A recent study from the Krembil Brain Institute provides insights into how a severe form of epilepsy known as Dravet syndrome affects older adults.
Dravet syndrome is a rare, lifelong condition that begins in infancy and causes frequent seizures. Other common symptoms in children with Dravet syndrome include developmental delay and problems with balance and walking. Seizure frequency tends to decrease in adulthood, but other symptoms of Dravet syndrome have not been well-characterized in adults.
To deepen our understanding of how Dravet syndrome affects adults, a team led by Dr. Danielle Andrade, a Clinician Investigator at the Krembil Brain Institute and Medical Director of UHN’s Epilepsy Program, examined motor symptoms, such as difficulty walking, resting tremor and abnormal body movements. Participants were recruited through the Adult Genetic Epilepsy (AGE) Program at Toronto Western Hospital.
“Parents of those with Dravet syndrome often report that their children lose certain skills, including the ability to walk, when they become adults,” says Arunan Selvarajah, an MSc graduate from Dr. Andrade’s lab and first author of the study. “We wanted to objectively test these age-related changes to better understand the disease and improve how we manage it.”
The team used standard assessment tools to evaluate two groups of patients: a smaller group of patients was observed over a five-year period between 2014 and 2019, and another larger group of patients was evaluated between 2019 and 2020.
The team found that five of the six individuals with Dravet syndrome in the smaller group experienced a worsening of motor symptoms over the five-year study period. Of note, the two oldest patients in the group were no longer able to walk five years after their first assessment.
Using tests of motor function in the larger group of participants, the researchers found that age was associated with more difficulty in rising from a chair and walking, as well as slower movement. In addition, patients with Dravet syndrome had more trouble walking than older individuals without the condition.
“To our knowledge, this is the first study to follow a group of adult patients with Dravet syndrome,” says Dr. Andrade. “We found that symptoms related to mobility worsen with age. Next steps for this research include determining why this happens and if it is possible to slow or prevent it.”
This work was supported by the Dravet Syndrome Foundation, Dravet Canada and the UHN Foundation. Dr. Danielle Andrade is a Professor of Medicine at the University of Toronto.
Dr. Andrade serves on the medical advisory boards of the Dravet Syndrome Foundation and Stoke Therapeutics. She is on the speakers bureau for Eisai and Biocodex, and has participated in investigator-initiated research for Biocodex and Dravet Syndrome Foundation. Dr. Berg is on the speakers bureau for Biomarin and sits on the advisory board for Zogenix and Neurocrin.
Selvarajah A, Gorodetsky C, Marques P, Zulfiqar Ali Q, Berg AT, Fasano A, Andrade DM. Progressive Worsening of Gait and Motor Abnormalities in Older Adults with Dravet Syndrome. Neurology. 2022 May 31. doi: 10.1212/WNL.0000000000200341.
Symptoms of Dravet syndrome begin in the first year of life. As affected individuals reach adulthood, caregivers often report worsening motor symptoms, such as a reduced ability to walk.