Parkinson’s disease is a progressive neurodegenerative disorder affecting movement.
It is caused by the degeneration of dopamine-producing neurons in the substantia nigra, a part of the brain that controls movement.
Causes
Genetic Factors: Mutations in specific genes (e.g., LRRK2, PARK2).
Environmental Factors: Exposure to toxins like pesticides and heavy metals.
Age: Incidence increases with age.
Gender: More common in men than in women.
Symptoms
1. Motor Symptoms:
Tremor: Shaking, often starting in one hand.
Bradykinesia: Slowness of movement.
Rigidity: Stiffness in limbs and trunk.
Postural Instability: Impaired balance and coordination.
2. Non-Motor Symptoms:
Cognitive impairment and dementia.
Mood disorders: Depression and anxiety.
Sleep disturbances: Insomnia, REM sleep behavior disorder.
Autonomic dysfunction: Constipation, orthostatic hypotension, and urinary problems.
Diagnosis
Clinical Evaluation: Based on medical history and neurological examination.
Imaging Tests: MRI or DaTscan (dopamine transporter scan) to support the diagnosis.
Response to Medication: Improvement of symptoms with dopaminergic medications supports the diagnosis.
Pathophysiology of Parkinson’s Disease
Dopamine Deficiency: Degeneration of dopaminergic neurons in the substantia nigra of the brain.
Lewy Bodies: Abnormal aggregates of the protein alpha-synuclein inside neurons.
Basal Ganglia Dysfunction: Impaired regulation of motor activity leading to symptoms like bradykinesia, tremors, and rigidity.
Treatment
1. Medications:
Levodopa: The most effective treatment, often combined with carbidopa.
Dopamine Agonists: Mimic dopamine effects (e.g., pramipexole, ropinirole).
MAO-B Inhibitors: Prevent breakdown of brain dopamine (e.g., selegiline, rasagiline).
COMT Inhibitors: Prolong the effect of levodopa (e.g., entacapone).
2. Surgical Treatment:
Deep brain stimulation (DBS) for patients with advanced symptoms not controlled by medication.
3. Physical Therapy:
To improve mobility, balance, and flexibility.
4. Occupational Therapy:
To assist with daily living activities.
5. Speech Therapy:
To address speech and swallowing difficulties.