Table 1 Clinical pointers and radiological features in parkinsonian syndromes by various imaging techniques [55]
From: Imaging modalities in differential diagnosis of Parkinson’s disease: opportunities and challenges
Syndrome | Clinical pointers | Radiological features |
|---|---|---|
Multiple system atrophy | ➢ May be indistinguishable from PD in early stages ➢ Jerky finger tremor related to mini-polymyoclonus ➢ “Strangulated” dysarthria ➢ Axial/craniocervical levodopa-induced dyskinesia | ➢ Cerebellar atrophy ➢ T2 high signal in degenerating pontocerebellar fibers leading to “hot-cross bun” sign (Fig. 2) ➢ T2 low signal in putamen with rim of increased signal on lateral edge |
Progressive supranuclear palsy | ➢ Erect posture with good step size at presentation ➢ Frequent falls and injuries early in the disease course ➢ Slowed saccadic eye movements may be subtle in early disease | ➢ Midbrain atrophy (with “hummingbird” sign on sagittal brainstem images, Fig. 3) ➢ 3rd ventricle dilatation |
Corticobasal degeneration | ➢ Markedly asymmetrical rigid/akinetic/apraxic limb with relatively normal contralateral limb in early disease | ➢ Asymmetric frontoparietal atrophy on MRI |
Essential tremor | ➢ High-frequency tremor ➢ The tremor is postural and kinetic, and improves with rest ➢ Absent PD non-motor features ➢ Head and neck tremor ➢ May have a long and benign course | ➢ DaTscan is normal |
Dystonic tremor | ➢ Thumb extension tremor ➢ Jerky tremor with flurries of tremor ➢ May be task-specific or task-exacerbated | ➢ DaTscan is normal |
Vascular parkinsonism | ➢ Presents as gait disorder ➢ “Lower body” parkinsonism with mild or absent upper body parkinsonism | ➢ Neuroimaging shows variable degrees of small-vessel ischemic changes |