Parkinson’s disease is a disorder associated with symptoms such as slowing of movement, muscle stiffness, muscle tremors, and postural instability. The most common form is called Parkinson’s disease. Parkinson’s disease usually takes a gradual course and is still not curable. However, with the right therapy – usually in the form of medication – the progression of the disease can be halted and the life expectancy of affected patients can be significantly increased. We inform you about the causes and symptoms as well as the diagnosis and treatment of Parkinson’s disease.
Parkinson’s disease: cause unknown
Parkinson’s is one of the most widespread neurological diseases in Germany. It primarily affects older people between the ages of 55 and 65, with only about ten percent younger than 40 at diagnosis. The number of people suffering from Parkinson’s increases with age: About one percent of those over 60 in Germany are affected, while the figure is already around two percent for those over 70 and three percent for those over 80.
Parkinson’s disease is characterized by a steadily progressive loss of nerve cells in the brain that produce dopamine. It is not yet known why the nerve cells die. That is why it is also called idiopathic Parkinson’s syndrome (idiopathic = without an identifiable cause).
Different forms of Parkinson’s disease
Idiopathic Parkinson’s syndrome is by far the most common form – there is no identifiable cause for about 75 percent of all Parkinson’s. However, some rarer forms of Parkinson’s exist alongside it, and their cause is known:
- Familial Parkinson’s syndrome: This form of Parkinson’s is caused by changes in the hereditary material and is therefore also hereditary. Often the symptoms occur at a young age, that is, under 40 years.
- Secondary (symptomatic) Parkinson’s syndrome: This form of Parkinson’s can be caused by environmental influences (for example, toxins), by certain drugs (for example, neuroleptics) or diseases (for example, brain tumors), as well as by repeated injuries to the brain (Boxer Parkinson’s).
- Atypical Parkinson’s syndrome: This includes various diseases that, just like Parkinson’s, are caused by a deterioration of nerve cells in a specific area of the brain – the basal ganglia. In addition to the typical Parkinson’s symptoms, those affected suffer from other complaints. Therefore, Atypical Parkinson’s syndrome is also called Parkinson’s plus syndrome.
Key role of dopamine in Parkinson’s disease
Dopamine is a neurotransmitter that is primarily important in the brain for the transmission of signals between nerve cells and is therefore also involved in the control of our movements. If too little dopamine is present in the brain, the deficiency causes the physical limitations typical of Parkinson’s disease, such as a slowing of movement (bradykinesis).
The dopamine deficiency also causes other neurotransmitters such as acetylcholine and glutamate to gain the upper hand in the brain. The imbalance triggers other typical signs such as muscle tremor (tremor) as well as muscle stiffness (rigor).
Loss of dopamine-producing neurons.
Dopamine deficiency is caused by a loss of dopamine-producing nerve cells in the brain. The loss is more pronounced in certain areas of the brain than in other regions: For example, the dopamine-producing nerve cells in the black matter (substantia nigra) and the nerve cells in the striatum are particularly affected.
Both the black substance and the striate body are involved in the control of movement sequences. If too little dopamine is present, the nerve cells in these areas cannot be sufficiently excited. As a result, movement patterns become slower and fine motor movements such as writing become more difficult.
