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P Mitsias

Publications and source records attributed to P Mitsias.

15 recordsLinked to original sources
PubMed2006

Predictors of recurrent stroke in African Americans.

BACKGROUND: Stroke incidence and mortality are disproportionately higher among African Americans than among whites. OBJECTIVE: To describe the recurrent stroke characteristics and determine the predictability of known vascular risk factors for stroke recurrence in African Americans. METHODS: The authors followed 1,809 African Americans in the African-American Antiplatelet Stroke Prevention Study with recent noncardioembolic ischemic stroke for recurrent stroke, recurrent stroke subtype, and disability. RESULTS: Of the subjects, 10.6% experienced a recurrent stroke during follow-up. The mean interval between eligibility and recurrent stroke was 325 days (median 287 days, SD = 224 days). Stroke recurrence resulted in an average 1.5-point increase in the National Institute of Health Stroke Scale (p < 0.001) and a 3.5-point decrease in modified Barthel Index (p < 0.001). Of previously nondisabled subjects, 48% became disabled or died after stroke recurrence (p < 0.0001). Longitudinal analysis resulted in a hazard for recurrent stroke for each 10-mm Hg increase in systolic blood pressure of 1.103 (95% CI: 1.031 to 1.179, p = 0.004), pulse pressure 1.123 (95% CI: 1.041 to 1.213, p = 0.003), and mean arterial pressure 1.123 (95% CI: 1.001 to 1.260, p = 0.048). Multivariate analysis revealed increases in the recurrent stroke hazard for increases in baseline Glasgow Outcome Score (1.449, 95% CI: 1.071 to 1.961, p = 0.016) and increases in longitudinal pulse pressure (1.009, 95% CI: 1.001 to 1.017, p = 0.029). CONCLUSION: Recurrent stroke leads to disability and disability predicts recurrent stroke. Hypertension is the most predictive modifiable stroke risk factor.

Activities of Daily Living↗
PubMed2001

Multiparametric MRI tissue characterization in clinical stroke with correlation to clinical outcome: part 2.

BACKGROUND AND PURPOSE: Multiparametric MRI generates different zones within the lesion that may reflect heterogeneity of tissue damage in cerebral ischemia. This study presents the application of a novel model of tissue characterization based on an angular separation between tissues obtained with the use of an objective (unsupervised) computer segmentation algorithm implementing a modified version of the Iterative Self-Organizing Data Analysis Technique (ISODATA). We test the utility of this model to identify ischemic tissue in clinical stroke. METHODS: MR parameters diffusion-, T2-, and T1-weighted imaging (DWI, T2WI, and T1WI, respectively) were obtained from 10 patients at 3 time points (30 studies) after stroke: acute (</=12 hours), subacute (3 to 5 days), and chronic (3 months). The National Institutes of Health Stroke Scale (NIHSS) was measured, and volumes were obtained from the ISODATA, DWI, and T2WI maps on patients at each time point. RESULTS: The acute (</=12 hours) multiparametric ISODATA volume was significantly correlated with the acute (</=12 hours) DWI (r=0.96, P<0.05; n=10) and chronic (3 months) T2WI volume (r=0.69, P<0.05; n=10). The ISODATA-defined tissue regions exhibited MR indices consistent with ischemic and/or infarcted tissue at each time point. The acute (</=12 hours) multiparametric ISODATA volumes were significantly correlated (r=0.82, P<0.009; n=10) with the final NIHSS score. In comparison, the acute (</=12 hours) DWI volumes were less correlated (r=0.77, P<0.05; n=10) and T2WI volume (</=12h) exhibited a marginal correlation (r=0.66, P<0.05; n=10) with the final NIHSS score. CONCLUSIONS: The integrated ISODATA approach to tissue segmentation and classification discriminated abnormal from normal tissue at each time point. The ISODATA volume was significantly correlated with the current MR standards used in the clinical setting and the 3-month clinical status of the patient.

Adult↗
PubMed1999

Agreement and variability in the interpretation of early CT changes in stroke patients qualifying for intravenous rtPA therapy.

BACKGROUND AND PURPOSE: Ischemic changes identified on CT scans performed in the first few hours after stroke onset, which are thought to possibly represent early cytotoxic edema and development of irreversible injury, may have important implications for subsequent treatment. However, insecurity and conflicting data exist over the ability of clinicians to correctly recognize and interpret these changes. We performed a detailed review of selected baseline CT scans from the NINDS rt-PA Stroke Trial to test agreement among experienced stroke specialists and other physicians on the presence of early CT ischemic changes. METHODS: Seventy baseline CT scans from the NINDS Stroke Trial were read and classified for the presence or absence of various early findings of ischemia by 16 individuals, including NINDS trial investigators, other neurologists, other emergency medicine physicians, and radiology or stroke fellows. CT scans included normal scans and scans from patients who later developed symptomatic intracranial hemorrhage, as well as scans on which the NINDS rt-PA Stroke Trial neuroradiologist identified clear-cut early CT changes. For each CT finding, kappa-statistics were used to assess the proportion of agreement beyond chance. RESULTS: kappa-Values (95% confidence interval [CI]) ranged from 0.20 (-0.20, 0.61) (fair agreement) to 0.41 (0.37, 0.45) (moderate agreement) among the 16 viewers, and the kappa-value was only 0.39 (0.29, 0.49) (fair) in answer to the question "do early CT changes involve more than one third of the MCA [middle cerebral artery] territory?" There was substantial variability within each specialty group and between groups. kappa-Values were only fair to moderate even among physicians experienced in selecting and treating acute stroke patients with rtPA. Observed agreement ranged from 68% to 85%. Physicians agreed on the finding of early CT changes involving >33% of the MCA territory 77% of the time, although the kappa-value of 0.39 suggested only moderate agreement beyond chance. CONCLUSIONS: There is considerable lack of agreement, even among experienced clinicians, in recognizing and quantifying early CT changes. Improved methods of recognizing and quantifying early ischemic brain damage are needed.

Cerebrovascular Disorders↗
PubMed1997

Cerebral venous thrombosis and anticardiolipin antibodies.

BACKGROUND AND PURPOSE: The association of cerebral venous thrombosis (CVT) with a variety of pathological states is well established. However, there are only rare isolated reports of CVT associated with anticardiolipin antibodies (aCL). METHODS: To clarify the clinical and neuradiological features as well as outcome of patients with CVT associated with aCL, we reviewed the records of all patients with CVT evaluated at our institution between 1989 and 1996 (retrospective and prospective) and systematically reviewed the pertinent literature. RESULTS: We identified 8 aCL+ and 7 aCL- patients with CVT. No patients with lupus anticoagulant (LA) were identified. The mean age was 23 +/- 11.01 (range, < 1 to 36) years in the aCL+ and 38 +/- 9.30 (range, 25 to 54) years in the aCL- patients (P = .016). Six of 8 aCL+ and 5 of 7 aCL- patients were women. The dural sinuses were involved in all aCL+ and in 6 of 7 aCL- patients, while deep venous system thrombosis occurred in 5 of 8 (63%) aCL+ and 1 of 7 (14%) aCL- patients. In the aCL+ patients CVT was associated with puerperium or oral contraceptive use (n = 6), and sickle cell trait (n = 1), and in the aCL- patients CVT was associated with systemic lupus erythromatosus (n = 1), myelodysplasti syndrome (n = 1), colonic cancer (n = 1), oral contraceptive use or puerperium (n = 3), and dehydration (n = 1). Seven aCL+ patients received either intrasinus urokinase or intravenous heparin sulfate, and 1 received aspirin. Four aCL+ patients developed new onset or worsening of preexisting migraine, 2 developed recurrent peripheral venous thrombosis, and 1 went on to have intracranial hypertension. Twenty additional patients with CVT associated with antiphospholipid antibodies (aPL) were found reported in the literature. The overall mean age was 36 +/- 11.6 (range, 21 to 62) years, and 14 (70%) were women. LA was present in 11 of 18 tested, aCL in 7 (35%), LA and aCL in 1, and the type of aPL was not reported in 3. The mean age for the aCL+ only group was 28 years and for the LA+ (with or without aCL+) was 34 years. Only 1 patient, whose aPL type was not specified, had thrombosis of the deep venous system in addition to involvement of the dural sinuses. CONCLUSIONS: Our series and review suggest that aCL may be an important factor contributing to development of CVT even in the presence of other potential etiologies or risk factors. Onset of aCL+ CVT occurs at a relative young age and with relatively more extensive superficial and deep cerebral venous system involvement than aCL- CVT.

Adult↗
PubMed1996

Cerebrovascular complications of Fabry's disease.

Fabry's disease (FD) is a rare, sex-linked disorder resulting from alpha-galactosidase deficiency. Cerebrovascular complications have been reported in the literature but have not been systematically analyzed. We report 2 patients and review 51 previously reported cases (descriptive meta-analysis) to clarify the clinical, radiologic, and pathologic features. The average age at onset of cerebrovascular symptoms was 33.8 years for hemizygous individuals (n = 43) and 40.3 years of heterozygotes (n = 10). The most frequent symptoms and signs were as follows (in descending order of frequency): hemiparesis, vertigo/dizziness, diplopia, dysarthria, nystagmus, nausea/vomiting, head pain, hemiataxia, and ataxia of gait, in the hemizygote group; and memory loss, dizziness, ataxia, hemiparesis, loss of consciousness and hemisensory symptoms, in the heterozygote group. The vertebrobasilar circulation was symptomatic in 67% of the hemizygotes and 60% of the heterozygotes. Intracerebral hemorrhage was found in 4 patients (3 hemizygotes and 1 heterozygote). Elongated, ectatic, tortuous vertebral and basilar arteries were the most common angiographic and pathologic features. For the hemizygotes, the recurrence rate for cerebrovascular disease was 76% and the death rate was 55%; 86% of the heterozygotes had recurrent cerebrovascular event(s) and 40% died. The cerebrovascular manifestations of FD, in both hemizygotes and heterozygotes, are predominantly due to dilative arteriopathy of the vertebrobasilar circulation, frequently recur, and portend a poor prognosis.

Adolescent↗
PubMed1996

A reappraisal of reliability and validity studies in stroke.

BACKGROUND: The emergence of prophylactic and therapeutic interventions in stroke has been accompanied by the widespread use of stroke classifications and scales that measure deficit (stroke scales) or resulting long-term handicap (handicap and disability scales). Although the accuracy of some scales and classifications has been studied, there is no updated systematic review appraising all of them. REVIEW: We reviewed the literature and selected 21 studies on classifications and scales. The International Classification of Diseases, 10th revision, achieved the highest interobserver agreement among seven stroke classifications. The National Institutes of Health Stroke Scale, the Canadian Neurological Scale, and the European Stroke Scale had the highest reliability across items among nine stroke scales. The Barthel Index was the most reliable disability scale. CONCLUSIONS: The identification of the most reliable stroke classifications and scales should encourage their use in selection of homogeneous populations of patients for clinical research studies and to improve communication among scientists. Further research is needed to investigate neglected aspects of the neurological examination and the validity of stroke classifications.

Cerebrovascular Disorders↗
PubMed1995

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.

Adult↗
PubMed1994

Large cerebral vessel occlusive disease in systemic lupus erythematosus.

We systematically investigated clinical, laboratory, radiologic, and pathologic features, including treatment and prognosis, of stroke syndromes in 30 patients, six from our institution and 24 from the literature, with systemic lupus erythematosus (SLE) and symptomatic large cerebral vessel occlusive disease, documented by angiography or autopsy. The average age at stroke onset was 35 years, and the diagnosis of SLE was made on average 4.4 years prior to that. At least 86% had active SLE at the time of their stroke. Headache was common at onset. We found major intracranial or extracranial vessel occlusive process by (1) thrombus, (2) dissection, (3) fibromuscular dysplasia or vasculitis, and (4) atherosclerosis. The presumed mechanisms were coagulopathy, cardiogenic embolism, large cerebral vessel vasculitis or occlusive vasculopathy, cervical arterial dissection, and premature atherosclerosis. The short-term death rate was 40% and the recurrent stroke rate was 13%. We conclude that symptomatic large cerebral vessel occlusive disease in SLE generally occurs several years after the diagnosis of SLE, usually during the active phase of the disease, is related to heterogeneous mechanisms, and carries a relatively poor short-term outcome.

Adult↗
PubMed1992

Headache in ischemic cerebrovascular disease. Part I: Clinical features.

Headache is a common, although under-emphasized, feature of ischemic cerebrovascular disease. In this review, we summarize the literature on the clinical features of headache in ischemic cerebrovascular disease (Part I) and elaborate upon the underlying mechanisms of the head pain (Part II--December issue).

Brain Ischemia↗