How should I interpret abnormal EEG findings in a patient with suspected epilepsy?

When interpreting abnormal electroencephalogram (EEG) findings in a patient with suspected epilepsy, it is essential to contextualize the EEG abnormalities within the clinical presentation and seizure history, as EEG alone cannot definitively diagnose epilepsy ¹.

Key considerations include:

• Recognizing that certain EEG patterns, such as sharp waves, spikes, or spike-and-wave discharges, are suggestive but not pathognomonic of epilepsy; these findings must be correlated with clinical seizure semiology and history ¹.
• Being aware that normal variants and physiological patterns during awake, drowsy, and sleep states can mimic epileptiform abnormalities, leading to potential overinterpretation; thus, expertise in distinguishing these is critical to avoid misdiagnosis (Asadi-Pooya and Sperling, 2019) ¹.
• Considering that EEG sensitivity is limited; a normal EEG does not exclude epilepsy, and repeated or prolonged EEG monitoring, including sleep EEG, may increase diagnostic yield ¹.
• Interpreting EEG abnormalities in the context of the patient’s age, epilepsy syndrome, and comorbidities, as some epilepsies have characteristic EEG signatures that aid diagnosis and classification ¹.
• Understanding that in complex clinical settings, such as ICU patients or those with systemic illness, EEG abnormalities may reflect encephalopathy or other non-epileptic processes, requiring careful clinical correlation (Gélisse et al., 2020) ¹.

In summary, abnormal EEG findings should be interpreted as part of a comprehensive clinical assessment, with caution to avoid overinterpretation of normal variants, and recognition that EEG is a supportive rather than definitive diagnostic tool in epilepsy ¹.