Abstracts

Nonconvulsive status epilepticus (NCSE) is an uncommon occurrence in children. It is often difficult to identify without an electrographic correlate, especially in children who are critically ill or receiving medications that may alter level of consciousness. Additionally, NCSE has been induced in patients after introduction or acute withdrawal of medications such as benzodiazepines. We report a 4-year-old child with the acute onset of mental status changes in association with oro-facial automatisms clinically consistent with complex partial seizures after acute withdrawal of high dose midazolam.
The patient was admitted to the ICU for treatment of epiglottitis. He required high-dose midazolam for agitation and airway stabilization. He received this up to a rate of 270 [mu]g/kg/hr. Infusion was stopped 24 hours prior to extubation. After extubation, the patient was alert, awake, with normal speech and ability to identify parents. Six hours later, he had acute onset of mental status changes, manifest as a [ldquo]twilight state:[rdquo] eyes open with oro-facial automatisms and low amplitude myoclonic jerks. He was occasionally able to comply with simple commands. No change was noted over the next 8 hours. Upon transfer, concerns regarding NCSE arose. An EEG demonstrated diffuse slowing with no evidence of electrographic seizures. Although the EEG was reassuring, the clinical manifestations prompted continued suspicion of NCSE. A trial-dose of intravenous lorazepam was given without clinical or electrographic change. Oro-facial automatisms continued with waxing and waning level of consciousness over the next several days. MRI of brain, spinal tap and laboratory values were normal. Forty eight hours after symptom onset, the patient began to manifest unusual stereotypies, visual hallucinations and inappropriate laughter. He returned slowly to baseline over the next 72 hours without residual symptoms or deficits.
This patient[rsquo]s initial clinical manifestation, occurring after prolonged administration of high dose midazolam closely mimicked NCSE. Reports of NCSE after benzodiazepine withdrawal prompted concerns regarding this syndrome. However, in children, withdrawal from high-dose midazolam has been reported to cause a syndrome distinct from NCSE, consisting of acute onset dyskinesias, chorea, ataxia and mental status changes. Evaluation for an epileptic substrate in several of these patients was negative. This syndrome typically resolved over days to weeks, without residua in the majority of children.
Acute withdrawal from high dose midazolam is associated with a distinct clinical syndrome closely mimicking NCSE in children. Children who manifest orofacial dyskinesias/automatisms in association with mental status changes after such withdrawal should be urgently evaluated for NCSE. If diagnostic studies are negative, a movement disorder induced by midazolam withdrawal should be considered. This disorder is typically short-lived, and full recovery can be expected.