Seizures in alcohol withdrawal

People undergoing planned or unplanned alcohol withdrawal are at risk of seizures caused by the withdrawal state, and are also at risk of a comorbid seizure disorder (eg posttraumatic epilepsy caused by head injury).

For people already taking antiepileptic drugs for a seizure disorder, consider nonadherence when assessing any seizure during alcohol withdrawal. In all patients, consider whether medications that reduce seizure threshold should be withheld during the withdrawal period.

Alcohol-withdrawal seizures are usually:

  • brief (not longer than 30 to 60 seconds)
  • generalised
  • seen in people with alcohol dependence with a long history of high alcohol intake
  • evident early in withdrawal.

In a person known to be dependent on alcohol, a witnessed brief seizure is likely to be caused by withdrawal if it is followed by features of adrenergic activity (eg tachycardia, agitation, sweating). In contrast, after a seizure, a person with epilepsy is usually calm, sleepy or drowsy, has normal vital signs and is not sweating. This distinction is useful to decide the extent of investigations, need for antiepileptics and duration of monitoring after a seizure.

Note: Tachycardia, sweating and agitation after a seizure support a diagnosis of a withdrawal seizure; a calm, drowsy postictal patient is likely to have a comorbid seizure disorder.

Seizures in alcohol withdrawal can occur before the blood alcohol concentration falls to zero; they can recur in 10 to 20% patients within 6 to 12 hours. After one withdrawal seizure, the likelihood of another in future episodes of alcohol withdrawal is up to 50%. In patients with risk factors for severe withdrawal prophylactic benzodiazepines using the loading-dose method very early during inpatient withdrawal substantially reduce the risk for alcohol-withdrawal seizures. The use of antiepileptic drugs before or after alcohol-withdrawal seizures has not been shown to be effective; in contrast, antiepileptics are indicated if the person has an established comorbid seizure disorder.

Note: Antiepileptics are indicated for comorbid seizure disorders in patients undergoing alcohol withdrawal but not to treat or prevent alcohol-withdrawal seizures.

Outcomes following a withdrawal seizure include delirium (more likely in people with alcohol dependence and acquired brain injury) and status epilepticus (more likely in people who are seizure-prone for other reasons). Exclude differential diagnoses such as head injury, subdural haematoma, central nervous system infection or other pathology and consider the need for neurological consultation. This approach is required for a first episode of seizure, patients with delirium after a seizure and patients known to have seizures whose presentation differs from their usual pattern. Free specialist advice is available from clinical advisory services around the country.

Note: Specialist advice is available by phone on any aspect of the management of substance use; contact is encouraged.