Man, 29, diagnosed with Dravet after seizure sharply affects walking
Frequent seizures throughout childhood treated with 'irrational' anticonvulsants
A case report from China describes a man who was diagnosed with Dravet syndrome at age 29, following an epileptic seizure that significantly worsened his walking and motor difficulties.
This decline eased after one week, but “recurrent epileptic seizures contribute in some way to the development of gait and motor impairments” in Dravet syndrome, the researchers wrote.
The report, “Epileptic seizures worsen the gait and motor abnormalities in adult patients with Dravet syndrome (with a case report and Literature Review),” was published in the journal Epilepsia Open.
Rare case of Dravet syndrome being diagnosed in an adult
Dravet syndrome is a severe type of epilepsy that usually manifests in infancy. In up to 80% of cases, the disease is associated with mutations in the SCN1A gene. Patients experience epileptic seizures and cognitive deficits and, in some cases, they can present with walking and other motor problems.
While disease manifestations during infancy are well described, a Dravet syndrome presentation in adults is less well known. Researchers at university hospitals in Shanxi and Fujian described a man first diagnosed with Dravet syndrome when he was 29, whose walking problems deteriorated rapidly following an epileptic seizure.
The patient developed and grew normally in early infancy, but at age 8 months he experienced monthly convulsions accompanied by fever.
At 1.5 years old, his seizures and convulsions, now without fever, continued and frequently were triggered by heat or hot baths. These included sudden involuntary muscle contractions, a condition known as myoclonus, which progressed into monthly secondary tonic-clonic seizures, involving both stiffening and twitching phases of muscle activity. Three to six seizures were reported on a monthly basis.
He was diagnosed with epilepsy and treated with different types of antiseizure medications, such as carbamazepine (sold as Tegretol, among others) and valproic acid (brand names include Depacon), albeit without observable improvements.
Since symptom onset, his psychomotor development had been significantly delayed: He couldn’t attend school or take care of himself.
At age 29, and within four days after an epileptic seizure, he developed camptocormia, a condition in which the head and trunk bend forward. The same was seen for his neck.
He walked in a crouching posture, scoring a four in the Functional Gait Assessment (FGA) scale, which evaluates walking activities. Scores here range from zero to 30, and lower scores indicate greater walking impairment.
These impairments were short lived, with his posture and walking ability, although impaired, returning within one week after the seizure. This change was deemed an “interesting phenomenon” by the researchers.
His trunk retained a right-side bend, a feature known as Pisa syndrome, but overall his condition improved, as shown by a FGA score of 12. However, he was found to have severe cognitive impairment, evidenced by a score of six in the mini-mental state examination (MMSE) test. Ranging from zero to 30, scores below 10 indicate severe impairments.
In MRI scans, no brain lesions were found or signs of significant brain shrinkage.
Levodopa, a Parkinson’s therapy, added to tailored treatments
Genetic analyses revealed he had a de novo mutation in the SCN1A gene, which was not inherited from his parents. This result, along with all the clinical presentation, led to a Dravet syndrome diagnosis as an adult.
His treatments were tailored to valproic acid, clonazepam (sold under the brand names Klonopin and Rivotril) and topiramate (sold as Topamax, among others brands), and the “irrational” carbamazepine was stopped, the scientists noted.
After two years with this regimen, his seizure frequency dropped to one every two months. During this period, he also received levodopa, a mainstay Parkinson’s disease treatment. The therapy significantly improved his walking speed and eased his facial rigidity, without side effects. His FGA score increased to 19.
Overall, “the frequency of convulsive seizures probably constitutes a risk factor for motor retardation,” the researchers wrote.
“Inappropriate medication treatments maybe correlate with cognitive and motor impairment in our patient. Therefore, early and correct intervention is very important” for better outcomes, they concluded.