Absence Seizures
This 5-year-old girl has absence seizures, characterized by brief episodes of staring with loss of awareness, no recollection of events, and a classic 3 Hz spike-and-wave pattern on EEG.
Clinical Presentation
The key diagnostic features in this case align perfectly with absence seizures:
- Brief episodes of behavioral arrest (staring spells lasting only seconds) with sudden onset and termination 1
- Complete lack of recollection of the events, indicating impairment of consciousness during the episodes 2
- No abnormal sensations or aura preceding the events 2
- Immediate resumption of activities as if nothing happened, without post-ictal confusion 2
- Age-appropriate presentation in a 5-year-old child, as typical absences usually start in childhood 2
EEG Confirmation
The electroencephalogram showing generalized 3 Hz spike-and-wave activity is pathognomonic for absence seizures 1, 2. This electroclinical pattern, combined with loss of awareness and responsiveness, defines absence seizures sensu stricto 3.
Differential Diagnosis Exclusions
Why not the other options:
Atonic seizures: These cause sudden loss of muscle tone and falls, not brief staring spells 4
Focal seizures with impaired awareness (complex partial seizures): These typically have longer duration (minutes rather than seconds), may have aura, demonstrate post-ictal confusion lasting more than a few seconds, and show focal rather than generalized EEG abnormalities 5
Focal seizures with intact awareness: By definition, consciousness is preserved, which contradicts the teacher's observation of the child being unresponsive during episodes 5
Normal behavior: The stereotypic nature of episodes, lack of recollection, and characteristic 3 Hz spike-and-wave EEG pattern definitively exclude normal behavior 1, 2
Clinical Significance
Absence seizures are easily precipitated by hyperventilation in approximately 90% of untreated patients 2. The impairment of consciousness in childhood absence epilepsy is typically more severe than in other absence syndromes 6. These seizures are characterized by opening of the eyes within 1-2 seconds of EEG discharge onset in childhood absence epilepsy 6.