Parkinson’s Disease (PD)(10/26/2008)Parkinson's disease (PD) is characterized by an insidious onset with slowing voluntary movement, muscular rigidity, postural abnormality and tremor. PD was first described in 1817 by James Parkinson . It is an age- related progressive neurodegenerative disease caused by selective loss of dopaminergic neurons in an area of the midbrain called the substantia nigra (SN) resulting in the loss of dopamine (DA). Dopamine is one of the most important neurotransmitters in brain neural circuits that carry information about movement.The cell bodies of the dopaminergic SN neurons primarily project into the putamen forming the nigostriatal pathway. The loss of these neurons, which contain large amounts of neuromelanin, results in neuropathological SN depigmentation observed in postmortem PD brains. The precise etiology of nigral cell loss is still unknown. PathologyThe predominant lesion in PD is cell degeneration and loss of pigmented neurons in the SN pars compacta. These nerones contain cytoplasmic inclusion bodies called Lewy bodies. Their origin is not clear. Lewy bodies are found in other parts of the brain. Clinical FeaturesThe onset is insidious and symptoms include tremor, stiffness, or clumsiness, difficulty in walking, fatigue, depression, dysarthria, or limb discomfort. The disease is generally asymmetrical at presentation. Suggested Reading:
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