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Biomedical subjects

Jack W Tsao

Publications and source records attributed to Jack W Tsao.

14 recordsLinked to original sources
PubMed2006

Cerebellar ataxia with progressive improvement.

BACKGROUND: Nonprogressive cerebellar ataxias are characterized by a persistent, nonprogressive ataxia associated with cognitive impairment. Cerebellar hypoplasia on imaging is variable but is not predictive of the degree of ataxia or cognitive impairment. OBJECTIVE: To describe a family with a nonprogressive cerebellar ataxia associated with cognitive and motor impairments that improve with age. DESIGN: Genetic study in a family with nonprogressive cerebellar ataxia. Clinical and imaging features are also described. SETTING: Community hospital. PATIENTS: Both parents and 3 children from an affected family. MAIN OUTCOME MEASURES: Clinical features, magnetic resonance imaging findings, and genetic findings. RESULTS: A genome-wide single nucleotide polymorphism screen did not show clear linkage to known spinocerebellar ataxia loci, in particular spinocerebellar ataxia type 15. Repeat spinocerebellar ataxia loci expansions were excluded. Magnetic resonance images of all affected individuals demonstrated cerebellar vermian abnormalities. CONCLUSIONS: These findings suggest that nonprogressive cerebellar ataxia is genetically heterogeneous and, when associated with gradual improvement in cognition and motor skills, likely represents a separate, distinct clinical entity.

Adult↗
PubMed2006

Callosal neglect in hydrocephalus.

A functional disconnection of the corpus callosum (CC) can induce a form of spatial neglect where each hand (e.g., left) when attempting to bisect lines in the opposite (e.g., right) hemispace deviates toward its own (e.g., left) hemispace. Patients with hydrocephalus often show thinning of the CC but callosal neglect has not been reported in this condition. Two right-handed patients with hydrocephalus and thinning of the CC, as well as six matched controls, were assessed for neglect by performing the line bisection task in left, right and center space with their right and left hands. When compared to controls neither patient, using either their right or left hands, demonstrated a bias in the center or left space conditions, but with lines in right space both subjects' left hand deviated significantly to the left. Thus, patients with hydrocephalic interhemispheric functional disconnection might show a form of callosal neglect. This hemispatial-hand asymmetry of deviation, however, also might be related to the disinhibition of the attentionally dominant right hemisphere.

Aged↗
PubMed2006

Prognostic significance of angiographically confirmed large vessel intracranial occlusion in patients presenting with acute brain ischemia.

INTRODUCTION: Independent predictors of outcome for ischemic stroke include age and initial stroke severity. Intracranial large-vessel occlusion would be expected to predict poor outcome. Because large-vessel occlusion and stroke severity are likely correlated, it is unclear if largevessel occlusion independently predicts outcome or is simply a marker for stroke severity. METHODS: A consecutive series of patients with suspected stroke or transient ischemic attack were imaged acutely with computed tomography angiography (CTA). CTAs were reviewed for intracranial large-vessel occlusion as the cause of the stroke. Baseline National Institutes of Health Stroke Scale (NIHSS) score, discharge modified Rankin score, and patient demographics were abstracted from hospital records. Poor neurological outcome was defined as modified Rankin score exceeding 2. RESULTS: Seventy-two consecutive patients with acute ischemic stroke were imaged with CTA. The median (range) time from stroke symptom onset to CT imaging was 183 minutes (25 minutes to 4 days). Median NIHSS score was 6 (1-32) and intracranial large-vessel occlusion was found in 28 (38.9%) patients. Fifty-six percent of patients had a good neurological outcome. In multivariate logistic regression analysis, two variables predicted poor neurological outcome: baseline NIHSS score (OR 1.21, 95% CI [1.07-1.37]) and presence of intracranial large-vessel occlusion (OR 4.48, 95% CI [1.19-16.9]). The predictive value of large-vessel occlusion on outcome was similar to an 8-point increase in NIHSS score. CONCLUSION: In patients presenting with acute brain ischemia, intracranial large-vessel occlusion independently predicts poor neurological outcome at hospital discharge, as does the presence of a high NIHSS score. Performing routine intracranial vascular imaging on acute stroke patients may allow for more accurate determination of prognosis and may also guide therapy.

Aged↗
PubMed2005

Initial Glasgow Coma Scale score predicts outcome following thrombolysis for posterior circulation stroke.

BACKGROUND: Randomized trials of thrombolytic stroke treatment have either excluded patients with posterior circulation ischemia or used inclusion criteria making enrollment of these patients less likely. Consequently, there is less published information on thrombolytic therapy for posterior circulation stroke. OBJECTIVE: To determine effective thrombolytic treatment times for posterior circulation stroke and factors that might help predict clinical outcome. DESIGN: We describe our experience treating 21 consecutive patients with either intravenous or intra-arterial thrombolytic therapy for posterior circulation ischemic stroke between October 9, 1993, and February 19, 2001. MAIN OUTCOME MEASURES: National Institutes of Health Stroke Scale, Glasgow Coma Scale, and modified Rankin Scale scores were evaluated at baseline, and the modified Rankin Scale was measured 3 months after stroke, with a good outcome being a modified Rankin Scale score of 2 or less. RESULTS: Nine patients received intravenous therapy; 12 patients received intra-arterial therapy. The median National Institutes of Health Stroke Scale score at onset was 20 (range, 2-39), and the median Glasgow Coma Scale score was 9 (range, 3-15). Twelve patients were treated within 8 hours of symptom onset (range, 1 1/2 hours to 16 days). Nine patients (43%) had a modified Rankin Scale score of 2 or less at 3 months. The initial Glasgow Coma Scale score and treatment within 8 hours of symptom onset were each associated with good outcome, but the initial National Institutes of Health Stroke Scale score was not predictive. CONCLUSIONS: Thrombolytic therapy for posterior circulation stroke may be beneficial even when initiated 8 hours after symptom onset. Level of consciousness, as measured by Glasgow Coma Scale score, seems to be a more important predictor of outcome than the initial National Institutes of Health Stroke Scale score.

Adult↗
PubMed2005

Antimuscarinic drugs for overactive bladder and their potential effects on cognitive function in older patients.

Antimuscarinic agents are the predominant pharmacological treatment for patients with overactive bladder (OAB). These drugs are thought to act primarily through antagonism at muscarinic M3 receptors located at neuromuscular junctions in the human bladder detrusor muscle. Several of these drugs have been shown to be efficacious in ameliorating the symptoms of OAB in older patients, but most currently available agents lack selectivity for the M3 receptor subtype, and interaction with other muscarinic receptor subtypes throughout the body may adversely affect a variety of physiological functions and result in unwanted side effects, including cognitive dysfunction. With the recent availability of antimuscarinic agents that show increased selectivity for M3 receptors relative to other muscarinic subtypes, an invitational expert panel meeting was convened to review not only the mechanisms by which antimuscarinic agents could affect cognitive function, but also the published literature on cognitive adverse events. A review of the literature shows that the cholinergic system in the central nervous system (CNS) exerts a major influence on cognitive processes, in particular memory via M1 cholinergic receptors. In addition, recent evidence suggests a role for M2 receptors in mediating cognitive function. Thus, cognitive dysfunction (including memory loss) during treatment with nonselective antimuscarinic agents for OAB is of growing concern, particularly in older patients and those with mild cognitive impairment or dementia. Increased blood-brain barrier permeability, which can occur with advanced age and certain comorbidities, may also facilitate CNS access of antimuscarinic agents (regardless of their physiochemical properties) and add to antimuscarinic burden. On the basis of available evidence, antimuscarinic agents with selectivity for M3 over M1 and M2 receptors, limited CNS penetration, or both may therefore offer a favorable balance of efficacy in treating OAB together with a reduced risk of adverse cognitive events in the older population.

Age Factors↗
PubMed2002

Presentation, diagnosis, and management of arterial mycotic pseudoaneurysms in injection drug users.

Injection drug users frequently present with abscess, cellulitis, and endocarditis. The development of arterial mycotic pseudoaneurysm (AMP) as a sequela of injection drug use, however, is much less frequently reported. We undertook a study to determine the prevalence and presenting clinical characteristics of AMP, utilizing a retrospective review of all emergency department cases seen at one city public hospital for the 5-year period 1994-1999. Initial evaluation included physical examination, CT scan, ultrasound, and/or angiography. There were 7,795 patient visits for complications of injection drug use; 11 patients had AMP (0.14%). AMP involved the brachial (n = 5), subclavian (n = 2), radial (n = 2), femoral (n = 1) and popliteal arteries (n = 1). Fever was absent in the majority of patients (7/11). Either pulsatility or a mass was noted in three cases, and both were seen in 6/11 (54%). AMP was not initially suspected in three cases, which were treated as abscesses and surgically incised, resulting in arterial rupture. The annual prevalence of AMP in the presenting population was estimated to be 0.03%. However, a high index of suspicion for AMP should be maintained with injection drug users presenting with a mass or pulsatility over an artery, as there is risk of rupture, rapid exsanguination, and distal embolization.

Adult↗