Choking, asphyxiation and the insular seizure

In this study, we report the clinical features of insular lobe seizures based on data from video and stereo-electroencephalographic (SEEG) ictal recordings and direct electric insular stimulation of the insular cortex performed in patients referred for presurgical evaluation of temporal lobe epilepsy (TLE). Since our first recordings of insular seizures, the insular cortex has been included as one of the targets of stereo-electroencephalographic (SEEG) electrode implantation in 50 consecutive patients with TLE whose seizures were suspected to originate from, or rapidly to propagate to, the perisylvian cortex. In six, a stereotyped sequence of ictal symptoms associated with intrainsular discharges could be identified. This ictal sequence occurred in full consciousness, beginning with a sensation of laryngeal constriction and paresthesiae, often unpleasant, affecting large cutaneous territories, most often at the onset of a complex partial seizure (five of the six patients). It was eventually followed by dysarthric speech and focal motor convulsive symptoms. The insular origin of these symptoms was supported by the data from functional cortical mapping of the insula by using direct cortical stimulations. This sequence of ictal symptoms looks reliable enough to characterize insular lobe epileptic seizures (ILESs). Observation of this clinical sequence at the onset of seizures on video-EEG recordings in TLE patients strongly suggests that the seizure-onset zone is located not in the temporal but in the insular lobe; recording directly from the insular cortex should occur before making any decision regarding epilepsy surgery. Copyright 2004 International League Against Epilepsy

The clinical and electroencephalographic features of 87 simple partial seizures in 14 patients were studied with video-EEG telemetry. The patients were able to respond to verbal stimuli during all seizures and, later, could clearly recall ictal events. To determine whether the EEG changes in simple partial seizures could be reliably observed, a reader blindly reviewed four EEGs of equal duration for each seizure. These EEGs consisted of one ictal and three nonictal recordings obtained at predetermined times before the seizure. There were 27 motor seizures (mean duration, 86 seconds; range, 2 to 250 seconds), all involving clonic movements of the head and/or upper extremities; 8 (30%) of these had a sensory component (pain in 6, paresthesia in 2). An EEG change, usually localized spikes or sharp waves over the contralateral or both rolandic regions, was identifiable in nine (33%) of the motor seizures. The 60 nonmotor seizures (mean duration, 63 seconds; range, 8 to 375 seconds) involved a variety of symptoms, including somatosensory/special sensory (3 seizures), autonomic (26 seizures), cognitive (1 seizure), affective (14 seizures), and mixed, or more than one category of nonmotor symptoms (16 seizures). In only nine (15%) of the nonmotor seizures was there an ictal EEG change, usually localized spikes or paroxysmal theta activity over the temporal region. Overall, among the 87 simple partial seizures, only 18 (21%) revealed ictal EEG changes. Thus, a normal EEG is common during simple partial seizures and does not exclude the diagnosis.