Autonomic Symptoms during Childhood Partial Epileptic Seizures

Abstract

To the Editors: I read with great interest the paper by Fogarasi and colleagues (Fogarasi et al., 2006) about autonomic symptoms and signs (AS/S) during partial epileptic seizures in 100 children with symptomatic focal epilepsies evaluated with video-EEG telemetry. It provides valuable information on an area we know too little about, and bridges the gap between symptomatic focal epilepsies in adults and idiopathic focal epilepsies of childhood, such as Panayiotopoulos syndrome (PS) (Ferrie et al., 2006) and others. Comparison of the relevant data would help understand not only if and how autonomic ictal semiology in symptomatic focal epilepsies may evolve with age, but also the relationship between symptomatic and idiopathic epileptogenesis in children. Data on adults come mainly from series of surgical candidates (Kramer et al., 1988; Devinski et al., 1995; Schauble et al., 2002). Here, ictal AS/S (mainly gastrointestinal, such as vomiting and hypersalivation) are rare, usually indicate involvement of the non-dominant temporal lobe, and tend to occur late in the seizure sequence during the phase of unresponsiveness of the complex partial seizure. On the other end, in idiopathic focal epileptogenesis with prominent autonomic seizures (PS) ictal AS/S occur as a rule early – frequently from onset – and in clear consciousness, and either persist as the sole ictal manifestations (purely autonomic seizures), or give way to more conventional seizure semeiology such as eye deviation, hemiconvulsions or rarely visual symptoms late in seizure sequence. Here seizures are prolonged and autonomic symptoms are usually multiple per seizure, with ictal vomiting occurring in up to 75% of children (Ferrie et al., 2006). Fogarasi and his colleagues report that at least one autonomic symptom was noted in 60 children (most with temporal lobe epilepsy); each child had no to three AS (median one), and only epigastric aura and postictal coughing (postictal symptoms were also included) localised to the temporal lobe; no AS/S lateralised the ictal onset zone. Interestingly, only 5 of the 60 children (8.3%) with AS/S during their seizures had vomiting, no child had both epigastric aura and vomiting, and papillary changes, cyanosis or pallor were either exceptional or were not observed at all. This paper describes information of extreme practical-clinical and theoretical significance. One can appreciate that a picture of ictal AS/S across different ages, syndromes and aetiologies is gradually coming into focus, and rightly one would like to learn more on autonomic semeiology in this – admittedly specific from the nosological aspect (all with medically intractable focal epilepsies) – group of children. The authors might wish to expand as much as this might be possible a posteriori on relevant points that are not easily deductible from the original paper. First, on the relative power and the timing of the AS/S within the ictal semeiology of the individual seizures, it is not clear whether AS/S were the quantitatively most predominant or clinically most important ictal manifestations in any of the children or they merely coexisted with conventional motor or sensory phenomena. It may also be interesting to know if AS/S and in particular ictal vomiting occurred early in the seizure sequence as in children with idiopathic autonomic seizures or late during the phase of unresponsiveness as in adults. Second, on seizure duration it would be interesting to know if focal seizures with autonomic symptoms lasted longer than those without and what was a typical length, and also whether the authors record or obtain historical evidence of partial status epilepticus with predominantly autonomic ymptoms. Third, did they observe or obtain historical evidence of episodes of sudden loss of muscle tone and awareness during the seizures, a phenomenon that has been reported (Ferrie et al., 2006) and recorded (Oguni et al., 1999) in children with PS.