Normally associated with the uncontrollable tremor of a hand or other unintended movements, Parkinson’s disease is much more complicated than the tremor that meets the eye.
Parkinson’s disease is a brain disorder that affects more men than women, and its symptoms start gradually, usually after age 60, and worsen with. time. It is a type of movement disorder that causes parts of the brain to deteriorate progressively. It affects the nervous system and parts of the body controlled by this area of the brain. Experts estimate that worldwide at least 1% of people over 60 are affected.
Parkinson’s disease is best known for the way it affects muscle control, balance, and movement, but it can also affect mood, mental health, thinking ability, and sleep, amongst others. It can take years or even decades for severe effects to develop.
What happens in the Parkinson’s brain?
Parkinson’s disease causes an area in the brain called the basal ganglia to deteriorate, affecting the abilities controlled in this area. Certain brain cells (neurons) gradually break down or die, and many of the symptoms are caused by the loss of neurons that produce dopamine (a neurotransmitter) in the basal ganglia area of the brain, which controls movement.
The break-down of these brain cells is due to one of the proteins in the brain, alpha-synuclein, that starts to form clumps within brain cells, which the brain cells cannot break down. These clumps of abnormally folded proteins are known as Lewy bodies. Proteins are chemical molecules with a specific shape and when the proteins don’t have the correct shape (called protein misfolding), the brain cells cannot use them or break them down.
Decreased dopamine levels cause irregular brain activity, affecting activation signals that control muscle movement. Cells need dopamine to fine-tune your movements and a lack of dopamine results in the tremors and slowed movements associated with Parkinson’s disease.
The energy giving “batteries” of cells are called mitochondria, where energy from food gets converted and stored in a small molecule called adenosine triphosphate (ATP), which provides the energy for other biochemical reactions in the cell. Studies have shown that mitochondrial dysfunction may play key roles in the loss of brain cells in Parkinson’s disease. As dopaminergic brain cells, the main source of dopamine, have a high energy demand, cells affected by Parkinson’s disease exhibit mitochondrial dysfunction that promotes the loss of dopaminergic neurons.
What causes Parkinson’s disease?
Most cases happen for unknown reasons and the real cause of Parkinson’s disease is unknown, but a few factors seem to play a role:
- Inheriting certain genetic mutations may cause or increase the risk of Parkinson’s disease. Experts have linked at least seven different genes to Parkinson’s disease, which can be inherited from the father or the mother. Genetics make up about 10% of all cases.
- Environmental triggers such as exposure to certain toxins may increase the risk of later developing Parkinson’s disease.
- The risk of developing Parkinson’s disease increases with age, and it is more common in men.
Genetic and environmental factors can contribute to mitochondrial dysfunction in Parkinson’s disease.
Symptoms of Parkinson’s disease:
Although the loss of muscle control are the best-known symptoms of Parkinson’s disease, there are many other symptoms, of which not all are related to movement and muscle control, according to the Cleveland Clinic. (A nonprofit multi-specialty medical center in the USA that integrates clinical and hospital care with research and education.)
Movement-related (motor) symptoms:
- Tremors when the muscles are at rest, manifesting as a rhythmic shaking of muscles even when they are not being used. This symptom happens in about 80% of cases.
- Slowed movements, referred to as bradykinesia, due to muscle control problems and not a loss of strength.
- Rigidity or stiffness when moving a body part and it can also manifest as jerky movements.
- An unstable posture due to slowed movements or stiffness can result in a hunched over stance and walking with shorter shuffling strides and less swinging of the arms.
- Blinking less often than normal.
- Muscle control problems can result in cramped or small handwriting.
- The loss of facial muscle control can result in drooling.
- Reduced muscle control in the throat and chest can result in an unusually soft speaking voice.
- Reduced throat muscle control can result in having trouble swallowing
- Facial expressions can become mask-like, with very little change in facial expression or even none at all.
Non-movement (non-motor) symptoms:
- Autonomic nervous system symptoms can include gastrointestinal problems (such as constipation), urinary incontinence, sexual dysfunction, and low blood pressure when standing up.
- Depression and anxiety are often associated with Parkinson’s disease.
- The loss of sense of smell (anosmia) can occur.
- Parkinson’s-related dementia can manifest as having trouble thinking and focusing.
- Sleep problems are common, such as restless leg syndrome, periodic limb movement disorder, and rapid eye movement disorder.
The symptoms expand and intensify as the disease progresses, with later stages often affecting brain function and resulting in dementia-like symptoms and depression.
Conclusion:
Typical symptoms of Parkinson’s disease can vary greatly, from individual to individual, in terms of intensity and how they progress over time. This condition usually takes time to get worse and most people have a normal life span living with this condition. Parkinson’s disease is not contagious and cannot be contracted from another person.
While there is no cure or preventative treatments for Parkinson’s disease yet, many of the symptoms can be managed through medical intervention and healthy lifestyle choices, such as a healthy balanced diet, for example, the Mediterranean diet, and a regular exercise routine – which can make a big difference to mobility, balance, and coordination.
There is currently an enormous amount of research being directed as to the causes, prevention, and cure of Parkinson’s disease.
References:
Parkinson’s disease: Causes, symptoms, and treatments. Published online and content reviewed 14 April 2022. National Institute on Aging. National Institutes of Health. USA. (www.nia.nih.gov)
What is Parkinson’s disease? Published online. American Parkinson’s Disease Association. (www.apdaparkinson.org)
Parkinson’s disease. Published online and contents reviewed 15 April 2022. Cleveland Clinic. (A nonprofit multi-specialty medical center that integrates clinical and hospital care with research and education.) USA. (www.clevelandclinic.org)
Parkinson’s disease. Published 26 May 2023. Mayo Clinic. USA. (www.mayoclinic.org)
Mitochondrial dysfunction in Parkinson’s disease: From mechanistic insights to therapy. Published 20 June 2022. Frontiers in Aging Neuroscience. Volume 14 – 2022. Frontiers. (www.frontiersin.org)
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