The functional anatomy of motor recovery after stroke in humans: A study with positron emission tomography

TLDR

The study used PET scans in six stroke patients with a single hemispheric lesion and recovered brachial monoparesis, performing six measurements at rest and during finger movements of both hands, and applied a novel image‑analysis technique to reveal distinct thalamic‑cortical and thalamic‑cerebellar functional connections. Movement of the normal hand increased blood flow in contralateral primary sensorimotor cortex and ipsilateral cerebellum, while movement of the recovered hand activated both contralateral and ipsilateral primary sensorimotor cortex, both cerebellar hemispheres, and bilateral insula, inferior parietal, and premotor areas, indicating that ipsilateral motor pathways contribute to post‑stroke motor recovery.

Abstract

Abstract We have studied regional cerebral blood flow changes in 6 patients after their recovery from a first hemiplegic stroke. All had a single well‐defined hemispheric lesion and at least a brachial monoparesis that subsequently recovered. Each patient had 6 measurements of cerebral blood flow by positron tomography with 2 scans at rest, 2 during movement of fingers of the recovered hand, and 2 during movement of fingers of the normal hand. When the normal fingers were moved, regional cerebral blood flow increased significantly in contralateral primary sensorimotor cortex and in the ipsilateral cerebellar hemisphere. When the fingers of the recovered hand were moved, significant regional cerebral blood flow increases were observed in both contralateral and ipsilateral primary sensorimotor cortex and in both cerebellar hemispheres. Other regions, namely, insula, inferior parietal, and premotor cortex, were also bilaterally activated with movement of the recovered hand. We have also demonstrated, by using a new technique of image analysis, different functional connections between the thalamic nuclei and specific cortical and cerebellar regions during these movements. Our results suggest that ipsilateral motor pathways may play a role in the recovery of motor function after ischemic stroke.