Early detection of post-traumatic olivary hypertrophy by MRI.

Two patients are described, in whom MRI detected unilateral signal abnormalities in the region of the inferior olivary nuclei, suggesting an early stage of olivary hypertrophy. MRI was performed 4 and 7 weeks respectively after traumatic brain-stem injury. Palatal myoclonus was concomitantly observed in one patient, while the other showed no evidence of segmental myoclonus at the time of examination. The authors conclude that MRI is highly sensitive in the detection of olivary hypertrophy and of traumatic lesions of the dentato-rubro-olivary pathway.