Epilepsy and Mental Retardation in Children with Cerebral Palsy – Bulgarian Study

Epilepsy is common in children with cerebral palsy (CP). In a group of 521 children with cerebral palsy it was found that 58% (n = 303) of the affected had epilepsy and 74.5% (n = 388) had mental retardation. We found ahigher percentage of symptomatic epilepsy in a combination of CP with mental retardation – 84.2% (n = 255), while only 15.8% (n = 48) of children with normal intellect had epilepsy. In our CP patients, the focal seizures were the most common – 34.7% (n = 181), followed by the secondary generalized 29.6% (n = 154) and the generalized seizures (tonic, clonic and generalized tonicclonic) 25.3% (n = 132), most often with early onset, with 43.5% (n = 132) of them with onset in the first year of life. The earlier onset of the epileptic seizures correlated with a more severe mental retardation. We found that symptomatic epilepsy and severe mental retardation are most common in children with spastic quadriparesis.

Expanding the Spectrum of EEG Periodic Discharges in Subacute Sclerosing Panencephalitis: A Case Report

Background Atypical electroencephalogram (EEG) abnormalities emerge in patients with subacute sclerosing panencephalitis (SSPE), especially in cases with an atypical clinical presentation that can lead to diagnostic difficulties.

Case Report In this article, we presented a case of SSPE with an atypical onset with epileptic seizures and Parkinson's features. The neurological examination during the initial evaluation of the patient showed extrapyramidal syndrome, hyperreflexia, intention tremor, and dysmetria. Cranial magnetic resonance imaging was normal. Video EEGs were performed in wakefulness and sleep. In wakefulness, multiple brief seizures (1–1.5 seconds were recorded, consisting of gradual bending of the body forward and to the right that lacked the sudden characteristic of myoclonia. During those episodes, we recorded generalized epileptiform activity of 4 or 5 sharp waves, with higher amplitude in the anterior regions, in some of the paroxysms superimposed on a slow wave or followed by a high amplitude slow wave. The paroxysms appeared periodically every 15 to 30 seconds. However, 2 months later, the EEG showed typical periodic generalized activity of biphasic/triphasic slow waves (Radermecker complexes), accompanied by myoclonias.

Conclusion We reported a peculiar EEG pattern in a patient with SSPE that consists of periodic generalized activity of sharp waves. Atypical EEG patterns can appear when the disease progresses, but initially too, before typical periodic complexes and can complicate the diagnostic process.

SCN1A mutation spectrum in a cohort of Bulgarian patients with GEFS+ phenotype

BACKGROUND

Dravet syndrome (DS) is the most severe form of Generalized Epilepsy with Febrile Seizures plus (GEFS+) syndrome with a clear genetic component in 85% of the cases. It is characterized by fever-provoked seizure onset around six months of age and subsequent developmental deterioration later in life.

METHODS

In the current study, 60 patients with fever-provoked seizures and suspicion either of GEFS+ (50 patients) or of DS (10 patients) were referred for SCN1A gene sequence analysis.

RESULTS

SCN1A gene sequencing revealed clinically significant variants in 11 patients (18.3%); seven pathogenic (11.7%) and four likely pathogenic (6.7%). Five of these variants have not been reported previously. Among the preselected group of ten DS patients, five had pathogenic SCN1A variants which confirmed diagnosis of DS. In four patients with preliminary diagnosis GEFS+, the detected SCN1A variant enabled us to specify the diagnosis of DS in these patients. Thus, SCN1A sequencing led to confirmation of the genetic diagnosis in 50% (5/10) of DS patients, as well as clarification of the diagnosis of DS in 8% of GEFS+ patients (4/50). In this study, four patients with truncating mutations had refractory seizures and additional psychomotor abnormalities. Additionally, pathogenic missense mutations were detected in three children with comparable phenotypes, which support the observations that missense mutations in critical channel function regions can cause a devastating epileptic condition.

CONCLUSIONS

This is the first systematic screening of SCN1A gene in our country, which expands the spectrum of SCN1A variants with five novel variants from Bulgaria and demonstrates the clinical utility of confirmatory SCN1A testing, which helps clinicians make early and precise diagnoses. It is important for a better followup, choice of proper treatment, avoidance of development of refractory seizures and neuropsychological complications. Identification of pathogenic variants in SCN1A in the milder GEFS+ and severe DS cases, will help to offer adequate prenatal diagnosis and improve the genetic counselling provided to affected families.