Background
Degenerative neurological disorder characterized by progressive bradykinesia, rest tremor, rigidity, and postural instability
Pathophysiology
Destruction of substantia nigra
Clinical Manifestations
Rest tremor at 4-6 Hz, inhibited by movement and sleep, worsened by stress
Rigidity, with increased tone and cog-wheeling
No spasticity
Often worse with repeated flexion
Bradykinesia
Short, shuffling gait with festination
Loss of arm swing
Micrographia
Postural hypotension
Glabellar tap reflex, normally stops after 5-10 taps
JAMA Rational Clinical Exam
Change in speech (LR+ 2.6, LR- 0.73)
...
Differential Diagnosis
Management
Non-motor Symptoms
Psychosis
Usually worsened by antiparkinson medications
Evaluate and treat any triggers
Consider decreasing any anticholinergic drugs, followed by amantadine , dopamine agonists, monoamine oxidase type B inhibitors, and COMT inhibitors, and finally levodopa (as a last resort)
For refractory symptoms, consider quetiapine , pimavanserin , and clozapine
Other antipsychotics have higher risk of exacerbating Parkinson disease