A 43-year-old man with neurosarcoidosis developed twitching of the mouth, tongue, and throat. Oral movements were not voluntarily suppressible and even occurred while asleep. Oral examination and MRI brain images are shown in the Video and Figure 1, respectively. Neurological examination was otherwise unremarkable. Six years before, the patient had presented to an outside hospital with generalized seizures and leptomeningitis. He was treated with antiepileptics, but no immunosuppressants were started despite biopsy confirmation of sarcoidosis.
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What Is the Most Likely Cause of Palatal Movements?
Symptomatic palatal tremor (SPT)
Essential palatal tremor (EPT)
Palatal motor-phonic tic
Palatal tremor (PT) or palatal myoclonus is a movement disorder characterized by rhythmic palatal contractions with occasional synchronous spread to the tongue, face, extraocular muscles, or larynx. PT can be “symptomatic” when it is secondary to pathology involving the brainstem or cerebellum, or “essential” when there is no attributable structural cause. Clinically, palatal movement in EPT consists of tensor veli palatini contractions, whereas the levator veli palatini contracts in SPT. Pathophysiology of SPT is thought to occur secondary to lesions in the Guillain-Mollaret triangle, which disrupts the dentato-rubro-olivary pathway. This leads to denervation supersensitivity of the inferior olive, causing characteristic hypertrophic olivary degeneration (HOD). Our patient was diagnosed with SPT, given the lesion affecting the dentate nucleus and interconnecting fibers to the olive, and its immediate resolution after treatment with corticosteroids and infliximab, likely resulting from improvement of inflammation from recurrence of neurosarcoidosis. In this case, HOD was absent. HOD appears to occur only with disruption of the dentatorubral or rubro-olivary tracks (which causes olivary deafferentation), and not the olivodentate fibers.
(1) Research Project: A. Conception, B. Organization, C. Execution; (2) Statistical Analysis: A. Design, B. Execution, C. Review and Critique; (3) Manuscript: A. Writing of the First Draft, B. Review and Critique.
S.J.: 1A, 1B, 1C, 3A, 3B
N.S.: 1A, 1B, 1C, 3A, 3B
J.T.: 1A, 1B, 1C, 3A, 3B
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