What diagnostic tool can be used to confirm psychogenic nonepileptic seizures?

Psychogenic nonepileptic seizures (PNES) are episodes that resemble epileptic seizures but are not caused by abnormal electrical activity in the brain. The most effective diagnostic tool to confirm the diagnosis of PNES is the electroencephalogram (EEG). In cases of PNES, the EEG typically shows no evidence of epileptic activity during the seizure-like episodes; instead, it may demonstrate a normal or inconclusive pattern.

This lack of electrical activity during the episodes is a crucial differentiator from true epileptic seizures, where the EEG would show clear spikes or waves during the seizure. Thus, if an EEG reveals no epileptic activity during events that appear to be seizures, this strongly supports the diagnosis of psychogenic nonepileptic seizures.

Other diagnostic tools mentioned, such as MRI and CT scans, are primarily used to rule out structural causes of seizures, like tumors or brain lesions, but do not specifically confirm or rule out PNES. Blood tests for electrolyte levels are important for identifying metabolic causes of seizures but are not definitive for diagnosing PNES. Therefore, EEG showing no epileptic activity is definitive in this context.