What causes dystonia? VCU researchers search for answers in number of studies

By Sean Gorman

May 11, 2023

Researchers at the VCU Parkinson’s and Movement Disorders Center are seeking to shed light on what causes dystonia, a chronic and frequently disabling and painful neurological disorder that causes muscles to spasm forcing the body into abnormal movements and postures.

PMDC Director Brian Berman, MD, who has been interested in the disorder since his time in medical school, has worked to increase the center’s research portfolio in dystonia.

An estimated 300,000 people have dystonia in the U.S., but this number is thought to be an underestimate as it is an often-underdiagnosed disorder. “The problem with dystonia is that we think it affects a lot more people than who are diagnosed with it because it's underrecognized,” says Berman, an associate professor in the VCU School of Medicine’s Department of Neurology. “A lot of people have it and don't know that they have it, don't get the right treatment, or don’t get treated soon enough after the symptoms begin.”

Dystonia is considered the third most common movement disorder, Berman notes. The disorder can be a spontaneous isolated condition, or it can be seen in patients taking anti-psychotic medications as well as those with Parkinson’s disease or those who have suffered a stroke or traumatic brain injury. In many cases, the root cause of a patient’s dystonia remains a mystery.

“It’s clear that current treatment options are pretty poor. We do our best with medications, but they often aren't very effective or require repeated painful injections,” Berman says. “Ultimately, we want to have better treatments and hopefully cures.”

Berman wrote his first medical paper on botulinum toxin treatments for dystonia. During his neurology residency, he completed a study on how dystonia responds to deep brain stimulation.

“It’s a complex, challenging disorder,” he says. “Dystonia can be very disabling. If it affects the eyelids, it can cause functional blindness. If it affects the neck muscles, it can impact daily functioning and lead to diminished quality of life. If it affects the vocal cords, it can impair speech. If it affects limb muscles, it can impact handwriting and walking.”

Caileigh Dintino, B.S., a PMDC clinical research assistant working with dystonia patients involved in the Center’s studies, has learned from them about how the disorder impacts their way of life.

“Beyond the pain, a lot of people with dystonia end up not being able to drive, function at work, or complete daily tasks comfortably on their own,” she explains. “That’s a huge hit to someone’s independence.”

This June, Dintino will travel to the International Dystonia Symposium in Dublin, Ireland to present preliminary findings from a PMDC study investigating blepharospasm, which is when dystonia affects the muscles of the eyelids and upper face.  

Dozens of patients from around the U.S. are taking part in a half-dozen dystonia research projects that Berman leads at the PMDC. Those studies seek a better understanding of its cause, improved ways to diagnose dystonia, and better ways to treat it.

Several VCU PMDC research projects are being conducted through the Dystonia Coalition, a multicenter consortium of academic medical centers from around the globe. One of those projects uses patient surveys and videos of their neurological exams to train software to track symptom severity and gauge how symptoms change over time. Another seeks patient feedback on how botulinum toxin injections are affecting their motor and neuropsychiatric symptoms and impacting their activities of daily living. A third project draws samples of a patient’s blood in order to create a “biobank” for protein biomarker and DNA testing in order to better understand what causes the disorder.

Developing an effective tool to spot depression and anxiety in dystonia patients is the target of another VCU PMDC study. Further research is examining levels of a major inhibitory chemical in the brain known as GABA (Gamma-aminobutyric acid) and whether abnormal levels in patients with dystonia can be used to better diagnose dystonia and track its symptoms. (Find more information on the two GABA studies here and here).

As they’re undertaking these studies, a team of PMDC researchers are also seeking research funding to investigate the use of non-invasive transcranial neurostimulation techniques to alleviate dystonia symptoms. He says there are only a handful of movement disorders centers around the country undertaking the amount of clinical research into dystonia that the VCU PMDC is conducting.

“We’ve had an active and extensive research program in Parkinson’s disease as well as Huntington’s disease,” Berman says. “Our growing focus on dystonia is another way we’re trying to improve the lives of those impacted by movement disorders.”