Compression of the bilateral corticospinal tracts by bilateral pontine hemorrhage A diffusion tensor tractography study

Bilateral spontaneous pontine hemorrhage is rare. In addition, bilateral corticospinal tract （CST） involvement in the pons may accompany serious motor sequelae. A 45-year-old right-handed woman was admitted for bilateral pontine hemorrhage. The patient presented with moderate quadriparesis at stroke onset and quickly recovered to the point of being able to extend the muscles of all four extremities against resistance, at 2 weeks from onset. At 4 weeks after stroke onset, she was able to perform all fine motor activities, as well as to walk with a normal gait. Diffusion tensor tractography results showed that the CSTs of both hemispheres originated from the primary sensorimotor cortex and descended through the corona radiata, the posterior limb of the internal capsule, midbrain, anterior pons, and the anterior medulla, along the known pathway of the CST. However, at midbrain and pons, the CSTs were compressed posterolaterally. The contralateral primary sensorimotor cortex, centered on the precentral knob, was activated during movement of either hand of the patient, as shown by functional MRI, which indicates the preservation of lateral CST. Findings from this study suggest that diffusion tensor tractography may be helpful in the elucidation of the CST status in patients with pontine hemorrhage.