[Clinical usefulness of serial EEG examinations in the diagnostic of hereditary epileptic encephalopathies case of severe epileptic encephalopathy type 2].

BACKGROUND: Molecular studies allow to study background of many epilepsy types but qualification for genotyping is not easy, especially in initial stages of severe encephalopathy in newborns and infants. One of them is a type 2 severe epileptic encephalopathy (EIEE2), caused by dominant mutation in CDKL5 gene (Xp22.3). In this type of encephalopathy appearing mainly in females, treatment resistant epileptic seizures occur in the first two months of life, they are polymorphic-generalized or focal. Psychomotor development is significantly impaired and in course of time phenotype shows similarities to an Angelman syndrome or an atypical severe form of Rett syndrome. Correlation between clinical status and repeating EEG might be a diagnostic indicator for looking for CDKL5 gene mutation.

AIM: We report a case of 3.5 years old girl with refractory epilepsy and dysmorphia like in Angelman syndrome. Mutation in CDKL5 gene was supposed during clinical observation and EEG examination and finally was confirmed.

CASE REPORT: Family history and fetal & perinatal history were negative. The patient suffered from treatment resistant polymorphic epileptic seizures appearing from 3 months of life. Psychomotor impairment, significant flaccidity and microcephaly were observed from early infant period. Additionally, pale complexion, always opened mouth, protruding tongue, prognathia, wide-spaced teeth, frequent laughter/smiling were seen. Brain MRI (including MRS) was normal. Repeating EEG showed evolution from normal during infantile spasms to multifocal discharges and loss of sleep spindles. Metabolic disorders, Angelman and Rett syndromes were excluded. Finally, mutation in CDKL5 gene was confirmed at the age of 2.5 into genetic counseling.

CONCLUSIONS: There is a need to correlate phenotype features and sequential EEG and epileptic seizures evolution to determine indication for genotyping. Genetic testing looking for CDKL5 mutation is indicated in each female child with impaired psychomotor development, refractory epilepsy with early onset polymorphic seizures and clinical & EEG phenotype of atypical Rett/Angelman syndrome.