RESUMO
BACKGROUND: The leaves of "Khat" (Catha edulis), an indigenous shrub of Yemen and Arabian Peninsula are habitually chewed by the inhabitants for psychostimulant properties. OBJECTIVE: To describe a unique task specific Oro-mandibular dystonia (OMD) in Yemenese men, with a temporal association with chewing "Khat". METHODS: Multicentric, retrospective analysis (2009-2020) of patients with OMD associated with "Khat" chewing, evaluating clinical features and response to Onabotulinum toxin A. RESULTS: 35 Yemenese men with a negative family history, normal neuroimaging mean age of 44.31(±3.21) years and prolonged (20.31 ± 3.27 years) history of chewing Khat, around 5.16(±0.80) hours/day presented with OMD-20 jaw opening, 13 jaw closing and 2 mixed affecting chewing (n = 6), speech (n = 3), or both (n = 26). Additional lingual dystonia was seen in five. CONCLUSIONS: Chewing of khat is a repetitive task involving the jaw musculature and may be one of the causative factors of this task specific OMD. Recognition can prevent disability in these regions.
