Status epilepticus (SE) is a neurological emergency associated with a high rate of mortality and morbidity. There is a first peak in the incidence and prevalence rate of SE in infant and a second peak in the elderly subjects, which is often defined as 60 years.1,2 Elderly constitutes the largest and fastest-growing segment among the patients with SE. In major research conducted in Richmond, Virginia; SE was their first seizure for more than 70% of the elderly patients in this cohort.2 Various studies revealed 40–60% of SE patients have no previous history of epilepsy (de novo SE).3–5 Stroke, central nervous system (CNS) infection, systemic infection, or metabolic disorders were the most common etiologies of de novo SE in elderly population, followed by head injury, alcohol or drug intoxication, hypoxia, brain tumour, CNS lupus, and idiopathic/cryptogenic.6

In comparison to the patients with SE who had previous history of epilepsy, de novo SE had poorer prognosis. Poorer prognosis in patients with de novo SE is attributed to their advanced age at onset and the presence of potentially fatal brain illnesses such as hypoxic- ischemic encephalopathy or severe stroke, as well as infection of the CNS.6,7 There is a paucity of research on predictors of risk factors for poorer outcome in de novo SE, particularly in the elderly patients.8 The current study was aimed to find the clinical characteristics of de novo convulsive status epilepticus (CSE) and the predictors of in-hospital mortality.

A hospital-based, cross-sectional study on de novo CSE in the elderly (≥60 years of age) patients was conducted from July 2017 to September 2019. The institutional ethical committee approval was taken. Patients with pseudo seizures, non-CSE, and history of epilepsy or epileptic seizures before the age of 60 were excluded from the study. During this period, 122 elderly individuals with CSE were admitted, out of which 77 patients with de novo CSE met the inclusion criteria. CSE is defined as continuous seizure or intermittent seizures from which there is incomplete recovery of consciousness lasting ≥5 minutes.9

Patients’ age, gender, seizure semiology, duration and aetiology of CSE, neurological findings, treatment and length of hospital stay, and initial Glasgow coma scale (GCS) at the time of admission were all recorded. Routine investigations including blood gas analysis, blood glucose, electrolyte levels, liver and renal function tests were all performed. Patients were subjected to chest X-ray, ultrasound of the abdomen, echocardiogram, and cerebrospinal fluid examination if they were deemed necessary. Neuroimaging (computed tomography or magnetic resonance imaging) were done depending upon clinical indication. Within 12 hours of the termination of CSE, the 30-minute electroencephalogram (EEG) was recorded using the 10–20 electrode placement technique.

All CSE patients were given intravenous (IV) antiepileptic drugs, lorazepam and phenytoin as per the standard protocol (IV lorazepam [0.1 mg/kg], followed by the IV loading of phenytoin [20 mg/kg] as the first-line drugs). Second-line medications were given as an IV loading dose of valproate or levetiracetam in unresponsive cases and if CSE continued, patients were given general anaesthesia (coma induction). Patients also received mechanical ventilatory assistance if necessary as well as appropriate management of underlying disease.

A total of seventy-seven elderly patients with de novo CSE were recruited. Out of which 61 cases (79.2%) were male and the mean age of the study population were 65.96±6.72 years (range, 60–90). The main seizure type was focal with bilateral convulsive seizure in 59.7% of cases. De novo CSE was well controlled with the first-line drugs in 85.7% of cases. In de novo CSE, the most common aetiologies were acute symptomatic in 68.8% of cases, followed by remote symptomatic in 24.7%, and unknown in 6.5% of cases. The clinical characteristics of the patients are shown in Table 1. In-hospital mortality in the CSE in the elderly was 30 (38.9%) in our series. Immediate cause of death in 18 cases (16.4%) was due to underlying diseases and in 12 cases (9.8%) the cause of death was CSE. Amongst them, stroke was the most common cause of mortality (acute stroke in 23 cases, old infarct 1 case), followed by post-traumatic (n=4) and CNS infection (n=2). On multivariate analysis, it was found that the factors related with poorer prognosis were; GCS less than 8 with an adjusted OR (AOR) of 53.5; 95% CI, 5.15–555.14 and lack of response to first line treatment AOR of 0.06; 95% CI, 0.01–0.50 (Table 2).

Through our study, it was observed that in-hospital mortality in de novo CSE in the elderly was 38.9%. According to a retrospective investigation on factors that predict outcome in individuals with de novo SE, 36% died in hospital, 29% developed post-SE symptomatic epilepsy, and 8.43% had recurrent SE.6 Another retrospective study on patients hospitalized for reasons unrelated to epilepsy or recent seizures found that an overall mortality rate is 61%, with just 20% recovering to baseline and leaving the hospital.8

The level of consciousness at the time of presentation is a significant prognosis factor for outcome following SE,10 which is also a significant predictive element in our series. In our study, stroke was the most common cause of de novo CSE in the elderly, accounting for 59.7% of cases, and was also associated with higher mortality. Stroke is a common cause of SE in the elderly, especially in people who have never had a seizure before, according to epidemiological studies of SE. Long-term mortality in patients with a first episode of stroke-related SE was 57% in a population-based study from Germany, compared to 48% in patients with acute stroke without SE. Multivariate analysis showed that cases with SE of stroke origin had a significantly higher long-term fatality rate with a hazard ratio of 2.12, compared to acute stroke patients without seizure.11

We also found that mortality in de novo SE in the elderly was also linked to a lack of response to first-line therapy. Refractory SE is a dangerous and life-threatening condition that necessitates long-term, high-level intensive care and is frequently linked to poor functional outcomes.12,13 Tsai et al.6 reported that about one-fifth of de novo SE patients were resistant to first-line anticonvulsants, which was also related with a poor prognosis.