Peri-infarct reorganization of motor function in patients with pontine infarct.
OBJECTIVE
Combined functional MRI (fMRI) and diffusion tensor tractography (DTT) imaging provides a powerful vehicle for the investigation of motor recovery mechanisms. Using this combined method, we investigated the motor recovery mechanism in patients with pontine infarct.


METHODS
We evaluated six healthy control subjects and two patients with pontine infarct at 6 months from onset. fMRI was performed at 1.5 T with timed hand grasp-release movements. For DTT, we used each of the 32 noncollinear diffusion-sensitizing gradients. Three-dimensional reconstructions of the fiber tracts were obtained with FA <0.3, angle >45 degrees as termination criteria.


RESULTS
fMRI data revealed activation only in the contralateral primary sensorimotor cortex during movement of either hand. DTI findings from controls and the unaffected hemisphere of the patients showed that the corticospinal tract descended through the known corticospinal tract pathway. However, the tracts of the affected hemisphere in the patients were observed to pass along peri-infarct areas (patient 1: lateral, patient 2: posterior) in the pons.


CONCLUSIONS
It seems that the peri-infarct areas compensate for corticospinal tract damage at the pons; this may be one mechanism of motor recovery for patients with pontine infarct.
Ahn
Young Hwan
YH
Department of Neurosurgery, School of Medicine, Ajou University, Suwon, Republic of Korea.
You
Sung H
SH
Randolph
Marilys
M
Kim
Seong Ho
SH
Ahn
Sang Ho
SH
Byun
Woo Mok
WM
Yang
Dong Suk
DS
Jang
Sung Ho
SH
D000328:Adult; D000368:Aged; D020526:Brain Stem Infarctions / Q000473:pathology* / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology*; D013647:Task Performance and Analysis