Would stopping Keppra (levetiracetam) and repeating the EEG in a 6-year-old child with suspected seizure activity, normal MRI, and previous EEG findings of parietal slowing and rhythmic intermittent delta-theta slowing in P8-O2, provide a clearer picture of the child's baseline EEG activity?

Should You Stop Keppra and Repeat the EEG?

No, do not stop Keppra before repeating the EEG—instead, perform a prolonged video EEG (24-48 hours) while the child remains on current therapy to capture any ongoing epileptiform activity or subclinical seizures that may be masked by the medication. 1

Understanding the EEG Finding

The "rhythmic intermittent delta-theta slowing in P8-O2" represents focal slowing in the right posterior temporal-occipital region. This finding has several possible interpretations:

• Focal slowing may indicate underlying structural pathology that wasn't detected on the initial MRI, though an epilepsy-protocol MRI would be superior for identifying subtle epileptogenic lesions 1
• Post-ictal changes can persist as focal slowing that resolves over time, or it may represent ongoing epileptiform activity 1
• In children with focal EEG features, the yield of detecting abnormalities on advanced neuroimaging is significantly higher (47% in status epilepticus studies), suggesting persistent focal findings warrant consideration of repeat or enhanced imaging 1

Why Levetiracetam Affects EEG Interpretation

Levetiracetam can suppress epileptiform activity on EEG, which creates a diagnostic dilemma:

• Antiepileptic medications like levetiracetam suppress epileptiform discharges on EEG, potentially masking the true extent of epileptogenic activity 2
• However, stopping Keppra risks breakthrough seizures in a child with suspected seizure activity, which could cause additional brain injury 2
• The slowing you're seeing may represent either: (1) post-ictal changes that will resolve, (2) persistent structural abnormality, or (3) suppressed epileptiform activity that would worsen off medication 1

The Optimal Diagnostic Strategy

Perform prolonged video EEG monitoring (24-48 hours) while continuing Keppra rather than stopping it:

• The American Clinical Neurophysiology Society recommends 24-48 hour continuous monitoring to capture paroxysmal events, as approximately 28% of electrographic seizures are detected only after 24 hours 1
• This approach allows you to: (1) determine if current therapy is adequately suppressing epileptiform activity, (2) capture any breakthrough seizures or subclinical events, and (3) correlate clinical events with EEG changes 1
• Use ACNS terminology to classify any patterns—distinguishing between electrographic seizures (>2.5 Hz epileptiform discharges for ≥10 seconds), ictal-interictal continuum patterns, and benign variants 1

Critical Considerations for This 6-Year-Old

The normal MRI is reassuring but doesn't exclude all epileptogenic pathology:

• Consider epilepsy-protocol MRI if focal slowing persists, as standard MRI may miss subtle focal cortical dysplasia or other structural lesions 1
• Focal slowing in a child with suspected seizures warrants thorough investigation before attributing it solely to medication effects 1

Levetiracetam efficacy and tolerability in pediatric focal epilepsy:

• Levetiracetam is effective for focal seizures in children, with 44% achieving >50% seizure reduction and 16% achieving seizure freedom in refractory cases 3, 4
• The medication is generally well-tolerated, though behavioral adverse effects occur in some children and should be monitored 1
• If repeat EEG shows persistent epileptiform activity despite therapy, consider dose optimization (children may tolerate and benefit from doses up to 70-275 mg/kg/day in refractory cases) before adding alternative agents 4

Common Pitfalls to Avoid

Do not stop antiepileptic therapy without a clear plan:

• Untreated seizure activity may cause additional brain injury, making empiric discontinuation of effective therapy potentially harmful 2
• If you stop Keppra and the child has a breakthrough seizure, you've lost valuable time and potentially caused harm 2

Do not attribute all EEG abnormalities to medication effects:

• Focal slowing may represent underlying pathology requiring further investigation, not just medication suppression 1
• The distinction between medication effect and structural abnormality requires correlation with clinical history, seizure semiology, and potentially advanced imaging 1

Specific Monitoring Recommendations

During the repeat EEG:

• Ensure the child is not heavily sedated and metabolic parameters are normalized, as these can interfere with accurate interpretation 1
• Capture sleep and wake states to maximize detection of epileptiform activity 1
• Document any clinical events with video correlation to distinguish epileptic from non-epileptic events 1

If the prolonged EEG shows:

• Persistent focal slowing without epileptiform discharges: Consider epilepsy-protocol MRI and continue current Keppra dose with close clinical follow-up 1
• Ongoing epileptiform activity or subclinical seizures: Optimize Keppra dosing or consider adding alternative therapy 1
• Normal background with resolution of slowing: This suggests post-ictal changes that have resolved, supporting continuation of current therapy 1