Categoría: Papers con abstracts

PET studies have shown an association between changes in blood flow in the insular cortex and verbal memory. This study compared verbal memory profiles between a group of four right handed patients with right insular infarction and a group of six right handed patients with left insular infarction. Patient groups were comparable in age, education, and sex. Patients were administered memory tests about 4-8 weeks poststroke. Patients with left insular lesions showed significantly poorer immediate and delayed verbal memory as measured by story A of the WMS-R logical memory I (t=-2.73, p<0.03) and logical memory II (t=-4.1, p<0.004) subtests as well as the CERAD word list memory (delayed recall) (t=-2.4, p<0.05). These findings indicate that left insular damage is associated with poorer performance on verbal memory tasks. The findings suggest that the insula may be part of a functional network that mediates verbal memory.

The areas of seven subregions of the corpus callosum and three subregions of the cerebellum were examined on midsagittal magnetic resonance imaging scans of 27 low-IQ autistic individuals and 17 nonautistic individuals of comparable mental age. Autistic individuals had a significantly smaller corpus callosum (most marked in the body). No significant between-group differences were found in cerebellum areas. Results demonstrate that abnormalities of the corpus callosum reported in high-functioning autistic individuals are also present in autistic individuals with mental retardation and extend previous reports showing no evidence for a selective hypoplasia of cerebellar lobules VI-VII.

The neuropsychiatric effects of insular damage in humans have not previously been examined. We therefore examined the neuropsychiatric impairment in seven patients with left insular stroke, six patients with right insular stroke, six patients with left hemisphere noninsular stroke, and six patients with right hemisphere noninsular stroke. Between 4 and 8 weeks after acute stroke, patients were administered a neuropsychiatric battery. Patients with right insular lesions had a greater frequency of subjective anergia and underactivity (Fisher’s exact p = .002) as well as tiredness (Fisher’s exact p < .002) compared with patients with non-insular lesions or left insular lesions. Subjective feelings of impaired energy or drive after right insular damage may result from disconnection between the insula and the frontal lobe or the anterior cingulate cortex, structures that have been associated with willed action and motor behavior.

This study was undertaken to identify the clinical and pathoanatomical correlates of irritability in patients with closed head injuries. A consecutive series of 66 patients was assessed in hospital and at 3, 6, 9, and 12-month follow-ups. Patients fulfilling criteria for irritability were divided into 2 groups based on the immediate or delayed onset of their irritability and compared with patients without irritability for background characteristics, impairment variables, and lesion characteristics. There were 12 patients (18.2%) with acute onset irritability and 10 (15.1%) with delayed onset irritability. Acute onset irritability patients had a higher frequency of left cortical lesions. Delayed onset irritability patients showed a strong association with poor social functioning and greater impairment in activities of daily living. The findings suggest that post-brain injury irritability may have different causes and treatment in the acute and chronic stages.

Transcranial Magnetic Stimulation (TMS) is an exciting new technology that along with repetitive TMS (rTMS) offers the potential to explore and understand brain-behavior relationship in a way that builds on recent advances in functional neuroimaging (ie, PET, SPECT, fMRI imaging). rTMS as a relatively noninvasive probe of cortical function provides an opportunity to explore the relationships between regional brain activity and symptomatology across psychiatry illnesses. In this article we briefly review the current thinking regarding the neurobiology of mood and the effects of rTMS on mood in healthy and depressed subjects.

Advances in surgical procedures and new immunosuppressor therapies have improved the outcome of renal grafts. However, these changes have been accompanied by infectious, neoplastic and neurologic complications. The purpose of this study was to determine the incidence of neurologic complications among 542 patients receiving a renal transplant (from living or cadaveric donors) at CEMIC between 1970 and 1996. Neurologic complications occurred in 43 patients (8%) as follows: 8 meningitis (1.5%), 8 acute confusional syndrome (1.5%), 7 encephalitis (1.3%), 7 cerebrovascular accidents (1.3%), 6 convulsions (1.1%), 3 tumors (0.5%), 3 femoral nerve lesion (0.5%), and 1 epidural lipomatosis (0.1%). Etiologic agents most commonly observed in meningitis were: Cryptococcus neoformans, Listeria monocytogenes and Mycobacterium tuberculosis. Major difficulties arose in the diagnosis of encephalitis. Diagnosis of the above complications required clinical astuteness and repeated bacteriologic, serologic and imaging studies.

Clozapine has been shown not only to be effective in ameliorating dopaminomimetic psychosis but to improve parkinsonian symptomatology. Six parkinsonian patients with motor fluctuations under levodopa treatment and severe interdose «off » periods (believed to be mediated by an inhibitory effect of subthreshold levels of levodopa) underwent a trial of clozapine. The effects of this drug on levodopa response were measured by means of an acute levodopa test both before and after receiving clozapine. After 1 month of treatment, clozapine 25 mg/day reduced parkinsonian scores at all stages of the evaluation (pre-levodopa «off, » «on, » and interdose «off «). The effect was consistently more significant for the interdose «off. » Clozapine could be exerting its beneficial effects through the inhibition of an inhibitory effect mediated by low-level dopaminergic stimulation, thus behaving as an apparent anti-parkinsonian drug.

Depression and apathy are the two most frequent behavioral complications of stroke. This article reviews the prevalence of these conditions in poststroke patients, as well as their clinical correlates, longitudinal course, and possible mediators. A number of controlled clinical trials of the efficacy of various drugs in the treatment of poststroke depression are also reviewed.

This study examined the prevalence and correlates of pathological affect in Alzheimer’s disease. A consecutive series of 103 patients with Alzheimer’s disease were examined with a comprehensive psychiatric assessment that included the pathological laughing and crying scale (PLACS). Forty patients (39%) showed pathological affect: 25% showed crying episodes, and 14% showed laughing or mixed (laughing and crying) episodes. Patients with pathological affect crying showed significantly higher depression scores and a significantly higher frequency of major depression and dysthymia than patients with no pathological affect. Patients with mixed pathological affect showed significantly more subcortical atrophy on CT than patients with pathological affect crying. Forty seven per cent of the patients with pathological affect had no congruent mood disorder, and they showed a significantly longer duration of illness and more severe anosognosia than patients with pathological affect that was congruent with an underlying mood disorder. The study validates the PLACS, and shows the high prevalence of pathological affect in Alzheimer’s disease.

Huntington’s disease can particularly affect people’s recognition of disgust from facial expressions, and functional neuroimaging research has demonstrated that facial expressions of disgust consistently engage different brain areas (insula and putamen) than other facial expressions. However, it is not known whether these particular brain areas process only facial signals of disgust or disgust signals from multiple modalities. Here we describe evidence, from a patient with insula and putamen damage, for a neural system for recognizing social signals of disgust from multiple modalities.