Abdominal Epilepsy in an Adolescent with Bilateral Perisylvian Polymicrogyria

Summary: Purpose : We report a patient with recurrent episodes of severe periumbilical pain accompanied by headache, pallor, dizziness, and visual hallucinations who was subsequently diagnosed as having abdominal epilepsy and a bilateral sylvian cortical malformation.
Methods and Results: During an EEG examination, the patient had a simple partial seizure, manifested as intense abdominal pain. The ictal EEG showed a focal electrographic seizure arising from the left frontotemporal region. Computed tomography scan was normal; however, magnetic resonance imaging (MRI) revealed asymmetric lesions involving both sylvian fissures compatible with polymicrogyria. Onset of treatment with sodium valproate was followed by a significant reduction of seizures.
Conclusions: Abdominal epilepsy should be suspected in adolescents or adults with paroxysmal episodes of abdominal pain associated with migraine-like symptoms. EEG and MRI investigations are indicated. A developmental brain disorder should be considered as a possible etiology.     

Clinical Value of "Ictal" FDG-Positron Emission Tomography and the Routine Use of Simultaneous Scalp EEG Studies in Patients with Intractable Partial Epilepsies

Summary: Purpose: EEG is widely used during positron emission tomography (PET) to confirm the interictal state of the patient and assist in scan interpretation when a seizure occurs. Ictal scans usually reflect mixed interictal-ictal-postictal metabolic activity as seizures are brief in comparison to the 30-min uptake period of the tracer. We wished to determine whether routine EEG is justified and if seizures commonly affect the diagnostic information of the PET scan.
Methods: We examined the PET scans of 6 of 236 outpatients with intractable epilepsy with clinical and electrical evidence of a seizure during tracer uptake. We performed semi-quantitative analysis in 2 patients who had "ictal" and control interictal scans.
Results: Patients with single seizures lasting 23 s to 4 min [four complex partial seizures (CPS) and one absence seizure (AS)] had focal hypometabolism concordant with results of other investigations. One patient with complex partial status had irregular cortical uptake and focal hypometabolism, but the site of the ictal focus could not be confirmed.
Conclusions: In this group of patients, seizures occurred infrequently during tracer uptake. The interpretation of the PET scan when single seizures occurred did not appear to be influenced by the continuous scalp EEG (CSEEG) recordings. The value of routine CSEEG in outpatients treated with medication should be reappraised, with potential cost savings. In rare circumstances in which a true ictal study occurs (complex partial status, epilepsia partialis continua, and repetitive CPS), PET scanning may be inconclusive and repeat interictal scanning should be pursued.     

A multimodal diagnostic approach for lateralised rhythmic delta activity in the ictal‐interictal continuum∗

The ictal‐interictal continuum represents a diagnostic challenge even for expert neurrophysiologists, often requiring an additional multimodal diagnostic workup to understand its clinical significance. Lateralised rhythmic delta activity (LRDA) is an ictal‐interictal continuum pattern that has only recently been investigated and recognised as potentially ictogenic or sometimes even ictal. We describe a patient who presented with acute‐onset aphasia, initially suspected of having a stroke; advanced brain imaging with CT‐perfusion showed features suggesting regional left temporo‐parietal hyperperfusion and an EEG revealed LRDA with fluctuations and intermixed sharp waves in the same areas. Treatment with lacosamide caused both clinical and EEG improvement after a few hours, supporting the hypothesis that the EEG pattern represented an ictal/interictal phenomenon. In the literature, a correlation between metabolic/perfusion imaging and ictal‐interictal continuum patterns is described regarding lateralised periodic discharges but less studied for LRDA. In this case, we adopted a multimodal approach, integrating advanced imaging, EEG, clinical features, and response to therapy, to consider the overall clinical presentation as focal NCSE.     

Focal retrograde amnesia: Extending the clinical syndrome of transient epileptic amnesia

A 44-year-old woman presented with focal retrograde amnesia and complaints of rapid forgetting in the absence of episodes of transient cognitive disturbance. Her MRI and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) were normal. On standard neuropsychological tests she performed within the normal range although a test of autobiographical memory confirmed impoverished recall especially involving recent life events. The electroencephalograph (EEG) recordings were suggestive of temporal lobe epilepsy but no clear diagnosis was established. After 4 years the patient’s recurrent brief episodes of disorientation, suggestive of transient epileptic amnesia (TEA), were corroborated by her sister. This diagnosis was confirmed by an ambulatory EEG that revealed ictal activity.Several important points emerge from this study. Focal retrograde amnesia can be a prodromal symptom of TEA which can precede the full-blown syndrome by several years. Moreover, transient attacks might not be reported if patients live alone. The ictal EEG findings further substantiate the epileptic nature of the syndrome.     

Planned ictal FDG PET imaging for localization of extratemporal epileptic foci

PURPOSE: This work demonstrates the feasibility of planned ictal positron emission tomography (PET) with [18F]fluoro-2-deoxy-glucose (FDG) for localization of epileptic activity in patients with frequent partial seizures of extratemporal origin. METHODS: Ictal PET imaging was performed in four patients (two men and two women, ages 28-61) with continuous or very frequent (every 3-15 min) partial seizures. All patients had abnormalities apparent on magnetic resonance (MR) or computed tomographic (CT) imaging, two with extensive brain lesions that precluded precise localization of the seizure focus with interictal PET or single-photon emission tomography (SPECT) imaging. RESULTS: Ictal PET imaging demonstrated a restricted area of focal hypermetabolism concordant with surface electroencephalographic (EEG) recording in all cases. The PET images were registered to MR imaging data for further anatomic localization of hypermetabolic regions in three cases. The ictal PET data were used to guide neurosurgical intervention in one case. CONCLUSIONS: We conclude that planned ictal PET imaging may be a useful and potentially superior approach to ictal SPECT for identifying the epileptic focus in a selected group of patients with continuous or frequent simple partial seizures.     

Outcome after extended callosal section in patients with primary idiopathic generalized epilepsy

Purpose:   We report the outcome of patients with refractory idiopathic generalized epilepsy (IGE) who were submitted to extended one-stage callosal section.
Methods:   Eleven patients with IGE who were submitted to extended one-stage callosal section were studied. Preoperative workup included history and neurologic examination, interictal, and ictal electroencephalography (EEG) recording, high resolution 1.5T magnetic resonance imaging (MRI) and intelligence quotient (IQ) testing. All patients were submitted to extended one-stage microsurgical callosal section, leaving only the splenium intact.
Results:   Preoperative ictal patterns included repetitive spike and wave or polyspike and wave discharges or fast epileptic recruiting rhythm. MRI showed no focal lesions. Preoperatively, mean general IQ was 85. Postoperatively, at least a 75% reduction in the frequency of generalized tonic–clonic seizures was noted in all patients. In three patients absences disappeared completely, and the others had at least 90% reduction in seizure frequency. Only one patient had myoclonic seizures preoperatively, and these seizures disappeared after callosal section. After surgery, mean general IQ was 89. A very clear increase in attention level was noted in all patients. Postoperative interictal EEG recordings showed rupture of bilateral synchrony in all patients.
Discussion:   This article reports on a large and homogeneous series of patients with refractory IGE submitted for callosal section. There was a marked decrease in generalized seizure frequency and increase in the attention level in this patient population. Our results suggest that corticocortical interaction might have a role in IGE pathogenesis. Callosotomy is a safe, effective, and underused palliative procedure in these well-selected patients with refractory IGE.     

Ictal SPECT in Nonlesional Extratemporal Epilepsy

Summary:  Purpose: Ictal single-photon emission computed tomography (SPECT) may be a reliable indicator of the ictal onset zone in patients with intractable partial epilepsy who are being considered for epilepsy surgery. The rationale for the illustrated case report is to evaluate the use of an innovation in SPECT imaging in a patient with nonlesional extratemporal epilepsy.
Methods: We investigated the presurgical evaluation and operative outcome in a patient with intractable partial epilepsy. The ictal semiology indicated a "hypermotor" seizure with bipedal automatism. The electroclinical correlation and magnetic resonance imaging (MRI) did not suggest the appropriate localization of the epileptogenic zone. A subtraction periictal SPECT coregistered to MRI (SISCOM) was peformed.
Results: SISCOM revealed a region of localized hyperperfusion in the right supplementary sensorimotor area. Chronic intracranial EEG monitoring confirmed the relationship between the localized SISCOM alteration and the ictal onset zone. The patient was rendered seizure free after surgical treatment.
Conclusions: SISCOM may be used to identify potential candidates for surgical treatment of nonlesional extratemporal epilepsy. Periictal imaging may also alter the strategy for intracranial EEG recordings and focal cortical resection.     

Diffusion-weighted magnetic resonance imaging in patients with partial status epilepticus

Purpose:   Diffusion-weighted magnetic resonance imaging (DWI) is used to detect changes in the distribution of water molecules in regions affected by various pathologies. Like other conditions, ictal epileptic activity, such as status epilepticus (SE), can cause regional vasogenic/cytotoxic edema that reflects hemodynamic and metabolic changes. This study describes the electroclinical and neuroimaging findings in 10 patients with partial SE whose DWI evaluation disclosed periictal changes related to sustained epileptic activity.
Patients and Methods:   In this retrospective study we selected 10 patients with partial SE of different etiologies (six acute symptomatic SE; four with previous epilepsy and concomitant precipitating factors) who underwent video-EEG (electroencephalography) monitoring and a DWI study during the periictal phase. We analyzed ictal electroclinical features and DWI changes in the acute phase and during the follow-up period.
Results:   DWI images revealed significant signal alterations in different brain regions depending on the location of ictal activity. DWI changes were highly concordant with the electroclinical findings in all 10 patients. As the SE resolved and the clinical conditions improved, DWI follow-up showed that the signal alterations gradually disappeared, thereby documenting their close relationship with ictal activity.
Conclusions:   This study confirms the usefulness of DWI imaging in clinical practice for a more accurate definition of the hemodynamic/metabolic changes occurring during sustained epileptic activity.     

FDG-Positron Emission Tomography and Invasive EEG: Seizure Focus Detection and Surgical Outcome

Summary: Purpose : To study the value of [¹⁸F]2-deoxyglucose (FDG)-positron emission tomography when surface ictal EEG is nonlocalizing.
Methods : FDG-PET scans were performed in 46 patients with complex partial seizures (CPS) not localized by ictal SUT-face-sphenoidal video-EEG (VEEG) telemetry. Interictal PET was performed with continuous EEG monitoring, and images were analyzed with a standard template. Forty patients subsequently had subdural and 6 had depth electrodes (invasive EEG, IEEG); 22 had bilateral implants. A focus was detected in 40, and 35 had temporal lobectomy based on IEEG localization.
Results : There was a close association between IEEG and PET localization (p < 0.01): 26 patients had relative unilateral temporal FDG-PET hypometabolism, all had congruent IEEG, and 18 of 23 were seizure-free after temporal lobectomy. Five patients had unilateral frontotemporal hypometabolism (3 of 5 were seizure-free), 1 had frontal hypometabolism, and 14 had no lateralized PET abnormality (4 of 7 were seizure-free). Patients who became seizure-free had significantly higher lateral temporal asymmetry index (AI). PET showed 315% relative temporal hypometabolism (AI) in 12 of 22 patients with non-lateralized surface ictal VEEG and was capable of distinguishing between frontal and temporal foci in 16 of 24 patients with lateralized, but not localized, surface ictal video-EEG.
Conclusions : FDG-PET provides valuable data in patients with unlocalized surface ictal EEG and can reduce the number of patients who require IEEG studies. Quantitation is necessary for optimal PET interpretation.     

Effect of Seizures on Cerebral Blood Flow Measured with 15–H2O and Positron Emission Tomography

Summary: To study quantitative alterations in regional cerebral blood flow (rCBF) accompanying seizures, and to assess the utility of ictal activation PET scanning as a noninvasive clinical tool for localization of epileptogenic foci, we used pentylenetetrazole (F'TZ) to induce seizures during ¹⁵O-water positron emission tomography (PET) CBF measurement in 15 patients with uncontrolled complex partial seizures (CPS) who had been referred for surgical evaluation. Continuous EEG monitoring was performed during the PET scans. After baseline scans were obtained, each patient was injected with 150–300 mg PTZ. Two patients had generalized tonic-clonic seizures (GTCs). CBF increases were asymmetrical. Two patients (in 1 the seizure occurred spontaneously, without PTZ injection) who had CPS had bitemporal 70–80% increases in CBF. Thalamic CBF increased during both CPS and GTCS. Five patients had an increase in focal EEG in-terictal abnormality, accompanied by focal flow decreases in 3. PTZ injection not accompanied by clinical seizures did not increase CBF. Partial seizures may be associated with bilateral increases in CBF, and subcortical gray regions are involved in ictal activation.     

Drug resistant ADLTE and recurrent partial status epilepticus with dysphasic features in a family with a novel LGI1mutation: electroclinical, genetic, and EEG/fMRI findings

Purpose:   We characterized a family with autosomal dominant lateral temporal epilepsy (ADLTE) whose proband presented uncommon electroclinical findings such as drug-resistant seizures and recurrent episodes of status epilepticus with dysphasic features.
Methods:   The electroclinical characteristics and LGI1 genotype were defined in the family. In the proband, the ictal pattern was documented during video-EEG monitoring and epileptic activity was mapped by EEG/fMRI.
Results:   The affected members who were studied had drug-resistant seizures. In the proband, seizures with predominant dysphasic features often occurred as partial status epilepticus. The video-EEG-documented ictal activity and fMRI activation clearly indicated the elective involvement of the left posterior lateral temporal cortex. Sequencing of LGI1 exons revealed a heterozygous c.367G>A mutation in exon 4, resulting in a Glu123Lys substitution in the protein sequence.
Conclusions:   The uncommon clinical pattern (high seizure frequency, drug-resistance) highlights the variability of the ADLTE phenotype and extends our knowledge of the clinical spectrum associated with LGI1 mutations.     

Anxiety as the only manifestation of focal non-convulsive status epilepticus: case report and review of the literature

ABSTRACT

Psychiatric disorders represent common comorbidities in epileptic patients. Sometimes anxiety is part of the ictal semiology, especially during seizures arising from/involving frontal or temporal lobes. We describe a patient with focal epilepsy and recurrent hyperkinetic seizures who also presented prolonged episodes characterized by massive anxiety, alarm and fear. A Video-Electroencephalographic monitoring performed during one of these attacks revealed a continuous epileptiform activity over the right frontal regions, consistent with a focal non-convulsive status epilepticus accounting for the patient’s psychiatric symptoms. Our case confirms the complex relationship between epilepsy and anxiety. A review of the literature is also included.     

Episodic receptive aphasia in a child with Landau-Kleffner Syndrome: PET correlates

We report a four-year-old boy with Landau-Kleffner Syndrome (LKS) characterized by episodic receptive aphasia lasting for few weeks followed by gradual recovery of baseline language functions. Neuropsychological evaluation during an episode showed severe impairment in verbal skills and comprehension, but relative preservation of non-verbal skills. Although he could carry on a conversation during remission, neuropsychological evaluation demonstrated findings reflective of receptive language deficits. Prolonged EEG disclosed frequent sharp-wave activity in the left and right temporal regions but no electrographic seizures. Glucose metabolism PET scan during the fourth episode of aphasia revealed intense hypermetabolism in the left temporal neocortex. Awake EEG during the PET tracer uptake period showed 6.0 spikes/min in the left temporal region and 4.0 spikes/min in the right. A repeat PET scan during remission showed hypometabolism in the left temporal cortex. Awake EEG during the FDG uptake period showed 16.0 spikes/min in the right temporal region and 0.3 spikes/min in the left. During his fifth aphasic episode, EEG (without PET) showed 0.16 spikes/min in the right temporal region and none in the left. Intermittent short episodes of predominantly receptive aphasia with near-total recovery between episodes can be one of the clinical presentations of LKS. This case illustrates the dynamic changes of glucose metabolism in the temporal lobe during episodes of aphasia and remission in a case with LKS. The clinical course of our patient with transient EEG and PET findings suggest that glucose metabolism in LKS cannot be attributed solely to interictal epileptiform activities on scalp EEG.     

Focal lesions in the splenium of the corpus callosum in patients with epilepsy

Purpose:   A focal lesion in the splenium of the corpus callosum is a rare finding in patients with epilepsy. Intoxication with antiepileptic drugs, edema after generalized seizures, or a rapid change of antiepileptic drug levels have been proposed as possible mechanisms. The aim of the present study was to analyze the relationship between this lesion and possible etiologic factors.
Patients and methods:   We analyzed the magnetic resonance imaging (MRI) scans of 1,050 patients undergoing prolonged video-EEG (electroencephalography) monitoring and identified 24 patients with a focal lesion in the splenium of the corpus callosum. Twenty-four age- and gender-matched temporal lobe epilepsy patients without such a lesion served as a control group. We evaluated the following parameters for their possible etiologic significance: epilepsy syndrome, seizure types in medical history, seizure frequency during the past year prior to admission for prolonged video-EEG monitoring, localization of interictal spikes and ictal EEG patterns in patients with focal epilepsies as documented during prolonged video-EEG-monitoring, seizure types and seizure frequency during prolonged video-EEG monitoring, past as well as current antiepileptic medication, withdrawal of antiepileptic drugs during monitoring including duration of medication withdrawal, and finally drug levels above the therapeutic range.
Results :  The parameters analyzed showed no significant difference between the group of patients with focal lesions in the splenium of the corpus callosum and the control group.
Conclusion:   We could not identify a single etiologic factor responsible for the lesion in the splenium of the corpus callosum.     

Local cerebral metabolism during partial seizures

Interictal and ictal fluorodeoxyglucose scans were obtained with positron CT from four patients with spontaneous recurrent partial seizures, one with epilepsia partialis continua, and one with a single partial seizure induced by electrical stimulation of the hippocampus. Ictal metabolic patterns were different for each patient studied. Focal and generalized increased and decreased metabolism were observed. Ictal hypermetabolism may exceed six times the interictal rate and could represent activation of excitatory or inhibitory synapses in the epileptogenic region and its projection fields. Hypometabolism seen on ictal scans most likely reflects postictal depression and may indicate projection fields of inhibited neurons. No quantitative relationship between alterations in metabolism and EEG or behavioral measurements of ictal events could be demonstrated.     

Nonconvulsive Status Epilepticus: EEG Analysis in a Large Series

Summary: We analyzed EEG characteristics comprehensively in a large series of nonconvulsive status epilepticus (NCSE) cases. Eighty-five ictal episodes in 78 patients were analyzed. The ictal discharges were generalized (group G) in 59 episodes (69%), diffuse with focal predominance (group GF) in 15 (18%), and focal (group F) in 11 (13%). The morphologies and patterns of persistence varied greatly. Frequency of ictal discharge was also variable and was almost always <3 Hz. Demonstration of focal epileptic features in response to intravenous (i.v.) diazepam (DZP) and the presence of interictal focal epileptiform discharges in some cases in groups G and GF suggested possible focal onset secondarily generalized in these cases. This study suggests that electrographically NCSE is a highly heterogeneous epileptic state, and i.v. DZP may serve as a valuable diagnostic tool in differentiating generalized from focal onset NCSE.     

Complex partial status epilepticus in children with epilepsy

Purpose: Complex partial status epilepticus (CPSE) is often under-diagnosed, especially in children. The aim of this study was to clarify the characteristics and pathophysiology of CPSE in children with epilepsy. Subjects and methods: We retrospectively reviewed the medical records and EEGs of 17 children with epilepsy who were diagnosed as having CPSE by ictal or postictal EEGs to investigate clinical and EEG features. Results: The ages at diagnosis of CPSE ranged from 3 months to 17 years. At the time of diagnosis of CPSE, 13 patients had symptomatic localization-related epilepsy, two had epilepsy with continuous spike-waves during slow wave sleep, and each patient had cryptogenic localization-related epilepsy and idiopathic localization-related epilepsy. Only subtle symptoms including autonomic ones associated with disturbance of consciousness were the main clinical features in 12 of 44 CPSE episodes. Another 22 episodes showed minor focal motor elements, and the other 10 had major convulsive phase during or immediately before CPSE. Ictal EEGs of CPSE were divided into three types according to the degree of high-voltage slow waves (HVS) and spike components. Ictal EEGs could show spike-dominant or spike and HVS mixed patterns even if patients showed only subtle symptoms. The epileptogenic areas estimated by the ictal or postictal EEGs showed variability with only two cases of temporal origin. Conclusion: The close observation of clinical symptoms such as various subtle symptoms and/or mild convulsive elements and ictal EEGs are absolutely needed for the diagnosis of CPSE in children.     

Functional and morphological abnormalities in temporal lobe epilepsy: a comparison of interictal and ictal EEG,CT, MRI,SPECT and PET

Summary Ten patients suffering from drug-resistant complex partial seizures, with EEG abnormalities in the temporal region, were studied by means of non-invasive electrophysiological techniques (video-monitored, 16-channel, prolonged surface and sphenoidal EEG) as well as by imaging techniques (CT, MRI, SPECT and PET). Analysis of interictal and ictal EEG indicated the localization of epileptic activity in one side in eight cases. CT demonstrated focal abnormalities in three, SPECT in five unequivocally (in another four questionably, with the same lateralization as indicated by PET), MRI in eight, and PET in all cases. While only EEG provided specific diagnostic information, the focus definition was consistently good on PET images, poor on CT scans, and generally good but less consistent on MRI.     

Cortico-thalamic activation in generalized status epilepticus, a PET study

In a patient with a refractory generalized convulsive status epilepticus, the ictal distribution of regional cerebral glucose was assessed with positron emission tomography (PET). Synchronized seizure activity in the EEG was associated with bilateral metabolic activation of medial sensorimotor regions, anterior cingulate cortex, striatum and thalamus. This pattern with focal cortical activation supports the concept that a cortical focus may drive epilepsy, while the thalamus mediates synchronization of neuronal activity as reflected in the EEG.     

Absence status (petit mal status) with focal characteristics.

Two patients, aged 23 and 74 years, manifested prolonged episodes of mildly impaired consciousness in conjunction with rhythmical spike waves or spikes (mostly 3/s). This paroxysmal EEG activity was consistently accentuated unilaterally over the superior frontal regions. The first patient showed ictal aphasia and occasional right hemiparesis during these episodes, and partial left frontal lobectomy resulted in temporary freedom from seizures. The classification of these ictal episodes is difficult. They apparently fall into the category of absence status (petit mal status), but the focal neurological signs do not fit the presently valid definitions of absence status, nor does the lack of symmetrical bilateral-synchronous paroxysmal discharges. Perhaps a special category of status epilepticus should be established.