Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coltheart and co-workers [Castles, A., Bates, T. C., & Coltheart, M. (2006). John Marshall and the developmental dyslexias. Aphasiology, 20, 871-892; Coltheart, M., Rastle, K., Perry, C., Langdon, R., & Ziegler, J. (2001). DRC: A dual route cascaded model of visual word recognition and reading aloud. Psychological Review, 108, 204-256] have demonstrated that an equation derived from dual-route theory accurately predicts reading performance in young normal readers and in children with reading impairment due to developmental dyslexia or stroke. In this paper, we present evidence that the dual-route equation and a related multiple regression model also accurately predict both reading and spelling performance in adult neurological patients with acquired alexia and agraphia. These findings provide empirical support for dual-route theories of written language processing.
 ...
PMID:Do dual-route models accurately predict reading and spelling performance in individuals with acquired alexia and agraphia? 1748 18

Objectives. Both the number and type of higher cortical function deficits (HCFD) in acute stroke patients are important diagnostically and for gauging the extent of neurological deficits. Methods. The Stroke Data Bank (SDB) provided a large prospective data base for such evaluation. Thirty-one different HCFDs, each defined in the SDB manual, were considered. Results. Of 1,805 patients in the SDB, 641 instances of HCFD in 422 patients were recorded in alert patients at initial examination (within the first 7 to 10 days of ictus). Aphasia (41%) was the most commonly found HCFD, followed by neglect syndrome (27.2%), apraxia (11.7%), and anosognosia (11.1%). Agnosia (3.9%), alexia (3.3%), and aprosodia (1.5%) were less frequently found HCFDs. Cardioembolic infarct was most likely to have associated HCFDs (66%), and lacunar infarction was least likely to be accompanied by HCFDs (6%), with infarction caused by large artery thrombosis (50%) and infarct of undetermined cause (47%) having similar frequencies. The co-occurrence of sensory and motor deficits among the eight major subgroups of HCFD showed that neglect syndrome, apraxia, and anosognosia were most likely to be associated with long tract signs, whereas alexia, aprosodia, and agnosia invariably were not associated with sensorimotor impairment. Approximately half of aphasic patients had associated sensorimotor impairment. Conclusion. Our findings show that higher cortical function deficits are prevalent in the acute phase of stroke, particularly aphasia and neglect syndromes. They are more often associated with nonlacunar stroke and some are less likely to be associated with any sensorimotor deficits.
J Stroke Cerebrovasc Dis
PMID:Higher cortical function deficits among acute stroke patients: The stroke data bank experience. 1789 81

Lesions affecting the left fusiform gyrus (FG) commonly result in dyslexia and recovery largely depends on efficient reorganization of the reading network. We performed a follow-up fMRI study to elucidate the reorganization patterns of the FG according to the recovery of reading ability in two patients (MH with pure alexia and KM with alexia with agraphia) after stroke involving the left FG. Initially, MH was an effortful letter-by-letter (LBL) reader, and she improved to become a proficient LBL reader. The initial fMRI results showed scattered activation on occipital and ventral temporal cortex during reading, which was localized to right FG in the follow-up study. KM's severe alexia with agraphia did not improve, even after 6 months had passed since the onset of the alexia. The initial and follow-up fMRI results showed no significant activation in the bilateral FG or central higher language areas during word reading. Our results suggest that the reorganization of the FG is different according to the type of alexia and the amount of clinical recovery in each patient. Also, the successful reorganization of the visual component of reading in the right FG is responsible for the recovery of LBL reading in pure alexia.
 ...
PMID:Differential reorganization of fusiform gyrus in two types of alexia after stroke. 1878 41

Posterior fusiform gyrus (BA 37) is responsible for Hanja (ideogram) alexia in stroke patients. Patients with semantic dementia (SD) have lesions in the basal temporal area. The close proximity in these two lesions and the fact that reading ideograms requires holistic processing as is necessary in recognition of objects, suggests a possibility that ideogram alexia/agraphia may occur in patients with SD. We established and carried out Hanja and Hangul (phonogram) reading/writing tasks on six SD patients and nine Alzheimer's disease (AD) patients as control to see if these two patient groups show dissociation in the two sets of tests. SPM analysis was performed on the SD patients' PET images to look for any dysfunctions in the posterior fusiform gyrus. The SD patients manifested Hanja alexia/agraphia whereas Hangul reading/writing ability was relatively preserved. There were group differences between SD and AD in the Hanja tasks but not in the Hangul tasks. The SPM analysis revealed no hypometabolism in the posterior fusiform gyrus, but only in the middle and the anterior part of the temporal gyrus. Dysfunction in the middle temporal gyrus (BA 21) may have disrupted the temporal lobe connections preventing the function of the posterior fusiform gyrus.
 ...
PMID:Hanja (Ideogram) alexia and agraphia in patients with semantic dementia. 1996 97

Patients with phonologic alexia can be trained to read semantically impoverished words (e.g., functors) by pairing them with phonologically-related semantically rich words (e.g, nouns). What mechanisms underlie success in this cognitive re-training approach? Does the mechanism change if the skill is "overlearned", i.e., practiced beyond criterion? We utilized fMRI pre- and post-treatment, and after overlearning, to assess treatment-related functional reorganization in a patient with phonologic alexia, two years post left temporoparietal stroke. Pre-treatment, there were no statistically significant differences in activation profiles across the sets of words. Post-treatment, accuracy on the two trained sets improved. Compared with untrained words, reading trained words recruited larger and more significant clusters of activation in the right hemisphere, including right inferior frontal and inferior parietal cortex. Post-overlearning, with near normal performance on overlearned words, predominant activation shifted to left hemisphere regions, including perilesional activation in superior parietal lobe, when reading overlearned vs. untrained words.
 ...
PMID:Neural Mechanisms Underlying Learning following Semantic Mediation Treatment in a case of Phonologic Alexia. 2011 95

In pure alexia (PA)-an acquired reading disorder consequent on posterior left-hemisphere stroke-the hallmark is a pronounced and abnormal impact of word length on reading speed. Some patients with semantic dementia (SD)-a neurodegenerative condition affecting semantic memory-have also been reported to show an abnormal word length effect (AWLE) in reading, even though they are not thought to have the basic visual-processing deficits hypothesized to underlie this phenomenon in PA. In the current study, an AWLE in reading was consistently observed in both PA and SD patients, but further manipulations demonstrated marked differences between the groups in the conditions that produce the length effect, its specific manifestation, and the pattern of other deficits accompanying it. All of the results are compatible with the twin hypotheses that the AWLE in reading arises from a visual-processing deficit in PA but from reduced top-down lexical/semantic support for word identification in SD. In other words, the AWLE in the two patient groups appears to be a common symptom arising from different underlying deficits: one bird with two stones.
 ...
PMID:One bird with two stones: Abnormal word length effects in pure alexia and semantic dementia. 2104 71

After a cerebral infarction, some patients acutely demonstrate contralateral hemiplegia, or aphasia. Those are the obvious symptoms of a cerebral infarction. However, less visible but burdensome consequences may go unnoticed without closer investigation. The importance of a thorough clinical examination is exemplified by a single case study of a 72-year-old, right-handed male. Two years before he had suffered from an ischemic stroke in the territory of the left posterior cerebral artery, with right homonymous hemianopia and global alexia (i.e., impairment in letter recognition and profound impairment of reading) without agraphia. Naming was impaired on visual presentation (20%-39% correct), but improved significantly after tactile presentation (87% correct) or verbal definition (89%). Pre-semantic visual processing was normal (correct matching of different views of the same object), as was his access to structural knowledge from vision (he reliably distinguished real objects from non-objects). On a colour decision task he reliably indicated which of two items was coloured correctly. Though he was unable to mime how visually presented objects were used, he more reliably matched pictures of objects with pictures of a mime artist gesturing the use of the object. He obtained normal scores on word definition (WAIS-III), synonym judgment and word-picture matching tasks with perceptual and semantic distractors. He however failed when he had to match physically dissimilar specimens of the same object or when he had to decide which two of five objects were related associatively (Pyramids and Palm Trees Test). The patient thus showed a striking contrast in his intact ability to access knowledge of object shape or colour from vision and impaired functional and associative knowledge. As a result, he could not access a complete semantic representation, required for activating phonological representations to name visually presented objects. The pattern of impairments and preserved abilities is considered to be a specific difficulty to access a full semantic representation from an intact structural representation of visually presented objects, i.e., a form of visual object agnosia.
 ...
PMID:[Associative visual agnosia. The less visible consequences of a cerebral infarction]. 2140 Sep 59

Post-stroke language disorders are frequent and include aphasia, alexia, agraphia and acalculia. There are different definitions of aphasias, but the most widely accepted neurologic and/or neuropsychological definition is that aphasia is a loss or impairment of verbal communication, which occurs as a consequence of brain dysfunction. It manifests as impairment of almost all verbal abilities, e.g., abnormal verbal expression, difficulties in understanding spoken or written language, repetition, naming, reading and writing. During the history, many classifications of aphasia syndromes were established. For practical use, classification of aphasias according to fluency, comprehension and abilities of naming it seems to be most suitable (nonfluent aphasias: Broca's, transcortical motor, global and mixed transcortical aphasia; fluent aphasias: anomic, conduction, Wernicke's, transcortical sensory, subcortical aphasia). Aphasia is a common consequence of left hemispheric lesion and most common neuropsychological consequence of stroke, with a prevalence of one-third of all stroke patients in acute phase, although there are reports on even higher figures. Many speech impairments have a tendency of spontaneous recovery. Spontaneous recovery is most remarkable in the first three months after stroke onset. Recovery of aphasias caused by ischemic stroke occurs earlier and it is most intensive in the first two weeks. In aphasias caused by hemorrhagic stroke, spontaneous recovery is slower and occurs from the fourth to the eighth week after stroke. The course and outcome of aphasia depend greatly on the type of aphasia. Regardless of the fact that a significant number of aphasias spontaneously improve, it is necessary to start treatment as soon as possible. The writing and reading disorders in stroke patients (alexias and agraphias) are more frequent than verified on routine examination, not only in less developed but also in large neurologic departments. Alexia is an acquired type of sensory aphasia where damage to the brain causes the patient to lose the ability to read. It is also called word blindness, text blindness or visual aphasia. Alexia refers to an acquired inability to read due to brain damage and must be distinguished from dyslexia, a developmental abnormality in which the individual is unable to learn to read, and from illiteracy, which reflects a poor educational background. Most aphasics are also alexic, but alexia may occur in the absence of aphasia and may occasionally be the sole disability resulting from specific brain lesions. There are different classifications of alexias. Traditionally, alexias are divided into three categories: pure alexia with agraphia, pure alexia without agraphia, and alexia associated with aphasia ('aphasic alexia'). Agraphia is defined as disruption of previously intact writing skills by brain damage. Writing involves several elements: language processing, spelling, visual perception, visuospatial orientation for graphic symbols, motor planning, and motor control of writing. A disturbance of any of these processes can impair writing. Agraphia may occur by itself or in association with aphasias, alexia, agnosia and apraxia. Agraphia can also result from 'peripheral' involvement of the motor act of writing. Like alexia, agraphia must be distinguished from illiteracy, where writing skills were never developed. Acalculia is a clinical syndrome of acquired deficits in mathematical calculation, either mentally or with paper and pencil. These language disturbances can be classified differently, but there are three principal types of acalculia: acalculia associated with language disturbances, including number paraphasia, number agraphia, or number alexia; acalculia secondary to visuospatial dysfunction with malalignment of numbers and columns, and primary anarithmetria entailing disruption of the computation process.
 ...
PMID:Post-stroke language disorders. 2203 87

Management of the pregnant woman with a neuro-ophthalmic disorder may be challenging. Physiologic changes in pregnancy make vascular conditions more frequent, including retinal artery occlusion, spontaneous orbital hemorrhage, and pituitary apoplexy. Papilledema may signal cerebral venous sinus thrombosis or idiopathic intracranial hypertension. Manifestations of severe preeclampsia and eclampsia include choroidal infarction, serous retinal detachment, and disorders of higher cortical function, such as alexia, simultanagnosia, and cerebral blindness. Cranial neuropathies have also been reported. Transient Horner syndrome, intracranial hypotension with comitant esotropia may occur in the postpartum period. Treatment of the neuro-ophthalmic complications of pregnancy requires an understanding of the risks of medications. Taking optimal care of the mother will usually result in the best care for her baby.
 ...
PMID:Neuro-ophthalmology and pregnancy: what does a neuro-ophthalmologist need to know? 2208 2

Alexia may be divided into different subtypes, with semantic paralexia being particularly rare. A 57 year old woman with a discreet left thalamic stroke and semantic paralexia is described. Language evalution with the Boston Diagnostic Aphasia Battery confirmed the semantic paralexia (deep alexia). Multimodality magnetic resonance imaging brain scanning excluded other cerebral lesions. A good recovery ensued.
 ...
PMID:Thalamic semantic paralexia. 2259 10


<< Previous 1 2 3 4 5 6 Next >>