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At least 397 records · Page 22Linked to original sources

Cortical blindness caused by acute general cerebral swelling.

A 7-year-old girl who suffered from acute general cerebral swelling as a result of a traffic accident showed cortical blindness. Computed tomography (CT) scan on admission revealed marked slitlike ventricles and narrowing of the perimesencephalic cisterns, which indicated general cerebral swelling. While hospitalized, the patient developed transtentorial herniation twice on day 3, and CT scans at herniation episodes showed disappearance of the perimesencephalic cisterns. After recovery of consciousness, the patient showed cortical blindness, and during gradual recovery she showed pure alexia without agraphia. The visual evoked potentials at 8 weeks, 16 weeks, and 3 years 4 months after trauma showed normalization of the pattern, but revealed left occipital inactivity.

Acute Disease↗

Ideogram writing in a disconnection syndrome.

A case of disconnection-type agraphia coupled with alexia was reported. The patient showed several asymmetrical manual capacities between the two hands, i.e., dissociated difficulty of Kanji (ideogram) writing between the two hands, left unilateral difficulty of Kana (phonogram) writing, right unilateral dyscopia of letters as well as geometrical figures, and right unilateral difficulty in drawing without a model. Anatomically, lesions involved most of the corpus callosum in its posterior portion including the splenium and the left medial occipital lobe. From these data, a possible linguistic capacity of the right hemisphere was suggested.

Adolescent↗

Optic aphasia, optic apraxia, and loss of dreaming.

A 47-year-old man with a left temporo-occipital infarct in the area of the posterior cerebral artery is presented. The neuropsychological examination did not reveal aphasia or gross mental deficits. The patient presented with alexia without agraphia, color agnosia, but few visual perceptual deficits. The main impairment was in confrontation naming; he was incapable of naming objects and pictures, not from lack of recognition (excluding visual agnosia) but from lack of access to the appropriate word (optic aphasia). The patient also exhibited a deficit in the evocation of gesture from the visual presentation of an object (optic apraxia) and a difficulty in "conjuring up" visual images of objects (impaired visual imagery) and loss of dreams. The fundamental deficit of this patient is tentatively explained in terms of visuoverbal and visuogestural disconnection and a deficit of mental imagery.

Aphasia↗

Historical note: Jules Séglas on language in dementia.

In his book Des troubles du language chez les aliénés (1892) Séglas applied the model of language processing of his teacher, Charcot, to analyze the language disorders of various groups of mentally ill, including patients considered to suffer from dementia. Among the language phenomena he described from dementia are logorrhea, neologisms, embolalia, near-mutism, angophrasia, automatic speech, alexia, and agraphia. Séglas must be credited for his early descriptions of how language behaviors cluster in various psychiatric and dementing diseases.

Dementia↗

Anatomy of posterior pathways in reading: a reassessment.

Contemporary accounts of the neurology of reading stem from Dejerine's original visual-verbal disconnection hypothesis of pure alexia. Reassessment of Dejerine's traditional formulations for posterior left hemisphere pathways in reading suggests that the occipital cortex-left angular gyrus-Wernicke's area scheme is undoubtedly oversimplified. The role of left angular gyrus cortex in reading is unsettled, and although clinically undefined, more inferior portions of the left temporal lobe may also contribute to the reading process. Nevertheless, to a surprising extent, the neuroanatomic edifice erected by Dejerine remains largely intact.

Animals↗

The pattern of reading deterioration in dementia of the Alzheimer type: observations and implications.

Thirteen patients with dementia of the Alzheimer type (DAT) were tested for their ability to read aloud and to read with comprehension. Reading aloud was preserved in all but the most severely impaired cases and was found to be relatively independent of intellectual deterioration. Reading comprehension declined progressively with increasing dementia severity and correlated well with quantitative mental status assessments. The results suggest that the pattern of reading deterioration may aid in the clinical identification of DAT, that the disturbance of reading comprehension is a linguistic deficit rather than a product of visual-perceptual disturbances, and that the alexia is more consistent with an instrumental loss than a de-developmental model of dementia.

Aged↗

Isolated lexical agraphia in a right-handed patient with a posterior lesion of the right cerebral hemisphere.

Lexical agraphia is thought to result from impairment of the lexical spelling system and is characterized by better spelling of nonwords and regularly spelled words than irregularly spelled words. Previous reports have suggested a localization of this syndrome in the region of the left posterior-superior angular gyrus and parietal-occipital lobule, sparing the supramarginal gyrus. We describe a right-handed man who after open-heart surgery displayed lexical agraphia without aphasia, alexia, apraxia, or Gerstmann's syndrome. Computed tomography disclosed a lesion not on the left but on the right in the posterior parietal-occipital region.

Agraphia↗

Pure agraphia and Gerstmann's syndrome as a visuospatial-language dissociation: an experimental case study.

A right-handed man suffered a left parieto-occipital cerebral infarction, causing agraphia with Gerstmann's syndrome but without major aphasia, alexia, or apraxia. Oral spelling was superior to written spelling. Experiments were performed involving (1) analysis of errors in writing, (2) tasks of visual imagery, and (3) identifying letters drawn without leaving a visual trace. The results suggest that the agraphia and Gerstmann's syndrome are due to a dissociation of language skills and visuospatial skills caused by a dominant parieto-occipital lesion.

Aged↗

Left occipital lobectomy and the preangular anatomy of reading.

Two patients had alexias after left occipital lobectomies. Case 1 was a 55-year-old man with a glioblastoma. At 4 months after surgery he could read slowly, but reading was neither efficient nor pleasant. Case 2 was a 19-year-old male who had a more restricted, medial occipital lobectomy for an encapsulated mesenchymal chondrosarcoma. The tumor did not invade brain initially, and the patient recovered efficient reading after 15 months. It is postulated that Case 2 was able to recover efficient reading because he still had a field of left ventrolateral occipitotemporal cortex connected to homologous cortex on the right.

Adult↗

Errors resembling semantic paralexias in Spanish-speaking aphasics.

Forty-one Spanish-speaking left-hemisphere-damaged patients were selected and divided into seven groups (transcortical, Broca's aphasia, conduction aphasia, Wernicke's aphasia, anomic aphasia, alexia without agraphia, and global aphasia). A reading battery composed of eight different subtests was given to each patient (reading of letters, reading of syllables, reading of pseudowords, reading of words, reading of sentences, understanding commands, reading and comprehension of texts, and logographic reading). Different types of reading errors were analyzed. Only in the logographic reading subtest were some word-recognition errors found, resembling semantic paralexias. It is proposed that semantic paralexias in English (and other languages) depend upon the partial logographic nature of the reading system. The importance of cross-linguistic analysis of reading errors, taking into account reading system idiosyncracies, is emphasized.

Adult↗

Clinical subtypes of Alzheimer's disease.

The authors summarize the data of 60 patients of the Memory Clinic of the National Institute of Psychiatry and Neurology between 6 January 1992 and 6 June 1994 where the probable Alzheimer's disease (NINCDS-ADRDA) was diagnosed. It was examined whether it was possible to isolate homogenous subtypes based on clinical data. Interesting differences of tendency level could be demonstrated in the groups formed on the basis of data published in the literature. Differences of statistical significance level were as follows: occurrence of depression in the groups created on the basis of the patient age at the time of onset of the disease (early-late onset), and of alexia and autotopagnosia in the groups created on the basis of progression rate (slow - quick). The absence of epileptic seizures is extremely interesting. The authors' final conclusion is the following: the clinical symptoms unfortunately do not give sufficient possibility to form homogenous subtypes in the general frame of Alzheimer's disease.

Journal Article↗

Prosopagnosia: a defect in visual configural processing.

A patient with severe, lasting prosopagnosia could not get an immediate overview of a face sufficiently specific for successful identification. He also failed completely in tasks of visual closure despite adequate performances on numerous other tests of visual perception and memory. We conclude that prosopagnosia represents a loss of visual "configural processing"--a learned skill enabling immediate identification of individual members of a class without conscious visuospatial analysis or remembering. Prosopagnosia and agnosic alexia represent two distinct defects of configural processing: Alexics cannot identify items with distinctive features that are themselves identifiable. Prosopagnosics cannot identify objects whose critical distinguishing features have no independent identities.

Adult↗

The perceptions of students in the allied health professions towards stroke rehabilitation teams and the SLP's role.

UNLABELLED: The purpose of this study was to determine the perceptions and knowledge of final-year speech-language pathology (SLP), physical and occupational therapy (PT, OT) students toward stroke rehabilitation teams and the SLPs' roles on them. The investigators adapted a survey developed by (Felsher & Ross, 1994) and administered it to 35 PT, 35 OT, and 35 SLP final year students (n=105). We found that the students preferred the transdisciplinary team approach and agreed that the advantages of teamwork were the exchange of ideas, opportunities for participatory learning, and holistic treatment. Communication problems, time-consuming meetings, and role confusion were chosen as disadvantages. The students had clear perceptions of the SLP's role in aphasia, apraxia of speech, dysarthria, dysphagia, and auditory agnosia, but fewer recognized the SLP's role in alexia and memory. Some thought SLPs had a role in dressing apraxia and proprioceptive disorders. Suggestions to maximize the advantages and minimize possible disadvantages of teamwork are provided. LEARNING OUTCOMES: Learners will: (1) identify the perceived advantages and disadvantages of stroke rehabilitation teamwork; (2) discover some allied health students' perceptions of the SLP's roles in stroke rehabilitation; (3) infer methods to create positive perceptions of stroke rehabilitation team members.

Allied Health Personnel↗

Ubiquitin-positive frontotemporal lobar degeneration presenting with progressive Gogi (word-meaning) aphasia. A neuropsychological, radiological and pathological evaluation of a Japanese semantic dementia patient.

A patient with progressive anomia and alexia with agraphia for kanji (Japanese morphograms) is described. The patient showed a deficit in single-word comprehension and on-reading (a type of reading that conveys phonetic value) dominance in kanji reading, i.e. on-preceding (pronouncing first with on-reading, irrespective of its preferred reading) and kun-deletion (inability to recall and recognize kun-reading [another type of reading that conveys meaning]) when reading a single-character kanji. These features were due to loss of lexico-semantic information and thus the patient was regarded as having progressive Gogi (word-meaning) aphasia by Imura, a Japanese manifestation of semantic dementia. Macroscopically, neuropathological examination disclosed atrophy of the left frontotemporal lobe with accentuation in the anterior portion of the temporal lobe. Histologically, there was neuronal loss in the cerebral cortex, hippocampus, parahippocampal gyrus, amygdala, caudate nucleus, and putamen. Ubiquitin-immunoreactive neuronal inclusions were present in the hippocampal dentate granular cells. This case demonstrates that progressive Gogi aphasia is semiologically identical to semantic dementia, and our patient clinicopathologically resembled those of Rossor et al. [Rossor, M.N., Revesz, T., Lantos, P.L., Warrington, E.K. Semantic dementia with ubiquitin-positive tau-negative inclusion bodies. Brain 2000; 123: 267-76.] and Hodges et al. [Hodges, J.R., Davies, R.R., Xuereb, J.H., Casey, B., Broe, M., Bak, T.H., et al. Clinicopathological correlates in frontotemporal dementia. Ann Neurol 2004; 56: 399-406.].

Aged↗

Specialization within the ventral stream: the case for the visual word form area.

Is there specialization for visual word recognition within the visual ventral stream of literate human adults? We review the evidence for a specialized "visual word form area" and critically examine some of the arguments recently placed against this hypothesis. Three distinct forms of specialization must be distinguished: functional specialization, reproducible localization, and regional selectivity. Examination of the literature with this theoretical division in mind indicates that reading activates a precise subpart of the left ventral occipitotemporal sulcus, and that patients with pure alexia consistently exhibit lesions of this region (reproducible localization). Second, this region implements processes adequate for reading in a specific script, such as invariance across upper- and lower-case letters, and its lesion results in the selective loss of reading-specific processes (functional specialization). Third, the issue of regional selectivity, namely, the existence of putative cortical patches dedicated to letter and word recognition, cannot be resolved by positron emission tomography or lesion data, but requires high-resolution neuroimaging techniques. The available evidence from single-subject fMRI and intracranial recordings suggests that some cortical sites respond preferentially to letter strings than to other categories of visual stimuli such as faces or objects, though the preference is often relative rather than absolute. We conclude that learning to read results in the progressive development of an inferotemporal region increasingly responsive to visual words, which is aptly named the visual word form area (VWFA).

Dyslexia↗

Brain activations during letter-by-letter reading: a follow-up study.

Lesions affecting the ventral cortex of the left temporal lobe commonly yield a selective reading impairment known as pure alexia. It is thought to result from the disruption or deafferentation of the Visual Word Form Area (VWFA), a region in the left lateral occipitotemporal sulcus activated whenever normal subjects are viewing alphabetic strings. Most pure alexic patients retain the ability to identify single letters, and develop a strategy of letter-by-letter (LBL) reading. We recently studied fMRI activations in LBL readers and clarified the underlying mechanisms. However, LBL reading is a dynamic process which may improve over months or years of practice, although the cerebral bases of this continuing improvement are currently unknown. We had the opportunity to run the same behavioural testing and fMRI experiment a second time in an alexic patient, 8 months after collecting the data reported by Cohen et al. [Cohen, L., Henry, C., Dehaene, S., Molko, N., Lehéricy, S., Martinaud, O., Lemer, C., and Ferrieux, S. (2004). The pathophysiology of letter-by-letter reading. Neuropsychologia, 42, 1768-1780]. We analyze the changes that occurred over this period in the pattern of reading-related activations, while the patient's LBL reading improved. The activation level decreased in most of the overall network between the two sessions. This general trend contrasted with a focal increase restricted to specific left frontal and parietal areas. When studying the contrast between words and consonant strings, which may be taken as a correlate of LBL reading, we also found a general decrease, except for similar left frontal and parietal regions, which showed a significant increase. We suggest that the pattern of evolution fits with the minimal hypothesis of normal strategic abilities and skill learning, associated with perceptual tuning in right-hemispheric structures able to substitute the disrupted VWFA.

Adult↗

Number processing in posterior cortical atrophy--a neuropsycholgical case study.

Posterior cortical atrophy (PCA) is an uncommon syndrome of dementia with early onset, characterised by disorders of higher visual function, variable symptoms of Balint's syndrome, visual agnosia, alexia, agraphia, finger agnosia, right-left disorientation and dyscalculia [Benson D. F., Davis R. J., & Snyder B. D. (1988). Posterior cortical atrophy. Archives of Neurology, 45, 789-793]. In a single case study specific numerical deficits were observed which may be predicted by parietal neurodegeneration (more pronounced on the right side; verified by SPECT). Besides impairments in all tasks involving visuo-spatial abilities (e.g., dot counting, analog number scale task), deficits appeared in tasks requiring access to an internal representation of numbers such as mental number bisection, approximation, estimation and semantic facts. In number comparison an increased distance effect was found. In simple arithmetic, a striking dissociation between operations was found-multiplication and addition facts being preserved at a superficial level, subtraction and division being severely impaired. The study confirms the close relation between spatial and numerical processing and highlights the modular organisation of the semantic system (number semantics impaired). Moreover, the study adds evidence about the clinical manifestation of the particular degenerative syndrome.

Atrophy↗

Isolated numerical skills in posterior cortical atrophy--an fMRI study.

Posterior cortical atrophy (PCA) is characterized by bilateral parieto-occipito-temporal atrophy and hypometabolism. Neuropsychological impairments include complex visual disturbances, alexia, agraphia, finger agnosia, right-left disorientation and dyscalculia. A recent case study reported severe numerical deficits with some selectively preserved numerical skills in a patient affected by PCA [Delazer, M., Karner, E., Zamarian, L., Donnemiller, E., & Benke, T. (2006). Number processing in posterior cortical atrophy--a neuropsycholgical case study. Neuropsychologia]. In a functional magnetic resonance imaging (fMRI) study brain activation patterns related to these selectively preserved numerical skills were analyzed. Recitation of multiplication tables and counting forward were contrasted to word recitation in a block design. Contrasts between experimental conditions and control condition yielded significant activation of inferior and medial temporal structures. Since numerical processing is generally associated with parietal activation, it was hypothesized that preserved brain structures would compensate for the functional deficits.

Acoustic Stimulation↗