Periodic lateralized epileptiform discharges are most likely associated with which condition?

Periodic lateralized epileptiform discharges, often abbreviated as PLEDs, are a specific type of EEG finding that reflects focal cortical irritation. These discharges are characteristically associated with conditions that involve significant brain pathology or injury, particularly in the temporal lobe.

Herpes simplex encephalitis is known for causing acute viral infections within the central nervous system, leading to significant inflammatory changes and neuronal damage. This condition often results in seizures and, importantly, PLEDs on EEG recordings, as the inflammatory process affects the cortical areas.

In contrast, while meningitis and hepatic encephalopathy can also produce abnormalities on EEG, they do not typically exhibit periodic lateralized epileptiform discharges. Meningitis may show generalized slowing or diffuse changes, while hepatic encephalopathy is more likely to present with triphasic waves or diffuse slowing rather than lateralized discharges. Barbiturate withdrawal may lead to seizure activity and generalized EEG changes, but again, the characteristic findings of PLEDs are not a typical feature of this condition.

Therefore, the association of periodic lateralized epileptiform discharges with herpes simplex encephalitis underscores the importance of recognizing specific EEG patterns and their clinical significance in diagnosing and understanding various neurological conditions.