Are Interictal Discharges Associated with Neuronal Cell Loss in Electrical Status Epilepticus in Sleep?

Neuron-specific enolase is an established biomarker of neuronal damage. This study aimed to reveal the relationship between serum neuron-specific enolase level and continuous interictal discharges in a group of encephalopathy with electrical status epilepticus in sleep patients for the first time and determine whether there is a neuronal cell loss or damage.

We analyzed serum neuron-specific enolase levels in patients with an electrical status epilepticus in sleep pattern on their electroencephalographs with age- and sex-matched control subjects. Patients with a spike-wave index of at least 50% and acquired neuropsychological regression were included in the study. Magnetic resonance imaging of all electrical status epilepticus in sleep patients and control subjects included in the study was within normal limits. Neuron-specific enolase is measured by the enzyme-linked immunosorbent assay kit based on the sandwich technique.

In this study, 14 patients diagnosed with electrical status epilepticus in sleep and 21 healthy controls were included. The median age of electrical status epilepticus in sleep patients was 7.1 years (min-max: 4.5-10.7 years) and 7.7 years (min-max: 3.2-14 years) in the control subjects. According to the results of serum neuron-specific enolase measurements, the mean ± standard deviation level of neuron-specific enolase was 7.61 ± 3.19 ng/dL for the electrical status epilepticus in sleep group and 6.93 ± 2.55 ng/dL for the control group. Serum neuron-specific enolase levels between electrical status epilepticus in sleep patients and the control group were not statistically significant (P = .749).

No significant difference was observed in serum neuron-specific enolase levels between electrical status epilepticus in sleep patients and control subjects. Our results may indicate that frequent interictal discharges do not result in neuronal cell loss or damage in electrical status epilepticus in sleep patients.