Overcalling normal variants on EEG can lead to unnecessary interventions and anxiety for patients. To avoid this, consider the following:
1. Understand Normal Variants
- Wicket Spikes: Sharp waveforms seen in the temporal regions during drowsiness, lacking a slow wave afterward.
- Rhythmic Midtemporal Theta of Drowsiness (RMTD): Theta activity in bursts, often rhythmic and symmetric, seen during drowsiness.
- Small Sharp Spikes (SSS): Also called benign epileptiform transients of sleep (BETS), these are isolated, small, sharp waveforms seen during non-REM sleep.
- 14 and 6 Hz Positive Spikes: Brief bursts of activity in posterior regions during sleep, common in adolescents, and often benign.
2. Assess the Clinical Context
EEG findings should always align with the patient's clinical history and presentation. Normal variants are unlikely to explain significant neurological symptoms.
3. Look for Key Differentiators
- Normal variants are usually brief, isolated, and state-dependent (e.g., drowsiness, sleep).
- Pathological activity often includes aftercoming slow waves, asymmetry, or focality.
4. Use Reliable References and Tools
Consult EEG atlases and guidelines to distinguish normal variants from pathology. Digital tools can help clarify ambiguous findings.
5. Collaborate and Confirm
Seek input from an experienced neurophysiologist when in doubt. Team discussions can provide clarity on unclear patterns.
6. Avoid Overinterpretation
Do not automatically assume unusual patterns are pathological. Misinterpretation can lead to unnecessary tests or treatments.
7. Educate Patients and Clinicians
If a normal variant is identified, explain its benign nature to the referring clinician and, if necessary, to the patient.
Why Avoiding Overcalling Matters
Misinterpreting normal EEG variants as pathological can:
- Lead to unnecessary medical procedures.
- Result in inappropriate diagnoses and treatments.
- Cause anxiety and affect the patient's quality of life.
Careful analysis and understanding of normal EEG patterns ensure accurate diagnoses and proper patient management.