Adult nonconvulsive status epilepticus in a clinical setting: Semiology, aetiology, treatment and outcome

Abstract

Purpose: Our objective was to study the semiology, aetiology, treatment and outcome of nonconvulsive status epilepticus (NCSE) in adults.

Methods: All NCSE episodes in an unselected hospital cohort in the period 2004-2009 were identified, and the files reviewed. STESS (Status Epilepticus Severity Scale) was conducted retrospectively and correlated to outcome. Follow-up was undertaken after >2 years.

Results: 48 NCSEs in 39 patients, 22 men and 17 women, were found. Mean age was 63 years. 23/39 (59%) patients had established epilepsy. The underlying cause of NCSE was cerebrovascular disease in 17/39 (44%). 37/48 (77%) NCSEs were complex focal status epilepticus. 3/48 NCSEs (6.3%) lead to death, whereas 8.5% lead to severe sequelae. Cognitive sequelae were found after 14.9% of NCSEs. The outcome was worst in the group with no prior epilepsy (p=0.013). STESS had a negative predictive value of 96% (cut-off value of 3) for severe sequelae and death combined (p<0.002).

Conclusions: NCSE has a potential for severe sequelae and represents an emergency in need of intensive treatment. The major determinant of outcome is the underlying cause. The outcome was worse in patients without epilepsy than in patients with epilepsy. STESS is of value in predicting outcome. Cognitive sequelae following NCSE can occur, but need further investigation with prospective, systematic studies.

Keywords: Aetiology; Epilepsy; Nonconvulsive status epilepticus; Outcome; Status epilepticus.