Epileptic encephalopathy due to GLUT1 deficiency: a case report

Case presentation: H.M.B.R., female, 5 years, mother with gestational diabetes. Birth weight of 4240 g, full term, APGAR 9/9, neonatal hypoglycemia as intercurrence. At the age of 11 months and 14 days had her first epileptic seizure, being hospitalized and treated with phenobarbital, with no effective response. Family history of epilepsy. At 2 years and 8 months, was reassessed for the worsening of refractory epilepsy associated with neurological regression, presenting 6 or more daily episodes of generalized tonic-clonic seizures, followed by absence seizures, in addition to speech delay. She was diagnosed with myoclonic epilepsy and delayed neuropsychomotor development. EEG concluded paroxysmal abnormality through the occurrence of bursts of spike-slow wave complexes, 3–4 cm/s, generalized, prevalent in frontocentral areas. Even with the use of other antiepileptic drugs (levetiracetam, valproic acid, topiramate and clobazam) in a regimen of polytherapy combinations and in full doses, the patient remained with seizures.

Discussion: GLUT1 deficiency syndrome is caused by mutations in the SLC2A1 gene, responsible for encoding the type 1 brain glucose transporter. Due to its heterogeneous characteristics, few cases described in the literature and not being among the main known hypotheses of childhood epilepsies, the syndrome is often underdiagnosed. The first diagnosis of H.M.B.R. was based on clinical aspects. The picture of epilepsy refractory to orthodox treatment jointly with the regression of neuropsychomotor development, induced the realization of a Genetic Panel associated with epilepsy. The identification of the p.Gly76Ala variant, probably pathogenic in the SLC2A1 gene, was central for the understanding and managing of the case. The ketogenic diet, treatment initiated to the patient through follow-up with nutritionist and neurologist, consists of a diet high in fat and low in carbohydrates. The diet is considered the gold standard treatment of the syndrome. It supplies ketone bodies as a source of energy to the brain, generating an anti-epileptogenic and neuroprotective effect.

Final comments: After the introduction of a ketogenic diet combined with levetiracetam as treatment, at the age of 3.5 years, H.M.B.R. achieved total remission of the epileptic seizures during the period of 1 year, even with a gradual reduction of the medication dose. It is important to understand this pathology for the early diagnosis, since the syndrome affects significantly the quality and development of patients’ lives.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023