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.     

A case of parietal lobe epilepsy with distinctive clinical and neuroradiological features

We present a case of parietal lobe epilepsy, the epileptogenic focus of which was conspicuously demonstrated on magnetoencephalography (MEG). The remarkable fluctuation in the seizure frequency and the presence of atonic seizures were suggestive of atypical partial benign epilepsy of childhood (APBEC). An interictal positron emission tomography (PET) scan performed during the cluster of fits revealed hypermetabolism around the epileptogenic focus, which might be related to the marked tendency of clustering of seizures in this patient.     

Frontal lobe epilepsy presented as ictal aggression

Abstract Aggressive behaviour is rarely observed as an ictal semiology. Ictal aggression can occur in lesions of frontal and limbic structures. In limbic structure lesions, the main mechanism of aggressive behaviour is hyperactivity; whereas frontal lesions may cause aggressive behaviour with an indirect mechanism in which the suppression on limbic system is lost. Here we present a patient with ictal aggression. In this case a right frontoparietal epileptiform focus was detected during the postictal period. Magnetic resonance imaging showed cortical dysplasia on the right inferior frontal gyrus. The seizures disappeared completely after pharmacological treatment.     

Occipital lobe epilepsy with fear as leading ictal symptom

Ictal fear is a semiological feature which is commonly associated with mesial temporal lobe epilepsy. Here, we describe fear as a leading symptom in cryptogenic occipital lobe epilepsy. In a patient with negative MRI findings, intracranial EEG recordings documented a strict correlation between habitual ictal anxiety attacks and both spontaneous and stimulation-induced epileptic activity in a right occipital epileptogenic area with subsequent spreading to the symptomatogenic zone in the amygdala. Circumscribed occipital topectomy led to seizure freedom. Episodes of non-epileptic fear ceased shortly afterwards. This report provides insight into pathways of propagation of epileptic activity, illustrates different etiologies of pathologic fear and underlines the importance of ictal EEG recordings.     

A case with frontal lobe epilepsy presenting with absence seizures as cardinal manifestation: ictal EEG findings]

We report here a 9-year-old boy presenting with absence and complex partial seizures. Absence seizures occurred several times a day, with sudden arrest of speech and gesture, alteration of consciousness, myoclonus of unilateral or bilateral angles of the mouth, occasional simple automatism and brisk recovery of consciousness. Complex partial seizures occurred once to three times a month with loss of consciousness, salivation, deviation of the head and eyes toward the left, elevation of upper limbs and tonic convulsion of the left upper and lower limbs. Interictal EEG showed right frontal pole-dominant high-voltage slow waves or spike-and-waves. Ictal simultaneous video-EEG recordings of absence seizures revealed a frontal dominant 3-3.5 Hz spike-wave burst lasting several seconds. A partial seizure never preceded the absence seizure. Transverse topographical analysis revealed that the first spike component of the spike-wave burst of absence seizure always showed phase reversal on the right anterior temporal electrode. The following ones, however, showed phase reversal on the left anterior temporal electrode. Ictal EEG of the complex partial seizure could not be detected because it rarely occurred. There was no abnormal finding on brain MRI. Interictal single photon emission tomography (SPECT) indicated hypoperfusion of the dorsal and medial cortex of the right middle frontal lobe. Interictal positron emission tomography (PET) also indicated hypometabolic areas in the dorsal and medial cortex of the right frontal lobe, together with those in the right temporal and parietal cortex. EEG evolution and neuroimaging studies suggested that the epileptic focus of the absence seizure might have originated at the dorsal cortex of the right middle frontal lobe and immediately spread to the medial cortex. Both the seizures were well controlled by the combination of phenytoin and high dose sodium valproate.     

Characteristics of temporal lobe epilepsy with no ictal impairment of consciousness

Introduction

The predominant manifestations of temporal lobe epilepsy (TLE) are partial seizures with impairment of consciousness (type I.B of ILAE classification), although consciousness impairment is not necessary in all seizures of patients with TLE. Nevertheless, there have been very few reports of TLE patients with exclusive seizures with no impairment of consciousness (i.e. isolated auras). The objective of this study was to determine any differential characteristics of this subgroup of TLE patients.

Material and methods

Retrospective case-control study in 163 consecutive TLE patients from our hospital database. The patients were divided between those with and without ictal impairment of consciousness, based on directed semi-structured questionnaire to the patient and relatives and on video–EEG records. Ten independent variables (8 clinical and 2 paraclinical) were compared between the groups.

Results

14 patients (8.5%) formed the “TLE without ictal impairment of consciousness” group. This group was less refractory to medical treatment [Odds Ratio: 0.14 (0.03–0.64); p < 0.01] and had frequent ictal motor behaviour [Odds ratio: 5.33 (1.65–17.14); p = 0.008] and less frequent presence of automatisms [p < 0.001]. Non-significant tendencies were observed for a higher frequency of lesional substrate and fewer generalization episodes.

Discussion

TLE without ictal impairment of consciousness appears to be more frequent than previously thought. This subgroup of TLE patients shows differential characteristics that may possibly result from a differential propagation of the original epileptic activity towards frontal areas rather than towards neocortical and diencephalic structures, which may be related to the more frequent presence of structural lesions.     

Hyperventilation-induced ictal fear in nonlesional temporal lobe epilepsy

Hyperventilation is a traditional seizure-provoking procedure used mainly in idiopathic generalized epilepsy and with a relatively limited role in partial epilepsy. Ictal fear is a rare seizure semiology seen in temporal lobe epilepsy. It has been suggested that the amygdala and anterior hippocampus are involved in generating ictal fear. We describe a rare patient with nonlesional temporal epilepsy who, while hyperventilating during an electroencephalography recording, developed complex partial seizures presenting as ictal fear. The particular sensitivity of the anterior hippocampus (probably the amygdala) to hypocapnia might be an important factor contributing to seizures. To avoid misdiagnosing this unusual condition as a pseudo-seizure, a detailed history and seizure semiology, as well as a concurrent electroencephalography recording, are mandatory.     

Early ictal face wiping in frontal lobe epilepsy

We describe two patients with medication-resistant nonlesional mesial frontal lobe epilepsy and seizures that manifested with early face wiping prior to other motor phenomena. Ictal scalp monitoring either was nonlocalizing or involved the central regions. Intracranial monitoring demonstrated anterior mesial frontal ictal low-voltage gamma activity during the face wiping activity in both patients. Habitual seizures with the same clinical characteristics were induced during extraoperative functional mapping with stimulation of the same region. Ictal activation of mesial frontal regions can elicit early ictal face wiping activity, and this clinical sign may play a role in presurgical evaluation.     

A boy with occipital lobe epilepsy showing prolonged QTc in the ictal ECG

We report a 9-year-old boy with occipital lobe epilepsy who showed a prolonged QTc on the ictal electrocardiogram (ECG). He complained of sudden onset of blindness accompanied with vomiting and headache. Since ECG revealed a prolonged QTc, he was transferred to our pediatric emergency center. Occipital spike and slow wave complexes on the electroencephalogram (EEG) suggested the diagnosis of occipital lobe epilepsy. Administration of carbamazepine (190 mg) resulted in the disappearance of the blindness and abnormal waves on EEG. This is the first report to describe the occurrence of prolonged QTc during seizures of occipital lobe epilepsy. Because of the high risk of life-threatening ventricular arrhythmia induced by prolongation of QTc such as torsades de pointes, attention should be paid to the ECG findings in patients with occipital lobe epilepsy.     

Temporal lobe epilepsy with ictal ecstatic state and interictal behavior of hypergraphia

The authors describe an epileptic patient with ictal ecstatic experiences and an interictal behavioral change of hypergraphia. The patient had a temporal lobe EEG spike focus in the dominant hemisphere. The ecstatic states can be considered true epileptic auras, i.e., simple partial seizures originating in the temporal lobe or the nearby structures. Hypergraphia in this patient seemed to be related to temporal lobe ictal focus in the dominant hemisphere.     

Analysis of the initial ictal phenomenon in patients with temporal lobe epilepsy

We aimed to assess the localizing value of the initial semiological element in temporal lobe epilepsy (TLE). Video-EEG-documented seizures of 97 adult TLE patients were studied in relation to seizure origin (left versus right; mesial versus extra-mesial). Strikingly, seizures with mesial onset started with very few ictal phenomena, while seizures of extra-mesial origin began with a larger variety of ictal elements. Furthermore, following noticeable distributions were observed for the mesial group: (i) aura was the most common initial ictal phenomenon in the total patient collective, occurring significantly more frequently in mesial than in extra-mesial seizure onset. Aura appeared most often in seizures of left mesial origin. (ii) Vocalization presented a trend towards mesial left seizure origin. (iii) Oral automatisms showed a trend towards mesial seizure origin. Following noticeable distribution was observed for the extra-mesial group: In patients without aura, restlessness as initial ictal phenomenon appeared exclusively in seizures of extra-mesial right origin. Finally, behavioral arrest showed a trend towards left-sided seizure origin. In conclusion, the initial ictal element may add useful information concerning differentiation of seizure onset in TLE.     

Interictal and ictal magnetoencephalographic study in patients with medial frontal lobe epilepsy

PURPOSE: To determine whether magnetoencephalography (MEG) has any clinical value for the analysis of seizure discharges in patients with medial frontal lobe epilepsy (FLE). METHODS: Four patients were studied with 74-channel MEG. Interictal and ictal electroencephalographic (EEG) and MEG recordings were obtained. The equivalent current dipoles (ECDs) of the MEG spikes were calculated. RESULTS: In two patients with postural seizures, interictal EEG spikes occurred at Cz or Fz. The ECDs of interictal MEG spikes were localized around the supplementary motor area. In the other two patients with focal motor or oculomotor seizures, interictal EEG spikes occurred at Fz or Cz. The ECDs of interictal MEG spikes were localized at the top of the medial frontal region. The ECDs detected at MEG ictal onset were also localized in the same area as those of the interictal discharges. CONCLUSIONS: In medial FLE patients, interictal and ictal MEG indicated consistent ECD localization that corresponded to the semiology of clinical seizures. Our findings demonstrate that MEG is a useful tool for detecting epileptogenic focus.     

Lateralized ictal immobility of the upper limb in patients with temporal lobe epilepsy

The primary aim of this study was to establish the incidence and the lateralizing value of 'lateralized ictal immobility of the upper limb' (LIL) in patients suffering from temporal lobe epilepsy (TLE), and to describe the connection between LIL and other clinical ictal signs. We retrospectively reviewed video records of 87 patients with TLE. We reviewed a total of 276 focal epileptic seizures with or without secondary generalization. We studied the incidence of LIL, its lateralizing value, and its relationship to other ictal clinical signs. Of the 87 patients, 49 had undergone a successful resective surgery at least 1 year prior to the study. LIL is a late sign in the course of partial seizure. It occurred in 25 of our 87 patients (28.7%), and in 47 of 276 seizures (17.1%). In all of the evaluated seizures, LIL occurred contralateral to the side of seizure onset (P < 0.001). LIL was always associated with ipsilateral upper limb automatisms, and in 63.1% of the occurrences, it was immediately followed by ictal dystonia. LIL is a more accurate term to describe what has previously been called 'ictal paresis' in the literature. Due to the inability to execute proper testing during a partial seizure, it is better to use the term LIL when making a visual analysis of a seizure. LIL is a more suitable term to describe the studied ictal sign. It is a relatively frequent sign in patients with TLE. LIL has an excellent lateralizing value for the contralateral hemisphere. It is a negative motor sign, and its genesis is probably associated with the epileptic involvement of the contralateral frontal lobe.     

Clinical implications of scalp ictal EEG pattern in patients with temporal lobe epilepsy

ObjectiveTo determine the clinical implications of scalp ictal EEG pattern in patients with temporal lobe epilepsy (TLE).MethodsScalp EEG ictal patterns were retrospectively determined in 27 consecutive patients with medically refractory temporal lobe epilepsy who underwent phase-1 scalp video-EEG and phase-2 simultaneous scalp and intracranial video-EEG recordings for pre-surgical evaluation.ResultsOf the 192 temporal lobe seizures recorded during phase-1 and phase-2 scalp video-EEG studies, 124 (65%) seizures were associated with theta/alpha (5–9 Hz) ictal onset pattern, and 68 (35%) seizures were associated with delta (2–5 Hz) ictal onset pattern. Fourteen (52%) patients had exclusively theta/alpha ictal onset, 3 (11%) patients had exclusively delta ictal onset, and 10 (37%) patients had mixed theta/alpha and delta ictal onsets. MTLE was observed in 26 patients who had 124 seizures with theta/alpha ictal onset and 59 seizures with delta ictal onset. LTLE was observed in one patient who had 9 seizures with delta ictal onset. Scalp ictal EEG pattern was not significantly correlated with postsurgical seizure outcomes.ConclusionsBoth scalp delta and theta/alpha ictal onset patterns can be commonly found in patients with MTLE.SignificanceScalp delta ictal onset is not a unique EEG pattern for LTLE as commonly believed.     

Accuracy of ictal SPECT in mesial temporal lobe epilepsy with bilateral interictal spikes

OBJECTIVE: In mesial temporal lobe epilepsy (MTLE), the rate of correct seizure lateralization of ictal semiology and ictal EEG is better for patients with unilateral interictal spikes (UIS) than for patients with bilateral interictal spikes (BIS), possibly due to rapid seizure propagation patterns associated with bilateral epileptogenesis. In this study, the authors investigated if ictal SPECT is a reliable diagnostic test for both UIS and BIS patients. METHODS: Video-EEG recording was used as the gold standard to examine the accuracy of ictal SPECT and its relationship with interictal and ictal EEG. Ninety-three consecutive patients with MTLE associated with hippocampal sclerosis were included in the analysis. Ictal SPECT was considered accurate if two blinded observers independently lateralized the scan correctly. RESULTS: Ictal SPECT correctly lateralized 75 (80.6%) of 93 scans. The rate of correct seizure lateralization was 87.6% for the UIS group and only 55.0% for the BIS group (p = 0.0027). In the EEG epochs, 66.7% of BIS patients vs 43.4% of UIS patients had nonlateralized ictal EEG (p < 0.001). CONCLUSION: The authors conclude that the accuracy of ictal SPECT is worse for MTLE patients with BIS than for those with UIS. The role of ictal SPECT in presurgical evaluation of patients with BIS must be reviewed.     

Display of consistent ictal networks in refractory mesial temporal lobe epilepsy

ObjectiveExploration of emergent ictal networks was performed in homogeneous subjects with refractory medial temporal lobe epilepsy.MethodsMaximal Synchrony Index (SI) values were calculated for all electrode pairs for each second during 25 seizures and displayed as connectivity animations. Consistent temporal patterns of SI value and spatial connectivity were observed across seizures and subjects, and used to define a sequence of network stages.ResultsHighest SI values were found in electrodes within the area of surgical resection. Analysis of these electrodes by network stage demonstrated lateral temporal cortex dominance at seizure initiation, giving way to hippocampal synchrony during the major portion of the seizure, with lateral temporal regions re-emerging as the seizure terminated. SI values also corresponded to behavioral severity of seizures, and lower SI values were associated with post-surgical seizure freedom.ConclusionSI based methods of network characterization consistently display the intrinsic MTLE ictal network and may be sensitive to clinical features.SignificanceConsistency of EEG-derived network patterns is an important step as network features are applied towards improvement of clinical management. These data confirm consistency of network patterns within and across subjects and support the potential for these methods to distinguish relevant clinical variables.     

Independent component analysis of ictal EEG in medial temporal lobe epilepsy

PURPOSE: Application of independent component analysis (ICA) to interictal EEGs and to event-related potentials has helped noise reduction and source localization. However, ICA has not been used for the analysis of ictal EEGs in partial seizures. In this study, we applied ICA to the ictal EEGs of patients with medial temporal lobe epilepsy (TLE) and investigated whether ictal components can be separated and whether they indicate correct lateralization. METHODS: Twenty-four EEGs from medial TLE patients were analyzed with the extended ICA algorithm. Among the resultant 20 components in each EEG, we selected components with an ictal nature and reviewed their corresponding topographic maps for the lateralization. We then applied quantitative methods for the verification of increased quality of the reconstructed EEGs. RESULTS: All ictal EEGs were successfully decomposed into one or more ictal components and nonictal components. After EEG reconstruction with exclusion of artifacts, the lateralizing power of the ictal EEG was increased from 75 to 96%. CONCLUSIONS: ICA can separate successfully the manifold components of ictal rhythms and can improve EEG quality.