[Processing of "scripts" and frontal lobe function in Huntington's disease].
According to Norman and Shallice, the basal ganglia are involved in the activation and maintenance of overlearned or routine scripts in action planning. This study aimed to investigate how patients with Huntington disease manipulate scripts. Ten patients with Huntington's disease and 12 normal control subjects matched by age and education were asked to re-establish the sequential order of series of script actions which were given with or without distractor elements (i.e. with or without actions belonging to trivial scripts). Compared with normal controls, patients with Huntington disease made significantly more errors in script sequencing. However there was no significant difference in performance between patients with Huntington disease and normal control subjects in inhibiting irrelevant actions. These results suggest that early Huntington's disease patients exhibit early impairment in their ability to produce temporally coherent sequences without deficit in their ability to eliminate distractors in the action domain. These results support in part the predictions of Norman and Shallice's model. From a neuroanatomical point of view, this dissociation of performance fits with what is known about the neuropathological progression of Huntington's disease in which neuronal loss progresses in a dorsal-to-ventral direction and with what was shown in patients with circumscribed frontal lobe damage. In these patients, impairment in script sequencing is related to lesions in the lateral prefrontal regions.
Allain
P
P
Unité de Neuropsychologie, Département de Neurologie, CHU, Angers. PhAllain@chu-angers.fr
Verny
C
C
Aubin
G
G
Bonneau
D
D
Dubas
F
F
Le Gall
D
D
D000328:Adult; D003943:Diagnostic Techniques, Neurological; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D006816:Huntington Disease / Q000503:physiopathology*; D008297:Male; D013647:Task Performance and Analysis