Introduction

  • Electroencephalography (EEG) is an essential tool in pediatric neurology for evaluating seizures, encephalopathies, and other neurologic conditions.
  • Pediatric EEG interpretation requires understanding age-specific normal patterns and pathological findings, following standardized protocols set by international bodies such as the American Clinical Neurophysiology Society (ACNS) and the International Federation of Clinical Neurophysiology (IFCN).
  • This guide provides a step-by-step approach for senior pediatric neurology residents to read and interpret EEGs across all pediatric age groups and modalities (routine EEG, prolonged video EEG monitoring, neonatal EEG, and ICU continuous EEG).
  • Emphasis on a systematic reading protocol aligned with ACNS/IFCN standards, recognition of normal developmental variants, identification of epileptiform and ictal patterns, and proper reporting format.
  • Supplemented by a glossary of key EEG terminology.

Types of Pediatric EEG Studies

  • Routine EEG (Outpatient): Standard EEG (20–40 minutes), typically recorded in lab/clinic, includes wakefulness and sleep/drowsiness, standard 10–20 system electrodes, activation procedures like hyperventilation (HV) and photic stimulation.
  • Prolonged Video EEG Monitoring (EMU): Extended EEG (hours-days) with synchronized video, used for capturing ictal events and characterizing spells, requires correlation of EEG changes with clinical events on video.
  • Neonatal EEG: Uses 10–20 system or modified smaller montage, includes unique normal patterns (discontinuous activity, delta brushes), requires assessment of continuity, symmetry, synchrony, maturation appropriate to gestational age, often prolonged with amplitude-integrated EEG (aEEG).
  • ICU Continuous EEG (cEEG): Long-term monitoring for critically ill patients, detecting subclinical seizures, status epilepticus, diffuse slow/periodic patterns; requires use of ACNS critical care EEG terminology.

Preparing to Read: Clinical History and Indications

  • Patient Identity and Age: Confirm identity, age, gestational age or developmental status.
  • Relevant History: Evaluate indication (spells, seizures, encephalopathy), prior EEG results, clinical diagnoses.
  • Medications and State: Note sedatives, anti-seizure medications, sleep deprivation, recent seizures, level of consciousness.
  • Study Protocol: Check for use or omission of activating procedures (HV, photic stimulation), special protocols, video correlation, event markers.

Systematic EEG Review Protocol

1. Technical Check and Montage Selection

  • Electrode Montage: Confirm montage type, ensure international 10–20 system adherence, use multiple montages if available.
  • Calibration and Settings: Verify standard settings (30 mm/sec, 1–70 Hz bandpass, 7 µV/mm), impedance checks.
  • Integrity of Recording: Assess quality, note flat/noisy leads, verify EKG channel, identify non-standard electrode placements.

2. Assess the Background Activity

  • Frequency Content: Evaluate predominant frequency appropriate for age/state, posterior dominant rhythm (PDR).
  • Amplitude and Symmetry: Estimate amplitude, check hemispheric symmetry, frequency asymmetries.
  • Organization and Reactivity: Observe background organization, test reactivity with eye-opening, stimulation.
  • Continuity: Comment on continuity, particularly important in neonates and ICU patients.
  • Normal Rhythms for State: Recognize sleep architecture (vertex waves, sleep spindles, K-complexes, hypnagogic hypersynchrony).

3. Scan for Artifacts

  • Eye Movements/Blinks: Frontal diphasic slow waves.
  • Muscle (EMG): High-frequency irregular fast activity.
  • ECG (Pulse): Regular spikes synchronous with QRS complexes.
  • Respiratory/Sweat: Slow periodic waves synchronous with breathing.
  • Electrode Pop/Lead Artifact: Sudden large amplitude isolated channel deflections.
  • Environmental: AC interference, ICU equipment artifacts.

4. Survey for Interictal Epileptiform Discharges (IEDs)

  • Spikes vs Sharps: Duration classification (spike <70 ms, sharp wave 70–200 ms).
  • Locations and Fields: Identify focal, multifocal, generalized discharges.
  • Patterns: Single spikes, spike bursts, spike-and-wave complexes, polyspikes, generalized 3 Hz spike-wave in absence epilepsy.
  • Activation and State Effects: Sleep, HV, photic stimulation induced patterns.
  • Normal Variants vs True Spikes: Distinguish benign variants (BETS, wicket spikes) from pathological spikes.

Interictal Epileptiform Findings

Login to Read More

Login

Information
Published:04 May 2025
Modified: 05 May 2025