Action palatal tremor in a patient with primary intestinal lymphoma

We report the case of a 59-year-old man with primary intestinal T-cell non-Hodgkin's lymphoma who developed abnormal facial twitching synchronous with small palatal movements induced by attempts at speaking or swallowing. At rest, the electromyogram (EMG) showed no spontaneous muscular activity. Phonation triggered trains of synchronous, rhythmic EMG bursts at a frequency of 3-4 Hz lasting 10-20 s, with an average burst of 150 ms, which simultaneously involved palatal, facial, and neck muscles bilaterally with left-sided predominance. An enhanced blink reflex recovery curve was observed after stimulation of either side. Backaveraging electroencephalographic study revealed no activity that was time locked with the jerks. Axial T2-weighted magnetic resonance imaging showed an increased signal intensity and bilateral enlargement of the inferior olives. No antineuronal-specific antibodies were found in the blood or in the cerebrospinal fluid. All of these clinical findings were consistent with a symptomatic palatal tremor (PT). Because it was triggered by activation of cranial muscles, we termed this movement disorder action PT. To our knowledge, this is the first report of symptomatic PT displaying these features.