Effects of perampanel on cognition and quantitative electroencephalography in patients with epilepsy

Antiepileptic drugs are well known for their effects on cognition and electrophysiologic changes. However, perampanel is yet to be evaluated for its effects on cognitive function and electroencephalography (EEG). The purpose of the present study was to identify the effect of perampanel on neuropsychological (NP) tests and quantitative EEG (QEEG) and their relationship with the level of the drug in blood. Seventeen patients with epilepsy were enrolled in the study. Electroencephalographic recordings were obtained, and NP tests were conducted before perampanel intake and 6 months after treatment. The relative frequency band power, peak alpha frequency, and NP test scores were compared before and after drug administration. The serum concentration of perampanel was correlated with the QEEG changes. Delayed recall of the Rey Complex Figure showed significant improvement (20.03 vs. 22.94; P = 0.004) following perampanel administration. Other cognitive function tests showed no significant differences before and after drug administration. Theta frequency band power increased in all brain regions (P = 0.001-0.01), and alpha frequency power decreased in all brain regions (P = 0.006-0.03). The theta/alpha ratio, which represents background EEG slowing, increased in all brain areas (P = 0.003-0.02). The peak frequency of the alpha rhythm decreased after perampanel intake (t = 2.45, P = 0.03). Difference of relative alpha power in the central region positively correlated with the blood level of perampanel (r = 0.53, P = 0.03). Perampanel induced electrophysiological slowing, but cognitive decline was not observed. Because the controls were not compared in the study, the results of cognitive function tests should be interpreted conservatively. Background EEG slowing correlated with the serum concentration of perampanel. Our results show the effect of perampanel on cognitive function and background EEG in adult patients with epilepsy.