Tremor-Dominant Cervical Dystonia: a Cerebellar Syndrome

The objective of this study is to examine the role of the cerebellum in the tremor-dominant subtype of cervical dystonia (CD). CD patients with head tremor at onset (Tr-CD) were age- and sex-matched to CD patients without head tremor at onset (nTr-CD). All patients were evaluated for cerebellar disability using the Scale for the Assessment and Rating of Ataxia (SARA), gait variability using ProtoKinetics Zeno Walkway, and cerebellar volume analysis extracted from brain magnetic resonance imaging (MRI) using a semiquantitative scale. Compared to nTr-CD (n = 10, median age, 70.5 years), Tr-CD patients (n = 10, 71.5 years) exhibited higher median SARA scores (9 vs 7.5, p = 0.03) and greater median gait variability index (131 vs 124, p = 0.03). SARA scores inversely correlated with cerebellar volume in all patients (- 0.4, p = 0.04). Tr-CD patients exhibited greater superior vermian atrophy than nTr-CD patients (p = 0.01). Head tremor at onset heralds a CD subtype with prominent axial cerebellar disability and atrophy of the superior vermis of the cerebellum.