Limb apraxia in patients with damage confined to the left basal ganglia and thalamus.

Abstract

SUMMARY Limb apraxia was investigated with standardised tests in 14 patients whose CT scan provided evidence of a vascular lesion confined to the left basal ganglia, or the thalamus, or both, and not involving the cortex or adjacent white matter. Five patients were severely impaired in imitating movements and pantomiming object use. Four of them also performed poorly when tested with real objects. In two patients the lesion was primarily thalamic and in three the lesion was primarily in the lenticular nucleus and the posterior limb of the internal capsule. Patients without apraxia generally had smaller injuries, but there were exceptions. Apraxia is currently conceived of as due to damage of cortical areas and their cortico-cortical connections, but the present data suggest that the model should be enlarged to include the deep nuclei and the pathways running through them.The introduction of CT examination in neurological practice has opened new avenues to the understanding of the anatomical basis of higher nervous function disorders. On the basis of CT results, it has been discovered that deep hemispheric structures, play a hitherto unsuspected role in the genesis of symptoms that were thought to be the province of the neocortex and the underlying white matter.Depending on the side of lesion, Aphasia`6 and unilateral neglect' 2 7-10 have been reported to result from damage restricted to the striatum, or the thalamus, or both, suggesting that the circuits subserving language and lateral attention must be enlarged to include these structures. No comparable evidence has hitherto been reported for apraxia, a condition traditionally attributed to the involvement of parietal and frontal cortical areas of the hemisphere dominant for speech and/or to the fibre bundles connecting them within the same hemisphere and through the corpus callosum with the premotor cortex of the contralateral hemisphere." -

Impaired imitation of gestures in mild dementia: comparison of dementia with Lewy bodies, Alzheimer's disease and vascular dementia

“…Thus, imitation of finger gestures is through activity of the frontal and parietal regions, but imitation of hand gestures seems to depend mainly on the temporoparietal regions. Moreover, some brain lesion studies also suggest involvement of the basal ganglia in the process of imitation of finger gestures 5 6 14. These findings suggest that imitation of finger gestures depends on a larger scale brain network including the frontal and parietal cortices, and the basal ganglia, compared to the imitation of hand gestures.…”

Gait apraxia after bilateral supplementary motor area lesion

“…Individual scores are age and education adjusted. The cut off point (53) corresponds to the worst score found in a group of 187 controls 79 and represents the 95% outer tolerance limit of the normal population.…”

Action comprehension in aphasia: linguistic and non-linguistic deficits and their lesion correlates

“…Specifically, results on lesion correlates of impairments in action, pantomime and gesture comprehension deficits are few, and not entirely consistent. Heilman and colleagues have reported that apraxic patients with posterior lesions have more trouble in comprehending the meaning of pantomimes (Heilman, Rothi, & Valenstein, 1982;Rothi, Heilman, & Watson, 1985) and have suggested that posterior parietal regions of the cortex may mediate the production and comprehension of purposeful movements (see also De Renzi, Faglioni, Scarpa, & Crisi, 1986;Kertesz, Ferro & Shewan, 1984). On the other hand, Ferro, Martins, Mariano, and Castro Caldas (1983) reported that while gesture recognition impairments were most commonly associated with parietal lesions in chronic stages of brain damage, in acute stages it was the patients with left frontal and basal ganglia damage who showed deficiencies, but unfortunately this study had a rather small sample size.…”