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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present studies were undertaken to examine: (1) whether thrombotic infarction of the vibrissal cortical barrel-fields of the primary somatosensory cortex would produce behavioral consequences reflecting a sensory-motor deficit; and (2) whether there was any recovery of function up to two months after infarction. Specifically, in two different learning tasks requiring sensory-motor integration, rats were trained to perform a motor response consequent to the detection of vibrissal cues derived from either active exploration or from passive detection of vibrissal deflection. Once training was complete, unilateral, bilateral or sham-infarction restricted to the region of the primary somatosensory cortex was produced by a non-invasive photochemical technique, which induces platelet-activated vascular occlusion combined with blood-brain barrier changes and subsequent cell death. The results demonstrated that, regardless of the active or passive sensory characteristics of the task, unilateral and bilateral infarction resulted in a reliable performance deficit, which was not present in sham-operated control animals. Thus, the infarct disrupted the ability to integrate passively received or actively acquired vibrissal sensory information with a previously associated motor response. However, unlike the bilaterally infarcted animals, who displayed no recovery of performance level throughout the postinfarction testing sessions, the unilaterally infarcted animals exhibited a gradual improvement in performance beginning in the second or third week postinfarction and recovering to within 10-20% of preinfarction levels between postinfarction days 46-61. The similarity of the temporal pattern of behavioral recovery in the unilateral groups, despite large differences in the sensory-motor demands of the two tasks, may reflect several common underlying mechanisms of recovery. Since similar sensory-motor behavioral deficits and recovery have been described with human stroke, the present model incorporates many of the pathophysiological and behavioral properties present in the clinical situation and may be useful for future investigation of therapeutic intervention.
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PMID:Sensory-motor deficit and recovery from thrombotic infarction of the vibrissal barrel-field cortex. 235 58

There is little information available from which normal patterns of recovery from acute stroke can be ascertained. Most attention has been directed towards functional recovery in stroke patients but the neurological basis on which this occurs needs to be documented in a large cohort of patients. One hundred and fifty-seven patients admitted to hospital with a clinical diagnosis of acute stroke were examined daily for up to 28 days to determine the patterns of recovery of limb tone, power and reflexes. Changes in these variables during the first 28 days after stroke are described.
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PMID:Motor recovery following acute stroke. 236 78

A significant association between visual field deficits (VFD) and visuo-spatial neglect is well established, although cases of double-dissociation between the two conditions are not uncommon. It has been argued that VFD typically exacerbates the behavioural manifestations of neglect. We examined a series of 51 patients with unilateral right-hemisphere stroke for the presence of visual field deficit and visuo-spatial neglect. Patients were assigned to the neglect group (N+) or the non-neglect group (N-) on the basis of their aggregate scores on the recently standardised Behavioural Inattention Test (BIT). The association between neglect and VFD was confirmed. Four groups of eight patients (N+, VFD+; N+, VFD-; N-, VFD+; N-, VFD-) were then selected from the initial sample so that they were matched for age, IQ, and days post onset of stroke. Within the neglect groups, the severity of neglect did not differ significantly between those patients with and without VFD; within the non-neglect groups, scores on subtests of the BIT likewise did not differ (with the sole exception of Letter Cancellation) between the VFD+ and the VFD- subgroups. It was concluded that visual field deficits do not exacerbate neglect, and that poor functional recovery in many patients with VFDs is due to the association of sensory loss with the underlying causal factor of neglect.
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PMID:Do visual field deficits exacerbate visuo-spatial neglect? 238 Jul 29

This report summarizes the behavioural effects of a right occipital stroke in the author. An upper left quandrantanopia resolved over the first 50 poststroke days to leave a scotoma that included the left upper quadrant of the fovea and extended upwards about 6 degrees and lateral about 15 degrees. There was no further reduction in size over the next 4 years. In the early stages of recovery there was an inability to detect consciously either the presence of objects or their motion, except upon reflection once an object entered the intact visual field. This has been referred to previously as blindsight. On about the fourth day poststroke, part of the scotoma became visually active, producing a scintillating aura, which remains. Shortly thereafter colour perception returned in the scotoma, as did motion detection. Although there was little additional change in the field defect after 2 months, the author's visual abilities have continued to improve, in large part because of a shift in fixation such that information at the centre of the visual field now falls about 1.5 degrees into the lower right portion of the fovea. The implications of the visual and behavioural changes are discussed in the context of multiple visual systems and with respect to recovery of function.
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PMID:Recovery from occipital stroke: a self-report and an inquiry into visual processes. 238 11

A prospective study of 252 patients (average age 73, range 26-95) admitted to a regional general hospital over a 12-month period was carried out. 241 patients had stroke verified by the initial neurological examination and CT scan, and of these baseline data were not available on 27%. 34% died before or were not willing or able to provide data at follow-up. 39% survived and completed the study. Prestroke life events and social support could not predict the outcome of stroke rehabilitation measured as survival, length of stay, functional recovery (Barthel's Index) or placement at the follow-up 12 months after the onset of stroke. Age and arteriosclerotic heart disease predicted poor survival at follow-up. Premorbid hypertension, stroke, diabetes, obesity, tobacco smoking, and alcohol consumption did not significantly influence the outcome. Problems in stroke rehabilitation research are discussed.
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PMID:Life events and social support in prediction of stroke outcome. 248 93

Data from 357 conscious stroke patients taking part in an acute intervention trial and assessed within 48 hours of the onset of symptoms, were used to investigate the prevalence and natural history of swallowing problems. Nearly 30% of patients with single-hemisphere strokes were initially found to have difficulty swallowing a mouthful of water, but in most of those who survived, the deficit had resolved by the end of the first week. Strong correlations were found between dysphagia and speech impairment (comprehension and expression) and with facial weakness, but there was no association with the side of the stroke. After controlling for other markers of overall stroke severity such as conscious level, urinary continence, white blood cell count and strength in the affected limbs, swallowing impairment still showed a significant inverse correlation with functional ability at 1 and 6 months. These results indicate that, even if dysphagia itself is not responsible for much excess mortality in acute stroke, it might still lead to complications which hamper functional recovery.
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PMID:The natural history and functional consequences of dysphagia after hemispheric stroke. 256 84

Visuospatial neglect, a frequent consequence of unilateral (usually right-hemisphere) stroke, is associated with poor functional recovery and in many patients is resistant to remedial treatment. Studies of the nature and prevalence of the disorder have been hindered by problems of definition and assessment. In this study 80 unselected stroke patients were assessed for the presence and severity of neglect on the behavioural inattention test. The six subtests of this battery all intercorrelated highly, and a subsequent factor analysis showed that all tests loaded significantly on one underlying factor. The construct of neglect as defined by performance on the battery is therefore robust. Nonetheless, the individual tests differed substantially in their sensitivity. Star cancellation was the most sensitive measure of neglect and correctly diagnosed all patients whose aggregate score on the full battery fell below that of the control population.
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PMID:Visuospatial neglect: underlying factors and test sensitivity. 257 23

The value of strength of voluntary grip as an indicator of recovery of arm function was assessed by testing 38 recent stroke patients using a sensitive electronic dynamometer, and comparing the results with those from five other arm movement and function tests (Motricity Index, Motor Club Assessment, Nine Hole Peg Test, and Frenchay Arm Test). This procedure allowed measurement of grip in a large proportion of patients, and strength correlated highly with performance on the other tests. Measuring grip over a six month follow up period was a sensitive method of charting intrinsic neurological recovery. The presence of voluntary grip at one month indicates that there will be some functional recovery at six months.
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PMID:Arm function after stroke. An evaluation of grip strength as a measure of recovery and a prognostic indicator. 259 69

To study the effects of focal infarction on the capacity for functional activation of an ipsilateral somatosensory system remote from the lesion, we produced a small thrombotic infarct in the left frontal pole of male Wistar rats by a photochemical method. Five days later, the awake, restrained rats received tactile stimulation of the large whiskers (vibrissae) of the right side of the face, while a double-label 14C-autoradiographic study of local CMRglc (lCMRglc) and local CBF (lCBF) was performed. Unlesioned and unstimulated animals served as controls. In rats without frontal infarct, vibrissae stimulation led to activation of lCMRglc in the three synaptic relay stations of the barrel-field pathway (ipsilateral trigeminal medullary nucleus, contralateral ventrobasal thalamus, and contralateral barrel-field cortex). The mean increment in lCMRglc was 42% in lamina IV of barrel-field cortex and 49% in ventrobasal thalamus. Normalized lCBF tended to increase in superficial cortical laminae. In unstimulated animals with frontal infarct, lCMRglc was reduced by 20-30% throughout the ipsilateral barrel-field cortex as well as other ipsilateral cortical regions, but not in ventrobasal thalamus or other subcortical areas. In animals with frontal infarct subjected to contralateral vibrissae stimulation, a remarkable suppression of activation was observed throughout the barrel-field cortex so that left-less-than-right hemispheral lCMRglc asymmetry persisted despite stimulation. The ventrobasal thalamus, similarly, failed to increment its lCMRglc with vibrissae stimulation, whereas activation of the trigeminal nucleus was not suppressed. Similar trends were observed in the normalized lCBF data. These observations, which establish that a small frontal infarct is capable of suppressing normal physiological activation in remote ipsilateral brain structures, may have important implications with respect to suppression and recovery of function in human ischemic stroke.
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PMID:Acute thrombotic infarction suppresses metabolic activation of ipsilateral somatosensory cortex: evidence for functional diaschisis. 271 5

A consecutive series of 155 patients with a first-ever stroke and who were registered with the Oxfordshire Community Stroke Project (OCSP) were followed up. Their receipt of remedial therapy was recorded and their functional recovery was measured using the Barthel index of activities of daily living. Only a minority of patients received remedial therapy during the first 6 months after stroke. Those who were admitted to hospital during the first month following their stroke, or who were severely dependent, were significantly more likely to receive remedial therapy than those who remained in the community or were less dependent. A comparison of functional recovery amongst a matched subsample of patients who received remedial therapy and those who did not showed that there was comparable recovery amongst patients who did not receive remedial therapy.
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PMID:Remedial therapy and functional recovery in a total population of first-stroke patients. 276 36


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