An Uncommon Cause of Dysarthria in an Elderly Gentleman

摘要

A 76-year-old gentleman presented with mild slurred speech. Five months earlier, he had vomiting andunsteady gait. Magnetic resonance imaging (MRI) head then showed hematoma of the dentate nucleus ofthe right cerebellum ( Fig. 1 , black arrow). Now the clinical examination revealed mild dysarthria,asymmetric palatal tremor predominantly involving the right palatal arch, and pharyngeal myoclonus (). The current MRI head showed hypertrophy of the contralateral inferior olivary nucleus of themedulla ( Fig. 2 , black arrow). He had symptomatic palatal tremor because of the contraction of thelevator veli palatine muscle. We postulate that the pharyngeal myoclonus was due to the common vagalnerve supply. Hypertrophic olivary degeneration occurred secondary to a lesion in the Guillain–Mollarettriangle. The hallmark clinical feature of a lesion of the Guillain–Mollaret triangle is the palatal tremor.The unilateral palatal tremor happened due to the hypertrophic degeneration of the contralateral olivarynucleus. However, though bilateral symmetrical palatal tremor is common but an asymmetric bilateraltremor described in our patient was rarely reported in literature.