Response to dopaminergic therapy: One of the useful methods in diagnosing PD is patient response to dopaminergic therapy. Levodopa and apomorphine challenge tests in proven to be useful in distinguishing PD from other parkinsonian syndromes.
Autonomic testing: Autonomic testing including cardiac sympathetic denervation, urodynamic testing, anal or urethral EMG, sympathetic skin responses, quantitative sudomotor axon reflex test, tilt table test and heart rate variability during forced respirations are also useful in diagnosing PD.
Olfactory testing: Olfactory testing is a useful test since olfactory dysfunction in common in PD but not in other parkinsonian syndromes and essential tremor.
Parkinson's disease other diagnostic studies
Alzheimer's disease other diagnostic studies
Parkinson's disease differential diagnosis
Parkinson's disease other imaging findings
Dementia other diagnostic studies
Parkinson's disease MRI
Alzheimer's disease electrocardiogram
Parkinson's disease risk factors