From the Guidelines
Parkinson's disease is characterized by several common exam findings, primarily motor symptoms, including resting tremor, rigidity, bradykinesia, and postural instability, as well as non-motor findings such as cognitive impairment and autonomic dysfunction, as noted in the most recent study 1. The most notable motor symptoms include:
- Resting tremor, which typically affects the hands in a "pill-rolling" motion and diminishes with intentional movement
- Rigidity, felt as increased resistance during passive movement of limbs (often with a "cogwheel" quality)
- Bradykinesia, manifesting as slowness in initiating and executing movements
- Postural instability, which develops in later stages and causes balance problems Additional findings include:
- A shuffling gait with reduced arm swing
- Stooped posture
- Masked facial expression (hypomimia)
- Micrographia (small handwriting)
- Soft, monotone speech Non-motor findings may include:
- Cognitive impairment
- Depression
- Sleep disturbances
- Autonomic dysfunction such as orthostatic hypotension or constipation These symptoms result from progressive loss of dopaminergic neurons in the substantia nigra, leading to dopamine deficiency in the basal ganglia, as discussed in 1. The diagnosis is primarily clinical, based on the presence of these characteristic findings, with asymmetric onset being a key feature that helps distinguish Parkinson's disease from other parkinsonian syndromes, as noted in 1. In evaluating motor features, the validated UPDRS scales can be used to measure parkinsonism, and incorporating a survey for falls is also recommended, as suggested in 1.
From the Research
Common Exam Findings in Parkinson's Disease
The most common exam findings in Parkinson's disease include:
- Bradykinesia (slowness of movement) 2, 3, 4
- Rigidity (stiffness of the muscles) 2, 3, 4
- Resting tremor (shaking of the limbs at rest) 2, 3, 4
- Postural instability (imbalance or loss of balance) 2, 3, 4
Early Symptoms of Parkinson's Disease
Early symptoms of Parkinson's disease that may precede the onset of motor symptoms include:
- Hyposmia (loss of smell) 2
- REM sleep behavioral disorder (acting out dreams during sleep) 2
- Constipation 2
- Depression 2
Diagnostic Criteria
The diagnosis of Parkinson's disease is based on the UK Brain Bank Criteria, which requires the presence of bradykinesia and at least one additional symptom, such as rigidity, resting tremor, or postural instability 2. Imaging studies, such as cranial CT or MRI, may be helpful in distinguishing idiopathic Parkinson's disease from atypical or secondary Parkinson's disease 2.
Differential Diagnosis
It is essential to consider other causes of parkinsonism, including atypical Parkinsonian disorders, such as multiple system atrophy, dementia with Lewy bodies, progressive supranuclear palsy, and corticobasal syndrome, as well as secondary causes of parkinsonism 4.
Treatment-Related Findings
Treatment with dopaminergic medications, such as levodopa or pramipexole, can improve motor symptoms but may also be associated with adverse effects, such as dyskinesias, somnolence, and peripheral edema 3, 5, 6.