This case series adds to the limited literature about progressive ataxia with palatal tremor (PAPT) by describing clinical findings and the approach to diagnostic testing in six cases of PAPT.

PAPT is a rare clinical syndrome characterized by symptomatic palatal tremor and progressive cerebellar ataxia. Imaging typically shows bilateral hypertrophic olivary degeneration (HOD). Though published work based on autopsy cases suggests a novel tauopathy as a possible etiology of sporadic PAPT, the syndrome can arise from a variety of vascular, traumatic, autoimmune, or genetic causes. Despite its many possible underlying etiologies, the published literature provides little guidance on a systematic approach to diagnostic testing.

We retrospectively reviewed the charts of patients evaluated at the Ataxia Center at Massachusetts General Hospital between 2010-2022 with clinical findings consistent with PAPT. Data were collected about disease presentation, disease progression, imaging findings and diagnostic testing.

Six patients with PAPT were identified. Average age of symptom onset was 61, range 54-65. Presenting symptoms were gait imbalance in three, and dysarthria, dysphagia, and throat tremor, respectively, in the rest. All developed palatal tremor (patient 6 with ear clicks), appendicular ataxia, and ataxic eye movements throughout their course. All patients had evidence of bilateral HOD on brain MRI. PAPT was attributed to cavernous malformations in patient 2 and multicompartmental hemorrhage in patient 4. The causes in the remainder are unknown. Diagnostic testing varied. Four patients (inclusive of patients 2 and 4) underwent whole exome sequencing, two underwent cerebrospinal fluid analysis (both non-inflammatory), four had celiac testing, and one was tested broadly for neuronal autoantibodies.

PAPT is a clinical syndrome with a variety of etiologies. As in our study, literature suggests that diagnostic evaluation often varies. Systematic evaluation is important to find underlying causes and aid future research to better identify and study patients with idiopathic PAPT.