Clinical and Imaging Profile of Patients with Palatal Tremor.

Abstract

Palatal tremor (PT) is an uncommon movement disorder that may be classified into symptomatic (SPT) or essential (EPT). The etiology of SPT is varied, with involvement of the Guillain-Mollaret triangle (GMT) and inferior olivary hypertrophy. EPT is associated with ear clicks and normal imaging and may have a functional basis. This study aims to explore the clinical and radiological features of a large cohort of patients with PT. This is a retrospective chart review of patients with PT who were evaluated by the movement disorders subspeciality of the neurology department. Demographic, clinical, and imaging details of patients with PT were documented. A total of 22 patients with PT comprising 17 with SPT and 5 with EPT were included in this study. No patient was aware of the PT. Ear clicks were reported in 2 patients with SPT and in 3 patients with EPT. The most common etiology for SPT was vascular, followed by degenerative conditions. Patients with SPT had associated features such as tremor (70.6%), ataxia (64.7%), dystonia (52.9%), myoclonus (17.6%), and eye movement abnormalities (75%). Lesions involving the GMT were found in 82% of patients with SPT. Apart from PT, patients with EPT had no other motor symptoms, and imaging was normal. Of the patients with EPT, 2 had additional functional movement disorders. PT has significant etiological heterogeneity and can be easily missed because of the lack of awareness by patients. Involvement of the inferior olivary nucleus may not be necessarily observed. A functional etiology should be considered in cases of EPT.