J Korean Radiol Soc.  1994 Apr;30(4):633-637.

MR Findings in Palatal IVlyoclonus

• Lee JH
• Kim SJ
• Suh DC
• Park MS

Abstract

PURPOSE
Palatal myoclonus(PM) is an involuntary cyclic movement of the soft palate and is known to be caused by the hypertrophic degeneration of the inferior oilvary nucleus of the medulla, secondary to the dentato-rubro-tegmental tract lesions. Our purpose is to describe the brain magnetic resonance(MR) imaging findings in palatal myoclonus.
MATERIALS AND METHODS
We retrospectively analyzed the locations and causes of primary lesions in the dentato-rubro-tegmental tract and correlated them with changes in MR signal intensity and size of the inferior olive on T2-weighted MR images in 10 patients with palatal myoclonus.
RESULTS
All cases showed hyperintensity in one or both inferior olive and six cases showed accompaning enlargement. The locations of the primary lesions were dorsal aspect of pons(central tegmental tract) in eight patients and the dentate nucleus in one, and no lesion was found in the dentato-rubro-tegmental tract in one. Among eight patients who had lesions in the ports, the ipsilateral inferior olivary nuclei showed changes in five and bilateral olive were involved in three. In the case with a lesion in the dentate nucleus, the contralateral inferior olivary nucleus was involved. The causes of primary lesions were hemorrhage in eight cases and traumatic brain stem injury in one.
CONCLUSION
MR specifically showed enlargement and hyperintensity of the inferior olivary nucleus on T2-weighted images and matching lesions in the ports or the dentate nucleus in patients with palatal myoclonus.

MeSH Terms

Brain
Brain Stem
Cerebellar Nuclei
Hemorrhage
Humans
Myoclonus
Olea
Olivary Nucleus
Palate, Soft
Retrospective Studies