Recovery from apraxic deficits and its neural correlate

Abstract

Background and Objective: Apraxia is a deficit of motor cognition leading to difficulties in actual tool use, imitation of gestures, and pantomiming object use. To date, little data exist regarding the recovery from apraxic deficits after stroke, and no statistical lesion mapping study investigated the neural correlate of recovery from apraxia. Accordingly, we here examined recovery from apraxic deficits, differential associations of apraxia task (imitation vs. pantomime) and effector (bucco-facial vs. limb apraxia) with recovery, and the underlying neural correlates. Methods: We assessed apraxia in 39 patients with left hemisphere (LH) stroke both at admission and approximately 11 days later. Furthermore, we collected clinical imaging data to identify brain regions associated with recovery from apraxic deficits using voxel-based lesion-symptom mapping (VLSM). Results: Between the two assessments, a significant recovery from apraxic deficits was observed with a tendency of enhanced recovery of limb compared to bucco-facial apraxia. VLSM analyses revealed that within the lesion pattern initially associated with apraxia, lesions of the left insula were associated with remission of apraxic deficits, whereas lesions to the (inferior) parietal lobe (IPL; supramarginal and angular gyrus) and the superior longitudinal fasciculus (SLF) were associated with persistent apraxic deficits. Conclusion: Data suggest that lesions affecting the core regions (and white matter) of the fronto-parietal praxis network cause more persistent apraxic deficits than lesions affecting other regions (here: the left insula) that also contribute to motor cognition and apraxic deficits.

Speech apraxia and oral apraxia: association or dissociation? A multivariate lesion–symptom mapping study in acute stroke patients

“…Thus, it can be hypothesized that the insula acts as an integrator for oral praxis, between its verbal and non-verbal components, so that its lesioning mostly associates with co-occurring SA and OA. A similar hypothesis was also proposed by Kusch (Kusch et al 2018 ), who found that limb-apractic patients with insular lesions had a better prognosis than those with lesions in core lesions of the frontoparietal network. From this point of view, our results suggest that frontal regions (in particular precentral gyrus and SLF) may be exclusively responsible for the verbal component of oral praxis—i.e.…”

Anodal tDCS over left parietal cortex expedites recovery from stroke-induced apraxic imitation deficits: a pilot study

“…Furthermore, we examined the actual object use of the ipsilesional left hand with five single objects (hammer, toothbrush, pair of scissors, toy gun, and pencil eraser) and two multiple-object tasks (key & padlock, matchbox & candle [ 11 ];). However, in the current sample of stroke patients, object use deficits were rare ( n = 2, see also [ 28 , 29 ]). Note, that the two patients with impaired object use also performed below cut-off in the KAS and were thus classified as apraxic.…”

Gesture meaning modulates the neural correlates of effector-specific imitation deficits in left hemisphere stroke

“…Patients had provided written informed consent to participate in the original studies on motor cognition/apraxia ( Ant et al, 2019 , Binder et al, 2017 , Dafsari et al, 2019 , Dovern et al, 2016 , Kusch, Gillessen et al, 2018 , Kusch, Schmidt et al, 2018 ). These studies contributed 156 stroke patients to the current sample.…”

“…1 B, cf. also Kusch, Schmidt et al, 2018 , Raade et al, 1991 ), the interaction term was calculated as the difference of the difference between the mean imitation scores for ML bucco-facial vs ML arm/hand gestures and the difference of the mean imitation scores for MF bucco-facial vs MF arm/hand gestures: Interaction term = (ML bucco-facial gestures mean score − ML arm/hand gestures mean score ) − (MF bucco-facial gestures mean score − MF arm/hand gestures mean score ). The resulting interaction score was then entered into an SVR-LSM analysis.…”