Medical Myths: All about Parkinson’s disease

 April is Parkinson’s Awareness Month. With this in mind, this week’s edition of Medical Myths tackles the many misunderstandings that surround Parkinson’s disease. We discuss the symptoms and treatment, the outlook for people with the condition, and more.

Parkinson’s disease is a neurodegenerative movement disorder. Over time, dopamine-producing cells in a part of the brain called the substantia nigraTrusted Source deteriorate.

This deterioration, which leads to a reduction in dopamine, produces symptoms. The symptoms tend to develop slowly over time, often starting with a slight tremor in one hand or stiffness in movement.

Aside from tremor and stiffness, other symptoms include difficulties coordinating movements, changes in posture, a fixed facial expression, a reduced sense of smell, mood changes, and sleep problems.

As the disease progresses, some people with Parkinson’s develop dementia.

In 2016, an estimated 6.1 millionTrusted Source people worldwide had Parkinson’s disease. The number of cases has more than doubled in the last 25 years.

In this article, we dispel some of the most common myths associated with Parkinson’s disease.

Article highlights:

1. Parkinson’s only affects movement

It is true that the medical community considers Parkinson’s disease a motor disorder. However, people with the condition often also experience nonmotor symptoms, which can begin before the motor symptoms.

Nonmotor symptoms can include cognitive impairment or dementia, depression and anxiety, sleep dysfunction, pain, apathy, sexual dysfunction, and bowel incontinence.

People often overlook these symptoms, but they are important. As the authors of one paper on the topic explain:

“[N]onmotor symptoms dominate the clinical picture of advanced Parkinson’s disease and contribute to severe disability, impaired quality of life, and shortened life expectancy.”

2. Treatment only works for a few years

Although there is no cure for Parkinson’s disease, drugs can help people manage the condition. One of the most effectiveTrusted Source drugs is levodopa, which the body converts into dopamine once it enters the brain.

There is a long standing myth that levodopa can only relieve symptoms for about 5 years before it stops working. This is a myth. Levodopa can be effective for decades. However, over time, its effectiveness might reduce.

Medical News Today spoke with James Beck, Senior Vice President and Chief Scientific Officer of the Parkinson’s Foundation. He explained why levodopa becomes less potent:

“One of the cruel ironies about Parkinson’s disease is that the key enzyme that converts levodopa to dopamine (aromatic acid decarboxylase or AADC) is predominantly found in the dopamine neurons of the substantia nigra, which are lost during progression of the disease. So, the main way to make dopamine available to the Parkinson’s brain declines as the disease advances.”

In other words, it is not that levodopa stops being effective. Instead, the supply of the enzyme that it needs to be effective becomes more limited.

In the past, doctors and people with Parkinson’s have held off starting treatment because of fears that levodopa would slowly stop working. We now know, though, that this reduction in potency is due not to the length of time that a person takes levodopa but to the progression of the disease.

However, it is true that over time, each dose of levodopa might improve symptoms for a shorter period. This so-called wearing-off means that symptoms start to return before the next dose is due.

Source: Medical News Today