What is the approach to evaluating the history of a seizure?

Approach to Evaluating the History of a Seizure

A thorough seizure history evaluation should focus on identifying the seizure type, potential causes, and risk factors through detailed questioning about the event, with emphasis on pre-ictal, ictal, and post-ictal phases to guide appropriate diagnostic testing and management.

Key Components of Seizure History Evaluation

Pre-Seizure Information

• Gather information about potential triggers or warning signs (auras) that preceded the event 1
• Document any recent illness, fever, head trauma, sleep deprivation, alcohol use/withdrawal, or drug use 1
• Assess for history of prior seizures or seizure-like episodes that may have been unrecognized 2
• Inquire about family history of seizures or epilepsy 2

Seizure Event Details

• Obtain eyewitness accounts whenever possible, as patients typically have no memory of the event 3
• Document the exact sequence and evolution of symptoms (focal onset vs. generalized) 2
• Record duration of the seizure activity 1
• Note specific motor manifestations (tonic-clonic movements, automatisms, head/eye deviation) 3
• Document any loss of consciousness, incontinence, or tongue biting 3

Post-Seizure Phase

• Assess recovery time and return to baseline mental status 1
• Document any post-ictal confusion, headache, focal weakness (Todd's paralysis), or speech difficulties 4
• Note any injuries sustained during the event 2

Distinguishing Seizures from Mimics

• Evaluate for features suggestive of syncope (prodromal lightheadedness, brief loss of consciousness, rapid recovery) 3
• Consider psychogenic non-epileptic seizures (unusual movements, prolonged duration, emotional triggers) 3
• Assess for symptoms of stroke, TIA, sleep disorders, movement disorders, or migraines that can mimic seizures 3

Focused Physical Examination

• Perform a complete neurological examination, with special attention to focal deficits 1
• Check vital signs, particularly for fever which may suggest infection 1
• Examine for signs of head trauma or tongue biting 2
• Look for signs of intoxication or withdrawal 1

Diagnostic Testing Based on History

• For otherwise healthy adults with new-onset seizure who have returned to baseline:

  • Serum glucose and sodium levels 1
  • Pregnancy test for women of childbearing age 1

• Additional testing based on specific clinical scenarios:

  • Lumbar puncture for immunocompromised patients or those with fever/signs of infection 1
  • Head CT scan for patients with focal neurological deficits, persistent altered mental status, history of cancer, anticoagulation use, trauma, persistent headache, or age >40 years 1
  • EEG for all patients with first unprovoked seizure 5, 6
  • MRI (preferred over CT) for detailed evaluation except when acute intracranial bleeding is suspected 5
  • Toxicology screening when drug use/exposure is suspected 1

Common Pitfalls to Avoid

• Failing to distinguish between seizures and non-epileptic events such as syncope or psychogenic events 3
• Overlooking alcohol withdrawal as a potential cause, especially in first-time seizures 1
• Missing subtle focal seizures that may indicate structural brain lesions 2
• Neglecting to obtain eyewitness accounts, which are crucial for accurate diagnosis 3
• Initiating antiepileptic medications unnecessarily in patients with low risk of recurrence 4

Risk Assessment for Recurrence

• Higher risk factors include abnormal neurological examination, structural brain lesions on imaging, and abnormal EEG 1
• Patients with normal neurological examination, normal test results, and no structural brain disease have lower recurrence risk 4
• Consider driving restrictions regardless of etiology (laws vary by state) 5