Parkinson's Disease
Posted by Brady Bunch on
This article was shortened for my blog, a longer version can be found at www.whelehans.ie or call in to Whelehans pharmacy Mullingar
Parkinson's disease is a long-term disorder of caused by the degeneration of dopamine generating cells in the mid-section of the brain. Its cause is unknown. Symptoms gradually worsen over time. The main symptoms are stiffness, shaking (tremor) and slowing of movement. There is no cure but treatment can slow down its progression and can provide good relief of symptoms for several years in most patients. Modern treatment options means that people with Parkinson’s can have a normal or near normal life expectancy.
Parkinson’s usually develops in people over the age of 50 and is rare in people under 50. It affects about 5 in 1,000 people in their 60s about 40 in 1,000 people over 80. Men are one and a half times more likely to get Parkinson’s than women.
With Parkinson’s, cells in the substantia nigra (the main messaging area in the brain for controlling muscles) become damaged and die over time. Dopamine, the main neurotransmitter becomes depleted due to degeneration of this area which causes Parkinson symptoms.
The three main symptoms are slowness of movement, stiffness and tremor.
There is no cure for Parkinson’s but treatments can ease symptoms and slow progression. It can take 8 to 10 weeks from the start of treatment before the patient notices improvement in symptoms.
Levodopa tends to give a good improvement in symptoms. Levodopa is converted to dopamine in the brain. The dose is started low but tends to be increased to control symptoms. Levodopa is always used in combination with another medicine to prevent side effects (either benserazide or carbidopa). Brands available include Madopar® and Sinemet®. Side effects from Levodopa tend to be rare at low doses. Nausea is the most common side effect. Other side effects which may occur include vomiting, dizziness, low blood pressure; however these often ease after a few days of use. Levodopa can also cause movement disorders (head nodding, jerking and twitches) if used at too high a dose. The effect of Levodopa tends to wear off over time, usually over a period of 3 to 5 years.
Dopamine agonists mimic dopamine. Ropinirole (Requip®), pramipexole (Mirapexin®) and rotigotine (Neupro® patch) are used most commonly. Initial side-effects are similar to levodopa (nausea, vomiting and dizziness) however side-effects tend to ease within a few days or weeks. Despite being slight less effective than Levodopa, one potential advantage of them as compared with levodopa is that they have less risk of causing movement disorders (described above). A dopamine agonist may be used in combination with levodopa as the condition gets worse. In trials comparing levodopa and dopamine agonists, symptoms of Parkinson’s improved with levodopa by about 40 to 50% as compared with approximately 30% with dopamine agonists.
Sometimes used as alternative to levodopa for early Parkinson’s. They include selegiline (Eldepryl®) and rasagiline (Azilect®). They work by blocking the effect of monoamine-oxidase-B (MAOB) in the brain, a chemical that prevents the breakdown of levodopa and dopamine. Blocking the effect of MAO-B means the effect of dopamine lasts longer. MAOBs are often used in combination with levodopa as the condition progresses.
Catechol-O-methyltransferase (COMT) inhibitors have become available in the last 20 years. Entacapone (Comtess® and also an ingredient in Stalevo®) is an example. A COMT inhibitor is often added to levodopa (as it increases its effect) when levodopa is not controlling symptoms sufficiently alone or where the effect of levodopa wears off. This is why Stalevo® has grown in popularity in recent years.
A physiotherapist can advise and help with movement. They will concentrate on posture, walking and exercises, thus maximising the length the person can move and manage independently. An occupational therapist can advise on areas that will make the person’s day to day living easier to manage and will advise on home adaptations and devices which can simplify tasks that become difficult due to the condition. A speech and language therapist can help if difficulties with speech, swallowing or saliva occur; these difficulties normally only occur later on in the condition.
Surgery will not cure Parkinson’s but may help ease symptoms when medicines are not working well. An example is chronic deep brain stimulation, a technique that involves putting a pulse generator (like a heart pacemaker) in the chest wall. Clinical trials are still underway for this therapy as long-term safety of this surgery is not certain so it is rarely used at the moment.
Limit caffeine intake as caffeine can act as a diuretic and increase the frequency of urination. Decrease fluids to either two hours before bedtime, this will reduce waking up at night to use the bathroom. Sleep deprivation can exacerbate symptoms of Parkinson's. At night, a portable urinal and or bedpan can be an alternative to getting out of bed to make trips to the bathroom which can be difficult. The shower area should be fitted with at least two handrails.
Symptoms tend to get worse with time but the speed of progression may vary significantly from person to person. Many do not need treatment initially as symptoms may be relatively mild. When symptoms become worse, medication can give several years of good or reasonable control of the symptoms. It is difficult to predict how quick the condition will progress. Some people may only have mild symptoms 20 years after diagnosis with other being disabled after only 10 years.
For comprehensive and free health advice and information call in to Whelehans, log on to www.whelehans.ie or dial 04493 34591. You can also e-mail queries to info@whelehans.ie.
Disclaimer: Please ensure you consult with your healthcare professional before making any changes recommended