A case of Panayiotopoulos syndrome showing an atypical course

We describe herein a patient with Panayiotopoulos syndrome (PS) showing an atypical course. The patient initially had seizures typical of this syndrome from 3 to 5 years of age. EEG showed right occipital high-amplitude sharp and slow-wave complexes followed by brief generalized discharges of slow waves. Sequential EEGs obtained from 5 to 11 years of age showed both multifocal discharges and generalized spike and wave complexes. With these changes in EEG findings, the patient experienced various types of seizures. The seizures were frequent and showed oculocephalic deviation followed by absence, atonic seizures, generalized tonic clonic convulsions and clonic seizures of the eyelids, which were observed between 7 and 10 years of age. Antiepileptic drugs were only partially effective for these seizures. Ictal EEG recorded at 8 years of age revealed high-voltage slow waves from the bilateral frontal and occipital regions prior to diffuse high-amplitude spike-wave bursts. At 9 years of age, magnetoencephalography (MEG) revealed the calculated dipoles of the preceding bifrontal spike-wave discharges to be in the frontal areas, while those of the following generalized spike-wave bursts were in the bilateral mid-temporal areas. In PS, reportedly, dipoles of multifocal epileptic discharges are usually located in the occipital and Rolandic areas. The unique clinical evolution in our case may be associated with the unusual frontal localization of dipoles detected by MEG.     

Magnetoencephalography and diffusion tensor imaging in gelastic seizures secondary to a cingulate gyrus lesion

Gelastic seizures are relatively uncommon and rarely observed secondary to frontal lobe lesions. This report presents magnetoencephalography (MEG) and diffusion tensor imaging (DTI) findings in an adolescent with gelastic seizures secondary to a left anterior cingulate gyrus lesion. Ictal scalp video EEG showed bilateral frontal 4 Hz theta discharges. Interictal EEG showed left fronto-temporal spikes or sharp waves. Interictal MEG showed spike sources over bilateral temporal regions. DTI and tractography delineated slightly shifted corpus callosum posterior to the lesion, unaffected uncinate and inferior longitudinal fasciculi. The patient became seizure free for 12 months after surgical excision of a pleomorphic xanthoastrocytoma in the left anterior cingulate region. In our patient, MEG and EEG did not localize the deep-seated epileptogenic zone. The combination of DTI and neurophysiologic studies, however, possibly disclosed neuronal connections within the epileptic network and indicated that epileptic discharges propagated via the uncinate fibers from the primary epileptogenic zone in the anterior cingulate region to the mesial temporal region in this case with gelastic seizures secondary to a cingulate lesion.     

Ictal MEG in two children with partial seizures

We report on the successful identification of epileptic foci in two children with partial epilepsy using ictal magnetoencephalography (MEG). Case 1 is a 12-year-old male suffering with simple partial seizures with leftwards nystagmus. Ictal SPECT revealed a hyperperfusion area in the right lateral occipital area, and MRI revealed cortical dysplasia in the same area. Interictal EEG dipoles were concentrated in the right mesial occipital lobe. Both interictal and ictal MEG dipoles were concentrated in the right mesial occipital lobe, which corresponded well with neuroimaging data and his clinical features. Case 2 is a 5-year-old female suffering with simple partial seizures with left-side facial twitching. Interictal EEG dipoles were located in her left motor area, the pre-sylvian fissure, close to the location of the interictal MEG-estimated dipoles. Ictal EEGs showed no remarkable changes associated with her clinical manifestations. However, ictal MEG showed high-voltage slow waves over her left hemisphere, and ictal MEG iso-contour maps revealed a clear dipolar pattern, which suggested that the MEG dipole was located in the area of the sylvian fissure. Ictal SPECT revealed hyperperfusion areas around the left sylvian fissure. Conclusion: Ictal MEG is useful for determining the precise location of epileptic focus in patients with motionless seizures, including children.     

Bilateral mesial temporal lobe epilepsy: comparison of scalp EEG and hippocampal MRI-T2 relaxometry

OBJECTIVE: Bilateral hippocampal abnormality is frequent in mesial temporal lobe sclerosis and might affect outcome in epilepsy surgery. The objective of this study was to compare the lateralization of interictal and ictal scalp EEG with MRI T2 relaxometry. MATERIAL AND METHODS: Forty-nine consecutive patients with intractable mesial temporal lobe epilepsy (MTLE) were studied with scalp EEG/video monitoring and MRI T2 relaxometry. RESULTS: Bilateral prolongation of hippocampal T2 time was significantly associated with following bitemporal scalp EEG changes: (i) in ictal EEG left and right temporal EEG seizure onsets in different seizures, or, after regionalized EEG onset, evolution of an independent ictal EEG over the contralateral temporal lobe (left and right temporal asynchronous frequencies or lateralization switch; P = 0.002); (ii) in interictal EEG both left and right temporal interictal slowing (P = 0.007). Bitemporal T2 changes were not, however, associated with bitemporal interictal epileptiform discharges (IED). Lateralization of bilateral asymmetric or unilateral abnormal T2 findings were associated with initial regionalization of the ictal EEG in all but one patient (P < 0.005), with lateralization of IED in all patients (P < 0.005), and with scalp EEG slowing in 28 (82,4%) of 34 patients (P = 0.007). CONCLUSION: Our data suggest that EEG seizure propagation is more closely related to hippocampal T2 abnormalities than IED. Interictal and ictal scalp EEG, including the recognition of ictal propagation patterns, and MRI T2 relaxometry can help to identify patients with bitemporal damage in MTLE. Further studies are needed to estimate the impact of bilateral EEG and MRI abnormal findings on the surgical outcome.     

Ipsilateral and Bilateral EEG Activity from the Hippocampus

Abstract: Using scalp and depth electroencephalography (EEG), we examined the relationship between the surface EEG activity and abnormal EEG discharges in the ipsilateral hippocampus in order to study the neuronal connection between the two cerebral regions. Ictal EEG was divided into 4 groups: 1) unitempo-ipsilateral-bifrontal slow waves, 2) unitempo-ipsilateral-bilateral slow waves, 3) bilateral slow waves, and 4) bilateral slow waves with repetitive spikes. Abnormal depth EEG activity in the hippocampus was classified into paroxysmal discharges and recruiting rhythms. Ictally and interictally, repetitive sharp waves or spikes in the unilateral hippocampus were associated with sharp waves or spikes in the ipsilateral temporal region. These findings suggest that the ipsilateral projection of seizure activity originating in the unilateral hippocampus is dependent upon the function of the subiculum.     

Ictal magnetoencephalographic study in a patient with ring 20 syndrome

OBJECTIVE: To report the ictal magnetoencephalography (MEG) in a patient with ring chromosome 20 mosaicism, a rare chromosomal anomaly associated with intractable epilepsy. METHODS: MEG and simultaneous EEG were recorded with a 204 channel whole head MEG system. Ten habitual seizures occurred during the acquisition, which was done twice. The equivalent current dipoles (ECDs) for ictal discharges on MEG were calculated using a single dipole model. The ECDs were superimposed on a magnetic resonance image. RESULTS: During the seizures, EEG showed prolonged bursts of 5-6 Hz high voltage slow waves with spike components, dominantly in the bilateral frontal region. MEG showed epileptiform discharges corresponding to the ictal EEG. Ictal discharges on MEG were dominant in the frontal area in the initial portion, and then spread in the bilateral temporal area in the middle of the seizure. ECDs obtained from the spikes of the initial portion were clustered in the medial frontal lobe. CONCLUSIONS: The source of the ictal MEG was localised in the medial frontal lobe. The findings suggest that the mechanism underlying epilepsy in this case might be similar to medial frontal lobe epilepsy. Ictal MEG is a valuable tool for detecting the site of seizure onset.     

Ictal magnetoencephalographic discharges from elementary visual hallucinations of status epilepticus

PURPOSE: To report the rare opportunity to study ictal magnetoencephalography (MEG) in a 26 year old man with simple partial status epilepticus that presented as elementary visual hallucinations (EVHs) in the right upper visual field. METHODS: The patient described his EVHs as "snowing on TV," "flickering lights," and "rotating coloured balls" that continued for several days. MEG and simultaneous EEG were recorded twice: during an episode of EVHs (ictal recordings) and after EVHs were controlled by medications (interictal recordings). RESULTS: During EVHs, MEG showed continuous periodic epileptiform discharges over the left posterior superior temporal region, while simultaneous EEG showed rhythmic theta waves and sporadic spikes over the left temporal region. The MEG discharge consisted of a three phase spike complex. Equivalent current dipoles (ECDs), modelled from spike complexes, localised in the left superior temporal area. After drug treatment controlled the EVHs, interictal MEG and EEG showed rare spikes over the same left temporal region. The average ictal ECD moment (mean (SD)) (128.7 (32.8 nAm)) was significantly weaker than the average interictal ECD moment (233.0 (63.9) nAm) (p<0.05). CONCLUSIONS: The continuous, periodic, and clustered discharges seen on ictal MEG were the sources of EVH. The weaker ictal ECD sources were frequently not detected by scalp EEG, while the stronger interictal sources, presumably originating from an extensive interictal zone, were sufficiently large to be seen as EEG spikes.     

颞叶内侧癫癎发作期海马深部脑电图的特点

目的探讨颞叶内侧癫癎（medial temporal lobe epilepsy,MTLE）发作期海马深部脑电图的特点。方法回顾性分析记录双侧海马深部脑电图,行前颞叶切除术且长期预后良好的18例病人的临床资料,研究海马深部脑电图发作起源的波形特点和部位。结果发作期海马深部脑电图低幅快节律起源7例,棘（尖）波节律起源8例,高幅棘（尖）慢波起源占3例。起源点主要位于从海马头部向后3 cm之内的区域。结论低幅快节律、棘（尖）波节律是MTLE病人海马深部脑电图发作期的最主要两种波形。发作起源区主要位于海马前头部。     

Ictal magnetoencephalography in temporal and extratemporal lobe epilepsy

PURPOSE: We evaluated visual patterns and source localization of ictal magnetoencephalography (MEG) in patients with intractable temporal lobe epilepsy (TLE) and extratemporal epilepsy (ETE). METHODS: We performed spike and seizure recording simultaneously with EEG and MEG on two patients with TLE and five patients with ETE. Scalp EEG was recorded from 21 channels (10-20 international system), whereas MEG was recorded from two 37-channel sensors. We compared ictal EEG and MEG onset, frequency, and evolution and performed MEG dipole source localization of interictal spikes and early ictal discharges and co-registered dipoles to brain magnetic resonance imaging (MRI). We correlated dipole characteristics with intracranial EEG, surgical resection, and outcome. RESULTS: Ictal MEG lateralized seizure onset in both TLE patients and demonstrated ictal onset, frequency, and evolution in accordance with EEG. Ictal MEG source analysis revealed tangential vertical dipoles in the anterolateral angle in one patient, and anterior dipoles with anteroposterior orientation in the other. Intracranial EEG revealed regional entorhinal seizure onset in the first patient. Both patients became seizure free after temporal lobectomy. In ETE, ictal MEG demonstrated visual patterns similar to ictal EEG and had concordant localization with interictal MEG in all five patients. Two patients underwent surgery. Ictal MEG localization was concordant with intracranial EEG in both cases. One patient had successful outcome after surgery. The second patient did not improve after limited resection and multiple subpial transections. CONCLUSIONS: Ictal MEG can demonstrate ictal onset frequency and evolution and provide useful localizing information before epilepsy surgery.     

Abstracts of the 5th joint meeting of the German, Austrian, and Swiss Sections of the International League Against Epilepsy, Basle, May 16-19, 2007

Presidential Symposium ¹ E. Pataraia
¹ University Hospital of Neurology (Vienna, A) Goals, methodology: Epilepsy surgery is defined as any neurosurgical intervention with the primary goal to relieve intractable epilepsy. On the other hand essential brain regions like primary motor and sensory cortex as well as brain areas supporting language and memory functions have to be spared to avoid neurological deficits caused by the operation. Thus, the exact localization of the epileptogenic zone and of essential brain regions is crucial for the successful surgical treatment of seizures that can only be accomplished during a thorough presurgical work‐up. A new noninvasive brain mapping procedure magnetoencephalography (MEG) was employed during the presurgical evaluation for localization of the epileptogenic zones and for the determination of hemispheric dominance and intrahemispheric localization of linguistic functions in patients with drug‐resistant focal epilepsies. Results: The role of MEG for the localization of the epileptogenic zone in the noninvasive evaluation of patients with focal drug‐resistant epilepsies: We evaluated the sensitivity and selectivity of interictal MEG versus prolonged ictal and interictal scalp video‐ EEG in order to identify patient groups that would benefit from preoperative MEG testing. One hundred thirteen consecutive patients with medically refractory epilepsy who underwent surgery were included. The epileptogenic region predicted by interictal and ictal Video‐EEG (V‐EEG) and MEG was defined in relation to the resected area as perfectly overlapping with the resected area, partially overlapping, or nonoverlapping. Using MEG, we were able to localize the resected region in a greater proportion of patients (72.3%) than with noninvasive V‐EEG (40%). MEG contributed to the localization of the resected region in 58.8% of the patients with a non‐localizing V‐EEG study and 72.8% of the patients for whom V‐EEG only partially identified the resected zone. Overall, MEG and V‐EEG results were equivalent in 32.3% of the cases, and additional localization information was obtained using MEG in 40% of the patients. MEG was most useful for presurgical planning in patients who had either partially or nonlocalizing V‐EEG results. Functional organization of interictal spike complex in medial temporal lobe epilepsies: Thirty patients with mesial temporal lobe epilepsy (MTLE) using combined MEG and EEG recordings were icluded. Spikes could be recorded in 14 patients (47%) during the 2‐ to 3‐h MEG/EEG recording session. The MEG and EEG spikes were subjected to separate dipole analyses and the spike dipole localizations were superimposed on MRI scans. All spike dipoles could be localized to the temporal lobe with a clear preponderance in the medial region. Based on dipole orientations in MEG, patients could be classified into two groups: patients with anterior medial vertical (AMV) dipoles, suggesting epileptic activity in the mediobasal temporal lobe and patients with anterior medial horizontal (AMH) dipoles, indicating involvement of the temporal pole and the anterior parts of the lateral temporal lobe. Whereas patients with AMV dipoles had strictly unitemporal interictal and ictal EEG changes during prolonged video‐EEG monitoring, 50% of patients with AMH dipoles showed evidence of bitemporal affection on interictal and ictal EEG. Nine patients underwent epilepsy surgery so far: all five patients with AMV dipoles became completely seizure‐free postoperatively (Class Ia) and two out of four patients with AMH dipoles experienced persistent auras (Class Ib). Plasticity of the brain mechanisms for receptive language in patients with mesial temporal lobe epilepsy and structural lesions: We examined brain activation profiles for receptive language function in patients with left hemisphere space occupying lesions and patients with left temporal lobe epilepsy due to mesial temporal sclerosis (MTS) to assess whether cross‐ and intrahemispheric plasticity for language varied as a function of lesion type or location. We evaluated 44 patients: 21 patients with MTS and 23 lesional patients. All patients underwent preoperative language mapping while performing a word recognition task. The location of the activity sources was subsequently determined by co‐registering them with MRIs. The number of clustered, contiguous activity sources located in temporal and inferior parietal regions (excluding sources in somatosensory cortices) was then assessed. Hemispheric lateralization of language‐specific magnetic activity was determined as left hemispheric, right hemispheric and bilateral according to relation of the acceptable late activity sources in left and right hemispheres. Patients were classified into two groups based on the location of the cluster(s) of language‐specific activity sources within the dominant hemisphere: typical localization of receptive language‐specific cortex (if the cluster of activity sources fell within the cortical region that is commonly identified as Wernicke's area) and atypical localization of receptive language‐specific cortex (if the cluster of activity sources did not overlap with Wernicke's area). A higher incidence of atypical language lateralization was noted among patients with MTS compared with lesional patients (43% vs. 13%). The majority of MTS patients with early seizure onset (before 5 years of age) showed atypical language lateralization. In contrast, the precise location of receptive language‐specific cortex within the dominant hemisphere was found to be outside of Wernicke's area in 30% of lesional patients and only 14% of MTS patients. There is an increased probability of a partial or total displacement of key components of the brain mechanisms responsible for receptive language function to the nondominant hemisphere in MTS patients. Early onset of seizures was strongly associated with atypical language lateralization. Lesions in the dominant hemisphere tend to result in an intrahemispheric reorganization of linguistic function. Organization of receptive language‐specific cortex before and after left temporal lobectomy: In the present study we documented the reorganization of brain areas mediating receptive language function in patients with left temporal lobe epilepsy after a standard anterior temporal lobe resection. We evaluated which patients were most likely to show a change in the lateralization and localization of the mechanisms supporting receptive language and if such changes were associated with neuropsychological function. The results of preoperative Wada‐testing and pre‐ and post‐operative neuropsychological testing and MEG language mapping were compared. Patients with atypical (bilateral) hemispheric dominance pre‐operatively were significantly more likely than patients with (typical) left‐hemisphere dominance to show evidence of increased right hemisphere participation in language functions after surgery. Patients with left hemispheric dominance preoperatively were more likely to show intra‐hemispheric changes involving a slight inferior shift of the putative location of Wernicke's area. Patients with bilateral representation tended to perform worse on neuropsychological test measures obtained both pre‐ and postoperatively. Interhemispheric functional reorganization of language‐specific areas may occur in patients undergoing left anterior temporal lobectomy. Intrahemispheric reorganization may take place even when the resection does not directly impinge upon Wernicke's area. Conclusions: Combined MEG/EEG dipole modeling can identify subcompartments of the temporal lobe involved in epileptic activity and may be helpful to differentiate between subtypes of mesial temporal lobe epilepsy noninvasively. MEG is most useful for presurgical planning in patients who have either partially or nonlocalizing V‐EEG results in the noninvasive evaluation phase. We predict the replacement of the more invasive procedure with MEG in the near future for temporal lobe epilepsies, subsequent to the optimization of the conditions under which preoperative MEG is performed. MEG can be especially helpful in the localization of language‐critical cortex in sites other than those expected within the dominant hemisphere. Our findings also suggest that not only structural elements, but also functional factors have an effect on receptive language organization in the brain. Factors influencing atypical language lateralization have theoretical importance for understanding the organization and reorganization of higher cognitive functions, as well as practical implications, especially in brain surgery and neurological rehabilitation. MEG is a useful method in clinical practice, as it has the capacity to provide reliable images of the working brain of individual subjects, and it is capable of capturing relevant aspects of brain activation by reflecting the actual participation of a particular area in the function under investigation. Finally, it is capable of capturing both the spatial as well as the temporal features of that activation.     

Magnetoencephalographic correlates of different types of aura in temporal lobe epilepsy

Purpose: To estimate magnetoencephalography (MEG) correlates of different types of aura in temporal lobe epilepsy (TLE). Methods: MEG study was performed on 57 patients (26 male and 31 female) with TLE, whose ages ranged from 14–46 years (mean 27 years). Interictal magnetoencephalograms showing discharges were analyzed, and spike‐dipole clusters were categorized into left and right inferotemporal‐horizontal (IH) and superotemporal‐vertical (SV) types. Auras were classified into autonomic, auditory, and psychic seizures. The correlation between the four types of interictal spike‐dipole and three types of aura was analyzed using Fisher’s exact probability test. Results: IH type correlated with autonomic seizures (p = 0.0004), whereas SV type correlated with both auditory (p = 0.0002) and psychic seizures (p = 0.042). When subdivided into left and right, left IH type correlated with autonomic seizures (p = 0.046), but right IH type did not. Right SV type correlated with both auditory (p = 0.014) and psychic seizures (p = 0.002), but left SV did not correlate with either. Both types did not correlate with “no aura.” Conclusions: Using our proposed classification of spike‐dipoles, MEG distinguishes auras of mesial temporal origin from those of lateral temporal region. Furthermore, by adopting our classification, laterality of spike‐dipoles is clearly demonstrated in auditory and psychic seizures.     

Magnetoencephalography to confirm epileptiform discharges mimicking small sharp spikes in temporal lobe epilepsy

ObjectiveTo determine whether magnetoencephalography (MEG) can identify epileptiform discharges mimicking small sharp spikes (SSSs) on scalp electroencephalography (EEG) in patients with temporal lobe epilepsy (TLE).MethodsWe retrospectively reviewed simultaneous scalp EEG and MEG recordings of 83 consecutive patients with TLE and 49 with extra-TLE (ETLE).ResultsSSSs in scalp EEG were detected in 15 (18.1%) of 83 TLE patients compared to only two (4.1%) of 49 ETLE patients (p = 0.029). Five of the 15 TLE patients had MEG spikes with concurrent SSSs in EEG, but neither of the 2 ETLE patients. Three of these 5 TLE patients had additional interictal epileptiform discharges (IEDs) in EEG and MEG. Equivalent current dipoles (ECDs) of MEG spikes with concurrent SSSs and IEDs showed no difference in temporal lobe localization and horizontal orientation, whereas ECD moments were smaller in MEG spikes with concurrent SSSs than those with IEDs.ConclusionsSSSs were more common in TLE than in ETLE. At least some morphologically diagnosed SSSs are true but low-amplitude epileptiform discharges in TLE which can be identified with simultaneous MEG.SignificanceSimultaneous MEG is useful to identify epileptiform discharges mimicking SSSs in patients with TLE.     

Musicogenic epilepsy with ictal single photon emission computed tomography (SPECT): could these cases contribute to our knowledge of music processing?

Musicogenic epilepsy has a strong correlation with the temporal lobe with a right-sided preponderance. We report the case of a 48-year-old woman whose seizures began at the age of 32 years. Her prenatal, natal and childhood histories were unremarkable and her family history was negative for epilepsy. She had typical complex partial seizures with chewing automatisms. Cranial computed tomography, magnetic resonance imaging (MRI) and interictal SPECT showed no abnormality. Interictal EEG showed paroxysmal bitemporal sharp wave discharges predominant on the right side. Ictal EEG showed a combination of high voltage sharp and slow sharp waves and spikes that originated from the right temporal leads and then became generalized. Ictal activity on EEG started 4-5 min after the music stimulus. For the ictal SPECT study, i.v. injection of 20 mCi of HMPAO was administered approximately 30 s after the ictal activity started. Ictal SPECT demonstrated a right anterior and mesial temporal hyperperfusion. These results seem to support the dominant role of the right temporal lobe and the possible relation of mesial temporal structures to the affective content of music in musicogenic epilepsy.     

Magnetoencephalography in Focal Epilepsy

Summary: The introduction of whole-head magnetoencephalographic (MEG) systems facilitating simultaneous recording from the entire brain surface has led to a major breakthrough in the MEG evaluation of epilepsy patients. MEG localizations estimates of the interictal spike zone showed excellent agreement with invasive electrical recordings and were useful to clarify the spatial relationship of the irritative zone and structural lesions. MEG appears to be especially useful for study of patients with neocortical epilepsy, and helped to guide the placement of subdural grid electrodes in patients with nonlesional epilepsies. MEG could differentiate between patients with mesial and lateral temporal seizure onset. Spike propagation in the temporal lobe and the spatio–temporal organization of the interictal spike complex could be studied noninvasively. MEG was useful to delineate essential brain regions before surgical procedures adjacent to the central fissure. MEG appears to be more sensitive than scalp EEG for detection of epileptic discharges arising from the lateral neocortex, whereas only highly synchronized discharges arising from mesial temporal structures could be recorded. A major limitation of MEG has been the recording of seizures because long-term recordings cannot be performed on a routine basis with the available technology. Because MEG and EEG yield both complementary and confirmatory information, combined MEG–EEG recordings in conjunction with advanced source modeling techniques should improve the noninvasive evaluation of epilepsy patients and further reduce the need for invasive procedures.     

Efficacy of Thyrotropin-Releasing Hormone in the Treatment of Intractable Epilepsy

Purpose : The ictal EEG and magnetoencephalogram (MEG) for gelastic seizures were recorded in a 4-year-old girl with tuberous sclerosis. The sites of origin for the seizure activities were investigated by using an equivalent current dipole (ECD) with the MEG.
Methods : EEG and MEG were recorded simultaneously under the administration of diazepam (DZP). The MEG recording was performed on a system consisting of an array of 64 sensors uniformly distributed over the patient's whole head (CTF, Canada), and the estimated ECDs were superimposed on the magnetic resonance imaging (MRI) images (Siemens, 1.5 Tesla).
Results : Two laughing attacks lasting 5 s each were documented. The ictal EEG showed gradually increasing 11–Hz rhythmic α activities with dominance over the frontocentral areas bilaterally, followed by irregular spike-and-wave discharges. The ictal MEG detected bilateral frontal rhythmic sharp waves before the appearance of the activities on the EEG. The estimated ECDs were localized in the deep white matter of the right frontal lobe on the MRI. However, those dipoles did not coincide with the locations of her cortical tubers.
Conclusions : Although gelastic seizures accompanied with hypothalamic hamartomas are well known, several reports have suggested a temporal or frontal lobe origin for gelastic seizures. In this patient, the ECD indicated that the seizures originated in the frontal lobe, although ictal scalp EEG recordings could not determine the precise focus. Thus, in cases in which the use of ictal scalp EEG fails to show the sites of origin for the seizures, it is recommended that the origins be estimated by using the non-invasive method of ictal MEG analysis.     

Complex pattern of convulsive syncope in glossopharyngeal neuralgia: video/EEG report and short review

Ictal nonspeech vocalizations have been described as manifestations of either frontal or temporal epileptogenicity originating mainly from the dominant hemisphere. Ictal barking, particularly, has been considered a manifestation of mesial frontal epilepsy. A 42-year-old right-handed male with posttraumatic drug-resistant complex partial epilepsy manifested ictal barking near electrographic onset. Extraoperative electrocorticography with subdural electrode coverage of the right frontoparietal and temporal and left frontal surfaces provided surveillance of ictal origin and propagation. Ictal origin was identified in the right mesial temporal lobe with barking vocalization manifesting within 3s of electrographic onset. No subsequent spread of activity was noted beyond the temporal lobe. Resection of the mesial temporal structure resulted in seizure freedom. Pathology identified hippocampal sclerosis. This case supports the notion that an intrinsic, intralobar epileptogenic neural network in either hemisphere can act as a conduit into the limbic and memory circuits without a laterality bias to manifest as barking.     

An infant with multiple cavernous angiomas presenting with frequent epileptic seizures - detection of epileptic focus by magnetoencephalography

We report on a six-year-old girl with frequent partial seizures secondary to multiple cavernous angiomas (CAs) since the age of 17 months. MRI showed two CAs in the left parietal and right frontal lobes. Ictal scalp video EEG demonstrated complex partial seizures of left hemispheric origin, indicating that the left parietal CA was the epileptogenic lesion. Ictal SPECT showed extensive hyper-perfusion in the left frontal and parietal lobes, indicating the left hemispheric focus. Magnetoencephalography (MEG) showed clustered equivalent current dipoles of interictal spikes in the left parietal cortex adjacent to the left parietal CA. We performed lesionectomy of the left parietal CA at 19 months old. The patient became seizure-free for four years. Postoperative MEG yielded no residual interictal spikes. Our study suggests that early surgical intervention of CA may prevent from further development of epileptic seizures. MEG can identify both the epileptogenic zone and lesion underlying the multiple CAs in the infants with catastrophic partial seizures.     

A case of right mesial temporal lobe epilepsy accompanied with ictal polyopsia]

A 59-year-old, right-handed woman had a paroxysmal polyoptic visual illusion, in which multiple copies of the object she saw spread horizontally in the left hemi-visual field. Polyopsia appeared for a few seconds. Neurological examination was normal. Magnetic resonance imaging (MRI) showed a tumor-like lesion involving the cortical and subcortical matters in the right mesial temporal regions. An interictal EEG showed frequent spikes in the right mesial temporal area and intermittent theta waves in the right fronto-temporal area. Video-EEG monitoring using the sphenoidal electrodes showed the seizure discharges originating in the right sphenoidal lead accompanying the polyoptic visual illusion. The seizure discharges were restricted within the right mesial temporal lobe. Paroxysmal visual illusion disappeared after administration of anti-epileptic drugs. EEG showed rare spikes in the right mesial temporal area. Polyopsia in this patient presumed to be associated with right mesial temporal lobe epilepsy because polyopsia and seizure activities on the ictal EEG were coupled and polyopsia ceased after administration of anti-epileptic drugs. Polyopsia is recognized as visual perseveration in space and a rare visual illusion. The lesion causing polyopsia has been reported to be mostly within posterior cerebral areas including occipital, parietal and temporal regions. This patient whose ictal polyopsia associated with mesial temporal lobe epilepsy is a very rare case because most reported cases presenting ictal polyopsia are neocortical temporal lobe epilepsy. The precise mechanism of polyopsia remains unknown. The mesial temporal lobe includes the hippocampus and parahippocampal formation that have been reported to receive information from the diverse association cortex and work as memory controllers. Ictal polyopsia may result from dysfunction of the visual association cortex or visual memory systems induced by the epileptic activities in the mesial temporal lobe. Polyopsia is a rare ictal semeiology of mesial temporal lobe epilepsy and may be one of the important ictal symptoms.     

Lack of aura experience correlates with bitemporal dysfunction in mesial temporal lobe epilepsy

The diagnostic value of lack of aura experience in patients with temporal lobe epilepsy (TLE) is unclear. PURPOSE: To evaluate possible factors of bitemporal dysfunction in patients with mesial TLE who did not experience an aura in electroencephalography EEG/video monitoring for epilepsy surgery. METHODS: Ictal scalp EEG propagation patterns of 347 seizures of 58 patients with mesial temporal lobe sclerosis or non-lesional mesial TLE, interictal epileptiform discharges (IED), presence of unilateral mesial temporal lobe sclerosis in visual magnetic resonance imaging (MRI) analysis, prose memory performance, history or not of an aura, and postictal memory or absence of an aura were analyzed. The ictal EEG was categorized as follows. EEG seizure: (a) remaining regionalized, (b) non-lateralized, (c) showing later switch of lateralization or bitemporal asynchronous ictal patterns. RESULTS: Absent aura in monitoring was significantly correlated with absence of unitemporal MRI sclerosis (P=0.004), bitemporal IED (P=0.008), and propagation of the ictal EEG to the contralateral temporal lobe (P=0.001). Other historical data and interictal prose memory performance were not significantly correlated with absent aura. Ten of 11 patients without aura in monitoring also had absent or rare auras in their history. CONCLUSIONS: Lack of aura experience strongly correlates with indicators of bitemporal dysfunction such as bitemporal interictal sharp waves and bitemporal ictal propagation in scalp EEG, and absence of lateralized MRI sclerosis in patients with mesial TLE. The fact that absent auras are not correlated with episodic memory suggests a transient memory deficit, probably because of rapid propagation to the contralateral mesial temporal lobe.     

Benign Rolandic epilepsy: widespread increases in connectivity in a focal epilepsy syndrome

Aim. Benign Rolandic epilepsy (benign epilepsy with centrotemporal spikes; recently renamed self‐limited epilepsy with centrotemporal spikes) is associated with widespread deficits in cognition and behavior, suggesting abnormalities in networks that extend beyond the centrotemporal region. To assess functional connectivity in children with benign Rolandic epilepsy, we assessed EEG spectral power and coherence during awake and sleep records in 27 children with centrotemporal spikes. Coherence represents the consistency of the phase difference between two EEG signals when compared over time and serves as a measure of synchronization between two EEG signals based mainly on phase consistency. Methods. Epochs of EEG with and without centrotemporal spikes were compared during both waking and sleep. Results. During the spike epochs, there was an increase in spectral power at all frequencies, although statistical significance was seen primarily in the delta, theta and alpha bandwidths. This increase in absolute power was seen at all electrode sites and was similar in left and right‐sided electrodes. During centrotemporal spikes, there were significant changes in coherence compared to the EEG segments without spikes. In the theta, alpha and beta bandwidths, there were significant increases in coherence. The increases in coherences were widespread and bilateral, and involved electrode pairs outside the central and temporal regions. To determine if there was a relationship between location of the spikes and coherence values, right‐sided, left‐sided and bilateral centrotemporal spikes were compared. There was no relationship between location of the centrotemporal spikes and power or coherence values. Conclusion. These findings indicate that benign Rolandic epilepsy results in generalized changes in spectral power and connectivity and raises the suggestion that from a functional standpoint, benign Rolandic epilepsy resembles a generalized rather than focal seizure disorder.