Parkinson’s Disease

Symptoms start gradually, sometimes starting with a barely noticeable tremor in just one hand. Parkinson’s disease symptoms vary and tend to worsen as the condition progresses over time.

Parkinson’s signs and symptoms may include:

• Tremors, especially in hands or fingers, are common
• Pill-rolling tremor – rubbing thumb and forefinger back and forth
• Slowing of movement, making walking and other tasks difficult and time-consuming
• Muscle stiffness, in any part of the body, can be painful and limit movement
• Impaired posture and balance
• Loss of automatic unconscious movements, including facial expressions and swinging arms when walking

• Speech changes – speech may become soft or slurred

Symptoms often begin on one side of your body and usually remain worse on that side, even after symptoms begin to affect both sides.

Parkinson’s disease is often accompanied by these additional problems, which may be treatable:

• • Cognitive problems (dementia) and thinking difficulties, usually occur in the later stages of Parkinson’s disease. 
  • Depression and emotional changes, sometimes in the very early stages
  • Problems with eating, swallowing, and drooling

• Sleep problems and sleep disorders

• Bladder problems or constipation

• • Sudden drop in blood pressure when standing up (orthostatic hypotension)

• Smell dysfunction

• Fatigue

• Pain
• Sexual dysfunction

In Parkinson’s disease, certain nerve cells (neurons) in the brain gradually break down or die. This leads to a reduction in a chemical messenger in your brain called dopamine, leading to impaired movement and other symptoms.

The cause of Parkinson’s is currently unknown, but certain risk factors have been identified:

• Certain genetic variations appear to increase the risk of Parkinson’s disease -but with a relatively small for each of these genetic markers
• Genetic mutations – uncommon except in rare cases with many family members affected by Parkinson’s disease
• Exposure to certain toxins or environmental factors may increase the risk of later Parkinson’s disease – but the risk is relatively small
• Men are more likely to develop Parkinson’s disease than are women
• The risk increases with age and the condition is usually diagnosed in those aged 60 or older

Microscopic changes in the brains of people with Parkinson’s disease have been identified, including the presence of Lewy bodies – clumps of specific substances, including a protein called alpha-synuclein (a-synuclein) – within brain cells, although it is not clear why these changes occur:

• No specific test exists to diagnose Parkinson’s disease. 

  A specialist neurologist can diagnose Parkinson’s disease based on medical history, neurological and physical examination, and assessment of signs and symptoms over time. It can take time to reach a definitive diagnosis of Parkinson’s disease.

  Imaging tests, such as an MRI, ultrasound of the brain, and PET scans, may be used to help rule out other disorders but are not particularly helpful for diagnosing Parkinson’s disease.

  A dopamine transporter scan (DaTscan) using CT imaging, may provide beneficial insights to help a doctor confirm a Parkinson’s diagnosis in the early stages of the disease.

  Blood tests, or other lab tests, may be useful to rule out other conditions that may be causing symptoms.

  The Parkinson’s disease medication carbidopa-levodopa may be given as a test, in a sufficient dose. Significant improvement with this medication may confirm a diagnosis of Parkinson’s disease.

Parkinson’s disease cannot be cured, but medications which increase or substitute for dopamine can significantly improve symptoms. However, the benefits of drugs may diminish or become less consistent over time.

Medications your doctor may prescribe include:

• Levodopa (combined with carbidopa), the most effective Parkinson’s disease medication, is a natural chemical that passes into your brain and is converted to dopamine. Side effects may include nausea or light-headedness (orthostatic hypotension).

An inhaled form of carbidopa-levodopa (Inbrija) may be helpful in managing symptoms that arise when oral medications suddenly stop working during the day.

Carbidopa-levodopa may also be given as an infusion (Duopa) through a feeding tube directly to the small intestine for patients with more-advanced Parkinson’s who still respond to carbidopa-levodopa, but who have a lot of fluctuations in their response.  Placement of the tube requires a small surgical procedure. Risks associated with having the tube include the tube falling out or infections at the infusion site.

• Dopamine agonists which mimic dopamine effects in the brain are not as effective as levodopa. However, they last longer and may be used with levodopa to smooth the sometimes off-and-on effect of levodopa.

Some of the side effects of dopamine agonists are similar to the side effects of carbidopa-levodopa. But they can also include hallucinations, sleepiness and compulsive behaviours. If you are taking these medications and you behave in a way that is out of character for you, talk to your doctor.

• MAO B inhibitors may help prevent the breakdown of brain dopamine by inhibiting the brain enzyme monoamine oxidase B (MAO B). This enzyme metabolizes brain dopamine. 

Side effects of MAO B inhibitors may include headaches, nausea or insomnia. When added to carbidopa-levodopa, these medications increase the risk of hallucinations. There are potentially serious but rare reactions when taken with antidepressants or certain narcotics.

• Catechol O-methyltransferase (COMT) inhibitors can mildly prolong the effect of levodopa therapy by blocking an enzyme that breaks down dopamine.

Side effects, including an increased risk of involuntary movements (dyskinesia), mainly result from an enhanced levodopa effect. Other side effects include diarrhoea, nausea or vomiting.

• Anticholinergics were used for many years to help control the tremor associated with Parkinson’s disease. However, their modest benefits are often offset by side effects such as impaired memory, confusion, hallucinations, constipation, dry mouth and impaired urination.

• Amantadine may be prescribed alone to provide short-term relief of symptoms of mild, early-stage Parkinson’s disease. It may also be given with carbidopa-levodopa therapy during the later stages of Parkinson’s disease to control involuntary movements (dyskinesia) induced by carbidopa-levodopa. Side effects may include a purple mottling of the skin, ankle swelling or hallucinations.

Your doctor may also recommend lifestyle changes, especially ongoing aerobic exercise.

Physical therapy, focusing on balance and stretching may help in some cases.

A speech-language pathologist may help with speech problems.

Occasionally, your doctor may suggest surgery to regulate certain regions of your brain and improve your symptoms.

Deep brain stimulation (DBS), most often offered to people with advanced Parkinson’s disease who have unstable medication responses – involves implanting electrodes into a specific part of the brain to send electrical pulses to the brain which can stabilize medication fluctuations or reduce tremors.

Surgery involves risks, including infections, strokes or brain haemorrhage. Some people experience problems with the DBS system or have complications due to stimulation, and your doctor may need to adjust or replace some parts of the system.

As research is ongoing into the causes of Parkinson’s disease, there are currently no proven ways to prevent the disease.

Some research has shown that regular aerobic exercise might reduce the risk of Parkinson’s disease.