Parkinson's

The cause of Parkinson’s remains unknown and this is why it is referred to as Idiopathic Parkinson’s. It is not caused by overwork or overindulgence.

There are many theories regarding the cause, with genetic and environmental influences under much research.

Terms explained

Idiopathic – relating to any disease or condition which arises spontaneously or for which the cause is unknown.

The main symptoms of Parkinson’s on which diagnosis is based are:

• slowness of movement (bradykinesia)
• muscle rigidity
• tremor
• changes in balance (postural Instability)

In typical Idiopathic Parkinson’s (it is called this because the cause is unknown), these cardinal symptoms develop gradually and are initially seen on one side of the body or affecting a limb or limbs on one side. After a number of years this will involve both sides.

Slowness of movement (bradykinesia)

This is considered the most common and bothersome of Parkinson’s symptoms. Initially it presents as a general slowness of voluntary movements and is seen in combination with hypokinesia (reduced magnitude of movement). This is often noticeable as reduced or lack of one sided arm swing. Bradykinesia may lead to abnormal movements (akinesia) or a complete lack of voluntary movement.

Muscle rigidity

This may not be apparent to the person with Parkinson’s but is felt more by the medical practitioner or physiotherapist in the muscles of limbs when they are passively moved. Muscle rigidity is described as ’lead pipe’ or ‘cogwheel’ rigidity. Muscle rigidity is often present in the wrist, shoulder and neck, and may also be seen as a slightly flexed elbow on the affected side. Muscle rigidity can cause pain which is often underestimated in Parkinson’s. As the condition progresses muscle rigidity may lead to the characteristic forward flexed posture.

Tremor

Although tremor is the most easily recognised and visible symptom it is not present in all cases of Parkinson’s – 30% of those diagnosed with Parkinson’s will not develop tremor. Tremor is also common to other conditions. The classic Parkinson’s tremor is usually seen when the limb is at rest and is described as a ‘resting tremor’. It is regular and rhythmic and occurs at the rate of 4-6 times per second. Tremor is made worse by stress, anxiety and fatigue and it diminishes with voluntary action and is absent during sleep. Tremor is the least responsive symptom to Parkinson’s medications and it may be improved by Deep Brain Stimulation surgery if the patient is a good candidate.

Postural instability

Often develops later in the condition along with gait disturbances. Gait changes include reduced arm movement on one side and a shortened stride length and height which leads to the characteristic ‘shuffling ’ gait. Falls may occur because of impaired balance.

• Speech changes – the rate of speech may get faster or slower and volume often becomes lower with a decrease in clarity. The voice may become husky and a change in pitch can lead to a monotone. It is important to remember that the person speaking will hear their voice as unchanged so they should be reminded to ‘speak up’.
• Handwriting changes – this is a common and obvious symptom. Handwriting especially cursive writing becomes smaller and more difficult to read. 
• Swallowing changes – these may include difficulty in chewing and an increased time required to chew food. Coughing with food or liquids may suggest changes to the swallow process. This can lead to chest infections due to aspiration.
• Sleep changes – these are a common early symptom such as frequent dreams, sleep talking and broken sleep.
• Bowel and bladder changes – constipation is often an early symptom but it can also be a side effect of Parkinson’s medications and it should not be ignored. Bladder problems often take the form of an urgent urge to empty the bladder. This requires assessment as it may be due to other conditions such as prostate gland changes in males.
• Fatigue – this is a common symptom of Parkinson’s and it is vital that light exercise such as walking be done in spite of the fatigue.
• Mood changes – symptoms such as anxiety, lack of motivation and depression may be experienced and can be disabling. Referral to appropriate support is essential.

Although advancing age is a major risk factor for developing Parkinson’s, around 1 in 20 people become aware of symptoms before the age of 40. Young Onset Parkinson’s is defined as being diagnosed between the ages of 21 and 40.

While the cause of Parkinson’s remains unknown it is widely accepted that Young Onset Parkinson’s may have an increased genetic factor. The accepted theories on causes of Parkinson’s such as environmental triggers and oxidative stress remain possible associated risks.

Younger people with Parkinson’s have identified their challenges as:

• Accurate and prompt diagnosis – referral to a neurologist who specialises in Movement Disorders is essential as currently there are no definitive diagnostic tests to confirm the diagnosis.
• Education and future planning – Parkinson’s Associations throughout Australia provide accurate material and access to Young Onset Support Groups.
• Occupation and lifestyle support – the ability to continue and maintain employment is a major factor for the younger group. While stress may heighten symptoms, support and understanding from employers and work colleagues will assist with continuation of employment. If difficulties are experienced assessment by an Occupational Therapist may be of benefit.
• Family and relationships – there are many social aspects to having a diagnosis of Young Onset Parkinson’s. Support and education for the person and family is essential as they adjust to the diagnosis. Open communication between partners is the key to maintaining relationships as Parkinson’s may impact on intimate relationships.
• Appropriate treatment choices – Young Onset Parkinson’s usually progresses slowly and medication may not be required for some time. Expert advice from the treating neurologist is essential.
• Deep Brain Stimulation – as age is a consideration in selection for this form of treatment for complex Parkinson’s is more likely to be an option for the younger population. This is because being g diagnosed at a younger age may mean that the complex stage will be reached at a younger age. Appropriate selection for DBS is vital to ensure the best outcome.
• Pregnancy – females with Young Onset Parkinson’s may consider choices concerning pregnancy. There is minimal data on the safety of Parkinson’s medications and the impact on the pregnancy.

The onset of Parkinson’s is gradual and obtaining a firm medical diagnosis can take some time in spite of the obvious nature of many of the symptoms.

Currently there is no definitive biological test or radiological procedure which can diagnose Parkinson’s. Autopsy based studies have shown that even among neurologists, the accuracy of diagnosis results in up to 25% of cases being proven incorrect. In spite of medical advances in the management of Parkinson’s the provisional medical diagnosis continues to be based on the clinical picture of the 4 main symptoms described above and a positive response to levodopa medication when it is introduced.

Specialised medical diagnosis

Most people will visit their general practitioner as they become aware of the development of symptoms and it is recommended that they request a referral to a neurologist or geriatrician with an interest in Parkinson’s. Parkinson’s WA Inc. can provide a comprehensive list of locally based specialists who have an interest in the treatment of Parkinson’s. Some hospitals will have clinics which specialise in Parkinson’s and offer specialised allied health services.

Diagnostic investigations

Magnetic resonance imaging (MRI) will be carried out to rule out any other neurological conditions which may resemble Parkinson’s.

Computerised tomography (CT) does not reveal any Parkinson’s related changes but will rule out structural abnormalities which may result in Parkinson’s-like symptoms.

If available, DaTscan will indicate a reduced uptake of dopamine in the brain. This can be of value in making a differential diagnosis.

An MIBG (metaiodobenzylguanidine) scan may be ordered to assist the differential diagnosis between Parkinson’s and a group of conditions known as Atypical Parkinsonism.

Parkinson’s is mainly related to a lack of dopamine as a result of degeneration of dopamine producing neurons within the mid-brain. Dopamine is a neurotransmitter which is vital in ensuring effective planning, initiation and maintenance of movement.

Most medical treatment options focus on restoring the balance of dopamine and other neurotransmitters. It is important to understand that these are treatment options and that they are not curative.

The gold standard medication used in the treatment of Parkinson’s is levodopa and a positive response to this medication assists in confirming the diagnosis. Levodopa is efficient in treating the symptoms of bradykinesia and muscle rigidity. Tremor, however, is the least responsive symptom.

In Australia, levodopa is available as several forms of oral medication:

• Kinson®
• Levo- Carbidopa®
• Madopar®
• Sinemet®
• Duodopa® is a gel form of levodopa which is delivered directly into the duodenum via a tube.

There are several other types of medications used in the management of Parkinson’s and information about these is available from Parkinson’s WA Inc. (external site). The medical management of Parkinson’s is as personalised as the presentation of the condition.

In addition to medication, surgery is an option for some cases but it is not considered as being suitable for all cases. The most common type of surgery is presently Deep Brain Stimulation (DBS) which is available in several metropolitan centres. Referral to these centres will be initiated by the treating neurologist if the person with Parkinson’s is considered a suitable candidate. DBS is also a form of treatment and does not stop the progression of the condition nor is it curative.