Impaired Ideomotor Limb Apraxia in Cortical and Subcortical Dementia: A Comparison of Alzheimer’s and Huntington’s Disease

Abstract

Background: Although ideomotor limb apraxia is often considered to occur only in dementia with cortical involvement like Alzheimer’s disease (AD), it is also frequently seen in dementia with subcortical degeneration like Huntington’s disease (HD). Methods: To assess the occurrence of ideomotor limb apraxia, 46 patients with HD (27 men) and 37 patients with AD (16 men), matched for cognitive performance, were assessed with an apraxia test battery containing tests of the imitation of meaningless hand and finger gestures, the performance of meaningful gestures and of pantomimic movements. Results: There was a high frequency of ideomotor limb apraxia in both AD and HD patients. For the assessment of hands’ imitation 13.5% of the AD patients and 41.3% of the HD patients were apraxic, for fingers’ imitation 21.6% (AD) and 41.3% (HD) were apraxic, for gestures 27.0% (AD) and 32.6% (HD), and for the assessment of pantomimic movements 24.3% (AD) and 52.2% (HD) showed apraxia. In the AD patients, disease severity was related to the occurrence of apraxia. Conclusions: Ideomotor limb apraxia is a common sign in both groups of patients, occurring in a high percentage. For particular neuropsychological deficits, including ideomotor limb apraxia, a division of dementia in a subcortical and cortical subtype seems to be clinically not meaningful.

Apraxia for differentiating Alzheimer’s disease from subcortical vascular dementia and mild cognitive impairment

“…In a similar recent report assessing the occurrence of ideomotor apraxia in AD and Huntington disease patients, the authors concluded that ideomotor apraxia was a common sign in both groups of patients. Furthermore, they reported that significantly more Huntington disease patients had been classified as apraxic – according to the hands’ and finger’ imitation and pantomimic subtypes – than AD patients 26. However, our study found that apraxia was more frequent in AD than the SVaD patients.…”

“…For example, in Huntington disease, prominent heterogeneously cortical dysfunction overlapping with the brain areas of praxis function, even in early stages of the disease, can be a different pathological process from SVaD 29–31. As the authors of the Huntington disease study concluded, the cortical degeneration during the disease process may contribute highly to the development of apraxia 26. Previous studies have reported that thalamic and basal ganglia vascular lesions were more associated with apraxia 32.…”

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

“…Ideomotor apraxia is a prominent feature of the rare movement disorder, corticobasal degeneration 17. Holl et al 18 have also demonstrated that finger and hand imitation was more frequently impaired in patients with Huntington's disease than in those with AD, suggesting that a combination of cortical and subcortical damage may more significantly influence the imitation of finger and hand gestures.…”

Apraxia and Motor Dysfunction in Corticobasal Syndrome

“…Although apraxia may be seen in other neurodegenerative diseases,[16], [17] the severity of asymmetric limb apraxia appears to be distinctive in CBS [2], [3] and constitutes an important diagnostic feature [9]–[11]. Apraxia may be defined as the inability to perform a motor task, despite intact power, sensation, coordination, comprehension and cooperation [18] and is typically the earliest symptom in CBS [3].…”