This article originally appeared in the Winter 2007-2008 edition of PDF's quarterly newsletter, News & Review.
Tests of balance, probing questions, interviews of friends and family: to a person with Parkinson’s disease (PD), these assessments will sound familiar, because they represent several of the ways in which doctors diagnose PD.
Unlike other conditions that can be diagnosed through blood tests or biopsies, there is no definitive test or “biomarker” that can identify PD or trace its development. A clinician, researcher and teacher, Dr. Claire Henchcliffe is aiming her sights on finding that elusive biomarker.
Dr. Henchcliffe has had constant contact with patients during her past six years as a movement disorder specialist, a practice that began during her clinical fellowship with Dr. Stanley Fahn at Columbia University. Through her practice and her role as founder of a PD support group at Weill Cornell, she has seen first-hand the limitations that exist without a reliable PD measurement tool.
Why is a biomarker so important? Dr. Henchcliffe says a biomarker would enable physicians to diagnose Parkinson’s earlier, perhaps even before physical symptoms appear. This in turn would allow for earlier treatment, including the testing of therapies that may prevent the cell death that causes PD. Additionally, she says, “PD is a very heterogeneous disease.” Its symptoms, from tremors, to slowness, to depression, can vary tremendously among people with PD, as can responses to treatments. Since people with PD do not fall into a single category, neither, in Dr. Henchcliffe’s opinion, should their treatment. A biomarker would allow physicians to detect differences among patients and therefore develop individualized treatment plans.
As a researcher, Dr. Henchcliffe, under the tutelage of Dr. M. Flint Beal, is especially interested in the role of the mitochondria, the part of a cell that generates its energy, in Parkinson’s disease.
They are currently studying two potential avenues for biomarking that are related to the mitochondria. The first, magnetic resonance spectroscopy (MRS) would non-invasively measure specific chemicals in the brain to study both how well the mitochondria of the cell are functioning and whether there are any differences in metabolism among different areas of the brain. The team is also investigating a potential PD blood test that would utilize “metabolomics” to evaluate cellular processes, including cellular energy metabolism and mitochondrial function. Studies using both methods have demonstrated great promise to date.
Dr. Henchcliffe believes that using biomarkers could lead to improved treatments and is pursuing this path through her involvement in the clinical trial for Coenzyme Q10 (CoQ10), funded by the National Institute of Neurological Disorders and Stroke. CoQ10, a naturally occurring substance in the body, plays a key role in the function of the mitochondria. It is an over-the-counter diet supplement and may be capable of slowing the progression of PD. This winter, a CoQ10 clinical trial, led by Dr. Beal, will begin enrolling 600 people who have early-stage PD and who are not taking any medications.
In addition to her dual roles of clinician and researcher, Dr. Henchcliffe co-chairs the Working Group on Biomarkers of the Parkinson Study Group (PSG). She also mentors medical students and residents and frequently lectures and writes about PD.
Dr. Henchcliffe’s work is supported as part of PDF’s Center Grant to Weill Cornell Medical Center. For FY 2008, PDF’s grant of $100,000 provides partial funding to Dr. Henchcliffe’s research.