Parkinson’s Disease

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What is Parkinson’s Disease?

Parkinson’s disease is a disorder in which the nervous system gradually deteriorates. Movement is reduced. The disease most commonly starts with a small tremor in a person’s hand. Early symptoms also include slow movements, stiffness, lack of facial expression and slurred speech.

While there is no cure for Parkinson’s disease, there are medications to treat symptoms.

Symptoms of Parkinson’s Disease

The symptoms for Parkinson’s disease are different for each person. They usually include:

  • Tremors or shaking. This usually starts in the hands or fingers, especially the thumb and forefinger, even at rest.
  • Slowed movements (bradykinesia). As Parkinson’s progresses, the ability to move decreases and movements become slower. Walking and getting out of your seat becomes difficult.
  • Muscle stiffness. You may find that you have decreased range of motion, and pain caused by stiff muscles.
  • Poor posture and balance. You may have a stooped posture and/or problems balancing.
  • Reduction in automatic movements. You may find that you are unable to perform some unconscious actions like smiling and blinking.
  • Changes in speech. You may have problems with your speech, and/or find that your speech is soft, quick, or slurred. You may also start speaking with a monotone.
  • Changes with writing. You may no longer be able to write well, or you may only be able to write in small letters.

See a doctor right away if you notice that you have any of the above symptoms. This will help to diagnose the disease early and allow you to begin symptom-relieving treatments early.

survival in people with PDCauses of Parkinson’s Disease

Parkinson’s disease is called by the gradual death of nerve cells in the brain called neurons. The loss of neurons results in a decrease in a chemical messenger called dopamine that is produced by certain neurons. Due to the reduction in dopamine levels, the brain has abnormal activity that causes the symptoms observed in Parkinson’s.

The specific cause of Parkinson’s disease is not known. Factors known to contribute include:

  • Specific genetic mutations can cause Parkinson’s disease. These are uncommon. Some gene variations may also increase the risk of Parkinson’s disease, each by a small amount.
  • Having been exposed to some toxins can increase the risk of Parkinson’s disease later in life, but this has a small contribution.
  • Lewy bodies in the brain. Clumps of protein called Lewy bodies are found in brain cells of Parkinson’s patients. They are a hallmark of the disease, although it is unclear how they may cause Parkinson’s disease.
  • Alpha-synuclein in Lewy bodies. Many substances make up Lewy bodies, and one of them is called alpha-synuclein. It is usually found in clumps that cannot be broken down by the brain cells, and is a focus of Parkinson’s disease research.

Risk factors of Parkinson’s Disease

Risk factors for Parkinson’s include:

  • The risk of Parkinson’s increases with age. Parkinson’s normally develops around ages 60 and up.
  • Men have a greater risk of developing Parkinson’s than women.
  • Family history. If a close relative has or has had Parkinson’s, your risk is increased. This increase in risk is small unless many family members have had Parkinson’s.
  • Toxin exposure. There is an increased risk of Parkinson’s due to exposure to pesticides and herbicides.

Complications of Parkinson’s Disease

Additional problems arise in Parkinson’s disease, including:

  • Difficulties with thinking. In later stages of the disease, dementia and other thinking difficulties arise.
  • Emotional changes. Depression, anxiety, fear, and lack of motivation can be treated with medications.
  • Problems with swallowing. Due to a slowed or lost ability to swallow, drooling may occur.
  • Sleep problems. Parkinson’s results in frequent waking at night, waking up early, and sleeping during the day. Medications are available to relieve these problems.
  • Urination problems. There may be difficulty urinating, or an inability to control urination.
  • Constipation can be caused by the reduced functioning of the digestive tract.
  • Low blood pressure. Low blood pressure results in light-headedness and dizziness when quickly standing.
  • Problems with smelling. Odors may not be easily identified or distinguished.
  • Pain can occur in specific locations, or throughout the body.
  • Lack of energy and tiredness is found to occur in Parkinson’s.
  • Sexual dysfunction. Sexual performance and desire is reduced.

Tests and diagnosis of Parkinson’s Disease

There are no tests available to diagnose Parkinson’s. A neurologist, who is a doctor that specializes in the nervous system, uses a combination of symptoms, medical history and physical and neurological examinations to diagnose Parkinson’s. Blood tests and imaging tests (e.g., MRI, ultrasound and PET scans) may be used to rule out other causes of your symptoms.

A medication for Parkinson’s called carbidopa-levodopa may be given to you. A Parkinson’s diagnosis is confirmed if symptoms are significantly reduced by the drug.

A diagnosis sometimes requires multiple appointments with neurologists to track symptoms over time.

Medications

Although there isn’t a cure for Parkinson’s, there are medications that can help to relieve symptoms, sometimes significantly. For later stage Parkinson’s, surgery is an option.

Medications prescribed for Parkinson’s include:

  • Carbidopa-levodopa. Levodopa, a chemical that can enter the brain and is converted to dopamine, is the most effective treatment for Parkinson’s. It is combined with carbidopa, a chemical that prevents the conversion of levodopa to dopamine before it enters the brain. This medication can sometimes cause light-headedness or nausea. Higher levodopa doses may cause involuntary movements (dyskinesia).

The benefits from carbidopa-levodopa reduce and become less predictable (wax and wane) as the disease progresses.

As of 2015, carbidopa-levodopa is available in a gel form called Duopa. It is delivered straight to the small intestine through a feeding tube. This form of the medication helps to lessen the fluctuations in the benefits of the drug experienced by people with advanced Parkinson’s by making the drug levels more constant in the blood. A small surgery is required to place the feeding tube. The risks associated with having a tube include that it may fall out, or the placement site may become infected.

  • Dopamine agonists. These drugs are not converted into dopamine, but act like dopamine in the brain. They do not treat Parkinson’s symptoms as well as levodopa, but last longer and also help to relieve the waxing and waning of levodopa effects. Examples of dopamine agonists include ropinirole (Requip), and pramipexole (Mirapex), as well as rotigotine in patch form (Neupro), and apomorphine in injectable form (Apokyn).

Dopamine agonists can also cause light-headedness and nausea, as well as sleepiness, hallucinations and compulsive behaviours (e.g., gambling, heightened sex drive, and overeating).

  • MAO-B inhibitors. These medications helps to stop an enzyme called monoamine oxidase B (MAO-B) in the brain from breaking down dopamine. MAO-B inhibitors include rasagiline (Azilect) and selegiline (Zelapar, Eldepryl). They may cause sleeplessness, nausea, and, when combined with carbidopa-levodopa, hallucinations.
  • COMT inhibitors. This type of medication stops an enzyme called catechol-O-methyltransferase from breaking down dopamine in the brain. It is used as a supplement to levodopa. The most commonly used COMT inhibitor is entacapone (Comtan). There is also tolcapone (Tasmar), but because of the high risk of liver damage and liver failure associated with it, it is not usually prescribed. Side effects of COMT inhibitors are diarrhea and dyskinesias.
  • These drugs block the action of a chemical messenger in the brain called acetycholine that helps control muscle movement. They improve tremors, but do not help to relieve muscle stiffness and slowness as much. They were the first drugs to be widely used for the treatment of Parkinson’s, but are now less commonly used due to their many side effects, including constipation, confusion, memory impairment, hallucinations, dry mouth, and problems urinating.
  • Amantadine works by increasing dopamine release and blocking dopamine reuptake in the brain. It can be used alone for short-term relief of mild Parkinson’s disease, or combined with carbidopa-levodopa in advanced Parkinson’s to help control dyskinesias. Side effects include hallucinations, swelling of the ankles, and skin mottling.
  • Deep brain stimulation (DBS). DBS is a surgical procedure used to treat Parkinson’s, in which electrodes are implanted into a certain part of the brain. A generator to which the electrodes are attached is implanted near the collarbone. The generator sends electrical pulses through the electrodes to the brain to improve Parkinson’s symptoms.

The risks associated with DBS include stroke, hemorrhage and infections at implantation sites. Adjustments and replacements of different parts of the system are further complications.

DBS is usually prescribed for advanced Parkinson’s in which the benefits from levodopa have become unstable, and can also help with dyskinesias, tremors, and movement stiffness and slowness. Symptoms that do not respond to levodopa will not be helped by DBS, except for tremor.

Lifestyle

Lifestyle changes can play a big part in relieving the symptoms of Parkinson’s. Some lifestyle changes include:

  • Food choices. Eating food with lots of fiber and staying hydrated can relieve the constipation associated with Parkinson’s.
  • Routine exercise improves balance, flexibility and strength, and also reduces the cognitive symptoms of Parkinson’s including anxiety and depression.
  • Physical therapy. A physical therapist may be needed to design and facilitate an individualized exercise program. Programs can include exercises like dancing, swimming, stretching, walking, and water aerobics. There are also exercises specifically targeted to improving your balance, flexibility and walking ability.
  • Speech therapy. Speech problems can be improved with a speech-language pathologist.
  • Occupational therapy. An occupational therapist can help make daily activities easier including writing, eating, bathing and dressing.

Alternative medicine

Alternative medicine that can help with the symptoms of Parkinson’s include:

  • Massage helps to relieve stiff muscles and induce overall relaxation.
  • Tai chi. Tai chi is an ancient Chinese exercise appropriate for any age and ability that incorporates controlled, slow, and flowing movements. Tai chi can improve balance, flexibility and strength, reducing the risk of falls for advanced Parkinson’s patients.
  • This treatment involves the insertion of very thin needles into certain points of the body in order to relieve pain.
  • Stationary poses and gentle stretches help to improve balance, flexibility and muscle strength. Yoga can be adapted to all ages and abilities.
  • Quiet reflection and focusing the mind on the present moment can relieve stress and reduce pain.
  • Music, art, and pet therapy. These therapies are used to induce relaxation, and improve mood, speech and walking ability.
  • Alexander technique. This technique involves thinking about the use of muscles during posturing and balancing, and helps to relieve pain and stiffness in muscles.
  • Coenzyme Q10. Taking high doses of this supplement may help in early Parkinson’s disease if taken for 16 months and longer.

 

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References

David J. Brooks. “Parkinson’s disease: diagnosis.” Parkinsonism Relat Disord. 2012;Suppl 1:S31-33. doi: 10.1016/S1353-8020(11)70012-8.

Link: http://www.sciencedirect.com/science/article/pii/S1353802011700128

J Jankovic. “Parkinson’s disease: clinical features and diagnosis.” J Neurol Neurosurg Pyschiatry. 2008;79(4):368-376. doi: 10.1136/jnnp.2007.131045.

Link: http://jnnp.bmj.com/content/79/4/368.long

David J. Pedrosa & Lars Timmermann. “Review: management of Parkinson’s disease” Neuropsychiatr Dis Treat. 2013;9:321-340. doi: 10.2147/NDT.S32302.

Link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3592512/

Joshua M. Shulman, Philip L. De Jager, Mel B. Feany. “Parkinson’s Disease: Genetics and Pathogenesis.” Annu Rev Pathol. 2011;6:193-222. doi: 10.1146/annurev-pathol-011110-130242.

Link: http://www.annualreviews.org/doi/abs/10.1146/annurev-pathol-011110-130242?url_ver=Z39.88-2003&rfr_dat=cr_pub%3Dpubmed&rfr_id=ori%3Arid%3Acrossref.org&journalCode=pathmechdis

Karin Wirdefelt, Hans-Olov Adami, Philipe Cole, Dimitrios Trichopoulos, Jack Mandel. “Epidemiology and etiology of Parkinson’s disease: a review of the evidence.” Eur J Epidemiol. 2011;26:S1-S58. doi: 10.1007/s10654-011-9581-6.

Link: http://link.springer.com/article/10.1007%2Fs10654-011-9581-6