A patient who was found to be unconscious on the roadside was brought to the A&E. While transporting him, he had a seizure in the ambulance.
Which of the following best points towards a diagnosis of generalized epilepsy rather than a seizure associated with alcohol-related complications?
E. This question looks at the possible differential diagnoses in a case of alcohol-related seizure. All the given choices are results of laboratory investigations that may give us a clue of the possible cause for the seizure. Electrolyte imbalance, hypoglycaemia, subdural haematoma, and other substances in blood may be associated with an alcohol-induced seizure. EEG is useful in the setting of the first alcohol withdrawal seizure or where epilepsy is suspected, but not immediately after a seizure when a record of slow delta activity is found whatever the cause of the seizure. However, the inter-ictal EEG is usually within normal limits in alcohol withdrawal seizures, whereas a generalized spike and wave (epileptiform activity) patterns on the EEG points towards generalized epilepsy. Alcohol-related seizures do not predispose to epilepsy.
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Which of the following is the treatment of choice for status epilepticus in a case of alcohol withdrawal?
C. Benzodiazepines are the first-line treatment in alcohol withdrawal seizures. Lorazepam has been found to be superior to placebo in double-blind placebo-controlled studies of patients with chronic alcohol abuse presenting with a generalized seizure. The European treatment guidelines recommend either diazepam or lorazepam, although lorazepam is recommended over diazepam in the setting of status epilepticus. This is because lorazepam (although it has a shorter half-life than diazepam) maintains a steady plasma state for a longer time than diazepam, which is lipid soluble. The plasma levels of diazepam drop rapidly due to redistribution to fat. Placebo controlled trials have demonstrated phenytoin to be ineffective in the secondary prevention of alcohol withdrawal seizures.
Which of the following is a relative contraindication in a case of alcohol withdrawal delirium?
D. General guidelines on the management of alcohol withdrawal advise against the use of neuroleptic agents as the sole pharmacological agents in the setting of delirium tremens, as they are associated with a longer duration of delirium, higher complication rate,and, ultimately, a higher mortality. However, neuroleptic agents have a role as a selected adjunct to benzodiazepines when agitation,thought disorder, or perceptual disturbances are not sufficiently controlled by benzodiazepines. Although haloperidol is well established in this setting, chlorpromazine is contraindicated as it is more epileptogenic. There is little information available on atypical antipsychotics in this regard.
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Failure to diagnose and failure to institute adequate thiamine replacement therapy for Wernicke’s encephalopathy is associated with a mortality of nearly:
C. Failure to identify or consider Wernicke’s encephalopathy, and failure to institute adequate thiamine replacement therapy, has an associated mortality of 20%. Wernicke’s encephalopathy is an acute neuropsychiatric condition associated with biochemical brain lesion caused by the depletion of intracellular thiamine (vitamin B1). Although reversible in the early stages, continued depletion leads to cellular energy deficit, focal acidosis, regional increase in glutamate, and ultimately cell death. Ninety per cent of the cases in developed countries are associated with alcohol misuse. This deficiency may be due to dietary deficiency, reduced absorption, and the increased excretion of thiamine seen in alcohol users. Clinical features include delirium with prominent anterograde amnesia, ataxia, and ophthalmoplegia. Imaging may reveal the presence of small haemorrhages in mamillary bodies and thalami.
If left untreated what percentage of people who develop Wernicke’s encephalopathy goes on to develop a severe persistent amnestic syndrome (Korsakoff’s dementia)?
E. Seventy-five per cent of cases with Wernicke’s encephalopathy will be left with permanent brain damage involving severe short-term memory loss (Korsakoff’s dementia) if adequate parenteral therapy with thiamine is not instituted. In clinical practice, Wernicke’s encephalopathy may be difficult to recognize because all the classic symptoms may not be present. In addition, the symptoms may be colored by the presence of other comorbidities such as withdrawal delirium or seizures. Some authors also suggest the presence of a sub-syndromal version of the encephalopathy that may present only with minor symptoms and neuroimaging findings. Twenty-five per cent of patients with Korsakoff’s dementia will require long-term institutionalization.
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