Indications for surgical treatment of epilepsy in childhood: a clinical and neurophysiological approach L Fusco and F Vigevano Division of Neurology, Ospedale Pediatrico Bambino Gesu `, Research Institute, IRCCS, Rome, Italy Fusco L, Vigevano F. Indications for surgical treatment of epilepsy in childhood: a clinical and neurophysiological approach. Acta Pædiatr 2004; Suppl 445: 28–31. Stockholm. ISSN 0803-5326 Resistant epilepsy is defined as the persistence of unacceptable seizures, despite correct drug treatment, or control of seizures at the cost of excessive side effects. About 30% of partial seizures are resistant to treatment; many of them is potentially a candidate for surgical treatment. Selection of patients is based fundamentally on precise identification of the epileptogenic area and on the evaluation that possible removal of that area will not be followed by serious neurological or neuro- psychological deficits, or by onset of seizures in another part of the brain. To this end, careful clinical, neurophysiological and functional studies are conducted. Compared with adults, video- electroencephalographic (EEG) study of seizures in childhood is more difficult because of the lack of patient cooperation and, therefore, the lack of every subjective element in the seizures. Furthermore, the criteria for defining drug resistance in childhood are still under discussion, as many epilepsies are age dependent and seizures stop with growth. Despite this, the age at time of surgery has been steadily decreasing, in the conviction that the persistence of intractable partial epilepsy is detrimental to cognitive development and can damage brain areas that are apparently healthy. The clinical and EEG criteria for epilepsies that are secondary to some specific disorders have been defined, e.g. hemimegalencephalia and focal cortical dysplasias often produce epilepsy with onset in the first days of life characterized by partial seizures and subintrant spasms, EEG record of focal or hemispheric burst suppression and drug resistance that can be defined within the first months of life. Prolonged video-EEG monitoring is always necessary to establish congruence between the area in which the seizure originates and the brain lesion evidenced at neuroimaging. Correct monitoring of seizures means close cooperation between neurologist, neurophysiology technician and the patient, if the child is at least 5–6 y old. Absence of cooperation also limits the use of in-depth recording. Neuropsychological assessment of the child can be of great help in defining the area damaged by the epileptogenic site as well as the state of the other brain areas. Close cooperation between neurologist, radiologist, neuropsychologist and brain surgeon is necessary for a case-by-case assessment of indication for surgical treatment. Key words: Antiepileptic drugs, cerebral malformations, drug-resistant epilepsy, epilepsy surgery, pediatric epilepsy L Fusco, Division of Neurology, Ospedale Pediatrico Bambino Gesu `, IRCCS, Piazza S Onofrio, 4, I-00165 Rome, Italy (Tel. 39 06 6859 2044, fax. 39 06 6859 2463, e-mail. fusco@opbg.net) Concepts of drug-resistant epilepsy and early predictors of drug intractability Surgical therapy is a good opportunity for drug-resistant epilepsies and, more and more frequently, not the last chance. The first item to be addressed is: what is drug- resistant epilepsy? The definition of resistance to antiepileptic drugs has been changed over the years and the most acceptable recent definition is: “the persistence of an unacceptable quantity of epileptic seizures despite reasonable medical management” or “eradication of seizures only at the cost of drug toxicity” (1). What do unacceptable seizures mean? The unacceptability depends on the frequency and type of seizures, the lack of possibilities of spontaneous remission (that means that it is not an idiopathic epilepsy) and the presence of a progressive cognitive deterioration. The problem of drug-resistant epilepsy is a major one: 5% of the general population experiences at least one seizure in their life, 20% of these will have recurrent seizures and 65–75% of these become seizure free, but 15% of all cases will have true intractable epilepsy. There are some causes of apparent intractability: errors of diagnosis, e.g. pseudoseizures or paroxysmal non-epileptic fits instead of true epileptic seizures, and errors of classification, which lead to the wrong therapy and no clinical satisfactory response. Sometimes, epileptic seizures hide an underlying progressive central nervous system (CNS) disorder, usually a brain tumor  2004 Taylor & Francis. ISSN 0803-5326 Acta Pñdiatr Suppl 445: 28±31. 2004 DOI 10.0180/08035320310021165