Normal EEG variants.

Understanding common variations of normal EEG and benign variants of uncertain significance is essential to discern the boundary between normal and abnormal EEG. Wide variation and fluctuation can occur with normal signals generated by the brain, and these can be a pitfall for less-experienced electroencephalographers in accurately interpreting the EEG. Normal EEG variants are benign and do not portend specific pathological conditions. They can show predilection for the temporal lobes and mimic epileptiform discharges. These factors, along with the "spiky" appearance of these patterns, can often lead to erroneous interpretation of the recording and result in misdiagnosis. This chapter reviews the normal EEG variants that may confound the clinician and lead to misinterpretation that can result in suboptimal patient management.