Alcohol-related seizures, Part II: Clinical presentation and management

Pharmacotherapy for Alcohol Withdrawal

This feature examines the impact of pharmacologic interventions on the treatment of the critically ill patient — an area of health care that has become increasingly complex. Recent advances in drug therapy for adult ICU patients (including evolving and controversial data) will be reviewed and assessed in terms of clinical, humanistic, and economic outcomes. Direct questions or comments to Gil Fraser, PharmD, at fraseg@mmc.org .

Improved breath alcohol analysis in patients with depressed consciousness

Many patients in pre-hospital and emergency care are under the influence of alcohol. In addition, some of the more common pathological conditions can introduce a behaviour that can be mistaken to be related to alcohol inebriation. Fast quantitative determination of the breath alcohol concentration (BrAC) in emergency patients facilitates triage and medical assessment, but shallow expirations performed by non-cooperative patients reduce the measurement reliability. The aim of this study was to evaluate if breath alcohol analysis in non-cooperative patients can be improved with use of simultaneous measurement of the expired carbon dioxide (CO(2)). With prototypes of a handheld breath alcohol analyser based on infrared transmission spectroscopy the alcohol and CO(2) concentration in expired breath from 37 cooperative and non-cooperative patients were measured. The results show that enhanced breath sampling with use of a pump and estimation of the end expiratory BrAC with use of the ratio between the measured partial pressure of CO(2) (PCO2) and a reference value of the alveolar PCO2, provided adequate correlation with the blood alcohol concentration (BAC). This pre-clinical study has shown that breath alcohol analysis in shallow expirations from non-cooperative patients can be improved with use of CO(2) as a tracer gas.

Death from seizures induced by chronic alcohol abuse—Does it exist?

In a forensic setting, deaths due to seizures, either epileptic or other, present a well-known problem. Cause of death is rarely established on the basis of physical evidence, but on circumstantial evidence such as tongue biting or discharge of urine or faeces. Seizures have several different aetiologies, but in police reports a person known to have seizures is most likely to be reported as suffering from epilepsy. It is a well-known fact that alcoholics have seizures either due to "alcohol-induced epilepsy" or due to withdrawal from drinking. It also seems to be generally accepted that alcoholics may die from these seizures. A literature study was performed of deaths due to alcohol-induced seizures, either during withdrawal or as late-onset seizures where the aetiology was established as long time alcohol abuse and a necropsy had shown no other possible cause of death than a seizure.

RESULTS

It was not possible to find any well-documented cases. It is, however, difficult to compare cases in the literature, as there is no generally accepted classification or nomenclature of seizures related to alcohol abuse.

Management of Seizures in the Critically Ill

Seizures in a critically ill patient are not infrequent phenomena. Physicians are perplexed by the wide range of possible cranial or extracranial etiologies, alerted by the risk for further crucial organ compromise if seizures recur, and confused about the treatment options in an environment rich in complex drug interactions and multiple organ dysfunction. The advent of an armamentarium containing multiple new antiepileptic medications complicates the situation further, since several of them have less known mechanisms of action, side effects, or interactions with other intensive care unit (ICU) medications. This review contains useful information regarding the most common etiologies and treatment options for intensivists, consulting neurologists, neurosurgeons, or other specialized physicians treating ICU patients with seizures.

Alcohol and marijuana: effects on epilepsy and use by patients with epilepsy

We review the safety of alcohol or marijuana use by patients with epilepsy. Alcohol intake in small amounts (one to two drinks per day) usually does not increase seizure frequency or significantly affect serum levels of antiepileptic drugs (AEDs). Adult patients with epilepsy should therefore be allowed to consume alcohol in limited amounts. However, exceptions may include patients with a history of alcohol or substance abuse, or those with a history of alcohol-related seizures. The most serious risk of seizures in connection with alcohol use is withdrawal. Alcohol withdrawal lowers the seizure threshold, an effect that may be related to alcohol dose, rapidity of withdrawal, and chronicity of exposure. Individuals who chronically abuse alcohol are at significantly increased risk of developing seizures, which can occur during withdrawal or intoxication. Alcohol abuse predisposes to medical and metabolic disorders that can lower the seizure threshold or cause symptoms that mimic seizures. Therefore, in evaluating a seizure in a patient who is inebriated or has abused alcohol, one must carefully investigate to determine the cause. Animal and human research on the effects of marijuana on seizure activity are inconclusive. There are currently insufficient data to determine whether occasional or chronic marijuana use influences seizure frequency. Some evidence suggests that marijuana and its active cannabinoids have antiepileptic effects, but these may be specific to partial or tonic-clonic seizures. In some animal models, marijuana or its constituents can lower the seizure threshold. Preliminary, uncontrolled clinical studies suggest that cannabidiol may have antiepileptic effects in humans. Marijuana use can transiently impair short-term memory, and like alcohol use, may increase noncompliance with AEDs. Marijuana use or withdrawal could potentially trigger seizures in susceptible patients.

Alcohol withdrawal

Alcohol withdrawal syndrome is a significant cause of perioperative morbidity and mortality. Physicians should be able to: (1) identify high-risk patients preoperatively by using the various screening tests, (2) recognize patterns with AWS, and (3) use the appropriate supportive, behavioral, nutritional and pharmacological treatment.

Evaluation of the patient with seizures: an evidence based approach

Statistics tell us that as many as 1 in 20 members of the population will suffer a seizure at some point in their lifetime, a figure which becomes even more likely if one lives to the age of 80. Thus, a careful evidence based approach to the patient with seizure is immensely useful to the emergency physician. The authors evaluate current studies on the subject, discuss seizures as they relate to specific patient groups, and, ultimately, make recommendations on this important subject.

Medical causes of seizures

Seizures are commonly encountered in patients who do not have epilepsy. Factors that may provoke such seizures include organ failure, electrolyte imbalance, medication and medication withdrawal, and hypersensitive encephalopathy. There is usually one underlying cause, which may be reversible in some patients. A full assessment should be done to rule out primary neurological disease. Treatment of seizures in medically ill patients is aimed at correction of the underlying cause with appropriate short-term anticonvulsant medication. Phenytoin is ineffective in the management of seizures secondary to alcohol withdrawal, and in those due to theophylline or isoniazid toxicity. Control of blood pressure is important in patients with renal failure and seizures. Non-convulsive status epilepticus should be considered in any patient with confusion or coma of unclear cause, and electroencephalography should be done at the earliest opportunity. Most ill patients with secondary seizures do not have epilepsy, and this should be explained to patients and their families. Only those patients with recurrent seizures and uncorrectable predisposing factors need long-term treatment with anticonvulsant medication.

The effects of single and repeated episodes of thiamin deficiency on memory in alcohol-consuming rats

The underlying pathogenesis of Korsakoff's syndrome, an amnesic disorder most commonly found in alcoholics, is not well understood. Chronic alcoholism is associated with thiamin deficiency and current thinking is that this may be the causal factor. In Experiment 1, rats were given a 20% (v/v) ethanol/water mix as their only source of fluid for 156 days. Three groups were made thiamin deficient through the combination of a thiamin-deficient diet and the centrally acting thiamin antagonist pyrithiamin hydrobromide, after 4, 15, and 26 weeks exposure to ethanol, respectively. The control group was given ad lib access to laboratory chow and water throughout this period. There were no differences between groups on either the working or reference versions of the Morris water tank paradigm. In Experiment 2, to test the hypothesis that a single bout of thiamin deficiency, with or without concurrent alcohol intake, is not sufficient to cause severe memory impairments, two groups of rats were subjected to three bouts of thiamin deficiency. One of these groups consumed an ethanol/water mix, the other tap water. A third group was made thiamin deficient on only one occasion. The control group was not made thiamin deficient and consumed lab chow and tap water throughout. Once again, there were no between-group differences in the data derived from testing in either the eight-arm radial maze or the Morris water tank task. These experiments indicate that the aetiology of Korsakoff's syndrome is more complex than previously thought.