Symptomatic palatal tremor following multiple listerial brainstem abscesses.

Palatal tremor is a rare movement disorder characterised by continuous involuntary rhythmic movements of the soft palate, sometimes including other muscles innervated by cranial or spinal nerves. The condition may be essential or symptomatic [1]. We describe a case of symptomatic palatal tremor associated with hypertrophic olivary degeneration (HOD) following multiple brainstem abscesses caused by Listeria monocytogenes. To our best knowledge, this association has not previously been reported in the literature. A 45 year old manwith history of hepatitis C was admitted with a five day history of headache, vomiting, diplopia, left sided facial numbness and left sided limb weakness. Clinical examination demonstrated bilateral abducens nerve palsies, left peripheral facial nerve palsy, sensory impairment in the ophthalmic distribution of left trigeminal nerve and left sided pyramidal weakness. Contrast enhanced T1 weighted magnetic resonance imaging (MRI) of the brain demonstrated multiple ring enhancing lesions in the brainstem suggestive of multiple abscesses. These lesions were hyperintense on diffusion weighted imaging (DWI) with corresponding hypointensity on the apparent diffusion coefficient (ADC) sequences, consistent with restricted diffusion seen in brain abscess (Fig. 1AeD). Blood cultures were positive for L. monocytogenes, presumably of dietary origin. HIV serology was negative and echocardiography was normal. Lumbar puncture was not performed. He was treated with ampicillin and gentamycin for three months. He made a remarkable improvement but had residual oscillopsia and left peripheral facial nerve palsy. He was discharged home and had no difficulties in performing activities of daily living. At eight months follow up, he reported constant clicking in his ears. Examination demonstrated palatal tremor of approximately 3 Hz (video 1) which persisted in sleep. Repeat brain MRI demonstrated a T2 hyperintense and hypertrophied lesion in the right inferior olivary nucleus consistent with HOD (Fig. 1E&F). The previously seen pontine changes had resolved. Supplementary video related to this article can be found at http://dx.doi.org/10.1016/j.parkreldis.2013.11.003.