What is Parkinson’s Disease?
Parkinson’s disease (PD) is a progressive neurodegenerative disorder primarily affecting movement control. It is characterized by the loss of dopamine-producing neurons in the substantia nigra, a region of the midbrain. The incidence increases with age, typically manifesting in individuals over the age of 60, although younger-onset PD can occur. The prevalence is higher in men than in women.
Pathophysiology of Parkinson’s Disease
The primary pathological feature of Parkinson’s disease is the degeneration of dopaminergic neurons in the substantia nigra pars compacta. This leads to a significant reduction in dopamine levels in the striatum, a critical component of the basal ganglia circuitry involved in regulating movement. The exact cause of this neuronal loss remains unclear, but it is thought to involve a combination of genetic and environmental factors.
In addition to dopamine depletion, the presence of Lewy bodies—abnormal aggregates of the protein alpha-synuclein—within neurons is a key pathological hallmark of PD. These Lewy bodies disrupt normal cellular function and contribute to neuronal death.
Signs and Symptoms of Parkinson’s Disease
Parkinson’s disease presents with a range of motor and non-motor symptoms:
Motor Symptoms:
- Tremor: Often the first noticeable symptom, typically a resting tremor that begins unilaterally.
- Rigidity: Increased muscle tone leading to stiffness and resistance to movement.
- Bradykinesia: Slowness in initiating and executing movements, resulting in reduced spontaneous movements.
- Postural Instability: Impaired balance and coordination, leading to frequent falls.
Non-Motor Symptoms:
- Autonomic Dysfunction: Includes constipation, orthostatic hypotension, and urinary incontinence.
- Sleep Disturbances: Such as REM sleep behavior disorder and excessive daytime sleepiness.
- Cognitive Impairment: Ranging from mild cognitive decline to Parkinson’s disease dementia.
Mood Disorders: Depression and anxiety are common among PD patients.
Diagnosis of Parkinson’s Disease
The diagnosis of Parkinson’s disease involves assessment of your medical history and neurological examination by your healthcare provider. Key diagnostic criteria include the presence of bradykinesia along with at least one other motor symptom (tremor or rigidity). Supporting features such as a positive response to dopaminergic therapy can further confirm the diagnosis.
Neuroimaging techniques like MRI and DaTscan (dopamine transporter scan) may be used to exclude other conditions and support the diagnosis. Genetic testing is reserved for cases with a strong family history or early-onset PD.
Management of Parkinson’s Disease
There is currently no cure for Parkinson’s disease, but various treatment options can help manage symptoms and improve the quality of life. These include:
Pharmacological Treatments:
- Dopamine Agonists: Mimic dopamine effects in the brain and can be used alone or with levodopa.
- MAO-B Inhibitors: Prevent the breakdown of dopamine, prolonging its action.
- COMT Inhibitors: Extend the effect of levodopa by inhibiting its breakdown.
Non-Pharmacological Treatments:
- Physical Therapy: Helps maintain mobility, flexibility, and balance.
- Occupational Therapy: Assists with daily activities and adaptive techniques.
- Speech Therapy: Addresses speech and swallowing difficulties.
- Exercise: Regular physical activity can improve motor function and overall well-being.
Surgical Treatments:
- Deep Brain Stimulation (DBS): Involves implanting electrodes in specific brain areas to modulate abnormal signals. It is typically considered for patients with advanced PD who do not respond well to medications.
Other Geriatrics Services
