Nonconvulsive Status Epilepticus in the Elderly: A Case–Control Study

Abstract

Summary:Background: Nonconvulsive status epilepticus (NCSE) is a usually underdiagnosed and potentially treatable cause of altered awareness in the elderly. To assess etiologies, associations with other medical problems, and prognosis of NCSE in a population aged >75 years we performed a nested casecontrol study.Methods: We retrospectively evaluated the clinical manifestations and EEG findings in 19 consecutive elderly patients (mean age 83.3 years) presenting with NCSE and compared them with 34 elderly patients (mean age 83.3 years) with altered mental status but without EEG evidence of NCSE. The variables compared included brain lesions on CT or MRI, number of concomitant chronic active diseases, previous neurological disorders, acute medical problems, the use and withdrawal of medications, and outcome. Statistical analysis was performed using chi-square test, t-test, Fisher's exact two-tailed test, and Wilcoxon rank sum test.Results: The etiology of NCSE was epilepsy in 2, acute medical disorders in 14, and a cryptogenic cause in 4. The NCSE group had a more frequent history of epilepsy, 35% versus 8.8% (p = 0.028); tramadol use, 31% versus 0% (p = 0.00151); longer hospitalization, 25 days versus 7 days (p = 0.0004); and unfavorable outcome, 50% versus 5.8% (p = 0.00031). No significant differences were found in the other variables. Unfavorable outcome was associated with a higher number of comorbidities (>2) and to a severely altered mental status.Conclusions: NCSE is a serious cause of altered mental status in the elderly. Although its direct role in brain damage is controversial, elderly patients with NCSE have higher morbidity and worst prognosis than those with altered mental status without NCSE.

A Descriptive Analysis of Prognostic Indicators in Patients with Non-Convulsive Status Epilepticus in a Tertiary Hospital Population

“…Indeed, the majority of our study population sustained at least one concurrent life-threatening illness (85%), with many requiring critical care resources (68%). Intuitively and in accordance with previous research [11,14,20], we found that the number of life threatening comorbidities is independently associated with mortality (p < 0.0001). And while comorbidities often predate or contribute to the cause of NCSE, others are clearly the sequelae of refractory seizures, aggressive therapeutic interventions, and long hospital stays.…”

“…Yet there have been no large controlled studies of NCSE, with most of the literature centering on small case series [10,11,21,24,28,31,32,35,48,49] and a case control study of 19 elderly [20]. Aside from a single paper assessing morbidity and mortality in 100 patients with NCSE [14], our series is the largest descriptive study of NCSE to date and the only one to systematically correlate NCSE clinical and electrographic variables with functional disability at discharge.…”

“…Studies of SE have established that prognosis is also greatly influenced by level of consciousness at presentation [14,20,22,30,[42][43][44]. Not only are the causes of coma often fatal, but decreased level of consciousness predisposes to complications, such as respiratory compromise.…”

“…In fact, some studies have shown case fatalities upwards of fifty percent in NCSE in the critically ill or following convulsive status epilepticus (CSE) [11,[15][16][17]. Although comorbid acute medical and neurological illnesses have been found to impact NCSE outcomes [14,18,19], a recent case-control study showed that elderly patients with NCSE had a worse prognosis than age-matched controls with similar altered mental status and comorbidities [20].…”

Rapidly Progressive Cognitive Disturbances Due to Nonconvulsive Status Epilepticus Associated with a Cerebral Microbleed: Clinical Application of FDG-PET

“…While the mean duration of NCSE is 15-54 hours [10], the abnormal behaviors and cognitive disturbances in this patient continued for months. The prolonged symptoms may be attributed to seizure clustering and prolonged postictal state [11].…”