Clinical utility of EEG in alcohol-related seizures

Long-term outcome of alcohol withdrawal seizures

BACKGROUND AND PURPOSE

Alcohol withdrawal seizures (AWS) are a well-known complication of chronic alcohol abuse, but there is currently little knowledge of their long-term relapse rate and prognosis. The aims of this study were to identify risk factors for AWS recurrence and to study the overall outcome of patients after AWS.

METHODS

In this retrospective single-center study, we included patients who were admitted to the Emergency Department after an AWS between January 1, 2013 and August 10, 2021 and for whom an electroencephalogram (EEG) was requested. AWS relapses up until April 29, 2022 were researched. We compared history, treatment with benzodiazepines or antiseizure medications (ASMs), laboratory, EEG and computed tomography findings between patients with AWS relapse (r-AWS) and patients with no AWS relapse (nr-AWS).

RESULTS

A total of 199 patients were enrolled (mean age 53 ± 12 years; 78.9% men). AWS relapses occurred in 11% of patients, after a median time of 470.5 days. Brain computed tomography (n = 182) showed pathological findings in 35.7%. Risk factors for relapses were history of previous AWS (p = 0.013), skull fractures (p = 0.004) at the index AWS, and possibly epileptiform EEG abnormalities (p = 0.07). Benzodiazepines or other ASMs, taken before or after the index event, did not differ between the r-AWS and the nr-AWS group. The mortality rate was 2.9%/year of follow-up, which was 13 times higher compared to the general population. Risk factors for death were history of AWS (p < 0.001) and encephalopathic EEG (p = 0.043).

CONCLUSIONS

Delayed AWS relapses occur in 11% of patients and are associated with risk factors (previous AWS >24 h apart, skull fractures, and pathological EEG findings) that also increase the epilepsy risk, that is, predisposition for seizures, if not treated. Future prospective studies are mandatory to determine appropriate long-term diagnostic and therapeutic strategies, in order to reduce the risk of relapse and mortality associated with AWS.

Targeted Inhibition of Upregulated Sodium-Calcium Exchanger in Rat Inferior Colliculus Suppresses Alcohol Withdrawal Seizures

The inferior colliculus (IC) is critical in initiating acoustically evoked alcohol withdrawal-induced seizures (AWSs). Recently, we reported that systemic inhibition of Ca2+ entry via the reverse mode activity of the Na+/Ca2+ exchanger (NCXrev) suppressed AWSs, suggesting remodeling of NCX expression and function, at least in the IC, the site of AWS initiation. Here, we probe putative changes in protein expression in the IC of NCX isoforms, including NCX type 1 (NCX1), 2 (NCX2), and 3 (NCX3). We also evaluated the efficacy of targeted inhibition of NCX1rev and NCX3rev activity in the IC on the occurrence and severity of AWSs using SN-6 and KB-R943, respectively. We used our well-characterized alcohol intoxication/withdrawal model associated with enhanced AWS susceptibility. IC tissues from the alcohol-treated group were collected 3 h (before the onset of AWS susceptibility), 24 h (when AWS susceptibility is maximal), and 48 h (when AWS susceptibility is resolved) following alcohol withdrawal; in comparison, IC tissues from the control-treated group were collected at 24 h after the last gavage. Analysis shows that NCX1 protein levels were markedly higher 3 and 24 h following alcohol withdrawal. However, NCX3 protein levels were only higher 3 h following alcohol withdrawal. The analysis also reveals that bilateral microinjections of SN-6 (but not KB-R7943) within the IC markedly suppressed the occurrence and severity of AWSs. Together, these findings indicate that NCX1 is a novel molecular target that may play an essential role in the pathogenesis and pathophysiology of AWSs.

Quantitative electroencephalographic analysis of delirium tremens development following alcohol-withdrawal seizure based on a small number of male cases

INTRODUCTION

Seizures and delirium tremens (DTs) are recognized as severe alcohol-withdrawal symptoms. Prolonged admission and serious complications associated with alcohol withdrawal are responsible for increased costs and use of medical and social resources. This study investigated the predictive value of quantitative electroencephalography (QEEG) for developing alcohol-related DTs after alcohol-withdrawal seizure (AWS).

METHODS

We compared differences in QEEG in patients after AWS (n = 13). QEEG was performed in the intensive care unit within 48 h of admission, including in age- and sex-matched healthy controls. We also investigated the prognostic value of QEEG for the development of alcohol DTs after AWS in a retrospective, case-control study. The spectral power of each band frequency and the ratio of the theta to alpha band (TAR) in the electroencephalogram were analyzed using iSyncBrain^® (iMediSync, Inc., Korea).

RESULTS

The beta frequency and the alpha frequency band power were significantly higher and lower, respectively, in patients than in age- and sex-matched healthy controls. In AWS patients with DTs, the relative beta-3 power was lower, particularly in the left frontal area, and the TAR was significantly higher in the central channel than in those without DTs.

CONCLUSION

Quantitative EEG showed neuronal excitability and decreased cognitive activities characteristic of AWS associated with alcohol-withdrawal state, and we demonstrated that quantitative EEG might be a helpful tool for detecting patients at a high risk of developing DTs during an alcohol-dependence period.

Alcohol withdrawal syndrome: mechanisms, manifestations, and management

The alcohol withdrawal syndrome is a well‐known condition occurring after intentional or unintentional abrupt cessation of heavy/constant drinking in patients suffering from alcohol use disorders (AUDs). AUDs are common in neurological departments with patients admitted for coma, epileptic seizures, dementia, polyneuropathy, and gait disturbances. Nonetheless, diagnosis and treatment are often delayed until dramatic symptoms occur. The purpose of this review is to increase the awareness of the early clinical manifestations of AWS and the appropriate identification and management of this important condition in a neurological setting.

Alcohol-related seizures

The term alcohol-related seizures (ARS) is used to refer to all seizures in the aggregate associated with alcohol use, including the subset of alcohol withdrawal seizures (AWS). From 20% to 40% of patients with seizure who present to an emergency department have seizures related to alcohol abuse. However, it is critical to avoid prematurely labeling a seizure as being caused by alcohol withdrawal before performing a careful diagnostic evaluation. Benzodiazepines alone are sufficient to prevent AWS. The alcoholic patient with a documented history of ARS, who experiences a single seizure or a short burst of seizures should be treated with lorazepam, 2 mg intravenously.

Quantitative EEG in patients with alcohol-related seizures

BACKGROUND

To investigate whether quantitative electroencephalography (QEEG) recorded within a few days after a generalized seizure can improve the discrimination between alcohol-related seizures (ARSs), seizures in epilepsy and other seizures. In addition, we wanted to evaluate the influence of various external factors on QEEG, e.g., drug use, time from seizure occurrence, and alcohol intake.

METHODS

An ARS was defined by (i) scores ≥8 in the Alcohol Use Disorders Identification Test (AUDIT) and (ii) no history of epilepsy. Twenty-two ARS patients, 21 epileptic patients with seizures (ES), 30 AUDIT-negative patients with seizures (OS), and 37 well-controlled epileptic outpatients (EPO) were included. EEG from 79 sciatica patients (SC) served as an additional control group. EEG was recorded in relaxed wakefulness with eyes closed. Spectral analysis of ongoing resting EEG activity was performed. For the main analysis, spectral band amplitudes were averaged across 14 electrodes.

RESULTS

Major quantitative EEG abnormalities were mainly seen in the ES group. AUDIT score correlated negatively with QEEG band amplitudes in patients with seizures unrelated to alcohol, but not in the ARS group. Recent alcohol intake correlated negatively with delta and theta amplitude. We could not confirm that beta activity is increased in ARS subjects.

CONCLUSIONS

A QEEG with slightly reduced alpha amplitude supports a clinical diagnosis of ARS. An abnormally slow QEEG profile and asymmetry in the temporal regions indicates ES. QEEG predicted the clinical diagnosis better than standard EEG.

Quantitative EEG findings in patients with acute, brief depression combined with other fluctuating psychiatric symptoms: a controlled study from an acute psychiatric department

BACKGROUND

Patients with brief depressive episodes and concurrent rapidly fluctuating psychiatric symptoms do not fit current diagnostic criteria and they can be difficult to diagnose and treat in an acute psychiatric setting. We wanted to study whether these patients had signs of more epileptic or organic brain dysfunction than patients with depression without additional symptomatology.

METHODS

Sixteen acutely admitted patients diagnosed with a brief depressive episode as well as another concurrent psychiatric diagnosis were included. Sixteen patients with major depression served as controls. Three electroencephalographic studies (EEG) were visually interpreted and the background activity was also analysed with quantitative electroencephalography (QEEG).

RESULTS

The group with brief depression and concurrent symptoms had multiple abnormal features in their standard EEG compared to patients with major depression, but they did not show significantly more epileptiform activity. They also had significantly higher temporal QEEG delta amplitude and interhemispheric temporal delta asymmetry.

CONCLUSION

Organic brain dysfunction may be involved in the pathogenesis of patients with brief depressive episodes mixed with rapidly fluctuating psychiatric symptoms. This subgroup of depressed patients should be investigated further in order to clarify the pathophysiology and to establish the optimal evaluation scheme and treatment in an acute psychiatric setting.

Alcohol-related seizures

Alcohol-related seizures are defined as adult-onset seizures that occur in the setting of chronic alcohol dependence. Alcohol withdrawal is the cause of seizures in a subgroup of these patients; however, concurrent risk factors including pre-existing epilepsy, structural brain lesions, and the use of illicit drugs contribute to the development of seizures in many patients. New onset or a new pattern of alcohol-related seizures, e.g., focal seizures or status epilepticus, should prompt a thorough diagnostic evaluation. This is not indicated if patients have previously completed a comprehensive evaluation and the pattern of current seizures is consistent with past events. Treatment is initially directed at aggressively terminating current seizure activity. This should be followed by prevention of recurrent alcohol-related seizures and progression to status epilepticus during the ensuing 6-h high-risk period. Our purpose is to present recommendations for the diagnostic evaluation, treatment and disposition of these patients based on the current literature.

Update on the neurobiology of alcohol withdrawal seizures

Abrupt cessation of alcohol intake after prolonged heavy drinking may trigger alcohol withdrawal seizures. Generalized tonic-clonic seizures are the most characteristic and severe type of seizure that occur in this setting. Generalized seizures also occur in rodent models of alcohol withdrawal. In these models, the withdrawal seizures are triggered by neuronal networks in the brainstem, including the inferior colliculus; similar brainstem mechanisms may contribute to alcohol withdrawal seizures in humans. Alcohol causes intoxication through effects on diverse ion channels and neurotransmitter receptors, including GABA(A) receptors--particularly those containing delta subunits that are localized extrasynaptically and mediate tonic inhibition--and N-methyl-D-aspartate (NMDA) receptors. Alcohol dependence results from compensatory changes during prolonged alcohol exposure, including internalization of GABA(A) receptors, which allows adaptation to these effects. Withdrawal seizures are believed to reflect unmasking of these changes and may also involve specific withdrawal-induced cellular events, such as rapid increases in alpha4 subunit-containing GABA(A) receptors that confer reduced inhibitory function. Optimizing approaches to the prevention of alcohol withdrawal seizures requires an understanding of the distinct neurobiologic mechanisms that underlie these seizures.

EFNS guideline on the diagnosis and management of alcohol-related seizures: report of an EFNS task force

Despite being a considerable problem in neurological practice and responsible for one-third of seizure-related admissions, there is little consensus as to the optimal investigation and management of alcohol-related seizures. The final literature search was undertaken in September 2004. Consensus recommendations are given graded according to the EFNS guidance regulations. To support the history taking, use of a structured questionnaire is recommended. When the drinking history is inconclusive, elevated values of carbohydrate-deficient transferrin and/or gammaglutamyl transferase can support a clinical suspicion. A first epileptic seizure should prompt neuroimaging (CT or MRI). Before starting any carbohydrate containing fluids or food, patients presenting with suspected alcohol overuse should be given prophylactic thiamine parenterally. After an alcohol withdrawal seizure (AWS), the patient should be observed in hospital for at least 24 h and the severity of withdrawal symptoms needs to be followed. For patients with no history of withdrawal seizures and mild to moderate withdrawal symptoms, routine seizure preventive treatment is not necessary. Generally, benzodiazepines are efficacious and safe for primary and secondary seizure prevention; diazepam or, if available, lorazepam, is recommended. The efficacy of other drugs is insufficiently documented. Concerning long-term recommendations for non-alcohol dependent patients with partial epilepsy and controlled seizures, small amounts of alcohol may be safe. Alcohol-related seizures require particular attention both in the diagnostic work-up and treatment. Benzodiazepines should be chosen for the treatment and prevention of recurrent AWS.

Seizures in alcohol-dependent patients: epidemiology, pathophysiology and management

The relationship between alcohol and seizures is complex and multifaceted. The prevalence of epilepsy in alcohol-dependent patients of western industrialised countries may be at least triple that in the general population, whereas the prevalence of alcoholism is only slightly higher in patients with epilepsy than in the general population. The seizure threshold is raised by alcohol drinking and declines on cessation of drinking. As a result, during withdrawal from alcohol, usually 6-48 hours after the cessation of drinking, seizures may occur. Alcohol acts on the brain through several mechanisms that influence seizure threshold. These include effects on calcium and chloride flux through the ion-gated glutamate NMDA and GABA receptors. During prolonged intoxication, the CNS adapts to the effects of alcohol, resulting in tolerance; however, these adaptive effects seem to be transient, disappearing after alcohol intake is stopped. Although the relationship of seizures to alcohol use is likely to be dose dependent and causal, the available clinical data do not suggest that alcohol use results in seizure genesis. However, a genetic predisposition to alcohol withdrawal seizures is possible. Other seizures in alcohol-dependent individuals may be due to concurrent metabolic, toxic, infectious, traumatic, neoplastic and cerebrovascular diseases and are frequently partial-onset seizures. Alcohol abuse is a major precipitant of status epilepticus (9-25% of cases), which may even be the first-ever seizure type. Prompt treatment of alcohol withdrawal seizures is recommended to prevent status epilepticus. During the detoxification process, primary and secondary preventative measures can be taken. A meta-analysis of controlled trials for the primary prevention of alcohol withdrawal seizures demonstrated a highly significant risk reduction for seizures with benzodiazepines and antiepileptic drugs and an increased risk with antipsychotics. A meta-analysis of randomised, placebo-controlled trials for the secondary prevention of seizures after alcohol withdrawal showed lorazepam to be effective, whereas phenytoin was ineffective. Because withdrawal seizures do not recur if the patient remains abstinent, long-term administration of antiepileptic drugs is unnecessary in abstinent patients. The first seizure not related to alcohol withdrawal should not result in permanent drug treatment in an alcohol-dependent patient, because of poor compliance and the high likelihood of remission. The treatment of alcohol dependence is more important and should be prioritised before the prevention of further seizures.