PARKINSON'S DISEASE - A REVIEW

Parkinson's disease is a common neurological condition. Environmental, genetic factors and age are important predisposing factors, but there continues to be increasing evidence for a genetic component. Apoptosis and necrosis have been implicated in the loss of the nigral neurons in patients with parkinson's disease. Mitochondrial dysfunction, oxidative stress, the actions of excitotoxins, deficient neurotrophic support and immune mechanisms are contributory. Excessive activity of the subthalamic nucleus has also been found to contribute to the symptoms of parkinsons disease using the neurotransmitter glutamate, blockade of which might provide an effective treatment of parkinson's disease. Treatment could be preventive, symptomatic or restorative. Neuroprotective agents prevent apoptosis by upregulating apoptosis defence gene and down regulating apoptosis promoting genes. Selegilline (deprenyl) has selective anti apoptotic properties by increasing mitochondrial energy production and reducing generation of free radicals. Free radical scavengers such as α-tocopherol, high doses of ascorbate, antioxidants such as selenium and ubiquinone, drugs inhibiting glutamate release or receptor interaction such as N- methyl 4 - valine antagonist and aspirin, which down regulate glutamate receptors have been tried without proven benefit. Non-steroidal anti-inflammatory agents and interferon β have also been tried with no documented efficacy. Except for functional neurosurgical procedures, levodopa remains the most effective replacement therapy for parkinson's disease.