Frontal-onset absences in children: Associated with worse outcome? A replication study

Abstract

We studied the clinical and electroencephalographic features in 30 children who were diagnosed with childhood absence epilepsy. According to their EEG pattern we divided the 30 children into two groups: group A: 11 children with classical absences whose ictal EEG showed primary generalized spikes and waves and group B: 19 children with frontal onset of the EEG epileptic abnormalities ('frontal group'). In the frontal group, more frequently complex absences were seen. Although the majority of children responded very well to valproate monotherapy, ethosuximide has to be added in 3 children of the frontal group to achieve seizure freedom. In the frontal group, also more learning and behavioural problems were encountered. This study largely confirms a previous study of Lagae et al. [Lagae L, Pauwels J, Monte B, Verhelle J, Vervisch J. Frontal absences in children. Eur J Pediatr Neurol 2001;5:243-251]. It seems that frontal onset absences constitute a specific subtype within the childhood absence epilepsies.

Focal and generalized EEG paroxysms in childhood absence epilepsy: Topographic associations and distinctive behaviors during the first cycle of non‐REM sleep

“…We found anterior FSWDs in 10 of the 13 children (nearly 85% of the total FSWD) and absences of anterior onset in 12 children (almost 74% of the total absences). These percentages are comparable to (although slightly higher than) those in the literature: frontotemporal FSWDs have been reported in 60–67% of the children with CAE and no relapse (Lombroso, 1997; Yoshinaga et al., 2004; Jocić‐Jakubi et al., 2009; Ma et al., 2011; Mariani et al., 2011) (for before the 1989 ILAE syndrome classification, see Niedermeyer, 1966 and O’Brien et al., 1959), whereas a frontal lead has been reported in 16–60% of typical absences (Holmes et al., 1987; Jocić‐Jakubi et al., 2009). This row EEG evidence is supported (and expanded) by observations on craniocaudal occurrence of motor symptoms during absences (Stefan & Snead, 1997) and from recent EEG‐MEG studies (Stefan et al., 2009) including two children with CAE (Amor et al., 2009; Westmijse et al., 2009; Sakurai et al., 2010), and it indicates a prominent role of the frontal cortex in the generation of 3Hz GSWDs and the associated absences.…”

“…However, absences were not clinically different between the two groups, their frequency was similar, and those of the second group did not respond to carbamazepine and vigabatrin; despite the latter, the authors advocated the possible use of drugs for focal seizures in therapy‐resistant frontal absences, and even consideration of epilepsy surgery. Jocić‐Jakubi et al. (2009) also distinguished a group with “frontal” absences, which they strongly associated with automatisms, but could not really show a clear difference in short to midterm seizure outcome.…”

“…Although these observations advance our understanding of the role of the frontal lobe in corticothalamic epileptogenesis in humans, opinions may divide when it comes to their clinical interpretation, which can skew toward secondary generalization, particularly when focally lead‐in absences are complex with “lateralizing” or “focal” clinical signs (Jocić‐Jakubi et al., 2009), or resistant to standard treatment of IGE (Lagae et al., 2001). FSWDs are also of debated nature and ambivalent diagnostic value and prognosis (Leutmezer et al., 2002; Koutroumanidis & Smith, 2005; Szaflarski et al., 2010).…”

“…Because mid‐frontal pathology (Tükel & Jasper, 1952) and electrical stimulation of frontal areas in patients with frontal lobe epilepsies (Bancaud et al., 1974) can produce GSWDs and absence‐like seizures, the distinction between absence epilepsy and cryptogenic frontal lobe epilepsy may blur (Craiu et al., 2006), thereby affecting clinical EEG interpretation and therefore decisions about patient treatment and management (Lagae et al., 2001). Antithetical views are not only encountered in IGE phenotypes that are difficult to classify, but even in well‐recognized syndromes—childhood absence epilepsy (CAE) no less (Lagae et al., 2001; Yoshinaga et al., 2004; Jocić‐Jakubi et al., 2009; Ma et al., 2011; Mariani et al., 2011). The whole concept of such EEG focalities and their interpretation may appear even more complex and controversial when row scalp EEG evidence of occipital involvement in the generation of absences is taken into account (O’Brien et al., 1959; Craiu et al., 2006).…”

VNS in drug resistant epilepsy: preliminary report on a small group of patients

“…Earlier age at onset, the appearance of generalized tonic-clonic seizures (GTCSs), difficult and incomplete response to treatment, and the absence of seizure with focal onset of abnormalities, were considered to be factors indicating an unfavorable prognosis [12,17,18]. The pharmaco-resistance was confirmed in this patient by the fact that various drugs (more than 5) were used.…”