Understanding Parkinson's Disease
A degenerative, progressive brain disorder, Parkinson’s Disease (PD) primarily affects the dopamine-producing areas in the brain called basal ganglia and substantia nigra. Nerve cells in the latter create a neurotransmitter, dopamine, which relays messages for controlling body movements.
Beginning gradually but worsening over time, the symptoms may include stiffness, tremors, limb rigidity and difficulty in walking, including poor balance and coordination. Although symptom progression varies across individuals, it may later result in difficulty in walking and talking. Those affected could also experience sleep disruptions, memory issues, fatigue, depression as well as mental and behavioural changes.
Besides motor or movement-related symptoms, PD could have non-motor symptoms too. Therefore, those with PD can sometimes be more affected by non-motor symptoms such as apathy, difficulty in chewing/swallowing, urinary issues, constipation, cognitive impairment, skin problems and the loss of their sense of smell.
While its cause remains relatively unknown, men and women could both develop PD, though around 50% more men fall victim. Age is, however, one risk factor. Generally, persons with Parkinson’s have their first brush with the disease around the age of 60. But up to 10% experience an early onset, which happens before they turn 50. Some forms of early-onset PD are occasionally inherited, while others are linked to certain gene mutations.
Initial symptoms can occur gradually and subtly, such as experiencing mild tremors or difficulty in getting out of chairs. Their handwriting may slow down and they may begin speaking softly. Family and friends may be the first in noticing these changes, which can include an expressionless face and the arms and legs not moving normally. A tendency in leaning forward while walking, taking small but quick steps and lesser arm swinging while walking are other noticeable symptoms. These symptoms may occur on one side only. With disease progression, both sides may be affected, but with symptoms still being more severe on one side.
Such early symptoms are sometimes dismissed as normal signs of ageing. Since no medical tests exist for conclusively detecting Parkinson’s, accurate disease diagnosis is difficult. Presently, though no specific cure exists, treatment avenues can include medications and surgery. By itself, PD is not fatal. But complications from the disease could be serious, occasionally proving fatal. Consequently, it is essential to first understand the ailment and its progression.
Cause and Control
Parkinson’s occurs when the neurons/nerve cells in the region of the brain controlling movement are damaged and/or die. Typically, these neurons produce an essential chemical called dopamine. If the neurons are damaged or dead, less dopamine is produced, thereby triggering the movement complications identified with PD. What causes the dopamine-producing cells to die is unknown.
Persons with PD can also suffer the loss of nerve endings producing norepinephrine – which acts as the prime chemical messenger of the sympathetic nervous system. The latter controls many of the body’s automatic functions, including the heart rate and blood pressure. Besides dopamine deficiency in the nigrostriatal pathway, an imbalance occurs in the dopaminergic and cholinergic neurotransmitters responsible for motor symptoms. In-striatum imbalance of neurotransmitters such as serotonin, GABA, glutamate and neuropeptides like dynorphin and neurotensin are responsible for non-motor symptoms related to PD such as mood and behaviour, which includes psychiatric symptoms, cognitive decline and autonomic disturbances.
The loss of dopaminergic neurons leads to major motor symptoms such as bradykinesia (slowness of voluntary or ongoing movement), rigidity and rest tremors. Conversely, multiple neurotransmitter deficiencies occurring in the central and peripheral nervous system can trigger non-motor signs, including psychiatric (apathy, depression, delusions and hallucinations) and autonomic (orthostatic hypotension, constipation and urinary/genital disturbances) features, cognitive impairment, olfactory dysfunction, sleep disorders and pain, altogether contributing in worsening the person’s quality of life and disability.
Though some PD cases could be hereditary, others may arise from certain genetic mutations. Usually, however, PD occurs randomly and may not run in families. Today, researchers think PD arises from both genetic and environmental factors, including exposure to toxins.
Nonetheless, a good quality of life is possible by following the doctor’s advice and the recommended treatment regimens that manage the symptoms through dopaminergic medications. At present, PD therapies only alleviate symptoms without slowing or stopping its progress. The therapies comprise physical, occupational and speech therapies, addressing tremors and rigidity, gait and voice problems as well as deteriorating mental functions. The other supportive regimens include having a healthy diet and exercises that help in boosting muscle strength and improving balance.
If the above regimen is followed strictly, people with Parkinson’s can lead a normal life with minimal disruptions.