Parkinsonism is a syndrome consisting of three main
components:
Tremor
Muscular Rigidity
Hypokinesis
(Hypokinesis is
slowness in initiating & repeating voluntary
movements)
Overall prevalence
is about 1 / 1000 of the general population. There is low
prevalence of this disease among Indians. It is more common in elderly, the
prevalence rising to 1% of those over 60 years.
Aetiology
The cause of the
disease is not known. Genetic factors are not important
in a typical case.
Environmental toxins may be a contributing factor.
Country areas frequently sprayed by herbicides show
increased incidence of parkinsonism. Chemicals such as
(MPTP) methyl-phenyl-tetrahydopyridine, paraquet have
been implicated.
Clinical
Features
Both
sexes are affected equally. Onset of the disease is
usually after 50 years. Very occationally the symptoms
may start in 3rd & 4th decade. Initially the
classical symptoms may be absent. The disease may start
as Tiredness, aching limbs, mental slowness, depression
and small handwriting.
Face gives appearence of Expressionless face. Greasy
skin. Fixed posture.
Tremor:
Tremor at rest affecting one or both hands may be the
first symptom. Tremor may also affect tongue, legs,
mouth. Tremor may remain the only symptom for many years.
Tremor is intermittent present at rest and when
distracted. It diminishes on action.
Hypokinesis:
Difficulty in initiating rapid fine movements, slowness
of gait, difficulty in tasks such as fastening buttons
and writing.
Gait is typical - slow to start walking, shortened
stride, rapid small steps, tendency to run, reduced arm
swinging, impaired balance on turning.
Rigidity
of muscular tone: causes stifness and flexed posture.
Gradually the speech becomes softer and indistinct.
Postural balance is disturbed because of impairement in
the reflexes responsible for maintaining balance.Such
patients are prone to falls. Rigidity is known as
Cogwheel type in upper limbs and Plastic lead pipe type
in the lower limbs.
Featues
of parkinsonism may be unilateral in the begining but
gradually they become bilateral. Muscle strength and
reflexes remains normal. Facial reflexes are enhanced.
Tapping of the forehead causes rapid blinking known as
Glabellar tap sign. Intelectual faculties are not
markedly affected.Some patients may get depressed and
there may be some cognitive impairement as the disease
advances.
Diagnosis
Diagnosis
of the disease is done on clinical grounds. Specialized
investigation are needed in selected patients. In
patients under 50 years, or with unilateral signs. In
young patients Serum copper, caeruloplasmin, urine
copper, Liver functions.
Prognosis
Outlook
for the patients with parkinsonism is variable depending
on the age of onset. If the symptoms start in the middle
age the disease is slowly progressive and is likely to
shorten life span. If it starts after 70 it is unlikely
to to shorten life. Complications due to immobility and
liability to fall may create problems for the patient.
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