Ictal EEG Changes with Corpus Callosum Section

Summary: Corpus collosum section diminishes but does not completely abolish secondary bilaterally synchronous interictal EEG discharges, yet often causes cessation of generalized seizures. The effects of corpus callosum section on ictal EEG patterns have not been described. We contrasted ictal EEG patterns before and after anterior callosotomy in 18 patients and before and after total callosotomy in 10 patients. Bilaterally synchronous seizure onset was disrupted in 5 of 11 anterior section patients and 5 of 5 total section patients. Seven of 18 anterior section patients and 5 of 10 total section patients had more localized seizure onset after the procedure; localization to the frontal lobe was observed after anterior or total section, but only total section patients had newly demonstrated posterior locations of seizure onset. These data suggest that the mechanisms by which bilaterally synchronous interictal and ictal discharges are generated differ. Although brainstem or diencephalic structures may contribute to formation of interictal bilateral synchrony, the corpus callosum may be the only pathway used in producing apparent bilateral synchronous seizure onset in patients with secondarily generalized seizures.     

Does head-turning during a seizure have lateralizing or localizing significance?

Forced lateralized head-turning, occurring as the first clinical sign in 106 epileptic seizures in 43 patients, was recorded on videotape simultaneously with the EEG. Forty-five ictal EEGs were obtained with stereotaxically implanted intracerebral electrodes. Forced head-turning was seen with seizures that had a frontal, temporal, unilateral diffuse, or a generalized onset in the EEG. Ipsilateral was as common as contralateral head-turning in all groups, including the seizures with frontal lobe onset. Initial head-turning in a seizure has no localizing or lateralizing significance.     

Clinical Profile of Partial Seizures Beginning at Less Than Four Years of Age

Clinical features of all our 46 patients whose recurrent partial seizures began at age less than or equal to 47 months were studied. Thirty-seven (80%) had motor seizures which were exclusively unilateral in 14 patients, bilaterally synchronous in 8, and both unilateral and bilaterally synchronous in 15. Thirty-three patients (72%) had complex partial seizures (CPS), and 11 patients (24%) had simple partial somatosensory seizures. Clinical seizures were recorded by EEG in 18 patients (39%), and a subclinical (larval) seizure was recorded in 1; those in 10 patients arose from a temporal lobe, 4 were from a frontal lobe, and in 5 they involved two adjacent lobes from onset. Several extra-ictal features reliably indicated lobe or hemisphere of seizure onset. The lobe of principal interictal EEG spikes corresponded to seizure origin in 33 of 34 patients (97%), and regional delta activity corresponded to lobe of seizure origin in 22 of 24 patients (92%). The seizures of all 13 patients with unilateral neurologic signs corresponded to the hemisphere implicated by the deficit. Computed tomography (CT) scan showed lesions in 30 patients (65%) and corresponded to the lobe of seizure onset in 27 of the 30 (90%). Seizures arose primarily from a frontal lobe in 22 of 46 patients (48%), from a temporal lobe in 14 patients (30%), and from an occipital-parietal-posterotemporal region in 6 patients (13%); only the hemisphere of origin could be determined in 4 patients. Cortical developmental abnormalities were the most common known cause (12 patients, 26%); febrile seizures and primary brain tumors occurred in 10 and 8 patients, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intracranial EEG Substrates of Scalp Ictal Patterns from Temporal Lobe Foci

Summary: Purpose: To determine the intracranial EEG features responsible for producing the various ictal scalp rhythms, which we previously identified in a new EEG classification for temporal lobe seizures. Methods: In 24 patients, we analyzed simultaneous intracranial and surface ictal EEG recordings (64 total channels) obtained from a combination of intracerebral depth, subd-ural strip, and scalp electrodes. Results: Four of four patients with Type 1 scalp seizure patterns had mesial temporal seizure onsets. However, discharges confined to the hippocampus produced no scalp EEG rhythms. The regular 5- to 9-Hz subtemporal and temporal EEG pattern of Type 1a seizures required the synchronous recruitment of adjacent inferolateral temporal neocortex. Seizure discharges confined to the mesiobasal temporal cortex produced a vertex dominant rhythm (Type 1c) due to the net vertical orientation of dipolar sources located there. Ten of 13 patients with Type 2 seizures had inferolateral or lateral, temporal neocortical seizure onsets. Initial cerebral ictal activity was typically a focal or regional, low voltage, fast rhythm (20–40 Hz) that was often associated with widespread background flattening. Only an attenuation of normal rhythms was reflected in scalp electrodes. Irregular 2- to 4-Hz cortical ictal rhythms that commonly followed resulted in a comparably slow and irregular scalp EEG pattern (Type 2a). Type 2C seizures showed regional, periodic, 1– to 4-Hz sharp waves following intracranial seizure onset. Seven patients had Type 3 scalp seizures, which were characterized by diffuse slowing or attenuation of background scalp EEG activity. This resulted when seizure activity was confined to the hippocampus, when there was rapid seizure propagation to the contralateral temporal lobe, or when cortical ictal activity failed to achieve widespread synchrony. Conclusions: Type 1, 2, and 3 scalp EEG patterns of temporal lobe seizures are not a reflection of cortical activity at seizure onset. Differences in the subsequent development, propagation, and synchrony of cortical ictal discharges produce the characteristic scalp EEG rhythms.     

Localized Pain Associated with Seizures Originating in the Parietal Lobe

PURPOSE: Ictal pain is a rare symptom of seizures. Epileptic pain may be experienced unilaterally (lateral/ peripheral), cephalically, or in the abdomen. Painful seizures have been associated with seizure origin in both the parietal and the temporal lobes. We report on the different types of epileptic pain and discuss its etiology and possible localizing value. METHODS: We reviewed the records of patients referred to our epilepsy program over the last 6 years. Eight (1.4%) of 573 patients had pain as an early prominent symptom of their seizures. RESULTS: Pain was predominantly unilateral in three patients, cephalic in two, and abdominal in three patients. Seizure onset was in or involving the parietal lobe in all patients, and when the painful symptoms were lateralized, they were contralateral to the side of seizure origin. Parietal lobe seizure origin was determined by both intracranial EEG recording and neuroimaging [magnetic resonance imaging (MRI), ictal single photon emission computed tomography (SPECT)] in five patients, and by both scalp EEG and neuroimaging in three patients. CONCLUSIONS: We conclude that ictal pain is a rare symptom of parietal lobe seizure origin with lateralizing potential.     

Insular-opercular seizures manifesting with sleep-related paroxysmal motor behaviors: a stereo-EEG study

Purpose: Sleep‐related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nevertheless, recent studies also suggest that sleep‐related hypermotor seizures can originate in the insula. The present study describes the electroclinical features of eight drug‐resistant epileptic patients with insular‐opercular seizures manifesting with nocturnal complex motor seizures. Methods: Patients underwent a comprehensive presurgical evaluation, which included history, interictal electroencephalography (EEG), scalp video‐EEG monitoring, high‐resolution magnetic resonance imaging (MRI), and intracerebral recording by stereo‐EEG. Key Findings: Almost all patients reported an initial sensation consisting of viscerosensitive or somatosensory symptoms. Ictal clinical signs were represented by tonic–dystonic asymmetric posturing and/or hyperkinetic automatisms, including bimanual/bipedal activity and ballistic movements. Some patients exhibited dysarthric speech, hypersalivation, and apnea. Interictal and ictal EEG provided lateralizing information in the majority of patients. In three patients, MRI showed a focal anatomical abnormality in the insular‐opercular region. Stereo‐EEG ictal recordings demonstrated that the epileptic discharge involved simultaneously the insular cortex and the opercular region. Complex motor manifestations appeared when the ictal discharge showed an extrainsular spreading to frontomesial regions (cingulum, superior frontal gyrus, and supplementary motor area) and/or to internal and neocortical temporal lobe structures. Six patients received an insular‐opercular cortical resection; three of them are seizure free (minimum follow‐up 24 months) and in one a marked reduction in seizure frequency was obtained. Two patients have been operated on recently. Histology revealed a focal cortical dysplasia in three patients. One patient excluded from surgery died for sudden unexpected death in epilepsy during sleep. Significance: Our data strengthen the concept that sleep‐related complex motor attacks can originate in the insula, and provide useful electroclinical information to differentiate this localization from those with similar clinical characteristics. Furthermore, this study indicates that in these drug‐resistant patients, surgical treatment represents a highly effective treatment option.     

Are “Generalized” Seizures Truly Generalized? Evidence of Localized Mesial Frontal and Frontopolar Discharges in Absence

PURPOSE: To determine whether specific regions of cerebral cortex are activated at the onset and during the propagation of absence seizures. METHODS: Twenty-five absence seizures were recorded in five subjects (all women; age 19-58 years) with primary generalized epilepsy. To improve spatial resolution, all studies were performed with dense-array, 256-channel scalp EEG. Source analysis was conducted with equivalent dipole (BESA) and smoothed linear inverse (LORETA) methods. Analyses were applied to the spike components of each spike-wave burst in each seizure, with sources visualized with standard brain models. RESULTS: For each patient, the major findings were apparent on inspection of the scalp EEG maps and waveforms, and the two methods of source analysis gave generally convergent results. The onset of seizures was typically associated with activation of discrete, often unilateral areas of dorsolateral frontal or orbital frontal lobe. Consistently across all seizures, the negative slow wave was maximal over frontal cortex, and the spike that appeared to follow the slow wave was highly localized over frontopolar regions of orbital frontal lobe. In addition, sources in dorsomedial frontal cortex were engaged for each spike-wave cycle. Although each patient showed unique features, the absence seizures of all patients showed rapid, stereotyped evolution to engage both mesial frontal and orbital frontal cortex sources during the repeating cycles of spike-wave activity. CONCLUSIONS: These data suggest that absence seizures are not truly "generalized," with immediate global cortical involvement, but rather involve selective cortical networks, including orbital frontal and mesial frontal regions, in the propagation of ictal discharges.     

What is the Relationship Between Arachnoid Cysts and Seizure Foci?

Summary: Purpose: Arachnoid cysts are sometimes encountered in MRIs performed for a variety of reasons. In patients with epilepsy, particularly those with refractory epilepsy, arachnoid cysts are often assumed to be related to their seizure focus. We conducted a study to investigate this putative relationship.
Methods: A retrospective study on the incidence of arachnoid cysts was performed in patients seen in our Epilepsy Clinic who had CT or MRI scans, interictal EEGs or ictal EEGS. Locations of seizure foci in these patients were defined from clinical and electrophysiologic data.
Results: Seventeen of 867 patients had arachnoid cysts. Twelve patients had temporal lobe cysts and only 3 of them had temporal lobe seizures. Four patients had frontal lobe cysts and only 1 had frontal lobe seizures ipsilateral to the cyst. One patient had a cerebellopontine angle cyst and frontal lobe seizures. Thus, clinical manifestations of seizures and EEG findings (interictal and/or ictal) indicated that the seizure focus was adjacent to the cysts in only 4 patients (23.5%).
Conclusions: Our findings suggest that arachnoid cysts are often an incidental finding in patients with epilepsy and do not necessarily reflect the location of the seizure focus.     

表现有立毛运动的复杂部分性癫痫(附3例报告及文献复习)

目的了解立毛运动性发作的病理生理、病因及临床特点。方法结合3例立毛运动性发作病例及文献复习(已报过21例)，探讨立毛运动性发作的特点。结果立毛运动性发作的最重要临床表现是反复的立毛运动，可能与右颞叶额叶(眶面皮层，运动前区)下丘脑和边缘系统学结构有关，脑电图(EEG)表现为非特异性异常，但是大多数病例有发作期发放或癫痫样波，视频监测脑电图(Video—EEG)对于评价其分型及发作期、发作间期变化有帮助。结论立毛运动性发作极罕见。但是注意结合病史，体检和EEG检查还是可以发现的。     

Epileptic spasms in older pediatric patients: MEG and ictal high-frequency oscillations suggest focal-onset seizures in a subset of epileptic spasms

OBJECTIVES: To elucidate the pathophysiology of intractable epileptic spasms in older children by describing the interictal magnetoencephalography spike sources (MEGSSs), intracranial EEG ictal-onset zones (IOZs) and their ictal high-frequency oscillations (HFOs) and surgical outcomes. METHODS: We studied five patients (4.5-14 years) who underwent surgery following intracranial video-EEG (VEEG) monitoring. We analyzed clinical profiles, MRIs, scalp and intracranial VEEGs, and MEGSSs. We localized ictal HFOs using a sampling rate of 1000 Hz and multiple band frequency analysis (MBFA). RESULTS: Seizure onset ranged from 0.4 to 8 years. Three patients presented with asymmetrical spasms. Interictal scalp VEEG recorded predominantly unilateral epileptiform discharges in four; generalized and multifocal in one. Ictal scalp VEEG showed generalized high-amplitude slow waves with superimposed fast waves in four patients; hemispheric electrodecremental episodes in one. MRI findings were normal in three, hemispheric polymicrogyria and periventricular heterotopia in one each. All patients had unilateral MEGSS clusters. Ictal HFOs, ranging from 150 to 250 Hz, localized over Rolandic and frontal regions in four, with one also having extensive temporo-occipital HFOs. After cortical resection, three patients were seizure free; one had >90% reduction in seizure frequency. One patient experienced residual seizures after resection of the hemispheric ictal HFO region. CONCLUSION: Unilateral clusters of MEGSSs overlapped regional IOZs in older patients with epileptic spasms. High spatio-temporal MBFA before and during spasms revealed the regional ictal HFOs. Seizure-free outcomes following resection of zone with MEGSS clusters and ictal HFOs suggested that a subset of epileptic spasms was focal-onset seizures.     

Awareness and Responsiveness During Partial Seizures

Summary: We examined the impairment of consciousness during partial seizures (PS) arising from various brain sites according to the operational definition of the international classification, i.e., altered awareness and/or responsiveness. The subjects were 142 patients who underwent intracranial EEG evaluation and subsequent resective surgery. First, the patients were examined to determine whether they usually had been partially or completely aware of their seizures. Second, spontaneous habitual seizures that had been videotaped with simultaneous intracranial EEG recording were reviewed to determine responsiveness and recall during ictal behavioral alterations. In all, 114 patients were partially or completely aware of their seizures. Patients who tended not to be aware of their seizures were those with frontal lobe epilepsy (FLE) with extensive epileptogenic regions on the language nondominant side and those with temporal lobe epilepsy (TLE) with seizure origin in the lateral cortex of the language dominant side. Of the 21 patients with FLE, 88 with TLE, and 4 with occipital lobe epilepsy, 7, 22, and 2 patients responded to stimuli during the seizure, respectively, but only 11 of the patients with FLE and none of the other patients could recall the stimuli applied during the behavioral alterations. Bilateralization of seizure discharges correlated with impaired responsiveness. According to the International Classification, about half of patients with FLE had only simple partial seizures (SPS) and the other patients had complex partial seizures (CPS). Altered awareness and/or responsiveness occurred in most habitual partial seizures in our subjects. The term "complex" appears to be useful in clinical practice, although the contents of ictal behavior and the site or side of seizure origin are not implied.     

The impact of cerebral source area and synchrony on recording scalp electroencephalography ictal patterns

PURPOSE: To determine the cerebral electroencephalography (EEG) substrates of scalp EEG seizure patterns, such as source area and synchrony, and in so doing assess the limitations of scalp seizure recording in the localization of seizure onset zones in patients with temporal lobe epilepsy. METHODS: We recorded simultaneously 26 channels of scalp EEG with subtemporal supplementary electrodes and 46-98 channels of intracranial EEG in presurgical candidates with temporal lobe epilepsy. We correlated intracranial EEG source area and synchrony at seizure onset with the corresponding scalp EEG. Eighty-six simultaneous intracranial- and scalp-recorded seizures from 23 patients were evaluated. RESULTS: Thirty-four intracranial ictal discharges (40%) from 9 patients (39%) had sufficient cortical source area (namely > 10 cm(2)) and synchrony at seizure onset to produce a simultaneous or nearly simultaneous focal scalp EEG ictal pattern. Forty-one intracranial ictal discharges (48%) from 10 patients (43%) gradually achieved the necessary source area and synchrony over several seconds to generate a scalp EEG ictal pattern. These scalp rhythms were lateralized, but not localizable as to seizure origin. Eleven intracranial ictal discharges (13%) from 4 patients (17%) recruited the necessary source area, but lacked sufficient synchrony to result in a clearly localized or lateralized scalp ictal pattern. CONCLUSIONS: Sufficient source area and synchrony are mandatory cerebral EEG requirements for generating scalp-recordable ictal EEG patterns. The dynamic interaction of cortical source area and synchrony at the onset and during a seizure is a primary reason for heterogeneous scalp ictal EEG patterns.     

Significance of Simple Partial Seizures in Temporal Lobe Epilepsy

Summary: We determined how localization of simple partial seizures (SPS) correlated with localization of complex partial seizure (CPS) in scalp/sphenoidal EEG and assessed prognosis after temporal lobe resective surgery in patients with an ictal correlate of SPS in scalp/sphenoidal EEG recordings. EEGs were recorded with the 10–20 system of electrode placement and supplemented with sphenoidal electrodes. Between 1985 and 1992, 183 patients with temporal lobe epilepsy (TLE) reported an aura (SPS) during inpatient monitoring; all were eligible for inclusion in our study. The EEGs during SPS showed ictal changes in 51 patients (28%, 117 SPS). Forty-four patients had unilateral temporal interictal spikes (IIS), and SPS and CPS always arose from the same region. Seven patients had bitemporal interictal spikes; SPS colocalized with CPS in 4 patients (57%), SPS were contralateral to CPS in 2 patients, and 1 patient had bilateral independent CPS but unilateral SPS. SPS accompanied by EEG ictal changes conveyed a favorable prognosis in patients who underwent epilepsy surgery. Scalp/sphenoidal recorded IIS but were less reliable in identifying the location of CPS onset in patients with bitemporal spikes.     

Epileptiform EEG activities of the centromedian thalamic nuclei in patients with intractable partial motor, complex partial, and generalized seizures

Centromedian thalamic nuclei (CM) epileptiform EEG activities were recorded in patients with intractable partial motor, complex partial, and generalized seizures through implanted recording-stimulating electrodes, used for seizure control. CM epileptiform activities showed either little or no correlation to focal surface cortical and amygdaloid activities in patients with partial motor and complex partial seizures: CM paroxysmal discharges were correlated to focal epileptiform ictal activities only during the contraversive movements of partial motor and complex partial seizures. In contrast, CM epileptiform activities were consistently correlated to widespread surface cortical activities and clinical symptoms of fully developed nonconvulsive and convulsive tonic-clonic generalized seizures; i.e., unilateral CM double spike-wave complex discharges significantly preceded (p less than 0.001) the contralateral CM and bilateral surface cortical discharges and symptoms of nonconvulsive generalized seizures. Unilateral CM fast-slow-fast paroxysmal discharges significantly preceded (p less than 0.005) those of the contralateral CM and bilateral surface cortical regions and symptoms of the convulsive tonic-clonic generalized seizures. Individual spike-wave complexes from the frontal region preceded (p less than 0.001 and p less than 0.005) those at CM and other cortical regions during the nonconvulsive and clonic generalized attacks. No correlations between CM and cortical epileptiform activities were found, however, in the case of abortive, subclinical thalamocortical EEG discharges.     

Hyperkinetic seizures in patients with temporal lobe epilepsy: clinical features and outcome after temporal lobe resection

Purpose: Temporal lobe epilepsy (TLE) is usually associated with automatisms. Hyperkinetic seizures are supposed to be unusual. Because we witnessed several patients with TLE and ictal hyperkinetic symptoms, we retrospectively assessed the number, clinical findings, and seizure outcome in such patients who had undergone temporal lobe resection. Methods: We reviewed medical history, video–electroencephalography (EEG) recording and neuroimaging of adult patients who underwent epilepsy surgery for TLE at the Kork Epilepsy Center over the last 20 years with a minimum postoperative follow‐up of 12 months. Key Findings: Among 294 patients who were resected exclusively in the temporal region, we identified 17 (6%) who presented with hyperkinetic semiology such as violent vocalization, complex movements of the proximal segments of the limbs, rotation of the trunk, pelvic thrusting, or early tonic or dystonic posturing. Most of the patients had a preceding aura. Ictal EEG activity was located in the corresponding temporal region, usually with a wide distribution over temporal electrodes with fast spread to unilateral frontal electrodes and to the contralateral side. Neuroimaging revealed extended lesions in the temporal lobe involving mesial and neocortical structures. Most of the patients underwent classical anterior temporal lobe resection including amygdalo‐hippocampectomy. Fourteen patients (82%) became completely seizure‐free (Engel class Ia). Histopathology showed mainly focal cortical dysplasia plus hippocampal sclerosis. Significance: Hyperkinetic seizure semiology may occasionally occur in patients with TLE and is, therefore, no contradiction to the hypothesis of TLE if scalp EEG patterns and neuroimaging findings correspond. The postoperative seizure outcome is favorable in such patients and not different from outcome data in classical TLE.     

颞叶癫痫的痫性放电传导和临床症状的颅内电极脑电图研究

目的 探讨颞叶癫痫患者痫性放电的传导部位、时间和相应的临床症状变化.方法 对2003年6月至2007年5月确诊为颞叶癫痫并行颅内电极埋置检查的48例患者的颅内电极脑电图和发作期症状进行回顾性分析,通过在双侧海马放置的针状电极和颢叶、额叶等放置的条状皮层电极,找出发作起源部位、早期传导部位、传导时间及发作起始症状和传导后症状.结果 共记录126次临床癫痫发作,105次记录到传导部位,其中同侧颢叶内传导22次,额叶39次,顶枕叶18次,对侧海马10次,16次全脑放电.44.8%传导时间小于2.5 s,55.2%传导时间超过2.5 s,且有17.1%超过5 s.101次发作中出现初始症状,其中82.2%为意识水平下降、自动症、恐惧等;99次记录到传导后新症状,其中出现颞叶外传导者82.2%出现抽动或强直表现.结论 颞叶癫痫放电传导部位主要是同侧的额叶与颞叶内部,但也可直接到对侧海马结构,临床症状与传导位置有关,传导速度多较慢.     

Frontal lobe epilepsy

About one-quarter of patients with refractory focal epilepsies have frontal lobe epilepsy (FLE). The typical seizure semiology for FLE includes unilateral clonic, tonic asymmetric or hypermotor seizures. Interictal electroencephalograms (EEG) usually reveal interictal epileptiform discharges and rhythmical midline theta, which has localizing value. The usefulness of ictal EEG recordings is limited by frequent muscle artifacts in motor seizures and because a large portion of the frontal lobe cortex is “hidden” to scalp electrodes. Ictal single photon emission CT and positron emission tomography are able to localize FLE in about one-third of patients only. A pre-surgical evaluation should include, whenever possible, a subclassification of FLE as dorsolateral frontal, mesial frontal or basal frontal lobe epilepsy to allow a minimal cortical resection. A review of the typical findings of seizure semiology, interictal and ictal EEG regarding the different FLE subtypes is given. Etiology, medical treatment and surgery are also discussed.     

Frontal Localization of Absence Seizures Demonstrated by Ictal Positron Emission Tomography

Generalized absence seizures are rarely reported to originate from one frontal lobe. We report an 8-year-old girl with atypical absence seizures demonstrated to be of right frontal origin by ictal positron emission tomography (PET). She had a congenital left hemiparesis and intractable seizures since age 3, and was referred for epilepsy surgery. During electroencephalography-video monitoring numerous episodes of atypical absence seizures were recorded in association with generalized 3- to 3.3-Hz spike-and-wave discharges by EEG. PET was performed with simultaneous EEG recording. Six typical seizures occurred during the fluorodeoxyglucose (FDG) uptake period. The PET scan demonstrated marked increased FDG uptake in right frontal region. Partial seizures of frontal lobe origin can manifest themselves as atypical absence seizures, with generalization based on secondary bilateral synchrony. In patients with frequent seizures the frontal seizure origin may be demonstrated noninvasively with functional imaging using PET or single-photon emission computed tomography.     

Clinical and ictal characteristics of infantile seizures: EEG correlation via long-term video EEG monitoring

Purpose

The semiology of infantile seizures often shows different characteristics from that of adults. We performed this study to describe clinical and ictal characteristics of infantile seizures at less than two years of age.

Methods

A retrospective study was done for infants with epilepsy (ages: 1–24 months) who underwent long-term video electroencephalography (EEG) monitoring at Samsung medical center between November 1994 and February 2012. We analyzed the clinical and ictal characteristics of the 56 cases from 51 patients.

Results

In 69% of the patients, the seizure onset was before six months of age and the etiology was symptomatic in one third of the patients. Twelve seizure types were identified; spasms (24%), unilateral motor seizures (18%), and generalized tonic seizures (15%) were the three frequent types of seizure.All partial seizures were well correlated with the partial-onset ictal EEG, however 19.4% (7/36) of clinically generalized seizures revealed partial-onset ictal EEG. About one-thirds (4/11) of generalized tonic seizures had its ictal onset on unilateral or bilateral frontal areas and two out of seven generalized myoclonic seizures showed unilateral frontal rhythmic activities. Hypomotor seizures mainly arose from the temporal areas and hypermotor seizures from the frontal regions.

Conclusions

Even though most of the seizure semiology of infants is well correlated with ictal EEG, some of the generalized tonic seizures or myoclonic seizures revealed partial-onset ictal EEG suggesting localized epileptic focus. Accurate definition of seizures via video EEG monitoring is necessary for proper management of seizures in infancy, especially in some clinically generalized seizures.     

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.