Parkinson'S Disease

Also called Idiopathic parkinsonism, Hypokinetic Rigid Syndrome (HRS) or Paralysis Agitans.

It is a degenrative disorder related to nervous system which start occuring at old age. The disease affects movements of the body parts first slightly but later severly. At initiation, the patients suffers with slight shivering of limbs but later, the thinking ability and behavioural changes occurs in association with dementia.

It is the second most common disease after Alzheimer's disease and affects near about 7 million people all around the world.


The PD is caused by death of nerve cells of Substantia nigra region of mid brain that produce Dopamine, a neurotransmitter which controls the reward giving behaviour of person.

There are basically two reasons for death of neurons:

  • Exposure of certain insecticides & pesticides like Rotenone, Agent Orange or Organochlorines kills the neurons of Substantia nigra.
  • Rarely, PD is also caused by certain genetic mutations, but it is still not specifically identified.


The initiating symptoms of PD are Tremor, Bradykinesia (Slowness of Movement), Rigidity & Posture instability. They are also considered as motor symptoms as they are related to movement of patient.

But alongwith there are many neuropsychiatric symptoms are there like depression, apathy, anxiety, quiet speech, etc.

Most severe cases also show some hallucinating & delusionating effects.

Sometimes, the symptoms & signs also includes drowsiness in daytime and REM Sleep or insomnia in night. Rarely, Autonomic Nervous System also get altered & leads to orthostatic hypotension, urinary incontinence, gastric dysfuntion.


The pathological diagnosis includes the detection of Lewy bodies in the neurons on staining with alpha-synuclein. But as such no lab test are recognised for detection of PD.

The physician diagnoses the PD from the medical history of the patient and its neurological findings.

Computed tomography (CT) and Magnetic Resonance Imaging (MRI) usually appear normal for patient of PD. But a modified type of MRI, Diffusion MRI help to differentiate between typical and atypical PD but its diagnostic value is under investigation.

Different PET & SPECT radiotracers are used to measure dopaminergic function of basal ganglia.

Treatment & Cure

There is no particular cure of PD but medicines, surgery & multidisciplinary managements are used to provide relief from symptoms.

The drugs usually used to treat are Levodopa and some dopamine agonists like bromocriptine, ropinirole, lisuride, etc. These agonists bind with dopaminergic post synaptic receptors in the brain. These agonists have some side effects like drowsiness, hallucinations, constipation, insomnia, etc.

Some monoamine oxidase B inhibitors and other drugs like amantadine are also used.

Surgical methods as the treatment of PD are lesional and deep brain stimulation surgery. Out of these, the most common is DBS which involve the placement of brain pacemaker in deep sites of brain to control motor actions, but it fails to control neuropsychiatric problems.


The people who uptake a large amount of caffeine remain resistant to PD. Nicotine also shows the similar effect. The disease is also prevented by antioxidants like Vitamin C & D.