Nonconvulsive status epilepticus (NSE)

Non-convulsive status epilepticus

Non convulsive status epilepticus (NCSE) is when a patient has seizure activity seen on electroencephalogram (EEG) without the associated clinical features of genralised convulsive status epilepticus (GCSE) (1).

There are two discrete phenotypes of NCSE:

• the ‘‘wandering confused’’ patient seen in the emergency department
  • the patient may have a relatively good prognosis or chronic epileptic syndromes or
• the patient may be acutely ill
  • there can be severe impaired mental status, with or without subtle motor movements (e.g., rhythmic muscle twitches or tonic eye deviation that often occurs in the setting of acute brain injury)
  • is also known as ‘‘subtle status’’
  • frequently NCSE is seen after uncontrolled GCSE and is seen in the intensive care unit (1)

Spectrum of non-convulsive seizures is highly variable and can be divided into:

• negative symptoms - include anorexia, aphasia/mutism, amnesia, catatonia, coma, confusion, lethargy, and staring.
• positive symptoms - include agitation/aggression, automatisms, blinking, crying, delirium, delusions, echolalia, facial twitching, laughter, nausea/vomiting, nystagmus/eye deviation, perseveration, psychosis, and tremulousness.

Reference:

• (1) Brophy GM et al. Guidelines for the evaluation and management of status epilepticus. Neurocrit Care. 2012;17(1):3-23.