Topiramate: effect on EEG interictal abnormalities and background activity in patients affected by focal epilepsy.
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.
Placidi
Fabio
F
Neurofisiopatologia, Università di Roma Tor Vergata, V.le Oxford 81, Rome 00133, Italy. fbplacidi@libero.it
Tombini
Mario
M
Romigi
Andrea
A
Bianchi
Luigi
L
Izzi
Francesca
F
Sperli
Francesca
F
Mattia
Donatella
D
Cervellino
Angela
A
Marciani
Maria Grazia
MG
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
D000927:Anticonvulsants; D000077236:Topiramate; D005632:Fructose