Prognosis

In-hospital mortality and predictors

Overall mortality associated with status epilepticus approaches 20% and does not appear to be changing with time.[6][7]​​[63][64] One study of patients with generalised convulsive status epilepticus of all ages reported an in-hospital mortality rate of 3.45%.[65] Predictors of mortality included older age, higher comorbidity index, use of mechanical ventilation, and hypoxic brain injury. Despite changes in management, epidemiological studies have not shown a marked change in status epilepticus-related mortality rates in high-income countries over the past decades, although reported rates are variable across studies.[64] Numerous other studies have found acute symptomatic aetiology (such as cerebrovascular accidents or post-anoxic injuries) and longer duration of status epilepticus to predict a poorer prognosis.[64][66] Alcohol-related or poor-compliance-related status epilepticus carries a more favourable outcome than status epilepticus of other causes, but recovery of these patients is usually marked by a prolonged post-ictal state.[8][67]

Super-refractory status epilepticus (SRSE) is defined as status epilepticus that continues or recurs 24 hours or more after the onset of anaesthetic therapy or recurs on the reduction/withdrawal of anaesthesia.[68][69]​​ One systematic review and meta-analysis showed the outcome of SRSE is poor with a reported in-hospital mortality of 24.1%.[69]​​ Only around one-quarter of patients had an modified Rankin Scale (mRS) of 2 or less (2=slight disability, unable to perform all previous activities but able to look after own affairs without assistance; 1=no significant disability despite symptoms, able to carry out all usual duties and activities; 0=no symptoms) and less than 10% were completely independent at discharge.[69]

Long-term follow-up

Long-term outcomes of status epilepticus vary significantly according to the underlying aetiology, duration of seizures, age, sex, medical comorbidities, incidence of in-hospital complications, and treatment location.[70] One study reported that 7 of 8 survivors of refractory status epilepticus (treated with a standardised protocol of pentobarbital coma) remained stable for a mean 2.9 years following hospital discharge.[71] A subsequent report noted a 1-year recurrence rate of 17% for paediatric status epilepticus.[72] Patients recovering from status epilepticus often continue to have neurological deficits, especially in memory and other cognitive areas.[70] This is likely to be secondary to excitotoxic injury of one or both hippocampi.[73]

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