SPOTTERS MEDICINE
PARKINSON’S DISEASE
🔹 Definition:
Parkinson’s
disease (PD) is a chronic, progressive neurodegenerative disorder
characterized by motor symptoms due to dopamine deficiency in the
substantia nigra of the basal ganglia.
🔹 Etiology:
- Idiopathic (most common – primary PD)
- Genetic mutations (e.g., SNCA,
PARKIN genes)
- Environmental toxins (e.g.,
pesticides, manganese)
- Drug-induced parkinsonism (e.g.,
antipsychotics, metoclopramide)
- Post-encephalitic or
trauma-related
🔹 Pathophysiology:
- Loss of dopaminergic neurons in the substantia nigra pars
compacta
- Decreased dopamine in the nigrostriatal
pathway
- Presence of Lewy bodies
(α-synuclein aggregates) in neurons
🔹 Classic Motor Triad:
1.
Resting Tremor
– “pill-rolling” tremor, usually in hands
2.
Bradykinesia –
slowness of movement, difficulty initiating motion
3.
Rigidity –
cogwheel or lead-pipe type
4.
Postural Instability – loss of balance, frequent falls
Other signs:
masked facies, shuffling gait, stooped posture, micrographia
🔹 Non-Motor Features:
- Depression, anxiety
- Constipation
- Sleep disturbances (REM behavior
disorder)
- Cognitive decline / dementia
(late stage)
- Olfactory loss (early sign)
- Autonomic dysfunction
(orthostatic hypotension, urinary problems)
🔹 Diagnosis:
- Clinical diagnosis based on signs and symptoms
- No definitive test; MRI/CT usually normal
- Dopamine transporter (DaT) scan
(optional)
- Levodopa response test – strong supportive evidence
🔹 Differential Diagnosis:
- Parkinson-plus syndromes (MSA,
PSP, CBD)
- Essential tremor
- Normal pressure hydrocephalus
- Drug-induced parkinsonism
🔹 Treatment:
Pharmacologic:
- Levodopa + Carbidopa – most effective drug
- Dopamine agonists – pramipexole, ropinirole
- MAO-B inhibitors – selegiline, rasagiline
- COMT inhibitors – entacapone
- Anticholinergics (for tremor in
young patients)
Non-Pharmacologic:
- Physiotherapy, speech therapy
- Diet modifications
- Deep Brain Stimulation (DBS) –
for advanced cases
🔹 Complications:
- Motor fluctuations (“on-off”
phenomenon)
- Dyskinesias (involuntary
movements)
- Dementia and psychosis
- Autonomic failure
🔹 Prognosis:
- Slowly progressive
- Medications improve quality of
life
- Non-motor symptoms and
complications may impair independence in late stages
DR.C.GANESAN
M.D.,
PROFESSOR OF
MEDICINE
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