Brain Transplant: An End to Parkinsonism? :: Biology Essays Research Papers

The Modern Day Brain Transplant:An End to Parkinsonism or the Beginning of a Greater Debate? It sometimes begins with a feeling of lethargy, being "down in the dumps," or shakiness (1). Maybe it begins with a twitch of the pinky finger that was not there before. Speech becomes more difficult and softer to the level of a whisper; this is often accompanied by irritability. Movements become rigid, unsteady and slow (2). A tremor develops, with trembling of the hands, arms, legs, jaw, and face. Later, walking is often only accomplished through short and shuffling steps, intermixed with a loss of balance and instability (3). These symptoms usually progress until the person is incapacitated and unable to do simple tasks such as brushing their teeth, buttoning clothing, or turning newspaper pages (1). This is a description of a person living with Parkinson's disease. According to the Parkinson's Disease Foundation, there are one million people living with Parkinson's nationwide (1). Several public figures have also revealed their private struggles with Parkinson's including Michael J. Fox, Muhammad Ali, Janet Reno and Billy Graham (1). As evidenced by the names listed, Parkinson's strikes an array of people, it is generally a late onset disorder, however, in some cases, such as with Michael J. Fox, Parkinson's has a "young onset". Parkinson's disease is a disorder that results from the depletion of the neurotransmitter dopamine. The basal ganglia is the part of the brain responsible for movement. When 80% of the dopamine-secreting cells in a specific part of the basal ganglia, the substantia nigra, are lost Parkinson's symptoms develop (4). The cause for the neuropathology of Parkinson's is still unknown. Two possible causes of Parkinson's that have been researched include environmental factors such as toxins and defective genes (5). Treatments for the disease vary widely. The standard treatment is to prescribe levodopa (L-dopa) (4), the precursor of dopamine to patients. This is given because dopamine itself does not cross the blood-brain barrier. The levodopa is converted to dopamine inside the brain and is effective in improving the severity of symptoms dramatically. Unfortunately, long-term usage of levodopa causes a myriad of side effects, such as head bobbing, grimacing, abnormal movements of the trunk and limbs (2). With time, the side effects of levodopa become more dramatic than the original Parkinson's and the thus outweigh the benefits of giving the drug. Other treatments include a brain "pacemaker," deep brain stimulation with electrodes, and pallidotomy (destroying a portion of the globus pallidus in the brain).