Orofacial Drinking Tremor: A Case Series and Literature Review

BACKGROUND: Task-specific orofacial tremor is a rare condition in which rhythmic oscillations of orofacial muscles occur during specific actions. Drinking tremor represents a recurrent pattern in isolated reports, although its phenomenology and underlying mechanisms remain incompletely defined. CASES: We report three cases of orofacial drinking tremor, each showing a different pattern. Differences involved the distribution of orofacial muscle activity and the presence of additional signs, including tremor in other body regions or subtle dystonic postures. Variability in task dependence, posture sensitivity, and sensory modulation contributed to the heterogeneity of these presentations. LITERATURE REVIEW: Published reports describe a spectrum of orofacial drinking tremors, ranging from strictly task-specific patterns to mixed task- and position-dependent presentations. Some patients exhibit subtle dystonic features, whereas others show no clear additional neurological signs. Electrophysiology typically demonstrates regular 5-8 Hz rhythmic discharges in the orofacial muscles. Systemic pharmacological therapies offer limited benefit, whereas botulinum toxin remains the most effective option. CONCLUSIONS: Current evidence suggests that orofacial drinking tremor does not represent a single clinical entity. An approach integrating detailed phenomenological characterization with plausible pathophysiological mechanisms may improve diagnostic interpretation and guide individualized management strategies.