Parkinson's
Disease
Parkinson's disease (PD) is a progressive neurodegenerative movement disorder that impairs movements, speech and other functions. Classic form of PD which generally becomes apparent after 60 years of age affects about 1% of the population. Another form called YOPD, Young-adult Onset Parkinsonism Disease in 3-50 age goup, is estimated to constitute 5-10% of PD. The Parsi community concentrated in Mumbai is observed to have the highest prevalence of PD. PD is slow progressive and may not become incapacitating for many years.
PD is characterized by
motor symptoms and non-motor symptoms. Motor symptoms include tremor, muscular
rigidity,
bradykinesia (slowness
in movements), gait and posture disturbances. Non-motor symptoms include
depression, anxiety, cognitive impairment and psychosis. Dementia is common and
affects approximately 40% of PD patients during the course of the disease. Dementia is a
non-specific illness syndrome in which affected areas include cognition, memory,
attention, language, and problem solving.
Degenerative changes occur
deep within the midbrain causing loss of nerve cells that secrete
neurotransmitter dopamine. Dopamine is a chemical that sends a signal in the
brain.
The physician needs to
observe the affected person for a while to conclude that the symptoms are
consistently present before categorizing them symptoms normal aging.
To follow the
longitudinal course in patients, one of the rating scales called UPDRS, the
Unified Parkinson's Disease Rating Scale is used by the therapists.
Only symptomatic treatments
are available. Drugs such as L-dopa or levodopa, dopamine agonists, COMT enzyme
inhibitors are in use. Deep brain stimulation surgery once practiced commonly is
done only in certain advanced PD subjects.
English
physician James Parkinson in 1817 gave a detailed description of several cases
of PD in an essay.
Contributor:
Duraiswamy Navaneetham PhD.
Temple University School of Medicine
Philadelphia, PA, USA September 2009
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