Article

The ipsilateral motor pathway from the unaffected motor cortex to the affected
extremity is one of the mechanisms of motor recovery following stroke. We report
on a stroke patient who showed the ipsilateral motor pathway without the
contralateral motor pathway on functional MRI and diffusion tensor tractography.
A 53-year-old left hemiparetic patient with an infarct in the right middle
cerebral artery territory was evaluated. During a period of three months after
onset, motor function of the affected (left) hand had recovered slowly, to the
extent that the patient was able to overcome gravity. FMRI showed that only the
unaffected (left) primary sensorimotor cortex was activated by movements of the
unaffected (right) hand or of the affected (left) hand. On diffusion tensor
tractography, the corticospinal tract of the left hemisphere originated from the
primary sensori-motor cortex and descended through the known corticospinal tract
pathway. By contrast, the right corticospinal tract showed a disruption with
Wallerian degeneration to the upper medulla. We conclude that the motor function
of the affected (left) hand appeared to be controlled only by the ipsilateral
motor pathway from the left motor cortex to the left hand. Motor function of the
affected hand appeared to have been reorganized to the ipsilateral motor pathway
from the unaffected motor cortex to the affected hand.

Langue : ANGLAIS