Parkinson’s Disease

Parkinson’s Disease

What is Parkinson’s disease?

Parkinson’s disease is a progressive neurological disorder caused by loss of dopamine-producing neurons in the substantia nigra, a region of the brain that controls movement. As dopamine levels fall, movement and coordination become impaired.

What causes Parkinson’s disease?

The exact cause is unknown but involves a mix of factors:

  • Genetic mutations in a minority of cases
  • Environmental exposures such as pesticides or heavy metals
  • Advancing age—the greatest risk factor
  • Male gender (men are affected more often than women)
  • History of severe head injury

What are the symptoms?

Motor symptoms

  • Tremor at rest, often starting in a hand or fingers
  • Bradykinesia: slowness of movement and difficulty initiating tasks
  • Rigidity: muscle stiffness that limits range of motion
  • Postural instability: balance and coordination problems

Non-motor symptoms

  • Cognitive changes, including memory and attention issues
  • Mood disorders such as depression and anxiety
  • Sleep disturbances and daytime sleepiness
  • Autonomic dysfunction: constipation, bladder problems, orthostatic hypotension
  • Loss of smell, pain, and fatigue
  • Voice changes and weight loss in later stages

How is Parkinson’s disease diagnosed?

Diagnosis is clinical, based on history and exam:

  • Medical and family history
  • Neurological exam assessing tremor, rigidity, bradykinesia, and balance
  • Trial of dopaminergic medication—improvement supports the diagnosis
  • Imaging (MRI or CT) and lab tests to rule out other causes
  • Referral to a movement-disorder specialist for confirmation

How is Parkinson’s disease treated?

While there is no cure, treatments aim to manage symptoms:

Medications

  • Levodopa + carbidopa (e.g., Sinemet, Rytary)
  • Dopamine agonists (e.g., pramipexole, ropinirole)
  • MAO-B inhibitors (e.g., selegiline, rasagiline)
  • COMT inhibitors (e.g., entacapone)
  • Anticholinergics (for tremor in younger patients)

Surgical and procedural

  • Deep brain stimulation, targeting motor-control circuits
  • Focused ultrasound to ablate overactive regions

Therapies and lifestyle

  • Physical therapy for mobility and balance
  • Occupational therapy for daily living skills
  • Speech therapy for voice and swallowing
  • Regular exercise, healthy diet, and home safety modifications
  • Counseling or support groups for patients and caregivers

Sources

  • National Institute of Neurological Disorders and Stroke. Parkinson’s disease: Hope through research. Accessed Apr. 30, 2024.
  • Michael J. Fox Foundation. Parkinson’s 101. Accessed Apr. 30, 2024.
  • American Parkinson’s Disease Association. Parkinson’s Disease overview. Accessed Apr. 30, 2024.
  • Parkinson’s Foundation. What is Parkinson’s? Accessed Apr. 30, 2024.