Abstracts

Rationale: Autonomic seizure is defined as altered autonomic function at seizure onset or a seizure in which autonomic manifestations are clinically prominent and distinguished from secondary effects of the seizure on autonomic system. Due to the emergence from a complex and unexplained central network, a wide spectrum of clinical and electrophysiological findings can be observed in clinical practice. Methods: We evaluated 17 children with autonomic seizures at the video-EEG monitoring unit at Hacettepe University Children’s Hospital between 2013-2018. Results: Age at the time of seizure onset was 3.9 years (20 days - 10 years), age at the time of admission was 9.6 years (2 months - 16 years). Eight patients had focal seizures with autonomic features only, and seven patients had seizures with prominent autonomic findings accompanied by motor manifestations. Two patients who were on polytherapy were diagnosed with non-epileptiform event based on video-EEG findings. One of them was diagnosed with atrioventricular nodal reentrant tachycardia (AVNRT), radiofrequency ablation was performed. Ictal autonomic findings of the patients were cardiovascular (tachycardia, bradycardia) in 10 patients, respiratory (hyperventilation, tachypnea, coughing) in 6, gastrointestinal symptoms (retching, vomiting, feeling of fullness in the stomach, hypersalivation) in 8, cutaneous manifestations (pallor, flushing) in 3 and lacrimation in one. Interictal EEG was abnormal (slowing, epileptiform discharge or amplitude asymmetry), in all 15 patients with autonomic seizures; 3 patients had bilateral abnormalities, 12 showed focal findings over the right temporal (n=4), left temporal (n=5), left frontal (n=1), left parieto-occipital (n=1) areas, and right hemisphere (n=1). In 4/15 patients, ictal EEG showed no changes on scalp electrodes, 2 had bilateral findings, 3 had lateralizing findings (left hemisphere in 2, right hemisphere in one) and 6 had localizing findings (left temporal in 5, right temporal in one). MRI showed lesions in the temporal lobe, amygdala, insula and hippocampus (n = 8); other focal lesions (n = 6) and normal /nonspecific findings (n = 3). Etiological classification revealed structural cause in 14 patients (7 with cortical dysplasia, 3 with tumors, 2 with malformations of cortical development (MCD), 2 with perinatal insult); one patient had genetic cause (CDKL5 gene). Patients with tumors had surgery and pathological evaluations showed ganglioglioma in 2 patients and diffuse glial neoplasm in one. Of note, one of the patients, 11-year-old girl had a peculiar semiology wherein she woke up with tachycardia and lacrimation -without emotional facial expression or crying to suggest emotional seizure-, she fell asleep after looking blank. Ictal EEG was lateralizing to the left hemisphere, MRI showed disorganization of bilateral cerebellar folia and bilateral frontal cortical malformation. FDG-PET revealed hypometabolism in parietotemporal area bilaterally, and in the anterior sections of frontal lobes, more prominent on the left. All patients suffered from refractory seizures, except patients who underwent surgery. Conclusions: Video-EEG may help differentiate non-epileptiform events in patients with autonomic features and guide appropriate treatment, as in our patient with AVNRT. Lacrimation which is a rare manifestation of autonomic seizures was present in one patient, associated with MCD. One of the patients in our series had genetic epilepsy, reflecting the diversity of underlying etiology for autonomic seizures in childhood. Most patients had refractory seizures which could be due to selection bias. Funding: No funding