Background
Nonconvulsive status epilepticus (NCSE) represents an important challenge to modern neurology and epileptology. It occurs in 8–37% of the general ICU population. The diagnosis and treatment of NCSE are not straightforward and depend on many variables, including the clinical setting, etiology, electroencephalographic (EEG) findings, and the clinical status of the patients. It has a wide range of differential diagnosis including posthypoxic and metabolic encephalopathies. The current treatment options are still unsatisfactory, and mortality and morbidity rates remain high.
Objective
The aim of this study was to determine which cases of convulsive status epilepticus (CSE) are more prone to proceed to NCSE.
Patients and methods
A case series clinical study was undertaken in the Inpatient Pediatric Neurology and Emergency Units, Assiut University Hospital, Assiut City, Egypt. The study included 114 patients between the ages of 1 month and 18 years who had CSE (seizures lasting >5 min). Patients were grouped using EEG results into those with and without NCSE, and retrospectively, the clinical risk factors were studied.
Results
Our study revealed that the incidence of NCSE after control of CSE is 18.4%. The most common age group affected was from 6 to 10 years (52.4%). Mixed type of convulsions (47.6%), convulsions lasting more than 10 min (52.4%), and prolonged postictal period more than 30 min (80.9%) were common among patients with NCSE. Tachycardia (57.1%), dilated pupils (81%), and impaired level of consciousness were commonly found in NCSE group. Brain atrophic changes (28.6%), hydrocephalus (4.8%), cerebral edema (9.7%), and intracranial hemorrhage (5.4%) were detected in computed tomography brain of patients with NCSE. On the contrary, normal computed tomography brain result was found in 28.6% of patients. Midazolam was used to stop convulsions in 47.6% of patients with NCSE, each of phenobarbital and phenytoin was used in 9.5%, and a combination of anticonvulsants were used in 28.57% of patients with NCSE.
Conclusion
We found that in patients with suspected NCSE in whom an EEG is requested, several clinical risk factors–seizures in the acute setting, age more than 6 years, mixed seizures, prolonged seizures (>5 min), persistent tachycardia after control of convulsions, impaired consciousness, dilated pupils, the use of benzodiazepines for control of convulsion and ongoing central nervous system infection –influence the risk of NCSE. The risk of NCSE rises as the number of risk factors increases. By focusing on these risk factors at the bedside, the clinician can prioritize patients for EEG.