Of all the debilitating neurodegenerative diseases known, Parkinson's disease is among the worst. When it comes to its diagnosis stage, time is literally of the essence. Because the earlier the condition is detected, the easier its long-term management becomes. Now, a new study has demonstrated that a simple skin test helps in the accurate identification of the progressive nervous system ailment.
According to researchers from Iowa State University, the study is the first to substantiate the effectiveness of the method. The study outlines the manner in which the disease can be diagnosed using a chemical essay that can spot the clumping—the aggregation of cells and debris—of a protein known as alpha-synuclein found in skin samples.
"Since there's no easy and reliable test available for the early diagnosis of Parkinson's disease at present, we think there will be a lot interest in the potential use of skin samples for diagnosis," expressed Dr. Anumantha Kanthasamy, lead author of the study, in a statement. He also added that the early detection of the disease can help clinicians in testing novel therapeutic strategies meant for slowing or preventing the progression of symptoms.
Declining Neurological Functions
Parkinson's disease is a condition that leads to the gradual decline of the central nervous system functions. Unfortunately, the effect of the disease is irreversible and only worsens over a long-term period. It manifests in the form of deteriorating motor functions such as stiffness, shaking, loss of balance and coordination, and difficulty in walking.
Parkinson's disease is caused when neurons in the area of the brain that controls movement are damaged or die due to the accumulation of misfolded alpha-synuclein proteins. As the neurons are incapable of producing a vital chemical known as dopamine at optimum levels, it affects movements.
According to the US National Institute of Aging (NIH), the disease mostly begins developing in individuals who are aged around 60 years. However, 5 to 10 percent of patients are known to have an "early-onset" of the condition—before the age of 50. Currently, the only method of diagnosing Parkinson's disease is through the identification of clinical symptoms and signs, with a conclusive diagnosis received through an autopsy after death.
Finding Answers In the Skin
For the study, the authors carried out a blind study using 50 skin samples obtained from the Banner Sun Health Research Institute. Half of the samples were from individuals who did not have any neurological diseases (control group), while half came from patients suffering from Parkinson's disease.
The study borrows from a technique known as the real-time quaking-induced conversion assay. Interestingly, the test was designed for the diagnosis of mad cow disease or Bovine spongiform encephalopathy (BSE), which is a neurodegenerative disease in cattle.
Dr. Kanthasamy's team had re-calibrated the test to detect misfolded proteins in similar human and animal disorders. Co-investigators of the study have discovered that these misfolded alpha-synuclein proteins can accumulate in other tissues of the body, such as the skin.
Accurate Diagnosis of Parkinson's Disease
Employing the customized protein assay, the scientists were able to precisely diagnose 24/25 of patients with Parkinson's disease. Only one out of the 25 samples in the control group was found to have protein clumping. "These results indicate tremendously high sensitivity and specificity which is critical for a diagnostic test," said Dr. Charles Adler, a co-investigator of the study.
Dr. Thomas Beach, another co-investigator of the study, opined that accurate clinical diagnosis of Parkinson's disease was essential for the development of new and effective treatments for it. "The clinical diagnostic accuracy for early-stage PD has been quite poor, only around 50-70 percent. And since clinical trials really need to be done at an early stage to avoid further brain damage, they have been critically hampered because they have been including large percentages of people who may not actually have the disease," concluded Dr. Beach.