Below is a set of questions designed to assess signs, symptoms, and relevant clinical history, assigning points to responses that make PD more or less likely. The higher the score, the more likely the diagnosis is PD.
Parkinson’s Disease Differential Diagnosis Questionnaire
1. Age of Onset
A. Below 40 years (0 points)
B. 40-50 years (1 point)
C. 50-70 years (3 points)
D. Above 70 years (2 points)
2. Resting Tremor (unilateral or asymmetric at onset)
A. Yes (3 points)
B. No (0 points)
3. Bradykinesia (slowness of movement)
A. Present (3 points)
B. Absent (0 points)
4. Rigidity (muscle stiffness)
A. Present (2 points)
B. Absent (0 points)
5. Postural Instability (Unexplained frequent falls)
A. Early onset of postural instability (suggestive of conditions like Progressive Supranuclear Palsy or MSA) (0 points)
B. Late onset postural instability (3 points)
C. No postural instability (1 point)
6. Cognitive Decline (early in disease)
A. Present within the first year (suggests Lewy Body Dementia, Alzheimer’s, or Frontotemporal Dementia) (0 points)
B. Absent or develops later (3 points)
7. Eye Movement Abnormalities
A. Difficulty looking up or down (suggests Progressive Supranuclear Palsy) (0 points)
B. Normal eye movement (2 points)
8. Rapid Eye Movement (REM) Sleep Behavior Disorder (acting out dreams during sleep)
A. Present (suggestive of PD or Lewy Body Dementia) (2 points)
B. Absent (0 points)
9. Orthostatic Hypotension (drop in blood pressure on standing)
A. Present early (suggestive of MSA) (0 points)
B. Absent or late onset (2 points)
10. Response to Levodopa Treatment
A. Significant improvement (4 points)
B. Minimal or no response (suggests Atypical Parkinsonism) (0 points)
11. Onset of Symptoms
A. Symmetrical onset (suggests drug-induced parkinsonism or atypical causes like MSA, PSP) (0 points)
B. Asymmetrical onset (3 points)
12. History of Neuroleptic/Antipsychotic Use (possible drug-induced parkinsonism)
A. Yes (0 points)
B. No (2 points)
13. Family History of Parkinson’s Disease
A. Yes (2 points)
B. No (0 points)
14. Behavioral Changes (early personality changes, disinhibition)
A. Present (suggestive of Frontotemporal Dementia) (0 points)
B. Absent (2 points)
15. Gait Disturbance (apraxic gait or magnetic gait)
A. Present with wide-based, short steps (suggests Normal Pressure Hydrocephalus or cerebral tumors) (0 points)
B. Shuffling gait (2 points)
16. Presence of Autonomic Symptoms (urinary incontinence, severe constipation, erectile dysfunction)
A. Present early (suggestive of MSA) (0 points)
B. Absent or develops late (1 point)
17. Presence of Depressive Symptoms
A. Yes, but unrelated to motor symptoms (may indicate Depression mimicking PD) (0 points)
B. No (2 points)
18. History of Wilson’s Disease
A. Yes (0 points)
B. No (2 points)
19. Early Speech or Swallowing Problems
A. Yes (suggestive of Progressive Supranuclear Palsy, MSA) (0 points)
B. No (2 points)
20. MRI or Imaging Suggestive of Structural Lesion or Tumor
A. Yes (suggestive of cerebral tumor or other structural cause) (0 points)
B. No (2 points)
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Scoring System
0-10 Points: PD is unlikely. Consider differential diagnoses such as Atypical Parkinsonism (PSP, MSA), drug-induced parkinsonism, Wilson’s Disease, Normal Pressure Hydrocephalus, Lewy Body Dementia, Alzheimer’s, Frontotemporal Dementia, or depression.
11-20 Points: PD is possible but other conditions may still explain the symptoms. Further diagnostic work-up is necessary.
21-40 Points: PD is highly probable. Continue with appropriate management and treatment for Parkinson’s Disease.
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Interpretation Guidelines for Differential Diagnoses:
Multiple System Atrophy (MSA): Look for early autonomic dysfunction, symmetrical motor symptoms, lack of response to levodopa, and early postural instability.
Progressive Supranuclear Palsy (PSP): Look for early postural instability, vertical gaze palsy, and early speech or swallowing difficulties.
Lewy Body Dementia: Cognitive decline within the first year, REM sleep behavior disorder, and fluctuating cognition are key features.
Normal Pressure Hydrocephalus (NPH): Gait apraxia, urinary incontinence, and cognitive decline are prominent, with MRI showing ventricular enlargement.
Drug-Induced Parkinsonism: Check for a history of antipsychotic or dopamine-blocking drug use and symmetrical motor symptoms.
Wilson’s Disease: Early onset (<40 years), liver dysfunction, and psychiatric symptoms. Consider serum ceruloplasmin and copper studies.
Depression (pseudoparkinsonism): Evaluate for predominant depressive symptoms and mild motor slowing without other classic PD signs.
Cerebral Tumors: Imaging studies revealing structural abnormalities, along with new onset of focal neurological symptoms.
This questionnaire should be used as part of a comprehensive clinical assessment, including imaging, lab tests, and clinical judgment.
Verified by Dr. Petya Stefanova
