Anatomical correlates of recovery in apraxia: A longitudinal lesion-mapping study in stroke patients

Objective: This study investigates the clinical course of recovery of apraxia after lefthemisphere stroke and the underlying neuroanatomical correlates for persisting or recovering deficits in relation to the major processing streams in the network for motor cognition. Methods: 90 patients were examined during the acute (4.74 +/- 2.73 days) and chronic (14.3 +/- 15.39 months) stage after left-hemisphere stroke for deficits in meaningless imitation, as well as production and conceptual errors in tool use pantomime. Lesion correlates for persisting or recovering deficits were analyzed with an extension of the nonparametric Brunner-Munzel rank-order test for multi-factorial designs (two-way repeatedmeasures ANOVA) using acute images. Results: Meaningless imitation and tool use production deficits persisted into the chronic stage. Conceptual errors in tool use pantomime showed an almost complete recovery. Imitation errors persisted after occipitotemporal and superior temporal lesions in the dorso-dorsal stream. Chronic pantomime production errors were related to the supramarginal gyrus, the key structure of the ventro-dorsal stream. More anterior lesions in the ventro-dorsal stream (ventral premotor cortex) were additionally associated with poor recovery of production errors in pantomime. Conceptual errors in pantomime after

Automated summary

This study investigated the clinical recovery process of apraxia in patients after left hemisphere stroke, identifying persisting deficits in imitation and tool use production but almost complete recovery in conceptual errors. Lesion locations in specific processing streams were associated with the extent of recovery, with occipitotemporal and superior temporal lesions linked to imitation errors and ventro-dorsal stream lesions related to production errors in pantomime.