Biomedical subjects

R Wityk

Publications and source records attributed to R Wityk.

12 recordsLinked to original sources

PubMed2002

Don't throw in the towel! A case of reversible coma.

A young woman with pre-eclampsia became unresponsive shortly after delivery. Examination revealed extensive brain stem dysfunction with absent pupillary light reflexes and decerebrate posturing. Computed tomography showed hypodensity throughout the brain stem, and it was initially thought that she had suffered catastrophic brain stem infarction. However, magnetic resonance diffusion imaging and apparent diffusion coefficient mapping showed that she had brain stem vasogenic oedema (posterior reversible encephalopathy syndrome, PRES), rather than cytotoxic oedema. With antihypertensive and supportive treatment, she recovered rapidly, and had no abnormalities on repeat imaging.

Adult↗

PubMed2001

Correlation of aphasia and/or neglect with cortical infarction in a subpopulation of RANTTAS.

Classically in neurology, aphasia and neglect were accepted as reliable markers of cortical lesions. The actual prognostic values of aphasia and neglect have yet to be formally tested. This analysis sought to determine the predictive accuracy of aphasia and/or neglect in acute stroke for cortical infarction. Data from the RANTTAS investigation of tirilazad mesylate in stroke patients were reanalyzed, comparing acute National Institutes of Health Stroke Scale (NIHSS) measures of aphasia and neglect to lesion location on day 7-10 CT scans. Correlations between the presence of aphasia and/or neglect and the presence of a cortical lesion were only in the moderate range, and positive predictive values were far from perfect, as would be expected. 'Subcortical' aphasia or neglect was more likely in large, subcortical lesions. Aphasia and neglect, as determined in the acute setting by the NIHSS, are only moderately associated with cortical infarct identified on follow-up CT scans. If selective neuroprotection is envisioned for acute stroke patients, more accurate markers of cortical infarction may be needed.

Aphasia↗

PubMed2001

The cerebral angiographic findings in Cogan syndrome.

SUMMARY: Cogan syndrome is an uncommon disorder of unknown etiology characterized by vestibuloauditory dysfunction and nonsyphilitic interstitial keratitis. To our knowledge, the case herein is the first report to demonstrate the cerebral angiographic findings of a patient with this syndrome.

Cerebral Angiography↗

PubMed2000

Bilateral optic neuropathy associated with diffuse cerebral angiomatosis in Sturge-Weber syndrome.

Visual loss in patients with encephalotrigeminal angiomatosis or Sturge-Weber syndrome usually results from secondary glaucoma or from damage to the retrogeniculate pathways by the angiomatous lesions. Optic neuropathy has not been reported as a component of this syndrome. This report describes a patient who developed bilateral optic neuropathy with progressive visual loss associated with diffuse cerebral angiomatosis in the setting of Sturge-Weber syndrome.

Adult↗

PubMed1999

Infarct volume as a surrogate or auxiliary outcome measure in ischemic stroke clinical trials. The RANTTAS Investigators.

BACKGROUND AND PURPOSE: Reduction in infarct volume is the standard measure of therapeutic success in animal stroke models. Reduction in infarct volume has been advocated as a biological surrogate or auxiliary outcome measure for human stroke clinical trials to replace or supplement deficit, disability, and global clinical scales. However, few studies have investigated correlations between infarct volume and clinical end points in acute ischemic stroke patients. METHODS: CT scans at days 6 to 11 were acquired prospectively in 191 fully eligible patients enrolled in the Randomized Trial of Tirilazad Mesylate in Patients With Acute Stroke (RANTTAS). Patients were enrolled within 6 hours of onset of stroke in any vessel distribution. Infarct volume was measured by operator-assisted computerized planimetry. RESULTS: One hundred thirty-two patients had visible new supratentorial infarcts, with median infarct volume of 28.0 cm3 (interquartile range, 9.0 to 93.0 cm3). Fifty-nine patients had no visible new infarct. Correlations with standard 3-month outcome scales and mortality were as follows: Barthel Index, r=0.43; Glasgow Outcome Scale, r=0.53; National Institutes of Health Stroke Scale, r=0.54; mortality, r=0.31. For visible infarcts alone, correlations were as follows: BI, r=0.46; GOS, r=0.59; NIHSS, r=0.56; mortality, r=0.32. CONCLUSIONS: Subacute CT infarct volume correlates moderately with 3-month clinical outcome as assessed by widely used neurological and functional assessment scales. The modesty of this linkage constrains the use of infarct volume as a surrogate end point in ischemic stroke clinical trials.

Acute Disease↗

PubMed1998

Midbrain infarction: associations and aetiologies in the New England Medical Center Posterior Circulation Registry.

Most reports of midbrain infarction have described clinicoanatomical correlations rather than associations and aetiologies. Thirty nine patients with midbrain infarction (9.4%) are described out of a series of 415 patients with vertebrobasilar ischaemic lesions in the New England Medical Center Posterior Circulation Registry. Patients were categorised according to the rostral-caudal extent of infarction. The "proximal" vertebrobasilar territory includes the medulla and posterior inferior cerebellar artery territory. The "middle" territory includes the pons and anterior inferior cerebellar artery territory. The "distal" territory includes the rostral midbrain, thalami, superior cerebellum, and medial temporal and occipital lobes. Midbrain infarction was accompanied by "proximal" territory infarcts in four patients, and by "middle" territory infarction in 19 patients. Thirteen patients had associated "distal" territory infarcts, three of whom had occipital or temporal lobe infarcts. Only three patients had isolated midbrain infarcts. Cardioembolism (n=11), in situ thrombosis (n=9), large artery to artery embolism (n=7), and intrinsic branch penetrator disease (n=5) were the most common aetiologies. Bilateral infarction and accompanying pontine infarction were associated with the most extensive vertebrobasilar occlusive disease. Midbrain infarction was 10-fold more likely to be accompanied by ischaemia of neighbouring structures than it was to occur in isolation. Recognition of the different patterns of infarction may act as a guide to the underlying aetiology and vascular lesions.

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↗

PubMed1996

Traditional risk factors and ischemic stroke in young adults: the Baltimore-Washington Cooperative Young Stroke Study.

OBJECTIVE: To determine the association of hypertension, diabetes, and cigarette smoking with incidence of ischemic stroke in young adults. DESIGN: Case-control study. SETTING: Population-based sample of cases and controls. SUBJECTS: The study included 296 cases of incident ischemic stroke among black and white adults aged 18 to 44 years in central Maryland counties from the Baltimore-Washington Cooperative Young Stroke Study and 1220 black and white adults aged 18 to 44 years from the Maryland Behavioral Risk Factor Survey, a telephone survey of a random sample of the same region, to serve as controls. MAIN OUTCOME MEASURES: Logistic regression models were developed to determine the age-adjusted odds ratios for each risk factor. Population-attributable risk percent were computed based on the odds ratios and prevalence of each risk factor. RESULTS: The age-adjusted odds ratios (95% confidence intervals) for white men (WM), white women (WW), black men (BM), and black women (BW) were as follows: current cigarette smoking: WM, 2.0 (1.1-3.8), WW, 2.1 (1.1-4.3), BM, 3.3 (1.6-6.6), and BW, 2.2 (1.3-3.9); history of diabetes mellitus: WM, 22.9 (5.8-89.6), WW, 6.2 (1.9-20.2), BM, 4.2 (0.8-21.9), and BW, 3.3 (1.4-7.7); and history of hypertension: WM, 1.6 (0.7-3.2), WW, 2.5 (1.1-5.9), BM, 3.8 (1.8-7.9), and BW, 4.2 (2.4-7.5). The population-attributable risk percent (95% confidence intervals) were as follows: current cigarette smoking: WM, 22.6 (3.1-38.2), WW, 17.2 (4.0-34.0), BM, 40.5 (23.1-54.0), and BW, 29.1 (13.5-41.9); history of diabetes mellitus: WM, 19.0 (8.2-28.5), WW, 15.8 (3.8-26.3), BM, 13.2 (5.3-20.4), and BW, 22.1 (12.5-30.7); and history of hypertension: WM, 21.7 (6.2-34.6), WW, 21.3 (5.4-34.5), BM, 53.5 (39.0-64.4), and BW, 50.5 (37.1-61.1). CONCLUSIONS: Hypertension, diabetes mellitus, and current cigarette smoking are important risk factors in a biracial young adult population. Cigarette smoking and hypertension, the 2 most modifiable risk factors, were particularly important risk factors in young blacks.

Adolescent↗

PubMed1995

Diagnosis of probable cocaine-induced cerebral vasculitis by magnetic resonance angiography.

Cocaine-induced cerebral vasculitis is a serious but uncommon clinical entity. We present a case of probable cocaine-induced vasculitis that was unusual in that it was suggested by magnetic resonance angiography. The patient was a 42-year-old woman, who used cocaine both intravenously and intranasally, who was admitted with the acute onset of an illness that resembled bacterial meningitis. Results of the initial standard evaluation were negative, and a diagnosis of cerebral vasculitis was ultimately suggested by magnetic resonance angiography. We believe this to be the first reported case of the diagnosis of cocaine-induced cerebral vasculitis to be suggested by magnetic resonance angiography.

Adult↗

PubMed1994

Cerebellar infarcts in the New England Medical Center Posterior Circulation Stroke Registry.

We report the clinical findings and stroke mechanisms of 63 patients with cerebellar infarcts. We divided the intracranial vertebrobasilar circulation into the proximal territory (P), fed by the intracranial vertebral arteries and their branches; the middle territory (M), fed by the proximal and middle basilar artery and its branches; and the distal territory (D), fed by the rostral basilar artery and its branches. Cerebellar infarcts were classified by vascular territories P, M, D, P&D, and middle-plus (P&M, M&D, and P&M&D). Patients with P infarcts (11 patients) frequently had vertigo, gait instability, limb ataxia, and headache, whereas patients with D infarcts (15 patients) most often had limb ataxia, gait instability, and dysarthria. Patients with P&D infarcts (17 patients) had signs and symptoms of both groups combined. Infarcts in which the middle territory was involved, either alone (three patients) or combined with other territories (17 patients) were dominated by brainstem signs and symptoms. The predominant stroke mechanisms in the P, D, and P&D groups were embolic due to intra-arterial or cardiac embolism. When the M territory was involved, either alone or with P, D, or P&D territories, stroke mechanisms were more varied, and there was often large-artery occlusion with hemodynamic ischemia.

Adult↗

PubMed1993

MELAS syndrome masquerading as herpes simplex encephalitis.

Herpes simplex encephalitis (HSE) is commonly treated empirically with acyclovir without confirmatory brain biopsy. Three consecutive adults with molecularly verified mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome presented with, and were treated for, apparent HSE. MELAS syndrome in adults may present as an atypical, recurrent form of HSE and should be added to the list of neurologic diseases that can mimic HSE.

Adolescent↗

PubMedDate not supplied

Recent advances in the diagnosis and treatment of stroke.

Stroke is defined as an abnormality in brain function resulting from disruption of cerebral circulation. It is the third leading cause of death in the United States and the primary cause of long-term disability. The economic burden of stroke will only increase as the population ages, making prevention and treatment of stroke one of the most important public health issues of the upcoming millennium. New therapies for the treatment of acute stroke, especially thrombolysis, have turned what was once considered an inevitable deficit into a potentially treatable illness. It is increasingly important for all physicians to be able to identify symptoms of cerebral ischemia. Neurons have a very limited tolerance for ischemia, making the rapid evaluation and diagnosis of stroke critical. This is particularly relevant for the ophthalmologist, who may be the first physician to see individuals presenting with visual deficits. Trials are underway to look specifically at central retinal artery and basilar artery ischemia and their response to thrombolytic therapy. This review will focus on description of recent advances in treatment and diagnosis of stroke, including thrombolytic trials and the expanding role of neuroimaging.

Humans↗