Idiopathic Parkinson's disease can be diagnosed based on the presence of certain clinical features with the exclusion of certain conditions.


Key clinical findings:

(1) asymmetric resting tremor

(2) asymmetric rigidity

(3) asymmetric bradykinesia

(4) definite clinical response to anti-Parkinson drug(s)

First 3 Findings

4th Finding


2 or 3


clinically definite

2 or 3


clinically probable



clinically possible



clinically absent



• I would think that the presence of a definite clinical response to anti-Parkinson therapy and only 1 of the first 3 clinical findings might be more than "clinically possible".

• The authors referenced Calne et al (1992) and Ward and Gibb (1990) as the sources.


Clinical findings that exclude Parkinson's disease:

(1) cerebellar signs

(2) corticospinal tract findings

(3) oculomotor abnormalities other than slight limitation of upward gaze

(4) moderate to severe gait disturbance early

(5) moderate to severe dementia early

(6) severe dysautonomia (autonomic dysfunction)


Conditions that indicate an alternative diagnosis to idiopathic Parkinson's disease:

(1) exposure to drugs causing Parkinson disease-like reaction (neuroleptics, antiemetic drugs such as prochlorperazine or droperidol, tetrabenazine, reserpine, flunarizine, cinnarizine)

(2) history of encephalitis

(3) history of recurrent head injury

(4) family history of Parkinson's disease in 2 or more family members

(5) severe subcortical white matter disease

(6) hydrocephalus

(7) structural lesion that could account for Parkinson's disease


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