Parkinson’s disease
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Parkinson’s disease is a progressive nervous system disorder characterized by resting tremor, rigidity, bradykinesis (slowness of movement) and loss of postural reflexes.
The symptoms of Parkinson’s disease can vary from person to person. Symptoms usually start between 50 to 70 years. Parkinson’s signs and symptoms may include:
1. Tremor: It is most marked at rest and coarser than cerebellar tremor. It is typically a ‘pill rolling” of thumb over fingers.
2. Rigidity: increased resistance to passive stretch of muscles throughout range of movement (lead-pipe); tone may be broken-up by tremor (cogwheel rigidity).
3. Bradykinesis: Slowness of movement initiation with progressive reduction in speed and amplitude of repetitive actions; also monotonous speech.
4. Loss of postural reflexes: Short shuffling steps with flexed trunk as if forever a step behind one’s centre of gravity (festinant gait).
5. Dementia.
6. Expressionless face.
7. Decreased peristalsis, blink rate and fidgeting.
8. Micrographia.
Parkinson’s disease is idiopathic in an origin (having no specific known cause). Less common causes of Parkinson’s disease including genetic, toxins, head trauma, cerebral anoxia, and drug-induced Parkinson’s disease.
The symptom of Parkinson’s disease is due to degeneration of substantia nigra dopaminergic neurons; the pathological hallmark is Lewy bodies in this area. Degeneration may be related to mitochondrial DNA dysfunction.
Diagnosis of Parkinson’s disease is based on patient history and neurological examination.
There’s no cure for Parkinson’s disease, but medications can help control some of the symptoms of Parkinson’s disease, and in some case, surgery may be helpful.
Medication can help manage problems with walking, movement and tremor. Some medication that doctor may prescribe include:
- Dopaminergic drugs –eg.L.dopa: start at 50mg 2 times a day (after food, to avoid nausea/vomiting). Increased dose to 100mg 3 times a day, then slowly increased to 800 mg daily (in divided dose). Give peripheral dopa-decarvoxylase inhibitor.Over years, drugs may get less effective with switching between times of exaggerated involuntary movement and of immobility (on-off) .once it occurs, it may be irreversible : there is evidence that early use of dopaminergic agonists (eg ropinirole ) may reduce this, and allow lower doses of L-dopa.
- MAO B inhibitors. Eg. Selegiline (Eldepryl) and rasagiline (Azilect).
- Anticholinergics / antimuscarinics help motor symptoms (tremor) eg. Benztropine (Cogentin) and trihexyphenidyl.
- Catechol O-methyltransferase (COMT) inhibitors. Eg Tolcapone (Tasmar).
Filed Under: Medicine
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