Parkinsonism and other Extrapyramidal Diseases - Essay Example

In essence, I did the best I could with what I was provided. The normal functions of the human basal ganglia have largely been deduced from the study of functional problems associated with destructive or irritative lesions. To a large degree, the deficits are in motor function and, therefore, the extrapyramidal system and basal ganglia have been associated with movement disorders. Important interconnections of the basal ganglia are the nigrostriatal pathway, and the ansa and fasciculus lenticularis, and the fasciculus thalamicus, which interconnect the globus pallidus and the ventral lateral and ventral anterior (VL-VA) nuclei of the thalamusand the VL-VA thalamocortical fibers, the subthalamopallidal pathway, striatopallidal fibers, and cerebellothalamic interconnections Parkinson's disease, first described by James Parkinson in 1817, is one of the most important disabling illnesses of later life.

It is estimated to affect 1% of 70-year-olds, but is also seen in younger people, with 10% of cases occurring before the age of 50. Parkinson's disease is one of the most common neurodegenerative diseases, but estimating its incidence and prevalence is problematic, since there is no 'in-life' marker for idiopathic Parkinson's disease; estimates of the annual incidence of Parkinson's disease are in the range of 4 to 20 per 100000 individuals. A widely accepted figure for the prevalence of Parkinson's disease is approximately 200 per 100,000 populations.

In the UK, there are approximately 120,000 to 130,000 diagnosed cases, but there may be many more that remain undiagnosed. In the USA, it is estimated that between 750,000 and 1.5 million people have the disease. ( Ref)Age, Sex, and EthnicityBoth the incidence and prevalence of Parkinson's disease increase with age, and the prevalence may be as high as 1 in 50 for patients over the age of 80 years. Men are 1.5 times more likely than women to develop the condition are. Hospital-based studies have suggested that Parkinson's disease is less common in the black population.

PathologyThe main pathological feature of Parkinson's disease is the degeneration of neuromelanin-containing neurons in the pars compacta of the substantia nigra. Examination with the naked eye reveals pallor of this area, which is confirmed microscopically by a marked decrease in the number of neuromelanin-containing cells and the presence of Lewy bodies in the remaining nigral neurons. Degeneration of pigmented neurons in the brainstem is not limited to the nigra but extends to the locus ceruleus and the dorsal motor nucleus of the vagus.

Neuronal DegenerationThe cause of neuronal degeneration in Parkinson's disease is unknown. The susceptible neurons are located in astroglial-poor regions such as the ventral tier. Glia may offer neuroprotection by providing neurotrophic factors that prevent cell death. Several hypotheses for neuronal degeneration have been proposed, including:oxidative stress, induced by dopamine metabolism or other factorsdefective mitochondrial energy metabolismexcitotoxin- and xenobiotic-related cell deathprogrammed cell death (apoptosis) to the medial