Overview of anatomy and physiololgy
are damaged, the amount of dopamine that is produced is reduced. A combination of the reduction of cells and a low level of dopaminein the cells in this part of the brain causes nerve messages to the muscles to become slowed and abnormal.
Pathophysiology
A substance called dopamine acts as a messenger between twobrain areas – the substantia nigra and the corpus striatum – to produce smooth, controlled movements. Most of the movementrelated symptoms of Parkinson’s disease are caused by a lack of dopamine, due to the loss of dopamine‐producing cells in the substantia nigra. When the amount of dopamine is too low, communication between the substantia nigra and corpus striatum becomes ineffective, and movement becomes impaired; the greater the loss of dopamine, the worse the movement‐related symptoms. Other cells in the brain also degenerate to some degree and may contribute to non‐movement related symptoms of Parkinson’s disease.
Although it is well known that lack of dopamine causes the motor symptoms of Parkinson’s disease, it is not clear why the dopamineproducing brain cells deteriorate. Genetic and pathological studies have revealed that various dysfunctional cellular processes, inflammation and stress can all contribute to cell damage. In addition, abnormal clumps called Lewy bodies, which contain the protein alpha‐Â�synuclein, are found in many brain cells of individuals with Parkinson’s disease. The function of these clumps in regards to Parkinson’s disease is not understood. In general, scientists suspect that dopamine loss is due to a combination of genetic and environmental factors.
Signs and symptoms
The brain cells and nerves affected in Parkinson’s disease normally help to produce smooth, coordinated movements of muscles. Therefore, three common Parkinson’s symptoms that gradually develop are:
•â•¢ Slowness of movement (bradykinesia). For example, it may become more of an effort to walk or to get up out of a chair. When this first develops it may be mistaken for ‘getting on in years’. The diagnosis of Parkinson’s disease may not become apparent unless other symptoms occur. In time, a typical walking pattern often develops. This is a ‘shuffling’ walk with some difficulty in starting, stopping and turning easily.
•â•¢ Stiffness of muscles (rigidity), and muscles may feel more tense.
Also, arms do not tend to swing as much when walking.
•â•¢ Shaking (tremor) is common, but does not always occur. It typically
affects the fingers, thumbs, hands and arms, but can affect
other parts of the body. It is most noticeable when resting. It may become worse when anxious or emotional. It tends to become less when the hand is being used to do something such as picking up an object.
The symptoms tend slowly to become worse. However, the
speed in which symptoms become worse varies from person to
person. It may take several years before they become bad enough
to have much effect on daily life. At first, one side of the body may
be more affected than the other.
Management
Many early symptoms of Parkinson’s disease can be treated by a GP, with the help of the family and other care workers in the community. The progress of the disease may vary with individuals, but should the condition of the person worsen it may be necessary to
admit the person to hospital. The nursing staff and other healthcare workers, such as the
physiotherapist, speech therapist and occupational therapist should be able to advise the patient and their family on how to deal with problems interfering with activities of daily living.
As the disease process gets worse, mobility can be a problem. This includes walking, stopping walking, shuffling, tottering, falls and impaired balance. Nurses need to ensure that the person with PD is monitored all the time to prevent unnecessary injury through
their unsteady gait. Physiotherapy helps improve gait, balance and flexibility, aerobic
activity and movement initiation, increase independence and provide advice about fall prevention and other safety information. Avoid walking frames (flow of movement is interrupted) unless fitted with wheels and a brake. Occupational therapists give advice and help on maintaining all aspects relating to activities of daily living, both at work and at
home, with the aim of maintaining work and family relationships, encouraging self‐care where appropriate, assessing any safety issues, making cognitive assessments and arranging any appropriate interventions. Speech therapy ensures methods of communication are available.as the disease progresses and helps with swallowing difficulties
(reducing the risk of aspiration).To control symptoms of Parkinson’s disease medications such as levodopa and dopamine agonists may
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