An Approach to Neurometabolic Epilepsy in Children with an Underlying Neurometabolic Disorder

OBJECTIVE: Inborn errors of metabolism (IEM) are rare conditions, with an overall incidence of 1 per 1000 births. Approximately 40-60% of IEM cases present with epilepsy as one of the main clinical presentations of the disease. A substantial number of these patients require timely and accurate diagnosis, besides specific treatment to prevent the irreversible outcomes. MATERIALS & METHODS: In this two-year retrospective study, a total of 128 patients with documented neurometabolic disorders were selected and evaluated in Mofid Children Hospital of Tehran, Iran, using a questionnaire to investigate the prevalence of epilepsy and seizure phenotypes. The collected data were evaluated in SPSS version 23. RESULTS: Seizure was reported in 49% (63/128) of the patients. A single episode of seizure occurred in 7 (7%) patients. The prevalence of epilepsy was estimated at 42% (54/128). The most common seizure types were generalized tonic-clonic (43%), tonic (22%), and myoclonic (10%), respectively. Epilepsy was refractory in 30% (16/54) of the patients, and the mean number of administered anti-seizure drugs for refractory cases was 3.2. Overall, 50% of refractory cases had mixed-type seizures, and 25% had generalized tonic-clonic and myoclonic seizures. CONCLUSION: Neurometabolic disorders are rare, but treatable causes of epilepsy. A considerable number of patients (42%) in the current study presented with epilepsy as a clinical feature of IEM.