Overview
Parkinson’s disease is a long-term condition that usually develops gradually, often starting after age 60. It results from the loss of dopamine-producing brain cells, affecting the body's ability to coordinate smooth, purposeful movement.
Mechanism & Pathology
- Dopamine Depletion: PD occurs when neurons in the substantia nigra die or become impaired. Symptoms typically appear once 60-80% of these dopamine-producing cells are lost.
- Lewy Bodies: Brains affected by PD contain clumps of alpha-synuclein protein, known as Lewy bodies, which are linked to neuronal death.
- Causes: While often idiopathic, causes include genetic factors (10-15%) and environmental triggers like pesticides or head injuries.
Symptoms & Functions Affected
Motor Symptoms (Movement)
- Tremors: Rhythmic shaking, often a "pill-rolling" hand tremor at rest.
- Bradykinesia: Extreme slowness, making tasks like walking or buttoning clothes difficult.
- Rigidity: Muscle stiffness and reduced range of motion.
- Postural Instability: Impaired balance leading to increased fall risks.
Non-Motor Symptoms
- Cognitive/Mood: Memory trouble, depression, and anxiety.
- Autonomic: Loss of smell, sleep disturbances, and orthostatic hypotension (dizziness when standing).
Consequences and Complications
As the disease progresses, patients may face significant challenges:
- Loss of Independence: Increasing reliance on others for daily activities.
- Dysphagia: Difficulty swallowing or chewing, leading to drooling.
- Aspiration Pneumonia: A serious risk caused by the inability to clear food or saliva from airways.
- Mental Health: Decline in quality of life due to cognitive impairment and emotional distress.