Palatal Tremor Due to Medullary Infarction

OBJECTIVES

To discuss the disorder of palatal tremor (formerly, palatal myoclonus).
To distinguish the essential from symptomatic forms of palatal tremor.
To briefly review the main features of the medial medullary syndrome.

CASE SUMMARY

Our patient had multiple supratentorial and infratentorial ischemic strokes. He was confined to a wheelchair due to severe gait unsteadiness. Examination showed mild head titubation, dysarthria, asymmetric horizontal-torsional jerk nystagmus, and continuous rhythmic contractions affecting the palate. He did not complain of objective tinnitus or an ear click. Magnetic resonance imaging (MRI) showed multiple supratentorial and infratentorial infarcts including a right medial medullary infarction. There was hyperintensity in the inferior
olivary nuclei, suggesting early development of pseudohypertrophy. Magnetic resonance angiography (MRA) showed no evidence of vertebrobasilar dolichoectasia.

TABLE 61.1 DISTINGUISHING FEATURES BETWEEN ESSENTIAL AND SYMPTOMATIC PALATAL TREMORS

	Essential Palatal Tremor	Symptomatic Palatal Tremor
Ear clicks	Present	Absent
Palatal involvement	Proximal soft palate	Distal soft palate
Nerve affected	Tensor veli palatini	Levator veli palatini
Extrapalatal movements	No extrapalatal movements	Pharynx, larynx, diaphragmatic, and ocular muscles
Ataxia	Absent	Often present
Brain MRI	Normal	Lesions anywhere in the Guillain-Mollaret triangle and resulting olivary hypertrophy