Cerebellar dentate nucleus in progressive supranuclear palsy

Some patients with progressive supranuclear palsy (PSP) present with cerebellar dysfunction. Severe degeneration of the cerebellar dentate nucleus (CDN) was evident in these patients. We evaluated signal intensity on MRI in the CDN of PSP patients with or without cerebellar ataxia. We reviewed the clinical histories and brain MRI studies of 28 patients with clinically probable PSP. Three disease control groups were studied: a group of 28 sex- and age-matched patients with Parkinson’s disease (PD), a group of 15 patients with multiple system atrophy with predominant parkinsonian features (MSA-P), and 15 control subjects. Turbo spin-echo sequences for T2-weighted images were used using a 1.5 T magnetic resonance imager. Eight patients with PSP (28%) and one patient with MSA-P (6%) had heterogeneous regions in the CDN. This finding was not evident in the patients with PD or controls. Three out of four PSP patients with cerebellar ataxia had heterogeneous regions in the CDN and other one patient with cerebellar ataxia as the initial and principal symptoms had no heterogeneous regions in the CDN. Heterogeneous regions in the CDN on MRI do not always reflect cerebellar ataxia in PSP patients, and this finding might be an additional marker to support a probable diagnosis of PSP.