What Is Parkinson’s

Parkinson’s Disease (PD) is a progressive neurodegenera- tive movement disease affecting over 1% of people by the age of 60 and is the second most commonly occurring neurodegenerative disease in the elderly (after Alzheimers), with an estimated 8 million sufferers worldwide. The disease has been known for over 200 years and is named after an English doctor, James Parkinson, who published the first detailed description in ‘An Essay on the Shaking Palsy’ in 1817. The loss of dopamine-producing neurons, in a section of the mid-brain called the substantia nigra, results in a range of both motor (that is, referring to motion) and non-motor symptoms, and someone can have the disease for 5 to 10 years before it is diagnosed, by which time the majority of the neurons in the affected part of the brain may have already been lost. The cause of this cell death is poorly understood, but involves the build-up of misfolded proteins into Lewy bodies in the neurons. The underlying cause of PD is also unknown, with both inherited and environmental factors being believed to play a role. Those with a family member affected by PD are at an increased risk of getting the disease, with certain genes known to be inheritable risk factors. Other risk factors are those who have been exposed to certain pesticides (such as dieldrin and paraquat) and people who have prior head trauma. At present, diagnosis of PD relies on observation of patient movement and in a clinical setting it is commonly misdiag- nosed or missed completely – with primary care doctors making an incorrect diagnosis more than half of the time and only movement disorder specialists achieving reliable diagnostic accuracies. PD can cause tremor, slowness, stiffness, and walking and balance problems, and hence it is called a ‘movement disorder’. Even though there are existing treatments to alle- viate some of the effects of the disease, at present there is neither any cure nor any means of slowing its progression. The reason that people with PD may already have the disease for many years before it is diagnosed is because they only start noticing the symptoms later in the course of the disease, once a significant proportion of the substantia nigra neurons have gone. In addition to movement-related (‘motor’) symptoms, some Parkinson’s symptoms are unrelated to movement (‘non- motor’), and people with PD are often more impacted by their non-motor symptoms. Examples of the non-motor symptoms include apathy, depression, constipation, sleep behavior disorders, loss of sense of smell and cognitive impairment. Treatment aims to reduce the effects of the symptoms, with initial treatment typically being with the medications levodopa (L-DOPA), MAO-B inhibitors, or dopamine agonists. People with PD need this medication because they have low levels or are missing dopamine in the brain, due to the loss of neurons that produce it. On a positive note, it is possible for someone with PD to have a good quality of life for many years. Working with your doctor and following the recommended therapies are essential in successfully treating symptoms with dopamin- ergic medications.