Longitudinal changes in cerebral response to proprioceptive input in individual patients after stroke: an FMRI study.
OBJECTIVE
Functional magnetic resonance imaging (fMRI) provides an opportunity to study the relationship between cerebral reorganization and functional recovery after stroke. The authors set out to demonstrate the feasibility of using fMRI to investigate mechanisms of recovery in individual patients presenting with severe motor impairment.


METHODS
fMRI was performed during passive movement at both affected and unaffected wrists separately in 2 patients with pure motor stroke. Six scanning sessions were performed in each patient over the first 4 months after stroke. Seven control subjects were also studied, 1 of them over 6 sessions. The authors examined for longitudinal changes in cerebral responses to proprioceptive afferent input that correlated with motor recovery.


RESULTS
In control subjects, passive movement of either wrist led to relative increases in brain activation in the contralateral sensorimotor cortex and supplementary motor area, the bilateral inferior parietal cortex and secondary somatosensory areas, and the ipsilateral cerebellum. Increases in brain activation correlating with motor recovery were observed in both the ipsilesional primary sensory and primary motor cortex in 1 patient with good motor recovery but not in another patient with poor recovery. No longitudinal changes were seen in the control subject.


CONCLUSIONS
These 2 case reports demonstrate that functionally relevant changes in cerebral organization can be identified in individual patients.
Ward
Nick S
NS
Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London, UK. n.ward@fil.ion.ucl.ac.uk
Brown
Martin M
MM
Thompson
Alan J
AJ
Frackowiak
Richard S J
RS
D000328:Adult; D000368:Aged; D020520:Brain Infarction / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology*; D005240:Feasibility Studies; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010812:Physical Stimulation; D011434:Proprioception / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology; D020521:Stroke / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*