Researchers are calling it a breakthrough – a first-of-its-kind imaging tool to detect myelin damage in people suffering from multiple sclerosis (MS). The test could help physicians diagnose MS earlier, monitor the disease’s progression, and evaluate the effectiveness of treatment.
Scientists at Cleveland’s Case Western Reserve University School of Medicine have developed a molecular probe that can be detected by positron emission tomography (PET) imaging. The new molecular marker, called MeDAS, offers the first non-invasive visualization of myelin integrity of the entire spinal cord.
“While MS originates in the immune system, the damage occurs to the myelin structure of the central nervous system,” said Yanming Wang, PhD, associate professor of radiology and senior author of the study published in the journal Annals of Neurology.
The traditional imaging test for diagnosing MS is magnetic resonance imaging (MRI), which can show inflammation and is helpful at diagnosing the disease in its early stages, but cannot accurately track its progression.
By injecting MeDAS into the spinal cords of mice and rats that have an animal model of the disease, scientists were able to show and quantify the damage done to the animals’ myelin.
“Because of its shape and size, it is particularly difficult to directly detect myelin damage in the spinal cord. This is the first time we have been able to image its function at the molecular level,” said Wang.
“Our discovery brings new hope to clinicians who may be able to make an accurate diagnosis and prognosis in as little as a few hours compared to months or even years.”
The MeDAS molecular probe works like a homing device. Injected into the body intravenously, it is programmed to seek out and bind only to myelin in the central nervous system. A positron-emitting radioisotope label on the molecule allows a PET scanner to detect the targets and quantify their intensity and location. The data can then be reconstructed into an image.
“This is an indispensable tool to help find a new way to treat MS down the road” said Chunying Wu, PhD, first author of the study and instructor of radiology at Case Western Reserve. “It can also be used as a platform technology to unlock the mysteries of other myelin related diseases such as spinal cord injury.”
Currently, a long lag exists between the onset of MS and its diagnosis. The lesions or plaques detected by an MRI of the brain and spinal cord are not myelin specific, and thus poorly associated with a patient’s disease or progression. That’s created an urgent need to finding a new imaging marker that correlates with a patient’s pathology.
“This discovery has opened the door to develop new drugs that can truly restore nerve function, not just modify the symptoms,” said Robert Miller, PhD, co-author on the study and vice president for research for Case Western Reserve and the Allen C. Holmes Professor of Neurological Diseases at the School of Medicine.
“A cure for MS requires both repairing myelin and a tool to measure the mechanism.”
Wang said the technique may also be of use in other diseases that involve nervous system damage, such as Alzheimer’s disease, spinal cord injury and stroke.
The most common acquired autoimmune disease, MS affects about 400,000 Americans and more than two million people worldwide. The disease is two to three more times common in women.
MS is a chronic disease which attacks the body’s central nervous system and is characterized by the destruction of myelin, the membrane that protects nerves. Once damaged, it inhibits the nerves’ ability to transmit electrical impulses, causing cognitive impairment and mobility dysfunction.
For most people with MS, relapses are initially followed by recovery periods or remissions. Symptoms may be mild or severe, ranging from numbness in the limbs to paralysis or loss of vision.
The progression, severity and symptoms of MS are unpredictable and vary from one person to another. Over time, recovery periods may be incomplete, leading to progressive decline.
There is no cure for MS. The only therapies available are ones that modify its symptoms.
(Editor’s Note: Do you have MS and like to write? National Pain Report is looking for a monthly or bi-monthly columnist to write about their experiences dealing with MS, including medications, treatments and its impact on life, work, family, etc. A great opportunity to help spread awareness about MS.