Features Suggesting an Atypical or Secondary Cause of Parkinsonism
| Symptoms/Signs | Alternative Diagnosis to Consider |
|---|---|
| History | |
| Early speech and gait impairment (Lack of tremor, lack of motor asymmetry) | Atypical parkinsonism |
| Exposure to neuroleptics | Drug-induced parkinsonism |
| Onset prior to age 40 | Genetic form of PD |
| Liver disease | Wilson's disease, non-Wilsonian hepatolenticular degeneration |
| Early hallucinations and dementia with later development of PD features | Dementia with Lewy bodies |
| Diplopia, impaired down gaze | PSP |
| Poor or no response to an adequate trial of levodopa | Atypical or secondary parkinsonism |
| Physical Examination | |
| Dementia as first or early feature | Dementia with Lewy bodies |
| Prominent orthostatic hypotension | MSA-p |
| Prominent cerebellar signs | MSA-c |
| Slow saccades with impaired down gaze | PSP |
| High-frequency (6-10 Hz) symmetric postural tremor with a prominent kinetic component | Essential tremor |
Abbreviations: MSA-c, multiple-system atrophy-cerebellar type; MSA-p, multiple-system atrophy-Parkinson's type; PD, Parkinson's disease; PSP, progressive supranuclear palsy.