EEG Finding: Left Temporal Sharp Waves & Slowing – Clinical Correlation

The presence of infrequent left temporal sharp waves and slowing on electroencephalography (EEG) is an epileptiform abnormality consistent with a focal (partial) onset seizure disorder involving the left temporal lobe.

Interpretation

• Sharp waves – Transient, pointed waveforms (70–200 ms) distinct from background, indicating neuronal hyperexcitability.
• Slowing (theta/delta) – Suggests underlying structural or functional dysfunction in the left temporal region.
• Left temporal localization – Implicates structures such as the hippocampus, amygdala, and neocortex; common in mesial temporal lobe epilepsy (MTLE), often associated with hippocampal sclerosis.

Clinical Next Steps

1. Correlate with semiology: aura (epigastric rising, déjà vu, fear), automatisms (lip-smacking, fumbling), impaired awareness.
2. Neuroimaging: MRI brain with epilepsy protocol (high-resolution coronal T2/FLAIR through hippocampi).
3. Consider prolonged video-EEG monitoring if diagnosis unclear or surgery contemplated.
4. Neuropsychological testing for memory/language lateralization.

Note: EEG findings alone do not diagnose epilepsy; clinical correlation is essential. Interictal epileptiform discharges can occur in 0.5–2% of healthy people.