Much is known about Parkinson’s disease and our understanding of this illness is increasing rapidly. However, we still don’t know what causes it, why some people get it while others do not, and how can it be cured.
Since the discovery in 1959 that the brains of people with Parkinson’s disease were deficient in the neurotransmitter chemical dopamine, and the introduction of the medication levodopa in 1967, treatment for Parkinson’s disease has been largely driven by methods to replenish dopamine in the brain.
Now, work is underway not only to deliver medications more effectively and to reduce the need to take them orally, but also to address the disease itself rather than simply to treat its symptoms.
Treating Parkinson's before tremors begin
We also want to diagnose Parkinson’s disease much earlier, before signs of motor impairment, such as walking difficulties, posture problems and tremors when at rest. Over the last decade, we have identified several symptoms that may precede the onset of motor difficulties by many years.
For example, a sleep-associated symptom called “rapid eye movement sleep behavior disorder” has been found to be present in Parkinson’s disease patients perhaps decades before the initial motor symptoms of the disorder. This symptom is characterized by the inability to relax muscles while dreaming.
Catching other symptoms early
Another symptom is impaired sense of smell. Many Parkinson’s disease patients experienced a noticeable impairment in their sense of smell years before their initial motor symptoms.
A recently published study suggests Parkinson’s patients may experience constipation, anxiety and depression by about a decade before motor symptoms are evident.
If we are able to use these symptoms to diagnose Parkinson’s, it may be possible to develop curative treatments at the very earliest stages.