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Biomedical subjects

B R Ott

Publications and source records attributed to B R Ott.

32 records · Page 2Linked to original sources
PubMed1995

Risperidone versus clozapine in the treatment of psychosis in six patients with Parkinson's disease and other akinetic-rigid syndromes.

BACKGROUND: We report six cases of psychosis in patients with akinetic-rigid syndromes who were treated with risperidone. RESULTS: Five of the six patients experienced intolerable exacerbation of parkinsonism. Four subsequently did well on clozapine therapy. One patient required nursing home placement and a feeding gastrostomy as a result of the worsening parkinsonism during risperidone treatment, but was able to return home and have the gastrostomy removed after switching from risperidone to clozapine. Two of the five patients who worsened motorically also developed encephalopathy during risperidone treatment; the encephalopathy resolved when the patients were switched to clozapine treatment. Only one patient, the youngest, did well on risperidone therapy. CONCLUSION: We believe that risperidone is not a substitute for clozapine in treating psychosis in parkinsonian patients and should be used with caution.

Aged↗
PubMed1993

Coma due to ciguatera poisoning in Rhode Island.

A patient is presented who developed an acute gastrointestinal and neurologic syndrome progressing to coma after ingestion of a fish soup made in Rhode Island. Laboratory studies confirmed the clinical diagnosis of ciguatera poisoning. Physicians should be aware of the diagnostic features of this disease even in non-endemic areas.

Animals↗
PubMed1993

Unilateral amnesic stroke. Six new cases and a review of the literature.

BACKGROUND AND PURPOSE: Although persistent amnesia due to bilateral limbic system infarction is well described, reports of amnesic syndromes due to unilateral stroke have appeared infrequently and unsystematically. We report six new cases and review previously published reports to expand and consolidate knowledge regarding amnesic stroke. CASE DESCRIPTIONS: Six patients developed acute amnesia associated with unilateral stroke. Brain computed tomography or magnetic resonance imaging revealed lesions in limbic structures, which accounted for the memory deficit. Based on these as well as similar cases in the literature, we delineate three distinct syndromes of unilateral amnesic stroke involving the territories of the posterior cerebral, anterior choroidal, and thalamic penetrating arteries. Eighty-five percent of reported cases have involved the left hemisphere. CONCLUSIONS: Persistent as well as transient amnesia may be the sole or primary manifestation of unilateral hemispheric stroke. The vascular mechanisms of amnesic stroke are diverse. Patients presenting with acute amnesia possibly related to cerebral ischemia should be classified by documented or presumed lesion site as well as the involved vascular territory. Left amygdalohippocampal or diencephalic dysfunction may produce a particular vulnerability to global amnesia.

Adult↗
PubMed1992

Exacerbation of parkinsonism by tacrine.

A patient with Alzheimer's disease and mild features of parkinsonism was treated with tacrine. Tremor and gait dysfunction worsened but responded to the addition of levodopa without adversely affecting cognitive function. The implications for experimental treatment strategies of patients with combined Alzheimer's and Parkinson's disease are discussed.

Aged↗
PubMed1992

Acute quadriplegic myopathy: a complication of treatment with steroids, nondepolarizing blocking agents, or both.

We studied two patients who were given high-dose intravenous steroid therapy and were intubated for status asthmaticus. Both became quadriplegic and wasted within 2 weeks. EMG had myopathic abnormalities. Muscle biopsy revealed severe atrophy of most muscle fibers, with disorganization of myofibrils and selective loss of thick (myosin) filaments. Immunohistologic stains for myosin isoforms confirmed the decrease or absence of this protein. Both patients clinically improved over several months.

Acute Disease↗
PubMedDate not supplied

A single-photon emission computed tomography imaging study of driving impairment in patients with Alzheimer's disease.

Single-photon emission computed tomography (SPECT) was used in this study to examine the neurophysiologic basis of driving impairment in 79 subjects with dementia. Driving impairment, as measured by caregiver ratings, was significantly related to regional reduction of right hemisphere cortical perfusion on SPECT, particularly in the temporo-occipital area. With increased severity of driving impairment, frontal cortical perfusion was also reduced. Clock drawing was more significantly related to driving impairment than the Mini-Mental State Examination (MMSE). Driving impairment in Alzheimer's disease is related to changes in cortical function which vary according to the severity of the disease. Cognitive tests of visuoperceptual and executive functions may be more useful screening tools for identifying those at greatest risk for driving problems than examinations like the MMSE that are weighted toward left-hemisphere-based verbal tasks.

Activities of Daily Living↗
PubMedDate not supplied

A SPECT imaging study of MRI white matter hyperintensity in patients with degenerative dementia.

We investigated the correlation between cortical perfusion and white matter hyperintensities on magnetic resonance images (MRI) of patients with dementia. The study included 40 subjects, each of whom had undergone both MRI and single-photon emission computed tomography (SPECT) studies as part of their diagnostic evaluation for degenerative dementia. Two neuroradiologists rated the MRI films for severity of periventricular white matter changes on a 0-5 point scale and severity of subcortical white matter changes on a 0-4 point scale. Twelve regions of interest from association cortex were sampled for the semiquantitative analysis of SPECT images. No relationship was found between these global MRI ratings and semiquantitative or qualitative SPECT findings. Dementia severity as measured by the Mini-Mental State Examination and the Clinical Dementia Rating was significantly correlated with SPECT, whereas age was significantly correlated with MRI ratings, particularly in the periventricular regions. These data support the view that cortical SPECT abnormalities are not associated with global MRI abnormalities in the subcortical and periventricular regions of patients with a clinical picture of degenerative dementia.

Aged↗
PubMedDate not supplied

The clinical spectrum of hemorrhagic infarction.

The hospital records and head CT scans of 44 patients with hemorrhagic infarction were retrospectively analyzed. The majority of cases (73%) were embolic or possibly embolic in etiology, and 55% were not associated with anticoagulant therapy. Adverse prognosis was most clearly related to infarct size, underlying systemic illness, and symptomatic hemorrhage. Of the nineteen patients in whom serial CT scans documented conversion from bland to hemorrhagic infarction, 12 exhibited no clinical worsening at the time that hemorrhagic infarction was observed; the remaining seven, all of whom worsened, were receiving anticoagulant therapy at the time of documented conversion. Fourteen patients in whom anticoagulant therapy was used despite the findings of hemorrhagic infarction remained stable or improved during hospitalization.

Adult↗
PubMedDate not supplied

Cognition and behavior in patients with Alzheimer's disease.

Clinically relevant differences in cognition and behavior exist between men and women with Alzheimer's disease. Underlying these differences are variations in the topographic brain changes caused by pathologic processes, as well as differences in hormonal brain physiology and genetic influences. Our understanding of how these gender differences affect the clinical expression of Alzheimer's disease is in its infancy. Research in this area will likely yield further insights into potential therapies directed toward symptomatic and preventive interventions.

Aging↗
PubMedDate not supplied

Lateralized cortical perfusion in women with Alzheimer's disease.

OBJECTIVE: To define the pathophysiologic substrate of gender differences in cognition and behavior in Alzheimer's disease (AD). DESIGN: Hemispheric regional cerebral blood flow (rCBF) was studied in a consecutive series of dementia patients using single photon emission computed tomography (SPECT). PARTICIPANTS: Subjects included 300 outpatients who were studied with SPECT as part of a diagnostic evaluation for degenerative dementia or memory disorder. METHOD: Based on qualitative descriptions by a radiologist, subjects were classified as having unilateral left, unilateral right, bilateral, or no perfusion defects. Semiquantitative analysis of SPECT images was also performed using region of interest radionuclide counts normalized to the cerebellum. RESULTS: Among 174 females and 126 males, unilateral left hemisphere defects were found more commonly in women than men (24% vs 10%; chi 2 = 9.4; P = .009). This observation was most significant for the 103 females and 62 males regarded as having probable AD (26% vs 8%; chi 2 = 9.3; P = .01). In a multiple regression model of clinical variables, shorter duration of disease and female gender were significant independent predictors of the unilateral left hemisphere pattern among those with probable AD. Age, family history, education, handedness, and severity of cognitive impairment were not significant contributors. CONCLUSIONS: Women with AD exhibit greater heterogeneity in rCBF than men. Asymmetry in rCBF occurs more often in women. In some cases, this is related to relative preservation of right hemisphere function in women.

Aged↗
PubMedDate not supplied

Executive function and magnetic resonance imaging subcortical hyperintensities in vascular dementia.

OBJECTIVE: To determine the relation between subcortical hyperintensities (SHs) visible on magnetic resonance imaging and executive function among patients with vascular dementia. BACKGROUND: The relation between SHs and executive dysfunction is not well understood, because studies have varied widely in methodology and have produced conflicting results. METHOD: We examined the relation between SHs (expressed as a percentage of total brain volume, not including ventricular volume) and six tests of executive function in a well-defined group of 24 individuals with vascular dementia. Executive tests were divided in two groups: Attention/Speed and Abstraction/Problem Solving. Bivariate correlations were computed between individual neuropsychological variables and SHs. RESULTS: Results showed significant bivariate correlations between SHs and three of the four tests in the Attention/Speed domain. Subcortical hyperintensities shared virtually no association with performance on tests in the Abstraction/Problem-Solving domain. CONCLUSIONS: The finding that SHs are significantly associated with psychomotor slowing and attentional dysfunction is consistent with what is known about the behavioral manifestations of subcortical disease. More detailed investigations of the regional distribution of SHs as well as measures of atrophy, hypoperfusion, and hypometabolism may be necessary to accurately characterize the complex relation between vascular disease and different aspects of executive dysfunction.

Aged↗