What diagnosis is most likely indicated by evaluating a sample EEG showing hippocampal atrophy?

The presence of hippocampal atrophy on an EEG is most indicative of Hippocampal Sclerosis. This condition is characterized by the loss of neurons and the scarring of the hippocampus, which is the area of the brain primarily involved in memory and spatial navigation. Hippocampal Sclerosis is often associated with temporal lobe epilepsy, where abnormal electrical discharges can originate from this affected area, leading to seizures.

In the context of EEG findings, hippocampal atrophy provides a strong visual cue for identifying Hippocampal Sclerosis. The atrophy is a marker of structural changes in the brain that have significant clinical implications, particularly in the context of seizure disorders. Evaluating the EEG alongside clinical symptoms can aid in confirming this diagnosis.

Other conditions listed, like cortical dysplasia, neonatal seizures, and absence epilepsy, do not predominantly present with hippocampal atrophy. Cortical dysplasia involves abnormal development of the cortical layer of the brain rather than the hippocampus specifically. Neonatal seizures can have various underlying causes but do not typically result in localized hippocampal atrophy. Absence epilepsy is characterized by different EEG patterns, such as spike-and-wave discharges, rather than structural changes like hippocampal atrophy.