title: Topiramate: effect on EEG interictal abnormalities and background activity in patients affected by focal epilepsy.
abstract: OBJECTIVE
  To evaluate the effects of topiramate (TPM) on interictal epileptiform abnormalities (IEA) and background activity by means of a computerized EEG analysis, in adult patients affected by focal epilepsy, with or without secondarily generalization, treated with TPM as adjunctive therapy or monotherapy.
  
  
  METHODS
  Twenty-four patients affected by symptomatic or cryptogenic focal epilepsy underwent long-term video-EEG recording before and after TPM addition (mean dose 175+/-25 mg per day).
  
  
  RESULTS
  TPM addition induced a significant reduction of both partial and secondarily generalized tonic-clonic (SGTC) seizures; treatment responder patients (seizure reduction > or = 50%) were 19 out of 24 patients (79.1%), of whom 5 were seizure-free. Quantitative analysis of IEA showed a significant decrease in the mean number of spikes/10 min during TPM therapy ( 4.2+/-4.2 versus 2.2+/-4.4; P<0.003 ). The analysis of spatial distribution of interictal spikes showed that such reduction was more evident at the level of the epileptogenic area rather than on the spreading component. Statistical analysis revealed only a significant decrease of mean relative power of alpha band in the EEG spectral content, recorded at rest in a group of 18 out of 24 epileptic patients during TPM therapy. In addition, during TPM treatment we observed a significant reduction in alpha reactivity without any important changes of alpha indexes (peak frequency and median frequency).
  
  
  CONCLUSIONS
  These findings suggest that TPM has a strong inhibitory effect on IEA, probably acting on the generating processes, and, if used at low dosage and gradually titrated, seems to have only mild interferences with EEG background activity.
authors.affiliation: Neurofisiopatologia, Università di Roma Tor Vergata, V.le Oxford 81, Rome 00133, Italy. fbplacidi@libero.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Placidi
authors.forename: Mario
authors.initials: M
authors.lastname: Tombini
authors.forename: Andrea
authors.initials: A
authors.lastname: Romigi
authors.forename: Luigi
authors.initials: L
authors.lastname: Bianchi
authors.forename: Francesca
authors.initials: F
authors.lastname: Izzi
authors.forename: Francesca
authors.initials: F
authors.lastname: Sperli
authors.forename: Donatella
authors.initials: D
authors.lastname: Mattia
authors.forename: Angela
authors.initials: A
authors.lastname: Cervellino
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Marciani
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D001931:Brain Mapping; D004569:Electroencephalography / Q000187:drug effects*; D004828:Epilepsies, Partial / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D005632:Fructose / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077236:Topiramate; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants; D000077236:Topiramate; D005632:Fructose