Parkinson's Disease

 Parkinson’s disease is an idiopathic and has no known cause. It is normally due to the degeneration of dopaminergic neurones of the nigrostriatal tract and loss of DA neurotransmission in the striatum. The symptoms of this disease are a resting tremor, muscle rigidity and suppression of voluntary movements (hypokinesis).

The main 4 dopaminergic pathways are:-

• Nigrostriatal
– Substantia nigra to striatum

• Mesolimbic
– Ventral tegmental area to nucleus accumbens

• Mesocortical
– Ventral tegmental area to frontal cortex

• Tuberoinfundibular
– Arcuate nucleus to pituitary gland

The decarboxylase inhibitor – carbidopa, theMAO inhibitor: Selegiline and D2 receptor agonists like Bromocriptine can be used to treat Parkinson’s disease.