Repeated epileptic seizures in adult patients with Dravet syndrome (DS) appear to worsen postural and gait impairments, according to a case report and literature review published in Epilepsia Open.
In the case report, a 29-year-old male presented with severe head and neck flexion in the sagittal plane following a seizure attack which met the criteria for camptocormia and antecollis. The patient also had a “crouching gait” when walking and a functional gait assessment (FGA) score of 4 points.
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The camptocormia and antecollis resolved to baseline a week after the attack, however, a diagnosis of Pisa syndrome was observed with the patient leaning slightly to the right side. His FGA score increased to 12 points. A Mini-Mental State Examination (MMSE) score of 6 out of 30 points suggested severe cognitive impairment.
No definite lesions were observed in MRI scans, but video-electroencephalography (video-EEG) showed diffuse background slowing along with diffuse and multifocal spikes. DNA sequencing discovered a heterozygous mutation (c.1501C>G, p.) in the SCN1A gene leading to a diagnosis of DS.
The patient had a history of seizures and previous antiepileptic medications had been unsuccessful in improving symptoms. After the diagnosis, the patient discontinued carbamazepine, and treatment was adjusted to valproic acid, topiramate, and clonazepam. This treatment regimen reduced seizure frequency from 3 to 6 clusters per month to 1 seizure every 2 months.
Levodopa at 125 mg 3 times daily was also added to his treatment. This addition reduced his slowness of gait and facial rigidity with no side effects. After 2 years of treatment, his FGA score had improved to 19 points.
“In conclusion, DS is drug-resistant epilepsy, our patient [reveals] the late pattern of postural and gait impairment in [adults],” the authors wrote.
“Inappropriate medication treatments maybe correlate with cognitive and motor impairment in our patient. Therefore, early and correct intervention is very important for prognosis,” the authors continued.
In addition to the case report, the article also found that several other studies had observed gait and postural abnormalities in patients with DS. One study in 12 adult patients observed that all had head and neck flexion in the sagittal plane with some meeting the diagnostic criteria for antecollis. The severity of the flexion was significantly correlated with the patient’s age. Another study found that camptocormia only manifested in patients above 13 years old and was correlated with age.
The authors suggested that their patient’s good response to levodopa, combined with evidence of good response in a few patients in previous studies, suggest that the nigrostriatal dopamine system may be involved in the gait and postural abnormalities observed late in patients with DS. They did acknowledge that further research is needed.
Du X, Lian S, Sun M, et al. Epileptic seizures worsen the gait and motor abnormalities in adult patients with Dravet syndrome(with a case report and literature review). Epilepsia Open. Published online July 7, 2023. doi:10.1002/epi4.12780