Parkinson's Disease

Parkinson's disease is a neurological disorder that is fairly common in our population. It is typically a disease of the elderly; it progresses slowly and has gradually debilitating effect on the patient's health.


The cause lies deep in the brain. There are anatomical and functional structures called the basal ganglia. The nerve cells located in these structures have a great importance for control of locomotion and voluntary movement. A neuromediator known as dopamine has a great importance for proper function of basal ganglia as it helps to transmit neuroelectric signals among the cells of basal ganglia. Dopamine is formed in a part of the brain known as the "susbtantia nigra". Parkinson's disease is related to excessive deaths of cells that produce the dopamine. The process is gradual and initially it has no symptoms as the remaining cells are able to produce enough dopamine. However, as the number of cells decreases, the symptoms begin to occur.


Note: Symptoms similar to the Parkinson's disease is often caused by drugs from the group of neuroleptic medications. This is due to their damping effect on the dopamine neurotransmission in the brain.


The lack of dopamine leads to disruption of the basal ganglia and thus damaging the control of voluntary movements. However, the result is not the classical muscle paralysis but rather various problems in initiation of movements, coordination and targeting. The patient suffers from problems when initiating a movement – he or she can not stand up (when sitting) or start walking. The gait is abnormal and the patient makes small shuffling steps. The coordination between the lower extremities and the torso is disrupted and when the sick person stops, the torso tends to continue forward increasing the risk of accidental falls.


The patients also suffer from the well-known Parkinson's hand tremor. The tremor typically occurs when at rest and disappears during a targeted movement. For example, the patient sits at a table during meal and his hands shake. However, when he reaches for the spoon and begins to eat, the tremor disappears. The tremor also disappears during sleep. Patients with Parkinson's disease may have troubles when speaking and dysfunction of their facial muscles gives them a "mask" appearance. Stomach nerves may experience troubles causing impaired gastric emptying. The memory and intellect patient are usually normal, but the Parkinson's disease may occur together with Alzheimer's disease and in such there is a significant mental impairment.


The disease alone does not kill the patient, but when untreated, it can significantly shorten the life by decreasing the mobility and self-sufficiency and thus making the patient sensitive to infectious complications such as the pneumonia.


Patient with neurological symptoms being suspicious of Parkinson’s disease should be examined by a neurologist. The neurologists may use the so-called levodopa test. Levodopa is a drug used in treatment and when the status of the patient significantly improves after its administration, the diagnosis of Parkinson's disease is very likely.


It is not exactly clear why the disease occurs and therefore there is no effective way of prevention.


Treatment should be controlled by a skilled neurologist. There are various medications with different effects. The most classic and still widely used drug is a substance known as levodopa. When the mechanism of the disease was discovered, the physicians tried to supplement the patients with dopamine. However, dopamine is unable to get from the blood vessels into the brain. Levodopa turned to be the ideal solution as it can pass from blood into the brain and only then it converts to dopamine. The effect is rapid and effective. Regular doses of levodopa man completely return the patient to normal life and the symptoms disappear. Unfortunately, when used in long-term, the levodopa begins to lose its effect over the years. There are required higher and higher doses administered in shorter intervals. In addition, levodopa can cause side effects including nausea, vomiting and various psychological problems.


In addition, other medications may be used such as drugs supporting the formation and function of dopamine, or drugs prolonging the dopamine effect.


There is also a more invasive method of treatment known as the Deep brain stimulation (DBS). The doctors insert a thin electrode into the basal ganglia, which generates electric impulses and stimulate the brain. The method has a great outcome, but it is very expensive.


Complementary treatment is focused on treating secondary problems such as the depression, which is a common problem among the people with the Parkinson's disease. It is a logical response to restricted mobility and it must be often treated by various antidepressants.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources