What is causing recurrent generalized seizures in an elderly patient with a subdural hemorrhage (SDH) and history of ethanol (EtOH) use disorder, but no prior history of epilepsy?

Etiology of Recurrent Generalized Seizures in This Patient

The recurrent generalized seizures in this elderly patient are most likely caused by the subdural hemorrhage itself, representing acute symptomatic (provoked) seizures from the structural brain injury. 1, 2

Primary Seizure Etiology

The 9mm subdural hemorrhage is the most probable cause of these recurrent seizures, as:

• Subdural hematomas are well-established structural brain lesions that cause provoked seizures, particularly in the acute setting 1, 2, 3
• The American College of Emergency Physicians classifies seizures occurring within 7 days of an acute neurologic insult (including intracranial hemorrhage) as "provoked" or "acute symptomatic" seizures 1, 2
• Acute SDH carries a 28% incidence of early post-traumatic seizures, significantly higher than chronic SDH 3
• Hematoma thickness is the only variable significantly associated with seizure occurrence (OR 1.16 per mm increase), making this 9mm SDH a substantial risk factor 4

Why Alcohol Withdrawal is Less Likely

While this patient has alcohol use disorder, several factors argue against withdrawal as the primary cause:

• The clinical presentation states the patient "doesn't appear to be withdrawing from alcohol" - this clinical assessment is critical
• The recent drinking binge was only 4 days ago, meaning the patient may still have had recent alcohol exposure before the fall
• Alcohol withdrawal seizures typically occur 6-48 hours after cessation and are usually self-limited, not recurrent generalized seizures requiring ongoing management 5
• The presence of hemineglect and stable SDH on repeat imaging strongly suggests the structural lesion is driving the seizure activity

Additional Contributing Factors to Consider

Metabolic derangements must be evaluated and corrected, as they commonly coexist with SDH in elderly patients with alcohol use disorder:

• Electrolyte abnormalities (hyponatremia, hypocalcemia, hypomagnesemia) are significant seizure triggers and should be checked and corrected 2, 5
• Hypoglycemia can provoke seizures and should be ruled out 5
• Chronic alcohol use increases risk of nutritional deficiencies that may lower seizure threshold 3

Management Implications

This patient requires antiepileptic medication because these are provoked seizures from a structural brain lesion (SDH), not simple alcohol withdrawal:

• The American College of Emergency Physicians states that emergency physicians may initiate antiepileptic medication for patients with a first unprovoked seizure with remote history of brain disease or injury 1
• However, this patient has recurrent seizures (not just a single seizure), which substantially increases the indication for treatment 1
• For refractory seizures, benzodiazepines should be first-line, followed by second-line agents (levetiracetam, fosphenytoin, or valproate) 1
• Levetiracetam is preferred in SDH patients due to similar efficacy to phenytoin but significantly lower adverse effects (OR 0.1) 3

Critical Clinical Pitfall

Do not attribute these seizures solely to alcohol withdrawal and withhold antiepileptic therapy. The structural brain injury (SDH) with associated hemineglect indicates significant brain pathology that requires seizure management. The combination of:

• Recurrent (not single) generalized seizures
• Documented structural lesion (9mm SDH)
• Focal neurologic findings (hemineglect)
• Stable repeat imaging ruling out expansion

All point to the SDH as the primary seizure focus requiring aggressive antiepileptic management 3, 6.