Clinical and EEG Features of Complex Partial Seizures of Temporal Lobe Origin

Summary: The electrographic and clinical behavioural manifestations of 96 temporal lobe seizures are reviewed from recordings in 19 patients who were submitted to stereotaxic depth electrode implantation in temporal and frontal lobes. Focal onset in hippocampus was recorded in 40% of the seizures. Sixty percent of temporal lobe seizures exhibited a regional seizure onset but in two-thirds of these ictal changes were restricted to amygdaloid and hippocampal structures. Thus, in approximately 80% of seizures, the onset of ictal EEG changes resided in the mesial temporal structures. The main behavioral manifestations observed during seizure discharge restricted to one temporal lobe included warning (67%), motionless stare (24%), automatism (22%), and head-body turning (24%). The predominant ictal behavioural manifestations observed during seizure spread to contralateral temporal and extratemporal structures included warning (3%), motionless stare (36%), automatism (77%), and head-body turning (81%). The direction of head turning did not provide reliable lateralization as to the side of seizure onset.     

Long-Term Ambulatory Cassette EEG with Sphenoidal Recording in Complex Partial Seizures

Long-term ambulatory cassette EEG with sphenoidal recording (A/EEG-SP) was performed in 51 patients. Group A comprised 31 patients with a clinical diagnosis of complex partial seizures (CPS), and group B comprised 20 patients suspected of having CPS. In group A, detection of temporal spikes was 27% by routine EEG (R/EEG), 72% by sphenoidal EEG (SP/EEG), 27% by A/EEG with temporal chain montage, and 91% by A/EEG-SP. The highest yield achieved by A/EEG-SP as compared with other EEG recordings was documentation of spontaneous seizures of temporal lobe origin. The detection rate of spontaneous seizures by A/EEG-SP was approximately 30%, and the focal or regional onset of seizures could be determined in 60% of patients. In group B, detection of temporal spikes was 11% by R/EEG, 18% by SP/EEG, and 30% by A/EEG-SP. Spontaneous seizures were recorded by A/EEG-SP in two patients (10%). Thus, A/EEG-SP was more effective than A/EEG in detecting interictal and ictal temporal discharges, and A/EEG-SP was superior to SP/EEG in documenting spontaneous seizures of temporal lobe origin.     

The EEG Findings in Extratemporal Seizures

Summary: Extratemporal seizures originate from the frontal, central, parietal, occipital, and midline regions of the brain. The scalp EEG can show various types of interictal and ictal discharges consisting of spikes, spike and wave sharp waves, paroxysmal fast activity, or rhythmic activity in the β, α, θ, or δ frequency ranges. The discharges can occur as focal, regional, lateralized, or secondarily generalized discharges. Discharges arising from the frontal region are varied and at times complex. Centro-temporal spikes associated with benign epilepsy of childhood have a characteristic blunt spike and wave appearance. Centro-parietal spikes can occur in children with benign childhood epilepsy or in association with symptomatic epilepsies at any age. Occipital spike discharges have been seen in young children with visual problems, benign occipital epilepsy of childhood, the Sturge-Weber syndrome, and other symptomatic or structural lesions involving the occipital lobe. There may be problems with detection of the source of origin of seizures secondary to the anatomy of the various regions, deep foci, small restricted foci, rapid spread of epileptiform discharges, and contaminating effects of muscle and movement artifact. Depth or intracranial recordings may help in further localization of foci.     

Correlative Study of Interictal Electroencephalogram and Aura in Complex Partial Seizures

To understand further relationships of the interictal electroencephalogram to the aura in complex partial seizures (CPS), we studied the interictal EEG and aura in 144 patients with CPS. The ages of the patients studied ranged from 31 to 80 years (average 52.44 years). The duration of seizures ranged from 1 to 60 years (average 15.69 years). Seventy patients (49%) reported auras which were classified according to the guidelines recommended by the Commission of the International League Against Epilepsy. Statistical analysis revealed no relationship between presence, laterality, or localization of EEG abnormality and the number or type of aura. The results emphasize that more factors than electrophysiologic localization alone participate in the determination of aura in CPS. Our data support the position that aura has, at most, a limited relationship to lateralization or localization of interictal cerebral dysfunction in CPS.     

Complex Partial Seizures in Young Children

Summary: We retrospectively analyzed the clinical manifestations of complex partial seizures (CPS) in children aged 10 years using video and EEG telemetry and evaluated their course, investigations, management, and seizure status at follow-up. Seventeen patients with CPS were studied at the Prince of Wales Children's Hospital (POWCH) and Prince Henry Hospital (PHH) between 1987 and 1992. Because 1.5 of the 17 patients had intractable seizures, the population was selective. Mean age was 6.5 years; 4 patients were aged 2 years. Clinical features were normal or mild intellectual handicap (1 3); hemiplegia (5); and infantile spasms preceding CPS (4); of these, 2 also had simple partial motor seizures. Structural abnormalities were noted on scanning in 9 patients. Eighty-seven seizures were reviewed. Mean duration of each clinical seizure was 59.7 s (total population), 108 s (subgroup 1, aged 2 > years), and 48.5 s (subgroup 2, aged 2 years). Major ictal manifestations were auras (9), staring (9), autonomic changes (6), and automatisms (17). In subgroup 1, automatisms were simple and mainly oroalimentary and gestural. Two patients had no change in surface ictal recordings, and 2 had normal interictal EEGs. At follow-up, 8 patients were seizure-free for 6 months, 1 was partially controlled (more than two seizures a month), and 8 had intractable seizures (two or more seizures a month). Seven patients underwent operation for intractable epilepsy, and 4 achieved a class 1A outcome (Engel classification).     

Complex Partial Seizures of Hippocampal and Amygdalar Origin

We studied the first clinical manifestations of 72 complex partial seizures (CPS) in 17 drug-resistant patients. CPS were indicated to be of hippocampal-amygdalar origin by scalp and depth EEG. We asked: (a) Do all CPS of hippocampal-amygdalar origin start with an initial motionless stare and/or oroalimentary automatisms? (b) If not, what other clinical manifestations appear at onset of the CPS? Results showed that approximately 39% of CPS begin with motionless staring, 25% with nonfocal discrete movements, 21% with oroalimentary automatisms, 10% with perseverative stereotyped automatisms, and 6% with vocalizations. Nonfocal discrete movements and oroalimentary automatisms were identified as the most common second and third clinical sequential manifestations during a CPS. We conclude that although approximately 60% of CPS of hippocampal-amygdalar origin start with motionless staring or oroalimentary automatisms, 40% do not.     

Bicycling Movements as a Manifestation of Complex Partial Seizures of Temporal Lobe Origin

Alternating movements of the limbs during a seizure, especially bicycling movements of the legs, are often taken as strong evidence for the psychogenic origin of seizure activity in an adult population. A recent review of pseudoseizure manifestations concluded that alternating limb movements were "highly characteristic of pseudoseizures." We report two adult patients with complex partial seizures of temporal lobe origin, confirmed by ictal video EEG recording, in whom bicycling movements were the prominent ictal manifestation. Bicycling occurred 5-30 s after ictal onset and lasted 15-30 s. Use of video EEG recording continues to increase our understanding of the wide range of behaviors which may occur in the course of an epileptic seizure, particularly complex partial seizures. Few absolute clinical criteria remain to distinguish epileptic seizures from pseudoseizures. These two cases and one other reported case clearly remove bicycling movements from that category.     

Complex Partial Seizures of Temporal Lobe Origin in Children of Different Age Groups

Summary: The semiology of complex partial seizures(CPS) of temporal lobe origin in adults is well known and is important in establishing seizure localization in patients considered for epilepsy surgery. In contrast, the behavioral features of temporal lobe seizures (TLS) in children described in the literature have not been consistent. In the present study, we investigated children with TLS to compare their attacks to TLS occurring in adults. The study was based on video recordings of 29 children with TLS aged 18 months to 16 years. Children were included, if they became seizure-free after temporal lobectomy (except 4 children with a marked reduction in seizure frequency and 1 with isolated auras), and if clear unitemporal seizure onset in ictal EEG-recordings, unilateral radiological lesions, and corresponding histopathological findings were detected. Children aged >6 years had TLS with features similar to those of adults. In younger children, typical semiology included symmetric motor phenomena of the limbs, postures similar to frontal lobe seizures in adults, and head nodding as in infantile spasms. We concluded that the clinical features of TLS in younger children can be misleading and should therefore be considered with caution in selecting patients for surgical procedures on the temporal lobe.     

Felbamate: A Clinical Trial for Complex Partial Seizures

We performed a randomized, double-blind, three-period cross-over study of felbamate (FBM, 2-phenyl-1,3-propanediol dicarbamate: Carter-Wallace 554) in patients with complex partial seizures. Patients continued carbamazepine (CBZ) throughout the study and were observed in the hospital for the entire trial period. The entry criteria required at least six seizures in a 3-week baseline period (and no more than 1 week with a single seizure) with CBZ alone. Thirty subjects were randomized. Two left the study after randomization, 1 owing to seizure exacerbation, and 1 owing to hyponatremia, which may have been related to CBZ therapy. The daily dosage of 50 mg/kg (maximum 3,000 mg) FBM per day was well tolerated by all 28 patients who completed the study. Only mild adverse experience were observed during the trial. FBM reduced CBZ level (p less than 0.0001; 95% confidence interval -28%, -20%). There was no significant difference in seizure frequency between placebo and FBM periods (one-sided p = 0.172), but when a correction was made for the lower CBZ level noted during FBM periods, the data suggested a strong antiseizure effect of FBM.     

Effect of Naloxone Infusion on the Rate of Epileptiform Discharges in Patients with Complex Partial Seizures

In experimental studies, endogenous opioids have shown protective effects on seizure recurrence and facilitatory effects on postictal inhibition that were reversed by the opioid antagonist, naloxone. We evaluated the effect of all-night continuous infusion of 10 mg naloxone on the rate of focal interictal epileptiform discharges (FIEDs) during sleep in eight men with complex partial seizures (CPS) during 2 consecutive nights. Patients with abundant FIEDs during the control night showed a mean increase of 39% in the rate of FIEDs per unit of time during the naloxone infusion night. During the naloxone infusion night, mean nocturnal plasma prolactin (PRL) concentrations in this group of patients showed significant elevation, which was correlated with increased density of FIEDs. All-night infusion of naloxone failed to show any effect on the remaining three patients with minimal or no FIEDs during the control night. Mean nocturnal plasma PRL concentrations in this group of patients was significantly lower than in the former group. Our data support the notion that, in response to interictal or ictal discharges, endogenous opioid peptides may exert an inhibitory action that is reversible by administration of naloxone.