The olivopontocerebellar atrophies: a review.
About: This article is published in Medicine.The article was published on 1970-05-01. It has received 278 citations till now. The article focuses on the topics: Olivopontocerebellar atrophy & Cerebellar cortex.
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TL;DR: The results suggest that the domain of the cerebellar timing process is not limited to the motor system, but is employed by other perceptual and cognitive systems when temporally predictive computations are needed.
Abstract: This study investigated the effects of different types of neurological deficits on timing functions. The performance of Parkinson, cerebellar, cortical, and peripheral neuropathy patients was compared to age-matched control subjects on two separate measures of timing functions. The first task involved the production of timed intervals in which the subjects attempted to maintain a simple rhythm. The second task measured the subjects' perceptual ability to discriminate between small differences in the duration of two intervals.
The primacy of the cerebellum in timing functions was demonstrated by the finding that these were the only patients who showed a deficit in both the production and perception of timing tasks. The cerebellar group was found to have increased variability in performing rhythmic tapping and they were less accurate than the other groups in making perceptual discriminations regarding small differences in duration. Critically, this perceptual deficit appears to be specific to the perception of time since the cerebellar patients were unaffected in a control task measuring the perception of loudness.
It is argued that the operation of a timing mechanism can be conceptualized as an isolable component of the motor control system. Furthermore, the results suggest that the domain of the cerebellar timing process is not limited to the motor system, but is employed by other perceptual and cognitive systems when temporally predictive computations are needed.
1,288 citations
Cites background from "The olivopontocerebellar atrophies:..."
...The onset of these diseases varies greatly, but tends to occur in the third or fourth decade of life when there is a familial history ( Konigsmark & Weiner, 1970 ) and slightly later in sporadic cases (Plaitakis, 1982)....
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TL;DR: The presence of the until now unknown GCIs in all the 11 CNS, but not in age- and sex-matched control brains, indicates that GCI is a cellular change characteristic of multiple system atrophy and the three syndromes are various manifestations of the same disease.
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870 citations
TL;DR: Gonadal instability in SCA7 is greater than that observed in any of the seven known neuro-degenerative diseases caused by translated CAG repeat expansions, and is markedly associated with paternal transmissions.
Abstract: The gene for spinocerebellar ataxia 7 (SCA7) has been mapped to chromosome 3p12-13. By positional cloning, we have identified a new gene of unknown function containing a CAG repeat that is expanded in SCA7 patients. On mutated alleles, CAG repeat size is highly variable, ranging from 38 to 130 repeats, whereas on normal alleles it ranges from 7 to 17 repeats. Gonadal instability in SCA7 is greater than that observed in any of the seven known neuro-degenerative diseases caused by translated CAG repeat expansions, and is markedly associated with paternal transmissions. SCA7 is the first such disorder in which the degenerative process also affects the retina.
748 citations
TL;DR: It is concluded that the lateral regions of the cerebellum are critical for the accurate functioning of an internal timing system.
Abstract: In a previous study (Ivry and Keele, in press), cerebellar patients were found to be impaired on both a motor and a perceptual task which required accurate timing. This report presents case study analyses of seven patients with focal lesions in the cerebellum. The lesions were predominantly in the lateral, hemispheric regions for four of the patients. For the remaining three patients, the lesions were centered near the medial zone of the cerebellum. The clinical evaluation of the patients also was in agreement with the different lesion foci: lateral lesions primarily impaired fine motor coordination, especially apparent in movements with the distal extremities and medial lesions primarily disturbed balance and gait. All of the patients were found to have increased variability in performing rhythmic tapping when tapping with an effector (finger or foot) ipsilateral to the lesion in comparison to their performance with a contralateral effector. Separable estimates of a central timekeeper component and an implementation component were derived from the total variability scores following a model developed by Wing and Kristofferson (1973). This analysis indicated that the poor performance of patients with lateral lesions can be attributed to a deficit in the central timing process. In contrast, patients with medial lesions are able to accurately determine when to make a response, but are unable to implement the response at the desired time. A similar dissociation between the lateral and medial regions has been observed on a time perception task in patients with cerebellar atrophy. It is concluded that the lateral regions of the cerebellum are critical for the accurate functioning of an internal timing system.
649 citations