Carotid endarterectomy.
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Cerebrovascular Disorders↗
Biomedical subjects
S E Nadeau
Publications and source records attributed to S E Nadeau.
Watershed infarction on computed tomographic scan. An unreliable sign of hemodynamic stroke.
We identified three patients with computed tomography-defined infarctions that were partly or exclusively located in watershed territories; clinical evaluation and cerebral angiography suggested that the infarcts were of embolic origin. In two patients, arteriography demonstrated minimal carotid plaque without evidence of significant stenosis. The third patient did have high-grade stenosis of the petrous portion of the ipsilateral internal carotid artery, but arteriography demonstrated a branch artery occlusion corresponding to the territory of the infarction. Although most authors suggest that watershed territory infarctions arise from hemodynamic events, cerebral embolization may be a common cause.
Aged↗
Morphologic agrammatism following a right hemisphere stroke in a dextral patient.
There is evidence of two major components of grammatic function in the brain: (1) morphologic, probably based in the postcentral perisylvian cortex, encompassing the selection of individual words and inflectional endings according to the rules of grammar; and (2) syntactic, probably based in the frontal lobes, encompassing construction of the overall structure of a sentence (syntax) to match the concept being considered. We present a stroke patient with impaired morphology but, unlike Broca's aphasics, relative sparing of syntax. He omitted 43% of articles, 40% of complementizers, 20% of pronouns, 27% of semantically marked prepositions, 43% of purely grammatic prepositions, and 22% of auxiliary verbs, but his average sentence length was 9.8 words and 64% of his sentences contained embedded clauses. He frequently intermingled two sentences to convey a given concept, juxtaposing words in grammatically unacceptable ways. This intermingling may represent either a grammatic "conduite d'approche," or a failure of the filtering function of a defective morphologic processor. His great difficulty in completing syntactic frames suggests that a more general form of the processes underlying grammatic morphology may play an important role in phrase structure generation.
Aged↗
A possible pathophysiologic substrate of attention deficit hyperactivity disorder.
The attention deficit hyperactivity disorder (ADHD) is associated with defective attention and response inhibition and motor restlessness. Inattention, defective response inhibition, and impersistence are more commonly seen in adults with right than with left hemisphere dysfunction. In light of this fact and because children with ADHD not only appear to demonstrate these symptoms but also neglect the left side and have decreased activation of their right neostriatum, we propose that these children have a right hemisphere dysfunction. In addition, because both inattention and defective response inhibition can be seen in children with ADHD and in patients and animals who have frontal lobe and striatal dysfunction, we propose that children with ADHD have dysfunction in a right-sided frontal-striatal system. Motor restlessness may reflect frontal lobe dysfunction due to impairment of the mesocortical dopamine system.
Adolescent↗
Gaze-dependent hemianopia without hemispatial neglect.
A hemispheric field is the space defined by the midsagittal plane of the body. Hemianopia, in the absence of hemispheric spatial neglect, has been thought to be purely retinotopic. Confrontation testing of visual fields in eccentric positions of gaze in hemianopic patients permits the discrimination of hemispheric from retinotopic deficits. In the primary position of gaze, a patient with an ischemic lesion of the right occipital and temporal lobes, who was without unilateral spatial neglect, was unable to detect finger movement, name objects, or identify shapes or colors in the left retinotopic hemifield, but when gazing 30 degrees to the right (so that the left retinotopic field was in the right hemispheric field), he performed nearly as well in the left retinotopic field as in the right. The mechanism of this gaze-dependent hemifield visual impairment is unknown, but we discuss four possibilities: (1) eccentric gaze enhances an alternative visual system; (2) the lesion led to modality-specific hemispheric inattention that was corrected by directing intention (plan to act) and gazing to the right; (3) the lesion led to modality specific inattention that was corrected by compensatory mechanisms that may normally enhance attentive vigilance in central space during eccentric gaze; and (4) the neuronal substrate for hemispheric vision was destroyed, whereas that for retinotopic vision was preserved.
Attention↗
Multi-infarct dementia, subcortical dementia, and hydrocephalus.
The diagnostic evaluation of dementia is directed toward the identification of treatable causes. It can be facilitated by classification of the dementia into one of four categories: attentional, amnestic, cognitive, and intentional. Intentional dementia reflects dysfunction of frontal lobe systems, components of which include the frontal cortex, basal ganglia, thalamus, limbic structures, and subcortical white matter. Disorders that affect one or more of these components and produce intentional dementia include Binswanger's disease, Parkinson's disease, Huntington's disease, HIV infection, closed head injury, normal pressure hydrocephalus, neoplasms, syphilis, vitamin B12 deficiency, multiple sclerosis, and a number of uncommon degenerative and acquired syndromes. Depression may resemble intentional dementia. Guidelines for diagnosis and management are discussed.
Brain↗
Retrosplenial cortex: possible role in habituation of the orienting response.
A patient with a unilateral lesion that included the retrosplenial area had a propensity to attend to contralateral stimuli. To determine whether the retrosplenial-area lesion was inducing this defect, unilateral retrosplenial lesions were produced in rats by surgical aspiration. Animals were assessed preoperatively and postoperatively for orientation and habituation to bilateral simultaneous stimulation in 3 sensory modalities: visual, tactile, and auditory. At each session, the orientation test was terminated upon completion of 5 trials per modality, and the habituation test ended after 4 consecutive response failures or upon completion of 15 trials per modality. Postoperatively, contralateral orientation was not significantly different from ipsilateral orientation, suggesting that there was no neglect. However, there was a significant delay in habituation to contralateral stimulation in postoperative weeks 2 and 3-5. Our results suggest that rats with retrosplenial area lesions have normal orientation but fail to habituate to contralateral stimuli.
Acoustic Stimulation↗
Stroke.
The annual incidence of stroke in the elderly approaches 2 per cent. The major tasks of the physician are to attempt to prevent recurrence and to supervise rehabilitation. Prevention of recurrence involves a careful consideration of differential diagnosis, treatment of contributory disease, and the initiation of therapy specific to large vessel infarction (atherothrombotic or cardiogenic embolic), lacunar infarction, or intracerebral hemorrhage. The high prevalence of lacunar infarction and the focal nature of posterior circulation transient ischemic attacks and strokes are not generally appreciated. Cardiogenic embolism due to atrial fibrillation and intracerebral hemorrhage due to congophilic angiopathy are of particular importance in the elderly. Treatment of stroke or transient ischemic attacks should be initiated quickly as the risk of recurrence is highest immediately following the signal event. History, neurologic and neurobehavioral examinations are important adjuncts in compensating for the inadequacy of CT and MRI in enabling the stroke classification necessary for proper treatment. Supportive care and rehabilitation can have a major impact on stroke morbidity and mortality and the management of risk factors can significantly reduce stroke incidence.
Aged↗
A crossover trial of bromocriptine in the treatment of vascular dementia.
Seven patients with vascular dementia completed an 8-month randomized double-blind crossover trial of bromocriptine in a dosage of up to 30 mg per day. Patients were assessed using a modified UCLA Parkinson Rating Scale of symptoms and signs, and neuropsychological testing including the Wechsler Adult Intelligence Scale-Revised, Wechsler Memory Scale, modified Thurstone Word Fluency Test, Wisconsin Card Sort, a test of visual vigilance, and a reaction time task. Subjects failed to perform significantly better on any measure while on bromocriptine, and on several measures their performance while on the drug was worse.
Aged↗
Impaired grammar with normal fluency and phonology. Implications for Broca's aphasia.
Extensive testing of grammatical function, including assessment of spontaneous language, inflectional morphology, ability to produce grammatical structures, syntactic comprehension and grammatical judgement, was carried out in 2 patients with large dominant frontal lobe lesions, including but not confined to, the third frontal convolution. Both patients were fluent and had normal articulation and phonological production and neither was agrammatic, suggesting that even very large frontal lesions do not produce Broca's aphasia and that language cortex proper is confined to the postcentral perisylvian region. Both patients were impaired in the use of more complex syntactic structures and one, who in addition had severe generalized impairment in frontal lobe function, also had impaired judgement regarding the use and placement of functors. These data provide further support for the dissociability of syntactic and morphological aspects of grammar in aphasic patients and, together with other studies, link these functions with the frontal lobe and the postcentral perisylvian cortex, respectively. The sparing of grammatical judgement in 1 patient, despite a very extensive lesion, suggests that very large portions of the frontal lobe are involved in grammatical function. The nature of frontal lobe function in syntax appears to be congruent with the role of the frontal lobes in other aspects of behaviour.
Adult↗
Temporal arteritis: a decision-analytic approach to temporal artery biopsy.
The clinical indications for temporal artery biopsy were explored using clinical decision analysis. The analysis indicated that biopsy is most useful in patients with a high likelihood of steroid side effects. It is nearly always useful when the pre-biopsy likelihood of temporal arteritis is low, but loses its value when temporal arteritis is likely on clinical grounds, except when there is a very high probability of steroid side effects. With the low biopsy sensitivity likely to exist in most institutions, the value of biopsy falls off particularly steeply with rising clinical likelihood of temporal arteritis.
Biopsy↗
A variant of the anti-Purkinje cell antibody in a patient with paraneoplastic cerebellar degeneration.
An anti-Purkinje cell antibody was found in the serum and CSF of a man with adenocarcinoma of the lung and paraneoplastic cerebellar degeneration (PCD). This antibody differed from the autoantibodies found in patients with gynecologic cancer and PCD in that it produced a different pattern of Purkinje cell cytoplasmic staining, did not react with PCD antigens in Purkinje cell Western blots, and the antigen had a different species distribution. Unlike the antinuclear antibody found in patients with PCD and small-cell lung carcinoma, the antigen was restricted to the cytoplasm of Purkinje cells. If autoantibodies are important in the pathogenesis of PCD, this case illustrates that they can recognize different antigenic epitopes in the nervous system, but cause similar clinicopathologic syndromes.
Adenocarcinoma↗
Nonspecific dementia, cortical blindness, and Congophilic angiopathy. A clinicopathological report.
Postmortem examination of an elderly male with cortical blindness and features of both cortical and subcortical dementia revealed extensive neuronal dropout most marked in the occipital cortex, moderate gliosis, rare neuritic plaques, no neurofibrillary tangles, and extensive Congophilic angiopathy. The unprecedented association of Congophilic angiopathy with nonspecific dementia provides further support for the concept that Congophilic angiopathy is usually a nonspecific manifestation of neuronal degeneration and of little clinical significance except when it results in intracerebral hemorrhage.
Aged↗
Stroke due to cardiogenic embolism.
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Cerebrovascular Disorders↗
Crowding and mental health.
An epidemiologic investigation of the mental needs and services of 1645 respondents, aged 17 to 92 years and living in a representative southeastern county in Florida, revealed that 7.8% of the sample lived in crowded conditions. The crowded respondents scored significantly higher than did the uncrowded on both a depression scale and on the Health Opinion Survey. Associations between crowding and high scores on both scales were strongest among: respondents in the childrearing and middle years of life, blacks at all income levels, whites in the intermediate annual family income range of $6000 to $9999, and especially, females rather than males. Consistently, the crowded black population, and particularly, crowded white women, had much higher scores than did the uncrowded women. A multiple regression analysis showed that three variables--being a female, having a lower income, and crowding--accounted for 16.5% of the variance. The discussion emphasizes that the relationship between crowding and higher scores on indices of emotional distress is quite complicated. In crowded situations, depression may be a costly, semi-adaptive reaction to excessive interpersonal stimulation. Women living in crowded situations appear to be at high risk for depressive illness; their plight brings to mind the classic animal experiments which showed that the maternal behavior of females deteriorated in crowded situations.
Adolescent↗
Method for registering brain SPECT and MR images.
We have developed a simple method for locating functional regions of interest on successive SPECT scans obtained at different times and for locating neuroanatomical regions defined with MR on functional images obtained with SPECT. Plastic molds are made for each external auditory meatus and the glabella. A pocket is then made in each mold in which either a 57Co disk (for SPECT) or an identical disk containing CuSO4 solution (for MRI) can be placed. Transaxial tomographic slices are reconstructed with the same slice thickness in the two modalities. The SPECT software rotates both SPECT and MRI reconstructed images so that the three 57Co markers lie in one SPECT reference plane and the three CuSO4 markers lie in one MRI reference plane. Corresponding SPECT and MR images may then be displayed simultaneously to locate chosen regions of interest. The technique was validated by taping test markers to the forehead of 12 subjects; the difference between the positions of the centers of the test markers on SPECT and MR scans was within 1 SPECT acquisition pixel size.
Brain↗