New-onset refractory status epilepticus mimicking herpes virus encephalitis

Seizure burden and neuropsychological outcomes of new-onset refractory status epilepticus: Systematic review

Background

Long-term sequelae of the new onset refractory status epilepticus (NORSE) include the development of epilepsy, cognitive deficits, and behavioral disturbances. The prevalence of these complications has been previously highlighted in case reports and case series: however, their full scope has not been comprehensively assessed.

Methods

We conducted a systematic review of the literature (PROSPERO ID CRD42022361142) regarding neurological and functional outcomes of NORSE at 30 days or longer following discharge from the hospital. A systematic review protocol was developed using guidance from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results

Of the 1,602 records for unique publications, 33 reports on adults and 52 reports on children met our inclusion criteria. They contained the description of 280 adults and 587 children of whom only 75.7 and 85% of patients, respectively had data on long-term follow-up. The mean age of adult and pediatric patients was 34.3 and 7.9 years, respectively; and the longest duration of follow up were 11 and 20 years, respectively. Seizure outcomes received major attention and were highlighted for 93.4 and 96.6% of the adult and pediatric NORSE patients, respectively. Seizures remained medically refractory in 41.1% of adults and 57.7% of children, while seizure freedom was achieved in only 26 and 23.3% of these patients, respectively. The long-term cognitive outcome data was provided for just 10.4% of the adult patients. In contrast, cognitive health data were supplied for 68.9% of the described children of whom 31.9% were moderately or severely disabled. Long-term functional outcomes assessed with various standardized scales were reported in 62.2 and 25.5% of the adults and children, respectively with majority of patients not being able to return to a pre-morbid level of functioning. New onset psychiatric disorders were reported in 3.3% of adults and 11.2% of children recovering from NORSE.

Conclusion

These findings concur with previous observations that the majority of adult and pediatric patients continue to experience recurrent seizures and suffer from refractory epilepsy. Moderate to severe cognitive disability, loss of functional independence, and psychiatric disorders represent a hallmark of chronic NORSE signifying the major public health importance of this disorder.

Causes and outcomes of new onset status epilepticus and predictors of refractoriness to therapy

We aimed to evaluate the determinants of outcome in new onset refractory status epilepticus (SE). A retrospective analysis of patients with new onset SE admitted between May 2005 and October 2013 was performed. Regression analysis was used to determine factors that affect progression of new onset SE to refractory status epilepticus (RSE) and mortality. Among 114 patients with new onset SE, 52 patients progressed to RSE. Sixty seven (58.7%) were men. New onset RSE patients were younger than new onset SE patients (mean 35.9 ± standard deviation18.2 versus 28.7 ± 20.2 years; p=0.050). Cryptogenic aetiology was the most significant determinant of progression of new onset SE to RSE (Exp [β]=5.68; p=0.001). The overall mortality in the entire group was 23.7%, significantly higher in new onset RSE group (40.4% versus 9.7%; p<0.0001). New onset RSE patients with symptomatic and cryptogenic etiology did not differ for clinical characteristics and outcome. Acidosis was the strongest predictor of mortality in the entire cohort (Exp [β]=8.72; p=0.005). Nearly half of the patients with new onset SE progressed to RSE. While cryptogenic aetiology determined progression of new onset SE to RSE, acidosis was associated with mortality. The outcome was similar between symptomatic and cryptogenic new onset RSE.

[A case of new-onset refractory status epilepticus (NORSE) with an autoimmune etiology]

A 23-year-old man presented tonic-clonic seizure a week after an episode of antecedent infection. Although several anticonvulsants were used, convulsive attacks were not resolved and intravenous anesthetics were used to stop status epileptics. After combination of immunotherapies (high-dose intravenous methylprednisolone, immune absorbance and intravenous immunoglobulin (IVIg) therapies), frequency of convulsive attacks decreased, however, disturbance of consciousness was not recovered. All anti-neuronal antibodies tested were negative. Indirect immunofluorescence using the serum and rat brain section revealed positive signals in cytoplasm and nucleus in hippocampal neurons, strongly suggesting that this case has an autoimmune pathogenesis. The clinical features and course of this patient are well consistent with those in new-onset refractory status epilepticus (NORSE). The result of immunohistochemical analysis supports the hypothesis that NORSE has an autoimmune pathomechanism.

New onset refractory status epilepticus as an unusual presentation of a suspected organophosphate poisoning

New onset refractory status epilepticus (NORSE) is a new entity in medical literature. It has different infectious and noninfectious etiologies showing a devastating impact onto the clinical outcome of patients. Therapy with anaesthetic and antiepileptic agents often fails to improve the condition, unless the primary cause is rectified. Here is presented the case of a young female with a history of depression who after a recent bereavement came to the Emergency Department of Aga Khan University Hospital with complaints of drowsiness that lasted for few hours. Though she had no history of organophosphate poisoning, her physical examination and further investigations were suggestive of the diagnosis. During her hospital stay, she developed refractory status epilepticus. Her seizures did not respond to standard antiepileptic and intravenous anesthetic agents and subsided only after intravenous infusion of atropine for a few days. Organophosphate poisoning is a very common presentation in the developing world and the associated status epilepticus poses a devastating problem for emergency physicians. In patients with suspected organophosphate poisoning with favoring clinical exam findings, the continuation of atropine intravenous infusion can be a safe option to abate seizures.