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I have many more studies to add to this section. Please be patient. Unfortunately, I have not yet seen any studies on how to treat semantic dementia patients. Almost all of the studies have been published in the last six years. First Article Defining Semantic Dementia: Five patients with a stereotyped clinical syndrome characterized by fluent dysphasia with severe anomia, reduced vocabulary and prominent impairment of single-word comprehension, progressing to a stage of virtually complete dissolution of the semantic components of language are described. A marked reduction in the ability to generate exemplars from restricted semantic categories (e.g. animals, vehicles, etc.) was a consistent and early feature. Tests of semantic memory demonstrated a radically impoverished knowledge about a range of living and man-made items. In contrast, phonology and grammar of spoken language were largely preserved, as was comprehension of complex syntactic commands. Reading showed a pattern of surface dyslexia. Autobiographical and day-to-day (episodic) memory were relatively retained. Non-verbal memory, perceptual and visuospatial abilities were also strikingly preserved. In some cases, behavioral and personality changes may supervene; one patient developed features of the Kluver-Bucy Syndrome. Radiological investigations have shown marked focal temporal atrophy in all five patients, and functional imaging by single positron emission tomography and positron emission tomography (one case) have implicated the dominant temporal lobe in all five. In the older literature, such cases would have been subsumed under the rubric of Pick's disease. Semantic dementia. Progressive fluent aphasia with temporal lobe atrophy. Hodges JR, Patterson K, Oxbury S, Funnell E. University of Cambridge, UK. Brain. 1992 Dec;115 ( Pt 6):1783-806 Differentiate Corticobasal Degeneration from Semantic
Dementia by Number vs. Object Dissociation: Performance on several
simple measures requiring number representations (including addition and
magnitude judgments of single digits), and on a task that requires object
representations (an object naming task) in patients with corticobasal
degeneration (CBD; n = 13) and semantic dementia (SD; n = 15) was compared with
regional cortical atrophy using voxel-based morphometric analyses of high
resolution structural MRI in subgroups of five CBD patients and three SD
patients. CBD patients were consistently more impaired on simple addition and
magnitude judgment tasks requiring number representations compared to object
representations. Impaired performance with numbers in CBD was associated with
cortical atrophy in right parietal cortex. By comparison, SD patients
demonstrated a greater impairment on a naming task requiring object
representations relative to their performance on measures involving number
representations. This was associated with left anterior temporal cortical
atrophy. Dissociation of numbers and objects in corticobasal degeneration and
semantic dementia. Halpern CH, Glosser G, Clark R, Gee J, Moore P, Dennis K,
McMillan C, Colcher A, Grossman M. University of Pennsylvania. Neurology.
2004 Apr 13;62(7):1163-9 |