Abstracts

Rationale: It is reasonable to hypothesize that, in patients with similar ictal onset zones and similar ictal behaviors, the same neuroanatomical routes might be involved. As the first in a series of our ongoing studies aimed at mapping the anatomy of seizure propagation in patients with medial temporal lobe epilepsy, we mapped the type, the sequence, and the frequency of various ictal behaviors in a selected group of patients with reportedly similar seizure profiles. Although earlier semiological studies have provided invaluable information about the lateralizing value of various ictal behaviors and the lobar origin of ictal discharges associated with these behaviors, the issues of communality and order of ictal behavior in a particular group of patients with qualitatively similar seizures remain unknown. Methods: From a list of patients recently admitted to Stanford Medical Center with confirmed diagnosis of temporal lobe epilepsy (right or left), we selected 19 patients (5 male and 14 female, age 39.26 ± 7.7years, duration of seizures 17.47 ± 10.4), all of whom had reported seizure onset with lipsmacking. In total, 37 epileptic seizures were recorded during long term monitoring of these patients, and all seizures were verified by ictal EEGs originating from either temporal lobes. We reviewed video recordings of the events and noted the type, duration, and order of all exhibited behaviors. We used a combined seizure vocabulary based on previous semiological studies especially the ones by Manford et al (1996), Luders et al (1998), and Kotagal et al (2003). Using conventional statistical methods including our own matrix method, we analyzed the type, the frequency, and the order of ictal behavior associated with lip smacking. Results: By selection criteria, lipsmacking was present in 100% of our patients and occurred in all patients during the initial phase of seizures defined as the first third of total seizure length. Behaviors that co-occurred during the same phase of seizures were vocalization (84%) and upper extremity automatisms (79%). Patients, who exhibited vocalization, often had non-verbal sounds (74%), mumbling (21%), and/or verbal (21%) behavior. Of patients with upper extremity automatisms, 59.5% exhibited reaching and grasping behavior compared to simpler automatisms such as touching (53%), picking at things (42%), pill rolling (26%), hand clasping (21%), or clenching fists (11%). Conclusions: Lipsmacking is an initial ictal behavior and it is associated with a specific set of, rather than a random variation of, behaviors. This supports the notion of selective vulnerability of specific neuroanatomical pathways in seizure propagation. Given the pattern of ictal behaviors exhibited in our patients, it is reasonable to hypothesize that the seizure propagation in these patients, at least in the initial phase of propagation, recruits anatomical pathways from the temporal lobes to neural structures known to be involved in vocalization and upper extremity functions such as the anterior cingulate motor areas and the dorsolateral and opercular frontal lobes.