Neural correlates of proprioceptive integration in the contralesional hemisphere of very impaired patients shortly after a subcortical stroke: an FMRI study.
BACKGROUND
The effects of physiotherapy are difficult to assess in very impaired early stroke patients.


OBJECTIVE
The aim of the study was to characterize the impact of 4 weeks of passive proprioceptive training of the wrist on brain sensorimotor activation after stroke.


METHODS
Patients with a subcortical ischemic lesion of the pyramidal tract were randomly assigned to a control or a wrist-training group. All patients had a single pure motor hemiplegia with severe motor deficit. The control group (6 patients) underwent standard Bobath rehabilitation. The second, "trained," group (7 patients) received Bobath rehabilitation plus 4 weeks of proprioceptive training with daily passive calibrated wrist extension. Before and after the training period, patients were examined with validated clinical scales and functional MRI (fMRI) while executing a passive movement versus rest. The effect of standard rehabilitation on sensorimotor activation was assessed in the control group on the wrist, and the effect of standard rehabilitation plus proprioceptive training was assessed in the trained group. The effect of 4-week proprioceptive training alone was statistically evaluated by difference between groups.


RESULTS
Standard rehabilitation along with natural recovery mainly led to increases in ipsilesional activation and decreases in contralesional activation. On the contrary, standard rehabilitation and paretic wrist proprioceptive training increased contralesional activation. Proprioceptive training produced change in the supplementary motor area (SMA), prefrontal cortex, and a contralesional network including inferior parietal cortex (lower part of BA 40), secondary sensory cortex, and ventral premotor cortex (PMv).


CONCLUSIONS
We have demonstrated that purely passive proprioceptive training applied for 4 weeks is able to modify brain sensorimotor activity after a stroke. This training revealed fMRI change in the ventral premotor and parietal cortices of the contralesional hemisphere, which are secondary sensorimotor areas. Recent studies have demonstrated the crucial role of these areas in severely impaired patients. We propose that increased contralesional activity in secondary sensorimotor areas likely facilitates control of recovered motor function by simple proprioceptive integration in those patients with poor recovery.
Dechaumont-Palacin
S
S
UMR Inserm 825, Paul-Sabatier University, and IFR 96, Pôle Neurosciences, Purpan Hospital, Toulouse, France.
Marque
P
P
De Boissezon
X
X
Castel-Lacanal
E
E
Carel
C
C
Berry
I
I
Pastor
J
J
Albucher
J F
JF
Chollet
F
F
Loubinoux
I
I
D000344:Afferent Pathways / Q000033:anatomy & histology / Q000503:physiopathology; D000368:Aged; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000503:physiopathology; D002544:Cerebral Infarction / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation*; D004185:Disability Evaluation; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000033:anatomy & histology / Q000503:physiopathology; D009473:Neuronal Plasticity / Q000502:physiology; D017063:Outcome Assessment, Health Care / Q000379:methods*; D026741:Physical Therapy Modalities / Q000706:statistics & numerical data*; D020127:Recovery of Function / Q000502:physiology; D012720:Severity of Illness Index; D020886:Somatosensory Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation*; D020521:Stroke / Q000473:pathology / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome; D014955:Wrist Joint / Q000294:innervation / Q000503:physiopathology