What is PD?
PD is a disorder of the nervous system resulting in tremor, slow movement and stiff and inflexible muscles which get gradually worse. More men than women get PD of which the symptoms usually appear after the age of 50 but in about 5% of cases they occur before age 40. At present there is no cure for PD but treatments are available which alleviate the symptoms. Although everyday life can become more difficult as the disease progresses it usually has no impact on life expectancy.
The symptoms of PD vary from person to person both in their nature and severity. Slight tremor in one hand might be the first sign. As the disease progresses involuntary shaking increases and other characteristic problems arise including muscle stiffness, slower movements and difficulties with posture, balance, speech, writing and unconscious movements such as smiling and blinking. Some people may experience other problems relating to swallowing, the sense of smell, sleep, fatigue, bladder control, depression, memory and pain.
What causes PD?
In the human body dopamine, which is produced in the midbrain’s substantia nigra area, plays an important transmission role in controlling and coordinating muscle movements. When a significant number (over 60%) of the nerve cells which produce it are damaged or die symptoms of Parkinson’s disease start to appear. It is not clear why the brain cells concerned degenerate but genetic and/or environmental factors might be involved.
Types of Parkinson’s Disease and Parkinsonism
Parkinsonism is an umbrella term for neurological conditions which have similar symptoms to PD – mainly tremor, muscle rigidity, slowness of movement and balance problems. The following classifications are sometimes used:-
- Idiopathic Parkinson’s disease – the most common diagnosis in people, who are mostly over the age of 60, where the cause is not known and the main symptoms are tremor, rigidity and slowness of movement. In early onset cases, below age 50, the disease progresses at a slower rate but there is an increased risk of persistent abnormal postures (dystonia)
- Vascular parkinsonism – caused by a restricted blood supply to the brain, as a result possibly of a stroke. Older people who have diabetes are sometimes affected. In addition to the main symptoms of PD difficulties may be experienced with various activities including speech, swallowing, and thought.
- Drug-induced parkinsonism – A few of the people who are diagnosed with parkinsonism are found to have developed it as a result of taking medication often in the form of neuroleptic drugs. Most people recover within a short time after they stop taking the drugs which interfere with the production of dopamine in the brain.
- Inherited PD – It’s thought that up to 50% of early-onset PD before the age of 50 may have a genetic cause but the parts played by genes and environmental factors are not yet clearly understood.
- Juvenile parkinsonism – Rare and often overlooked as a diagnosis PD-like symptoms can occur in children and young people under the age of 20. Their involuntary movement disorders tend to be more pronounced
- Dementia with Lewy bodies – The main symptoms of PD are often present but there are other problems including difficulties with memory, thinking, and language.
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