modifiable behavioral and environmental factors appear to be significantly related to elevated tHcy levels in young women.

Adolescent↗

PubMed1999

Elevated tissue plasminogen activator antigen and stroke risk: The Stroke Prevention In Young Women Study.

BACKGROUND AND PURPOSE: Abnormalities in endogenous fibrinolysis are associated with an increased risk for stroke in men and older adults. We tested the hypothesis that elevated plasma tissue plasminogen activator (tPA) antigen, a marker for impaired endogenous fibrinolysis, is an independent risk factor for stroke in young women. METHODS: Subjects were 59 nondiabetic females ages 15 to 44 years with cerebral infarction from the Baltimore-Washington area and 97 control subjects frequency-matched for age who were recruited by random-digit dialing from the same geographic area. A history of cerebrovascular disease risk factors was obtained by face-to-face interview. Plasma tPA antigen was measured by enzyme-linked immunosorbent assay. RESULTS: Mean plasma tPA antigen levels were significantly higher in stroke patients than control subjects (4. 80+/-4.18 versus 3.23+/-3.67 ng/mL; P=0.015). After adjustment for age, hypertension, cigarette smoking, body mass index, and ischemic heart disease, there was a dose-response association between tPA antigen and stroke with a 3.9-fold odds ratio of stroke (95% CI, 1.2 to 12.4; P=0.03) for the upper quartile (>4.9 ng/mL) of tPA antigen compared with the lowest quartile. The dose-response relationship between tPA antigen and stroke was equally present in white and nonwhite women, and further adjustment for total and HDL cholesterol levels only modestly attenuated this association. CONCLUSIONS: This population-based case-control study shows that elevated plasma tPA antigen level is independently associated with an increased risk for ischemic stroke in nondiabetic females 15 to 44 years of age. These findings support the hypothesis that impaired endogenous fibrinolysis is an important risk factor for stroke in young women.

Adolescent↗

PubMed1999

"Task-oriented" exercise improves hamstring strength and spastic reflexes in chronic stroke patients.

BACKGROUND AND PURPOSE: Despite the belief that after cerebral infarction only limited functional gains are possible beyond the subacute period, we tested the hypothesis that a 12-week program of "task-oriented" treadmill exercise would increase muscle strength and decrease spastic reflexes in chronic hemiparetic patients. METHODS: Fourteen subjects, aged 66+/-3 (mean+/-SEM) years, with residual gait deviations due to remote stroke (>6 months), underwent repeated measures of reflexive and volitional (concentric and eccentric) torque with use of isokinetic dynamometry on the hamstring musculature bilaterally. Torque output was measured at 4 angular velocities (30(o), 60(o), 90(o), and 120(o)/s). RESULTS: After 3 months of 3 times/wk low-intensity aerobic exercise, there were significant main effects (2 legs [P<0.01]x2 times [P<0. 01]x4 angular velocities [P<0.05]) for concentric torque production. Torque/time production in the concentric mode also improved significantly in the paretic (50%, P<0.01) and nonparetic hamstrings (31%, P<0.01). Eccentric torque/time production increased by 21% (P<0.01) and 22% (P<0.01) in the paretic and nonparetic hamstrings, respectively. Passive (reflexive) torque/time generation in the paretic hamstrings decreased by 11% (P<0.027). Reflexive torque/time was unchanged in the nonparetic hamstrings (P=0.45). CONCLUSIONS: These findings provide evidence that progressive treadmill aerobic exercise training improves volitional torque and torque/time generation and reduces reflexive torque/time production in the hemiparetic limb. Strength changes associated with improved functional mobility in chronic hemiparetic stroke survivors after treadmill training will be reported in future articles.

Aged↗

PubMed1999

Brain-specific protein C activation during carotid artery occlusion in humans.

BACKGROUND AND PURPOSE: Activation of plasma protein C (PC) zymogen by thrombin-thrombomodulin at the endothelial surface is an important endogenous antithrombotic mechanism. It is unknown whether activated protein C (APC) is generated in vivo in the cerebrovasculature, because there is only limited thrombomodulin expression in human brain vascular endothelium. Therefore, we tested the hypothesis that carotid occlusion produces brain-specific PC activation. METHODS: Blood samples were simultaneously collected from the ipsilateral internal jugular vein and radial artery before and during carotid cross-clamping and on "de-occlusion" in 8 awake patients undergoing routine carotid endarterectomy. Plasma PC zymogen and circulating APC levels were measured using enzyme immunocapture assay and expressed as percent of pooled plasma controls. RESULTS: Internal jugular vein APC levels increased 28% exclusively during carotid occlusion and then decreased 32% with de-occlusion (F=8.1, P<0.005). PC zymogen increased only 5.9% with occlusion (F=6.3, P<0.02), consistent with hemoconcentration. There were no changes in radial artery PC or APC levels. CONCLUSIONS: These findings demonstrate brain-specific protein C activation in humans during carotid occlusion and suggest a protective role for endogenous APC generation during cerebrovascular occlusion.

Aged↗

PubMed1999

Homocyst(e)ine and risk of cerebral infarction in a biracial population : the stroke prevention in young women study.

BACKGROUND AND PURPOSE: Genetic enzyme variation and vitamin intake are important determinants of blood homocyst(e)ine levels. The prevalence of common genetic polymorphisms influencing homocyst(e)ine levels varies by race, and vitamin intake varies by socioeconomic status. Therefore, we examined the effect of vitamin intake, race, and socioeconomic status on the association of homocyst(e)ine with stroke risk. METHODS: All 59 hospitals in the greater Baltimore-Washington area participated in a population-based case-control study of stroke in young women. One hundred sixty-seven cases of first ischemic stroke among women aged 15 to 44 years were compared with 328 controls identified by random-digit dialing from the same region. Risk factor data were collected by standardized interview and nonfasting phlebotomy. Plasma homocyst(e)ine was measured by high-performance liquid chromatography and electrochemical detection. RESULTS: Blacks and whites did not differ in median homocyst(e)ine levels, nor did race modify the association between homocyst(e)ine and stroke. After adjustment for cigarettes per day, poverty status, and regular vitamin use, a plasma homocyst(e)ine level of >/=7.3 micromol/L was associated with an odds ratio for stroke of 1.6 (95% CI, 1.1 to 2.5). CONCLUSIONS: The association between elevated homocyst(e)ine and stroke was independent not only of traditional vascular risk factors but also of vitamin use and poverty status. The degree of homocyst(e)ine elevation associated with an increased stroke risk in young women is lower than that previously reported for middle-aged men and the elderly and was highly prevalent, being present in one third of the control group.

Adolescent↗

PubMed1998

Progressive intermittent claudication is associated with impaired fibrinolysis.

PURPOSE: Acute complications of atherosclerosis such as stroke and myocardial infarction are caused by thrombosis and may be associated with impaired fibrinolytic activity. The current study was performed to determine whether peripheral arterial disease (PAD) and its progression are also associated with impaired fibrinolysis, by measurement of tissue plasminogen activator (tPA, the activator of fibrinolysis) and its inhibitor plasminogen activator inhibitor-1 (PAI-1). METHODS: The study group consisted of 80 men with a mean age of 69 years. This included 18 patients with mild intermittent claudication (MC, pain-free walking distance > or = 200 meters) and 51 patients with severe claudication (SC, walking distance <200 meters). Eleven age- and sex-matched patients without PAD served as controls. All patients had measurements of serum tPA antigen using an enzyme-linked immunoadsorbent assay. Serum levels of tPA and PAI-1 activity were assayed with an amidolytic method. Mean +/- SEM levels of the enzyme levels in patients with progressively more severe PAD were compared with normal controls. RESULTS: Serum PAI-1 activity levels were significantly elevated in both PAD groups compared with normal controls (p < 0.02). There were no significant differences in the PAI-1 activity levels in groups with worsening degrees of PAD. There was a significant decrease in tPA activity levels in patients with SC (p = 0.01) relative to those with MC and the normal subjects. There was also a significant increase in tPA antigen level in the patients with SC compared with those with MC and the control subjects, as well as a significant inverse correlation between tPA antigen levels and pain-free walking time in patients with claudication (p = 0.001). CONCLUSIONS: All patients with PAD in this study had significant reductions in endogenous fibrinolytic activity. Patients with SC had more impaired fibrinolytic activity than those with MC and the control subjects, suggesting that the progression to more severe levels of PAD may be associated with worsening endogenous fibrinolysis.

Aged↗

PubMed1998

Platelet glycoprotein receptor IIIa polymorphism P1A2 and ischemic stroke risk: the Stroke Prevention in Young Women Study.

BACKGROUND AND PURPOSE: Platelet glycoprotein IIb/IIa (GpIIb-IIIa), a membrane receptor for fibrinogen and von Willebrand factor, has been implicated in the pathogenesis of acute coronary syndromes but has not been previously investigated in relation to stroke in young adults. METHODS: We used a population-based case-control design to examine the association of the GpIIIa polymorphism P1A2 with stroke in young women. Subjects were 65 cerebral infarction cases (18 patients with and 47 without an identified probable etiology) 15 to 44 years of age from the Baltimore-Washington region and 122 controls frequency matched by age from the same geographic area. A face-to-face interview for vascular disease risk factors and a blood sample for the P1A2 allele and serum cholesterol were obtained from each participant. Logistic regression was used to estimate the odds ratio for one or more P1A2 alleles after adjustment for other risk factors. RESULTS: Among cases and controls, the prevalence rates of one or more P1A2 alleles were 21% and 22% among blacks and 36% and 28% among whites, respectively. This genotype was significantly associated with hypertension only in black control subjects but otherwise not with any of the established vascular risk factors. The adjusted odds ratio for cerebral infarction of one or more P1A2 alleles was 1.1 (confidence interval [CI], 0.6 to 2.3) overall, 0.5 (CI, 0.1 to 7.1) among blacks, and 1.4 (CI, 0.5 to 3.7) among whites. For the cases with an identified probable etiology, the corresponding odds ratios were 3.0 (CI, 0.9 to 10.4) overall, 0.7 (CI, 0.1 to 7.1) among blacks, and 12.8 (CI, 1.2 to 135.0) among whites. CONCLUSIONS: No association was found between the P1A2 polymorphism of GpIIIa and young women with stroke. However, subgroup analyses showed that the P1A2 polymorphism of GpIIIa appeared to be associated with stroke risk among white women, particularly those with a clinically identified probable etiology for their stroke. Further work with an emphasis on stroke subtypes and with multiracial populations is warranted.

Adolescent↗

PubMed1998

Cerebral infarction in young adults: the Baltimore-Washington Cooperative Young Stroke Study.

BACKGROUND: Few reports on stroke in young adults have included cases from all community and referral hospitals in a defined geographic region. METHODS: At 46 hospitals in Baltimore City, 5 central Maryland counties, and Washington, DC, the chart of every patient 15 to 44 years of age with a primary or secondary diagnosis of possible cerebral arterial infarction during 1988 and 1991 was abstracted. Probable and possible etiologies were assigned following written guidelines. RESULTS: Of 428 first strokes, 212 (49.5%) were assigned at least one probable cause, 80 (18.7%) had no probable cause but at least one possible cause, and 136 (31.8%) had no identified probable or possible cause. Of the 212 with at least one probable cause, the distribution of etiologies was cardiac embolism (31.1%), hematologic and other (19.8%), small vessel (lacunar) disease (19.8%), nonatherosclerotic vasculopathy (11.3%), illicit drug use (9.4%), oral contraceptive use (5.2%), large artery atherosclerotic disease (3.8%), and migraine (1.4%). There were an additional 69 recurrent stroke patients. CONCLUSIONS: In this hospital-based registry within a region characterized by racial/ethnic diversity, cardiac embolism, hematologic and other causes, and lacunar stroke were the most common etiologies of cerebral infarction in young adults. Nearly a third of both first and recurrent strokes had no identified cause.

Adolescent↗

PubMed1998

Illicit drug-associated ischemic stroke in the Baltimore-Washington Young Stroke Study.

BACKGROUND: Limited information exists on the frequency, trends in occurrence, risk factors, mechanisms, and outcome of ischemic stroke associated with illicit drug use among young adults in a geographically defined population. METHODS: We reviewed ischemic stroke in young adults (aged 15 to 44 years) in 46 regional hospitals for 1988 and 1991. We examined stroke mechanisms and outcome in patients with recent drug use. RESULTS: Recent illicit drug use was noted in 51/422 (12.1%) stroke patients. Patients with drug use were more likely than other stroke patients to be black (p=0.01), aged 25 to 39 years (p=0.004), and smokers (p=0.006), and were less likely to have hypertension (p=0.004) or diabetes mellitus (p=0.004). Drug use was the probable cause of stroke in 20 (4.7%) patients. Among 31 (7.3%) patients with drug use as a possible stroke mechanism, more likely diagnoses included cardioembolic stroke in 18, hematologic/collagen vascular in 6, nonatherosclerotic vasculopathy in 5, and atherosclerosis in 3. There was no difference in outcome between drug-associated and non-drug associated stroke. CONCLUSIONS: Recent illicit drug use occurs in 12.1% of young adult stroke patients. Drug-associated young adult stroke seems to relate to vascular mechanisms other than those related to hypertension or diabetes. Case-control studies are needed.

Adolescent↗

PubMed1998

Stroke in children and sickle-cell disease: Baltimore-Washington Cooperative Young Stroke Study.

BACKGROUND/PURPOSE: The Baltimore-Washington Cooperative Young Stroke Study is the largest biracial urban-suburban population-based study to examine the etiology of strokes in children. METHODS: We identified all children aged 1 to 14 years discharged from all 46 hospitals in central Maryland and Washington, DC with a diagnosis of ischemic stroke and intracerebral hemorrhage in the years 1988 and 1991. Each medical record was reviewed by two neurologists for appropriateness of the diagnosis of stroke and for information on the patient's history, clinical presentation, pertinent investigations, hospital stay, and outcome at time of discharge. RESULTS: Eighteen children with ischemic infarction and 17 with intracerebral hemorrhage were identified. The most common cause of ischemic stroke was sickle-cell disease (39%), followed by vasculopathic (33%) and indeterminate (28%) causes. Causes of intracerebral hemorrhages were arteriovenous malformation (29%), hematologic (23%), vasculopathy (18%), surgical complication (12%), coagulopathy (6%), and indeterminate (12%). The overall incidence for childhood stroke was 1.29 per 100,000 per year, with ischemic stroke occurring at a rate of 0.58 per 100,000 and intracerebral hemorrhage occurring at a rate of 0.71 per 100,000. The incidence of stroke among children with sickle-cell disease was estimated to be 0.28% or 285 per 100,000 per year. CONCLUSION: Sickle-cell disease plays a disproportionately high role in childhood stroke when a biracial population is surveyed.

Adolescent↗