Language Functions in Huntington's Disease

Abstract

A comprehensive language test battery (Aachen Aphasia Test) was administered to 45 patients in the early, middle or later stages of Huntington's disease (HD) and to 20 control subjects. In spontaneous speech, many HD patients exhibited a loss of conversational initiative. Dysarthria was a common finding. Reading skills were found to be impaired mainly as a consequence of dysarthria; some HD patients displayed visual dyslexia. In addition to the characteristic disturbances of writing skills due to the choreiform movement disorder, the writing of HD patients with advanced dementia indicated constructional dysgraphia, characterized by frequent omissions, perseverations and substitutions. HD patients exhibited no evidence of word-finding difficulty or other semantic deficits in spontaneous speech. There was, however, a marked impairment in visual confrontation naming, with a significant rise in naming error rate as the disease progressed in severity. In most instances, the inappropriate names referred to an object visually similar to the target object, suggesting that visual misperception is the major cause of the naming disorder in HD. Syntactical structure of spontaneous speech was typically reduced to short, simple sentence construction. Verbal stereotypes were only rarely encountered and occurred late in the course of the disease. Tests of language comprehension reflected the general degree of dementia. It is concluded that there are no primary language changes in HD. Instead, a variety of language impairments develop secondary to other neurological and neuropsychological changes.

The Role of the Caudate in Nonmotor Behaviors in Huntington’s Disease

“…Others have confirmed relative sparing of semantic content in HD by demonstrating that even late in the disease, only a minority of patients had language problems, most notably with confrontation naming (Bayles and Tomoeda, 1983;Podoll et at., 1988;Hodges et at., 1991). Analysis of naming error type shows a greater proportion than normal of errors misnaming objects with names of visually similar objects and fewer errors with semantically associated objects (Bayles and Tomoeda, 1983;Podoll et at., 1988;Hodges et at., 1991). The error type analysis implies that defective visual processing (visual naming) rather than flawed semantic associative processing is the primary process.…”

“…Problems of motoric output which commonly affect prosody in HD patients include dysarthria and respiratory problems (Gordon and Illes, 1987;Podoll et at., 1988). Patients with early HD have hesitations and press of speech.…”

“…Patients with advanced HD may produce short, syntactically simple but correct sentences and may ultimately become mute (Folstein and McHugh, 1983;Podoll et at., 1988). This problem cannot be considered strictly a motoric speech output problem because agraphia also occurs and may involve inexplicable halts in the act of writing and omission of letters (Gordon and Illes, 1987;Podoll et at., 1988).…”

“…This problem cannot be considered strictly a motoric speech output problem because agraphia also occurs and may involve inexplicable halts in the act of writing and omission of letters (Gordon and Illes, 1987;Podoll et at., 1988).…”

Imaging in cell-based therapy for neurodegenerative diseases

“…[56] for discussion). Nevertheless, the cognitive deficits observed in HD are very similar to those observed following lesions of the frontal cortex and perseverative behavior as well as severe impairment in set-shifting strategies ("cognitive flexibility") are key features of the frontal-type HD syndrome.…”