Differentiating non‐epileptic seizures from epileptic seizures in Glut1 deficiency syndrome

Abstract

AbstractAimTo investigate the clinical characteristics of non‐epileptic seizures due to transient brain dysfunction caused by energy deficiency after prolonged fasting or exercise in individuals with glucose transporter type 1 deficiency syndrome (Glut1DS), and then elucidate further the seizure features to distinguish non‐epileptic seizures from epileptic seizures.MethodThis retrospective case–control study included 57 non‐epileptic seizures and 23 epileptic seizures (control group) in 14 individuals (11 males, three females; aged 5–44 years, median = 20 years) with Glut1DS, all with a heterozygous pathogenic SLC2A1 mutation.ResultsNon‐epileptic seizures were classified as paroxysmal altered consciousness (n = 8), movement disorders (n = 35) (eye‐head movements, ataxia, spasticity, weakness, involuntary movement), dysaesthesia (n = 8), and vomiting (n = 6) at the peak ages at onset of 5 to 10 years. Ketogenic diet therapy was effective in 33 of 43 (77%) non‐epileptic seizures. Providing supplementary food before high‐impact exercise or during attacks prevented or mitigated non‐epileptic seizures in some individuals. Glut1DS‐associated non‐epileptic seizures are fundamentally situation‐related seizures with specific provoking and ameliorating factors. Non‐epileptic seizures can be distinguished from epileptic seizures by the absence of complete consciousness loss and rapid postictal recovery despite prolonged seizures.InterpretationNon‐epileptic seizures are not well recognized but require different therapeutic approaches compared to epileptic seizures. Awareness of the differentiation of non‐epileptic seizures from epileptic seizures is essential when performing preventive or therapeutic decision‐making for acute exacerbation seizures.