Diagnosis and management of non-convulsive status epilepticus

Abstract

Non-convulsive status epilepticus is a complication of certain chronic seizure disorders in childhood. Complex partial status and pure petit mal status occur in childhood but are uncommon. The usual form of non-convulsive status in children is atypical absence status occurring most often in children with the Lennox-Gastaut Syndrome. Patients with Wests Syndrome can also be considered to be in a form of non-convulsive status. Non-convulsive status is often difficult to recognise, particularly when occurring in a mentally retarded child. It is usually recognised by a change in the behaviour of the child manifesting as a change in motor behaviour, affect, arousal, cognitive behaviour and memory. This is associated with an EEG appearance of continuous or near continuous paroxysmal activity. The causes of non-convulsive status are in general the same as those for the underlying epileptic encephalopathy. However, in many cases no cause is found. There is controversy as to whether episodes of non-convulsive status lead to subsequent dementia in children. There are many mechanisms by which such a deterioration could occur, such as excitotoxicity or alteration in brain protein metabolism. These have not to date been demonstrated in patients. The treatment of non-convulsive status in children is unsatisfactory. Complex partial and true petit mal status respond well to benzodiazepines and/or phenytoin in the case of complex partial status. There is no universally effective treatment for atypical absence status. Benzodiazepines are worth a trial but do not work in many cases. Ketogenic diet is effective in some cases and intravenous immunoglobulins may prove to be of value in the future.