Prevalence and characteristics of apraxic deficits after left and right hemisphere stroke

Investigations of apraxia typically focus on the role of the left hemisphere (LH), although apraxic deficits can also be observed after a right hemispheric (RH) stroke. We directly compared the prevalence and severity of apraxic deficits in patients with LH (n = 66) and RH (n = 73) stroke, after controlling for the effects of age and language performance. Apraxic deficits were assessed using the KAS (Cologne Apraxia Screening, including subscales for pantomiming and the imitation of bucco-facial and hand/arm gestures) as well as the Goldenberg Hand and Finger Imitation Test. Subsequently, we evaluated the effect of age, language performance, and hemisphere on the prevalence and characteristics of apraxic deficits by regression analyses and mixed design ANOVAS. For the imitation of hand positions, no significant difference was found between LH and RH stroke patients, when controlling for age and language performance. Consistent with the literature, RH stroke patients showed a poorer performance when imitating finger configurations. RH stroke patients also performed worse in the bucco-facial items of the KAS, particularly due to lower scores in upper-face gestures. For both patient groups, the language performance was related more to the pantomime than to the imitation subscales of the KAS. Data suggest that a comparable prevalence and severity of apraxic deficits can be found after LH and RH stroke when controlling for age and language abilities. As a consequence, an apraxic work-up should be included in the assessment of both LH and RH stroke patients prior to neurorehabilitation.