Acute confusion or altered mental state: consider nonconvulsive status epilepticus

EEG and semiology in the elderly: A systematic review

INTRODUCTION

The prevalence and incidence of epileptic seizures and epilepsy increases among the elderly. Epileptic seizures in older people remain often unreported and undiagnosed, contributing to incorrect or delayed treatment. The goal of our review paper is to increase awareness of seizures in the elderly, to improve the diagnostic process in this growing population.

METHODS

We present a systematic review of the literature on EEG findings and seizure semiology among the elderly according to the PRISMA statement. One hundred and two original studies were included and findings were divided in four groups: EEG among elderly without seizures, EEG among elderly with seizures or epilepsy, semiology, and status epilepticus.

CONCLUSIONS

EEG abnormalities are found in approximately half of the geriatric population referred to routine EEG. Slowing (both focal and diffuse) is the most common finding among seniors with and without seizures. Interictal epileptiform discharges (IEDs) are likewise seen among healthy seniors, which reduces their specificity as biomarker for epilepsy. Focal onset seizures prevail among the aged. Generalized seizures are uncommon, starting usually earlier in life but exacerbating in later years. Motor phenomena are less frequently seen than among younger individuals. Seizures are mainly characterized by impairment of awareness, disturbed cognition and confusion, both ictally and postictally. Unresponsiveness may occur during non-epileptic events too, which further challenges seizure recognition. Epilepsy and dementia are bi-directionally related: dementia carries an increased risk of developing epilepsy and vice versa. Up to 45 % of the aged with new onset seizures present with status epilepticus (SE). SE among the elderly is more often focal motor; non-convulsive status epilepticus (NSCE) constitutes 10-25 %.

Neurological diagnostic tests for patients with and without delirium: a prospective observational study

Since most of the precipitating factors of delirium are not due to neurological disorders, neurological diagnostic tests (NDTs) may be of limited value. We hypothesized that delirium has a high burden of NDTs with a low diagnostic yield. All patients admitted to the internal medicine wards of a single secondary teaching hospital between November 2019 and January 2020 were eligible. Within the first 48 h of their admission, they had a formal evaluation by a neuropsychologist to screen for presence of delirium. NDTs (brain MRI, brain CT, electroencephalography (EEG), and lumbar puncture) performed during the hospital stay were compared between patients with and without delirium using a logistic regression model stratified by a propensity score. The proportions of diagnostic yield (acute anomalies that changed the treatment management) provided by each type of examination were compared. Of 217 patients included, 19/32 patients (61%) with delirium had one or more NDTs, compared to 48/185 (26%) without delirium (adjusted OR 2.7; 95%CI 1.1-6.7; p = 0.027). The proportions of NDT results affecting management for patients with and without delirium were 13 and 20% for brain CT scans (p = 0.71), 29 and 38% for brain MRI (p = 0.99), and 20 and 10% for EEGs (p = 0.99), respectively. The higher proportion of NDTs performed on patients with delirium was associated with a low diagnostic yield, although not statistically different from those performed among inpatients without delirium. There is a need for restrictive, evidence-based guidelines to help with the work-up for patients with delirium.

On epilepsy perception: Unravelling gaps and issues

Epilepsy is one of the most common neurological diseases, but it can sometimes be under-reported or have a time delay in diagnosis. This data is not surprising if we consider that a person often seeks medical attention only after presenting a generalized tonic-clonic seizure. Epilepsy diagnostic delay is caused by several factors: under-reporting by patients, under-diagnosed epileptic manifestations by inexperienced clinicians, and lack of time in the emergency setting. The consequences of this delay are increased accidents, a high rate of premature mortality, and economic expanses for the healthcare system. Moreover, people with epilepsy have a higher probability of comorbidities than the general population, such as mood disorders or cognitive problems. Along with recurrent seizures, these comorbid diseases promote isolation and stigmatization of people with epilepsy, who suffer from discrimination at school, in the workplace, and even in social relationships. Public awareness of epilepsy and its comorbidities is necessary to prevent diagnostic delays and overcome social and professional iniquities for people with epilepsy.

Role of Epileptic Activity in Older Adults With Delirium, a Prospective Continuous EEG Study

Background/Objectives: Delirium occurs in up to 50 % of hospitalized old patients and is associated with increased morbidity and mortality. Acute medical conditions favor delirium, but the pathophysiology is unclear. Preliminary evidence from retrospective and prospective studies suggests that a substantial minority of old patients with unexplained delirium have non-convulsive seizures or status epilepticus (NCSE). Yet, seeking epileptic activity only in unexplained cases of delirium might result in misinterpretation of its actual prevalence. We aimed to systematically investigate the role of epileptic activity in all older patients with delirium regardless of the underlying etiology.

Design, Setting: Prospective observational study in a tertiary medical center. Adults >65 years with delirium underwent at least 24 h of continuous electro-encephalographic monitoring (cEEG). Background patterns and ictal and interictal epileptic discharges were identified, as well as clinical and biological characteristics.

Participants: Fifty patients were included in the study.

Results: NCSE was found in 6 (12%) patients and interictal discharges in 15 (30%). There was no difference in the prevalence of epileptic activity rates between delirium associated with an acute medical condition and delirium of unknown etiology.

Conclusion: Epileptic activity may play a substantial role in the pathophysiology of delirium by altering brain functioning and neuronal metabolism. No clinical or biological marker was found to distinguish delirious patients with or without epileptic activity, underlining the importance of cEEG in this context.

Cognitive function after status epilepticus versus after multiple generalized tonic-clonic seizures

OBJECTIVES

Status epilepticus (SE) is considered a risk for cognitive impairment. Studies have indicated that SE cause more cognitive decline than multiple lifetime generalized tonic clonic (GTC) seizures. The aim of the study was to investigate whether patients suffering from SE or from multiple lifetime GTC seizures have cognitive dysfunction, and if the disabilities differ between these groups.

MATERIALS AND METHODS

Patients suffering from SE were evaluated shortly after the clinical post-ictal phase and again after one year. Their follow-up results were compared to results from patients with ≥10 GTC seizures and a group of control subjects. Tests from Cambridge Neuropsychological Test Automated Battery (CANTAB) were used. Motor Screening Test (MOT) assessed motor speed, Delayed Matching to Sample (DMS) and Paired Associates Learning (PAL) assessed memory, and Stockings of Cambridge (SOC) assessed executive function. Estimated premorbid IQ and radiologically visible brain lesions were controlled for in adjusted results. Outcome measures were z-scores, the number of standard deviations a score deviates from the mean of a norm population. Negative z-scores indicate poor performance.

RESULTS

After the clinical post-ictal phase, performances of SE patients were poor on all domains (n = 46). Mean z-scores with 95% confidence intervals were below zero for tests of psychomotor speed, executive thinking times and memory. Both SE patients at follow-up (n = 39) and patients with multiple GTC seizures (n = 24) performed poorer than controls (n = 20) on tests of memory. These group differences remained significant after covariate adjustments. SE patients at follow-up scored below patients with multiple GTC seizures on tests of psychomotor speed (mean difference -0.59, P = 0.020), but after adjusting for covariates this difference was no longer significant.

CONCLUSIONS

Our data do not allow a firm conclusion as to whether SE is a more pronounced risk factor for cognitive dysfunction than repeated generalized tonic clonic seizures. In both patient groups, memory and learning dysfunction remained significant after adjusting for estimated premorbid IQ and structural brain lesions.

Overuse of Head Computed Tomography in Cirrhosis With Altered Mental Status

BACKGROUND

Head computed tomography (CT) scans are ordered in patients with cirrhosis along with altered mental status (AMS) during admission, often, despite lack of evidence of any structural abnormality. Thus, we aimed to examine the use of head CT scans in patients with cirrhosis along with AMS and to correlate scan abnormalities with causes of AMS and physical findings.

MATERIALS AND METHODS

We defined AMS as having impaired cognition, diminished attention, reduced awareness or altered level of consciousness or all of these, and categorized AMS into the following groups: hepatic encephalopathy (HE), sepsis or infectious, metabolic, exogenous drugs or toxins, structural lesions or psychiatric abnormalities. The primary outcome was presence of any structural brain lesion on head CT scan in patients with cirrhosis along with AMS with correlation of focal neurologic deficits, specifically in patients with HE.

RESULTS

In total, 349 of 1,218 patients with cirrhosis who were admitted to the hospital had AMS; HE was the most common cause of AMS (164 of 349, 47%). A total of 64% (223 of 349) of patients with cirrhosis along with AMS underwent head CT scanning on admission, including 99 of 164 (60%) patients with HE. No patient with HE had focal neurologic findings, or a focal abnormality on head CT scan. Of the patients with focal abnormalities on CT scans, 100% had focal neurologic findings. Patients with cirrhosis along with AMS undergoing head CT scan had similar mortality (76 of 223, 34%) as those with AMS not undergoing head CT scans (47 of 126, 37%; P = nonsignificant).

CONCLUSIONS

Nearly two-thirds of patients with cirrhosis along with AMS had head CT scans performed on admission; all patients with a structural lesion on head CT scan had abnormal neurologic examinations. The data suggest that routine brain imaging in patients with cirrhosis that do not have focal neurologic findings is likely not indicated.

Nonconvulsive status epilepticus in the elderly associated with newer antidepressants used at therapeutic doses: A report of three cases

Classic antidepressants have been known to induce convulsive seizures and nonconvulsive status epilepticus (NCSE). On the other hand, many reports have emphasized the safety of novel antidepressants. However, we encountered three cases of NCSE in the elderly associated with the use of newer antidepressants at therapeutic doses. All three patients were male and were 73 years of age or older. One patient was recently diagnosed with temporal lobe epilepsy and treated with low-dose lamotrigine. In all patients, newer antidepressants were initiated because of depressive symptoms. After titrating to therapeutic doses (paroxetine 20 mg/day, sertraline 50 mg/day, and combination of sertraline 50 mg/day and mirtazapine 30 mg/day in one patient each), impaired consciousness appeared. Electroencephalography (EEG) showed generalized slow waves with intermittent spike-slow-wave complexes. Intravenous injection of antiepileptic drugs improved EEG findings and clinical symptoms. After discontinuance of the abovementioned antidepressants, NCSE did not recur in any of patients. These reports raise the question of whether the newer antidepressants, like classic antidepressants, might also induce NCSE in the elderly, even when used at therapeutic doses. Physicians should consider monitoring for possible NCSE when using newer antidepressants in patients who may have low drug tolerability. Active continuous video-EEG monitoring is essential when behavioral and psychological symptoms or change in consciousness level is suspected.

EEG patterns compatible with nonconvulsive status epilepticus are common in elderly patients with delirium: a prospective study with continuous EEG monitoring

INTRODUCTION

Delirium is a leading cause of hospitalization and morbidity in elderly persons. Nonconvulsive status epilepticus (NCSE) and delirium share many risk factors. We tested the hypothesis that NCSE plays an important role in delirium by performing continuous EEG (cEEG) monitoring in elderly patients with delirium of any cause.

MATERIAL AND METHODS

Patients over 65 years old presenting with delirium in the emergency room were prospectively included and underwent either routine 20-minute EEG or cEEG within 24h after admission. Clinical, biological, and imaging characteristics, length of hospitalization, and outcome were compared between patients with possible NCSE and patients without epileptic discharges.

RESULTS

There were 32 patients in each group. Continuous EEG detected patterns compatible with NCSE in 28% and focal interictal epileptiform discharges (IEDs) in 16% of the patients. Routine EEG detected patterns compatible with NCSE in 6% and focal IEDs in 16% of the patients. History of cognitive impairment and use of antibiotics and hypernatremia were significantly associated with the presence of possible NCSE. Delirium in patients with possible NCSE was initially attributed to another cause in over 80% of the cases. Patterns compatible with NCSE were associated with a longer hospitalization stay and a higher mortality rate.

CONCLUSION

Electroencephalographic patterns compatible with NCSE are found in 28% of elderly with delirium when cEEG monitoring is performed. No clinical or paraclinical parameter can reliably distinguish elderly patients with delirium with or without patterns compatible with NCSE in the absence of cEEG monitoring. Elderly patients with delirium and patterns compatible with NCSE have significantly higher mortality rates and longer hospital stays.

Anaesthesia and epilepsy

Epilepsy is the most common serious neurological disorder, with a prevalence of 0.5-1% of the population. While the traditional antiepileptic drugs (AEDs) still play a significant role in treatment of seizures, there has been an influx of newer agents over the last 20 yr, which are now in common usage. Anaesthetists are frequently faced with patients with epilepsy undergoing emergency or elective surgery and patients suffering seizures and status epilepticus in the intensive care unit (ICU). This review examines perioperative epilepsy management, the mode of action of AEDs and their interaction with anaesthetic agents, potential adverse effects of anaesthetic agents, and the acute management of seizures and refractory status epilepticus on the ICU. Relevant literature was identified by a Pubmed search of epilepsy and status epilepticus in conjunction with individual anaesthetic agents.

Acute confusional state of unknown cause in the elderly: a study with continuous EEG monitoring

INTRODUCTION

Acute confusional state (ACS) is a frequent cause of emergency consultation in the elderly. Many causes of ACS are also risk factors for seizures. Both non-convulsive seizures and status epilepticus can cause acute confusion. The yield of routine EEG may not be optimal in case of prolonged post-ictal confusion. We thus, sought to evaluate the yield of CEEG in identifying seizures in elderly patients with ACS of unknown origin.

METHODS

We reviewed our CEEG database for patients over 75 years with ACS and collected EEG, CEEG and clinical information.

RESULTS

Thirty-one percent (15/48) of the CEEG performed in elderly patients were done for ACS. Routine EEG did not reveal any epileptic anomalies in 7/15 patients. Among those, CEEG identified interictal epileptiform discharges (IED) in 2 and NCSE in 1. In 8/15 patients, routine EEG revealed epileptiform abnormalities: 3 with IED (including 1 with periodic lateralized discharges), 3 with non-convulsive seizures (NCSz) and 2 with non-convulsive status epilepticus (NCSE). Among patients with only IED, CEEG revealed NCSz in 1 and NCSE in 2.

CONCLUSION

This retrospective study suggests that NCSz and NCSE may account for more cases of ACS than what was previously thought. A single negative routine EEG does not exclude this diagnosis. Continuous EEG (CEEG) monitoring is more revealing than routine EEG for the detection of NCSE and NCSz in confused elderly. The presence of IED in the first routine EEG strongly suggests concomitant NCSz or NCSE. Prospective studies are required to further determine the role of CEEG monitoring in the assessment of ACS in the elderly and to establish the incidence of NCSz and NCSE in this setting.

Seizures as a cause of altered mental status

The differential diagnosis and empiric management of altered mental status and seizures often overlap. Altered mental status may accompany seizures or simply be the manifestation of a postictal state. This article provides an overview of the numerous causes of altered mental status and seizures: metabolic, toxic, malignant, infectious, and endocrine causes. The article focuses on those agents that should prompt the emergency physician to initiate unique therapy to abate the seizure and correct the underlying cause.

De novo epileptic confusion in the elderly: a 1-year prospective study

PURPOSE

Nonconvulsive status epilepticus (NCSE) is clinically difficult to diagnose, especially in old patients without epilepsy, and requires electroencephalography (EEG) for diagnosis. Its incidence among elderly patients with confusion of unknown origin (CUO) remains undetermined.

METHODS

A 1-year prospective study was conducted in patients aged 60 years or older, for whom EEG was requested because of confusion considered to be of unknown origin after initial clinical, biologic, and imaging investigations. Diagnosis criteria included a validated clinical assessment scale to confirm confusion.

RESULTS

Of 44 patients with confirmed CUO, 7 presented with de novo NCSE. NCSE population had a mean age of 76 years (range, 60-97 years). No statistically significant differences were found between NCSE patients and others for age, drugs, presence of myoclonia, eyelid myoclonia, tachycardia, or agitation. In contrast, an acute onset (<24 h), gender (100% female among NCSE patients), and lack of clinical response to simple commands were significantly associated with NCSE. No differences between the two groups were evidenced for mortality and morbidity (length of hospitalization, social outcome, and so on).

DISCUSSION

Almost 16% of patients aged 60 or older with confusion of unknown origin had NCSE, according to this first prospective study. Female patients with rapid onset (<24 h) of symptoms and lack of response to simple commands were at a higher risk of presenting with NCSE.

Epilepsy in later life

Epilepsy is most likely to develop in later life. The burden of this disorder on health-care resources will rise further as the world's population continues to age. Making a secure diagnosis can be challenging because the clinical manifestations of seizures and the differential diagnoses and causes of epilepsy can be different in older individuals compared with younger individuals. Obtaining a reliable account of the events for accurate assessment is particularly important in guiding the appropriate choice and interpretation of investigations to arrive at the correct diagnosis. In older age, unique pharmacokinetic and pharmacodynamic changes occur. The use and selection of antiepileptic drugs is often further complicated by the presence of comorbidities, polypharmacy, and concomitant functional impairment, but there is a paucity of high-level clinical evidence on the effects of these factors as well as on the choice of treatment in the elderly. A comprehensive model of care should combine expertise in the diagnosis and treatment of epilepsy with effective assessment and management of the psychosocial effects to improve the prognosis in this vulnerable and poorly studied group of patients.

Acute confusional state in type 2 diabetic patient: non-convulsive status epilepticus

The etiology of acute confusional state in elderly patients with type 2 diabetes mellitus is broad, including hypoglycemia or hyperglycemia, electrolyte imbalance as hyponatremia or hypercalcemia, cerebrovascular disease and drug intoxication among others. Herein, we present an 80-year-old female type 2 diabetic patient in an acute confusional state due to non-convulsive status epilepticus (NCSE). Timely electroencephalogram at an emergency department when available is the only tool for the diagnosis of NCSE when clinically suspected. All clinicians must consider the possibility of NCSE in the differential diagnosis of acute confusional patients when diagnosis is uncertain.