Parkinson's disease is a progressive neurodegenerative disorder that is common, age-related and chronic.

It is caused by loss or degeneration of dopaminergic neurons in the substantia nigra of the midbrain.

Onset of symptoms and progression of the disease is gradual.

Motor signs and symptoms include resting tremor, rigidity, bradykinesia and postural instability.

Parkinson's disease dementia indicates loss of intellectual functions including memory, significant deterioration in the ability to carry out day-to-day activities and changes in social behavior are often noted.


  • Parkinson's Disease (PD) is a common, age-related, chronic, progressive disorder caused by loss or degeneration of dopaminergic neurons in the substantia nigra of the midbrain
  • Pathologic hallmark is loss of dopaminergic substantia nigra neurons with surviving neurons often containing a characteristic cytoplasmic inclusion body (Lewy body)
  • Increased prevalence & incidence rates are noted in the elderly
  • Men have higher incidence rate, with relative risk 1.5 times more than in women

Signs and Symptoms

  • Early symptoms are subtle and occur gradually

Motor signs and symptoms

  • Resting tremor
  • Rigidity
  • Bradykinesia
  • Postural instability

Nonmotor signs and symptoms

  • Autonomic (eg gastrointestinal dysfunction, urinary and sexual dysfunction, orthostatic hypotension, hyperhidrosis)
  • Sleep disorders (eg impaired sleep initiation and maintenance, rapid eye movement sleep behavior disorder and excessive daytime sleepiness)
  • Sensory (eg pain, hyposmia, visual dysfunction)
  • Neuropsychiatric (eg depression, anxiety and panic attacks, dementia, psychosis)
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