What to ask in a patient's medical history when evaluating a seizure?

Essential History Elements for Seizure Evaluation

Immediate Classification: Provoked vs. Unprovoked Seizure

The first and most critical step is to determine whether the seizure was provoked (acute symptomatic) or unprovoked, as this fundamentally determines both etiology and management. 1

• Provoked seizures occur within 7 days of an acute insult including metabolic disturbances, toxic ingestions, substance withdrawal, CNS infections, or acute brain injury 1, 2
• Unprovoked seizures occur without acute precipitating factors and include remote symptomatic seizures (>7 days from insult), CNS mass lesions, progressive CNS disease, or idiopathic seizures 1, 2

Critical Historical Elements to Obtain

Seizure Event Details

• Onset characteristics: Ask specifically whether tonic-clonic movements were prolonged and began simultaneously with loss of consciousness, as this strongly suggests true seizure 2
• Focal vs. generalized onset: Determine if there were focal features before generalization, as focal onset increases risk of structural lesions 2
• Duration of event: Document total seizure duration and time to return to baseline 1
• Postictal state: Ask about confusion, focal deficits (Todd's paralysis), or prolonged altered mental status, as these predict higher recurrence risk 1, 2

Acute Precipitating Factors (Within 7 Days)

• Metabolic disturbances: Recent vomiting, diarrhea, dehydration, or symptoms suggesting hypoglycemia or hyponatremia 2
• Substance use/withdrawal: Alcohol use patterns, recent cessation, or binge drinking; cocaine or other stimulant use 3, 2
• Toxic ingestions: Any new medications, overdoses, or drug exposures 2
• CNS infection symptoms: Fever, headache, neck stiffness, or altered mental status preceding the seizure 1, 2
• Head trauma: Any recent head injury, even if seemingly minor 2

Past Medical History

• Prior seizures: Distinguish between truly first-time seizure vs. unrecognized prior events; note that family history information is often inaccurate, particularly for parental seizures (only 32% sensitivity) 4
• Remote brain insults (>7 days ago): Prior stroke, traumatic brain injury, CNS infections, or neurosurgery 1, 2
• Cardiac history: Conduction disturbances, arrhythmias, or structural heart disease (important for both differential diagnosis and if carbamazepine considered) 5
• Liver disease: Any history of hepatic dysfunction, as this affects both seizure risk and antiepileptic drug selection 5
• Renal disease: Chronic kidney disease or dialysis, as this increases risk of electrolyte abnormalities and affects drug dosing 2, 6
• Malignancy: Active cancer or history of cancer, particularly brain metastases 2
• HIV/immunocompromised status: HIV infection, immunosuppressive medications, or transplant history, as 40% of HIV patients with new-onset seizures have acute lesions requiring admission 3, 1

Medication History

• Current antiepileptic drugs: If previously prescribed, assess compliance and recent changes 7
• Medications lowering seizure threshold: Antibiotics (particularly fluoroquinolones), antidepressants, antipsychotics, tramadol 8
• Anticoagulation: Warfarin or other anticoagulants increase risk of intracranial hemorrhage 2
• Diuretics: Increase risk of electrolyte abnormalities 6

Social and Substance Use History

• Alcohol: Detailed quantification of daily use, recent changes in consumption, or withdrawal symptoms; alcohol-related seizures should be diagnosis of exclusion 1, 2
• Illicit drugs: Cocaine, amphetamines, or other stimulants 3
• Sleep deprivation: Recent pattern of inadequate sleep 8

Age-Specific Considerations

• Pediatric patients (6 months-5 years): Recent fever or febrile illness, as febrile seizures are most common in this age group 1
• Adults: Idiopathic, alcohol-related, and cerebrovascular disease are most common etiologies 1
• Geriatric patients (>60 years): Cerebrovascular disease and brain tumors predominate; obtain detailed vascular risk factor history 1

Reproductive History (Women of Childbearing Age)

• Pregnancy status: Essential to obtain, as this affects testing, disposition, and antiepileptic drug selection 2, 6
• Menstrual cycle: Catamenial epilepsy patterns 8

Common Pitfalls to Avoid

• Misdiagnosing nonepileptic events: Approximately 28-48% of suspected first seizures are actually syncope, nonepileptic seizures, or panic attacks; detailed event description is critical 2
• Accepting "alcohol withdrawal seizure" without exclusion of other causes: Always search for symptomatic causes before labeling as withdrawal, especially in first-time seizures 2
• Inadequate family history: Recognize that family history sensitivity is only 62% for epilepsy and much lower (32%) when asking about parents 4
• Missing immunocompromised status: These patients require more extensive evaluation including lumbar puncture 1, 2, 6