1. What is the classification of viral encephalitis with epilepsy?
Seizures can occur in the acute, recovery and sequelae phases of viral encephalitis, which are called acute symptomatic seizures (seizures appear in the acute phase of viral encephalitis) and secondary epilepsy after viral encephalitis (seizures appear in the sequelae phase of viral encephalitis).
2. What is the pathogenesis of viral encephalitis with epilepsy?
In the acute phase of viral encephalitis, cortical vein or arterial thrombosis, cerebral edema, accumulation of toxins and metabolites of the pathogen can affect the stability of nerve cell membranes and become epileptogenic through related mechanisms; necrosis of brain cells, infiltration of inflammatory cells and other pathological changes can affect the permeability and normal function of nerve cells to produce abnormal discharge, thus causing seizures.
After the acute phase of infection, the lesion site is left with permanent epileptic foci, which are seen as neuronal necrosis, deficiency, structural disorder, teratogenic proliferation, impaired blood supply, biochemical metabolic disorders, decreased γ-aminobutyric acid synthesis, dysregulation of cell membrane proton pump, potassium outflow, and calcium inflow. Continuous depolarization leads to abnormal discharges and causes secondary epilepsy.
3. What are the clinical features of viral encephalitis with seizures?
The acute phase of viral encephalitis with seizures is mainly in the form of generalized seizures, simple partial seizures, complex partial seizures, partial secondary generalized seizures and continuous status epilepticus, among which generalized seizures are the most common, accounting for about half of all kinds of seizures. In patients with secondary epilepsy during the post-viral encephalitis period, the most common form of seizures is secondary tonic clonic seizures, followed by complex partial seizures and simple seizures, with temporal lobe epilepsy being the most common.
The use of antiepileptic drugs in patients with viral encephalitis with epilepsy: There is still disagreement about the need to use antiepileptic drugs in patients with seizures in the acute phase of viral encephalitis, and there is a lack of relevant treatment guidelines at home and abroad.
The sequelae of viral encephalitis are often refractory epilepsy, and there is a greater difficulty in the use of antiepileptic drugs.