From acute neglect to chronic constructional deficits: parietotemporal contributions to long-term post-stroke...

Patients with acute hemispheric stroke exhibit various visuospatial impairments. While many recover rapidly, others remain impaired. Better defining which symptoms characterize the acute and chronic phases and which brain areas and connections are implicated could help to improve diagnostic and rehabilitation tools and inform effective rehabilitation strategies. Here, we report a systematic anatomo-functional study of two populations of acute and chronic hemispheric stroke patients (cross-sectional design). Patients were examined by a series of neuropsychological tests assessing different post-stroke clinical manifestations in the visuospatial domain. We first performed a statistical factorial analysis of patients' behavioural performance across tests to break down symptoms into coherent profiles of co-varying deficits and determine whether any factors may be specific to each post-stroke phase. We then conducted voxel- and atlas-based lesion-symptom mapping, as well as disconnection-symptom mapping in the two populations. We found different patterns of behavioural impairment across groups, with acute symptoms mostly characterized by lateralized attentional deficits and chronic symptoms manifesting as constructional spatial impairments. Lesions to and/or disconnections of frontal and precentral gyri correlated with lateralized visuospatial symptoms in the acute but not chronic phase, whereas lesions to and/or disconnections of temporoparietal areas correlated with constructional deficits in the chronic phase. Our results indicate that constructional spatial deficits and damage/disconnection of dorsoventral higher-order visual areas most pervasively impair stroke patients in the long term. Such deficits might be overlooked or disregarded by rehabilitation strategies focusing on the (mainly acute) lateralized component of their visuospatial deficits and ignoring concomitant, more object-based deficits. This work may help design more specific diagnostic tests and guide future rehabilitation strategies, ultimately promoting better and more extensive recovery beyond lateralized deficits in attention and spatial awareness.