Medial Temporal Sclerosis Research Articles

Efficacy of Frameless Radiosurgical Entorhino-Amygdalohippocampectomy for Pharmacoresistant Medial Temporal Lobe Epilepsy

<h3>Purpose/Objective(s)</h3> Evaluate the efficacy and safety of Linac based surgery in the treatment of pharmaco-resistant epilepsies of mesial temporal lobe origin due to medial temporal sclerosis. <h3>Materials/Methods</h3> Retrospective single institution study comprised of 12 MTLE pts. (10 pts. with MT Sclerosis on Dominant side) who underwent SRS between August 2015 to Jan 2019. The epileptogenic substrate was localized using invasive video-EEG monitoring with foramen ovale electrodes, magnetic resonance imaging, metabolic (PET) imaging. All patients underwent detailed neuropsychological testing and the ESI-55 quality-of-life questionnaire. The radiosurgical target included Anterior part of parahippocampal region; entorhinal area adjacent to the collateral sulcus & rhinal sulcus; hippocampus - head & Anterior part and Amygdalofugal part of the amygdaloid complex. Non-coplanar Volumetrically modulated plans or non-isocentric CK plans using variable collimator were generated for prescribed mean dose of 22gy (range: 20-24 Gy), without any dose heterogeneity. Normal structures doses were within acceptable limits. Radiosurgical treatment was performed by using the C-Arm Linac with hexapod robotics (9 pts.) or frameless robotic radiosurgery system with skull tracking (3pts.). A minimum 2-year follow-up period included clinical, neuropsychological, ophthalmic (Visual field charting) & radiologic evaluations. <h3>Results</h3> Median age at diagnosis is 28 yrs (Range: 17-42yrs). At each 6-month follow-up evaluation, the frequency of seizures was significantly smaller than that at the previous visit. The median seizure frequency of 10.25 the month before treatment was reduced to 0.33 at 2 years after treatment. At 2 years, 67% of the patients (8 of 12) were seizure free - 4 Engel class 1A, 3 Engel class 1B, 1 Engel class 2A responses. The median latent interval from SRS to seizure cessation was 9.5 months (range 6–20 months). One patient was immediately seizure free. The median latency in aura cessation was 14 months (range 9–22 months). Morphological changes, edema, on magnetic resonance imaging were visible at 10 months (median) after SRS (range 7–22 months) in nearly all patients. During the onset period of these radiological changes, three patients experienced headache associated, in two cases, with nausea and vomiting. In these three patients the signs resolved immediately after short course of low doses of steroids. No cases of permanent neurological deficit (except three cases of monosymptomatic visual field deficit), or morbidity, or mortality were observed <h3>Conclusion</h3> Initial experience of Frameless SRS, as non-invasive technique, for MTLE provides benefits especially in young patients requiring high social skills with dominant lobe involvement in the traditional realms of safety with short- to middle-term efficacy & superior neuropsychological outcomes, similar to published series in GKS studies but with appreciated realms of patient acceptance, comfort and costs. Further long-term follow up is required.

Reduced synaptic vesicle protein 2A binding in temporal lobe epilepsy: A [11 C]UCB-J positron emission tomography study.

In this positron emission tomography (PET) study with [11 C]UCB-J, we evaluated synaptic vesicle glycoprotein 2A (SV2A) binding, which is decreased in resected brain tissues from epilepsy patients, in subjects with temporal lobe epilepsy (TLE) and compared the regional binding pattern to [18 F]fluorodeoxyglucose (FDG) uptake. Twelve TLE subjects and 12 control subjects were examined. Regional [11 C]UCB-J binding potential (BPND ) values were estimated using the centrum semiovale as a reference region. [18 F]FDG uptake in TLE subjects was quantified using mean radioactivity values. Asymmetry in outcome measures was assessed by comparison of ipsilateral and contralateral regions. Partial volume correction (PVC) with the iterative Yang algorithm was applied based on the FreeSurfer segmentation. In 11 TLE subjects with medial temporal lobe sclerosis (MTS), the hippocampal volumetric asymmetry was 25±11%. After PVC, [11 C]UCB-J BPND asymmetry indices were 37±19% in the hippocampus, with very limited asymmetry in other brain regions. Reductions in [11 C]UCB-J BPND values were restricted to the sclerotic hippocampus when compared to control subjects. The corresponding asymmetry in hippocampal [18 F]FDG uptake was 22±7% and correlated with that of [11 C]UCB-J BPND across subjects (R2 =.38). Hippocampal asymmetries in [11 C]UCB-J binding were 1.7-fold larger than those of [18 F]FDG uptake. [11 C]UCB-J binding is reduced in the seizure onset zone of TLE subjects with MTS. PET imaging of SV2A may be a promising biomarker approach in the presurgical selection and evaluation of TLE patients and may improve the sensitivity of molecular imaging for seizure focus detection.

Very long-term outcome in resected and non-resected patients with temporal lobe epilepsy with medial temporal lobe sclerosis: A multiple case-study

PurposeTo investigate the very long-term (i.e., ≥15 years) seizure, cognitive and psycho-social outcomes in resected patients (RP) with TLE compared to control patients not having undergone epilepsy surgery. MethodsWe applied a multiple case-study design including three non-resected patients (NRP) who were compared to a group of six RP. The latter were matched to the NRP according to clinical-demographic data. Outcome measures were various seizure, cognitive, and psycho-social variables. ResultsPatients were 56–72 years old. Seizure and AED outcome was more favourable among RP. RP reported better self-perceived overall health but higher subjective memory complaints. Upon formal neuropsychological testing, RP presented with lower verbal memory scores. Very long-term memory decline was evident in left-sided RP with good baseline memory scores, while RP with lower baseline performance, right-sided RP and NRP remained stable. Seizure-freedom had remarkable effects on the relationship between objective and subjective outcome: seizure-free patients, in general, subjectively reported the best psychosocial and cognitive outcome – irrespective of neuropsychological test results. ConclusionOur study suggests positive effects of TLE surgery in the very long-term course of ≥15 years postoperatively. Long-term seizure-freedom appears to have the strongest impact on patients’ subjectively perceived psycho-social and cognitive outcome and may even outweigh actual memory disturbances and/or decline. Overall, our data do not support the assumption of a generally accelerated cognitive decline in patients with TLE.

Effect of Extent of Hippocampal and Amygdala Resection on Seizure Outcome in Patients with Refractory Epilepsy Secondary to Medial Temporal Sclerosis

Effect of Extent of Hippocampal and Amygdala Resection on Seizure Outcome in Patients with Refractory Epilepsy Secondary to Medial Temporal Sclerosis

External cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy.

Background:Accessing the hippocampus for amygdalohippocampectomy and minimally invasive procedures, such as depth electrode placement, require an accurate knowledge regarding the location of the hippocampus.Methods:The authors removed 10 human cadaveric brains from the cranium and observed the relationships between the lateral temporal neocortex and the underlying hippocampus. They then measured the distance between the hippocampus and superficial landmarks. The authors also validated their study using magnetic resonance imaging (MRI) scans of 10 patients suffering from medial temporal lobe sclerosis where the distance from the hippocampal head to the anterior temporal tip was measured.Results:In general, the length of the hippocampus was along the inferior temporal sulcus and inferior aspect of the middle temporal gyrus. Although the hippocampus tended to be more superiorly located in female specimens and on the left side, this did not reach statistical significance. The length of the hippocampus tended to be shorter in females, but this too failed to reach statistical significance. The mean distance from the anterior temporal tip to the hippocampal head was identical in the cadavers and MRIs of patients with medial temporal lobe sclerosis.Conclusions:Additional landmarks for localizing the underlying hippocampus may be helpful in temporal lobe surgery. Based on this study, there are relatively constant anatomical landmarks between the hippocampus and overlying temporal cortex. Such landmarks may be used in localizing the hippocampus during amygdalohippocampectomy and depth electrode implantation in verifying the accuracy of image-guided methods and as adjuvant methodologies when these latter technologies are not used or are unavailable.

Stereotactic bilateral transfrontal minimal radiofrequency thermocoagulation of the amygdalohippocampal complex for bilateral medial temporal lobe epilepsy: a retrospective study of 12 patients.

Some patients with temporal lobe epilepsy have bilateral discharges and a few have bilateral medial temporal sclerosis. Stereotactic bilateral radiofrequency thermocoagulation (RFTC) of the amygdalohippocampal complex can terminate seizures or reduce seizure severity in patients with bilateral medial temporal lobe epilepsy (BMTLE). To explore the safety and efficacy of bilateral transfrontal minimal RFTC of the amygdalohippocampal complex for the treatment of BMTLE. A total of 12 BMTLE patients were treated with bilateral transfrontal minimal RFTC of the amygdalohippocampal complex under limited coagulations. The volumes of coagulated lesions were less than 0.6cm3 Clinical outcomes were evaluated using Engel's classification, the Liverpool Seizure Severity Scale (LSSS) 2.0, Wechsler Adult Intelligence Scale-Revised (WAIS-R), and Wechsler Memory Scale-Revised (WMS-R). Quality of life (QOL) was evaluated using the 36-item Short Form Health Survey (SF-36). Of the 12 patients, five (42%) were assessed as Engel Class I during 12-62 months of follow-up. LSSS scores declined sharply compared with the baseline of patients not in the seizure-free category. Functions of memory and intelligence declined transiently without statistical significance (p>0.05) immediately after surgery, but improved significantly (p<0.05) six months later. The qualities of life improved except vitality. Bilateral transfrontal minimal RFTC of the amygdalohippocampal complex may terminate seizures or reduce seizure severity in patients with BMTLE. Under limited coagulations, neuropsychological function was not affected but improved along with seizure control.

Long-term outcomes of epilepsy surgery in 85 pediatric patients followed up for over 10 years: a retrospective survey.

OBJECTIVE The aim of this study was to investigate the treatment outcomes and social engagement of patients who had undergone pediatric epilepsy surgery more than 10 years earlier. METHODS Between 1983 and 2005, 110 patients younger than 16 years underwent epilepsy surgery at the National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders. The authors sent a questionnaire to 103 patients who had undergone follow-up for more than 10 years after surgery; 85 patients (82.5%) responded. The survey contained 4 categories: seizure outcome, use of antiepileptic drugs, social participation, and general satisfaction with the surgical treatment (resection of the epileptic focus, including 4 hemispherectomies). The mean patient age at the time of surgery was 9.8 ± 4.2 (SD) years, and the mean duration of postoperative follow-up was 15.4 ± 5.0 years. Of the 85 patients, 79 (92.9%) presented with a lesional pathology, such as medial temporal sclerosis, developmental/neoplastic lesions, focal cortical dysplasia, and gliosis in a single lobe. RESULTS For 65 of the 85 responders (76.5%), the outcome was recorded as Engel Class I (including 15 [93.8%] of 16 patients with medial temporal sclerosis, 20 [80.0%] of 25 with developmental/neoplastic lesions, and 27 [73.0%] of 37 with focal cortical dysplasia). Of these, 29 (44.6%) were not taking antiepileptic drugs at the time of our survey, 29 (44.6%) held full-time jobs, and 33 of 59 patients (55.9%) eligible to drive had a driver's license. Among 73 patients who reported their degree of satisfaction, 58 (79.5%) were very satisfied with the treatment outcome. CONCLUSIONS The seizure outcome in patients who underwent resective surgery in childhood and underwent followup for more than 10 years was good. Of 85 respondents, 65 (76.5%) were classified in Engel Class I. The degree of social engagement was relatively high, and the satisfaction level with the treatment outcome was also high. From the perspective of seizure control and social adaptation, resective surgery yielded longitudinal benefits in children with intractable epilepsy, especially those with a lesional pathology in a single lobe.

Can Neuropsychological Rehabilitation Determine the Candidacy for Epilepsy Surgery? Implications for Cognitive Reserve Theorizing

Objective: The purpose of this study was to explore the effectiveness of a neuro-optimization intervention to determine the suitability for surgery in a patient suffering from left medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). The rehabilitation program was aimed at amplifying cognitive resources and improving memory functioning, particularly in the non-dominant healthy hemisphere. Method: A preoperative neuro-optimization program, inspired by the functional reserve model and the right hemisphere’s verbal processing potential, was adopted. This neuro-optimization program targeted global cognitive and metacognitive enhancement with an emphasis on memory functions of the right temporal lobe, i.e., the functional upgrade of the healthy right hippocampus and related structures to assist memory after surgery. Results: After a 32 weeks neuro-optimization program, the patient once again underwent intracarotid amobarbital test (IAT). This time his right hemisphere memory functioning yielded a borderline score, allowing us to consider surgery. Immediately after surgery, the patient was seizure free and did not show any clinically significant memory impairment. At six months post-surgery he had largely preserved memory optimization gains. Conclusion: Preoperative optimization interventions aiming at enhancing cognition, in general and memory of the healthy hemisphere, in particular, may contribute to a positive memory outcome after left selective amygdalohippocampectomy.

Trends in epilepsy surgery: stable surgical numbers despite increasing presurgical volumes

IntroductionDespite the success of epilepsy surgery, recent reports suggest a decline in surgical numbers. We tested these trends in our cohort to elucidate potential reasons.Patients and methodsPresurgical, surgical and postsurgical...

Network Analysis on Predicting Mean Diffusivity Change at Group Level in Temporal Lobe Epilepsy.

The two most common types of temporal lobe epilepsy are medial temporal sclerosis (TLE-MTS) epilepsy and MRI-normal temporal lobe epilepsy (TLE-no). TLE-MTS is specified by its stereotyped focus and spread pattern of neuronal damage, with pronounced neuronal loss in the hippocampus. TLE-no exhibits normal-appearing hippocampus and more widespread neuronal loss. In both cases, neuronal loss spread appears to be constrained by the white matter connections. Both varieties of epilepsy reveal pathological abnormalities in increased mean diffusivity (MD). We model MD distribution as a simple consequence of the propagation of neuronal damage. By applying this model on the structural brain connectivity network of healthy subjects, we can predict at group level the MD gray matter change in the epilepsy cohorts relative to a control group. Diffusion tensor imaging images were acquired from 10 patients with TLE-MTS, 11 patients with TLE-no, and 35 healthy subjects. Statistical validation at the group level suggests high correlation with measured neuronal loss (R = 0.56 for the TLE-MTS group and R = 0.364 for the TLE-no group). The results of this exploratory work pave the way for potential future clinical application of the proposed model on individual patients, including predicting neuronal loss spread, identification of seizure onset zones, and helping in surgical planning.

Forgetting in temporal lobe epilepsy: When does it become accelerated?

The notion of ‘accelerated long-term forgetting’ has often been attributed to disrupted ‘late’ memory consolidation. Nevertheless, methodological issues in the literature have left this theory unproven, leading some to suggest such findings may be reflective of subtle acquisition or early retention deficits. This study attempts to address such issues, and also to explore which pathophysiological variables are associated with forgetting rates. Eighteen participants with temporal lobe epilepsy (TLE) and eighteen matched controls completed background neuropsychological measurement of immediate and short-delay memory that showed comparable performance, both on verbal and visual tests. Using two novel experimental tasks to measure long-term forgetting, cued recall of verbal and visuospatial material was tested 30 sec, 10 min, one day, and one week after learning. Forgetting of verbal material was found to be progressively faster during the course of a week in the TLE group. For visuospatial memory, participants in the TLE group exhibited faster early forgetting in the first 10 min after learning, as indicated by planned comparisons, with comparable forgetting rates thereafter. Our findings provide evidence for two patterns of disruption to ‘early’ memory consolidation in this population, occurring either at the initial delay only or continuing progressively through time. Differences in how soon after learning accelerated forgetting was detectable were related to factors associated with greater severity of epilepsy, such as presence of medial temporal lobe sclerosis (MTS) on magnetic resonance imaging (MRI) and use of multiple anti-epileptic agents.

Beyond Jugular and Subclavian: The Axillary Vein, First Option for Centrally Inserted Central Lines

Human herpesvirus (HHV)-6 is a β-herpesvirus that infects most infants by 2 years of age and persists in a variety of host cells after primary infection, with intermittent reactivation typically during periods of immunosuppression. HHV-6 has two closely related species, HHV-6A and B, which are both neurotropic and can be detected in up to 85% of brain samples at autopsy. This pleiotropic virus has been implicated in many central nervous system (CNS) diseases, including febrile seizures (FS), epilepsy due to medial temporal lobe sclerosis, multiple sclerosis, encephalomyelitis, progressive multifocal leukoencephalopathy, chronic fatigue syndrome, and cognitive dysfunction. The significance of HHV-6 infection is often controversial due to the challenge implicit in attributing disease to a commensal virus of the brain. Studies have used a variety of unstandardized techniques on an array of sample sources to detect HHV-6, making direct comparisons problematic. In addition, many detection methods do not distinguish between latent and active infection. However, there is accumulating evidence implicating HHV-6 as a cause of CNS pathology, especially in FS and encephalitis. Treatment options are limited, fraught with side-effects, and poorly studied. Whether HHV-6 is a commensal pathogen of the brain, marker of immune dysregulation, trigger of autoimmunity, or directly neurotoxic mediator of CNS disease will remain uncertain for many CNS diseases until more refined studies are performed.

Relating Cortical Atrophy in Temporal Lobe Epilepsy with Graph Diffusion-Based Network Models.

Mesial temporal lobe epilepsy (TLE) is characterized by stereotyped origination and spread pattern of epileptogenic activity, which is reflected in stereotyped topographic distribution of neuronal atrophy on magnetic resonance imaging (MRI). Both epileptogenic activity and atrophy spread appear to follow white matter connections. We model the networked spread of activity and atrophy in TLE from first principles via two simple first order network diffusion models. Atrophy distribution is modeled as a simple consequence of the propagation of epileptogenic activity in one model, and as a progressive degenerative process in the other. We show that the network models closely reproduce the regional volumetric gray matter atrophy distribution of two epilepsy cohorts: 29 TLE subjects with medial temporal sclerosis (TLE-MTS), and 50 TLE subjects with normal appearance on MRI (TLE-no). Statistical validation at the group level suggests high correlation with measured atrophy (R = 0.586 for TLE-MTS, R = 0.283 for TLE-no). We conclude that atrophy spread model out-performs the hyperactivity spread model. These results pave the way for future clinical application of the proposed model on individual patients, including estimating future spread of atrophy, identification of seizure onset zones and surgical planning.

Superficial cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy.

Background:Accessing the hippocampus for amygdalohippocampectomy and procedures such as depth electrode placement requires accurate knowledge regarding the location of the hippocampus.Methods:The authors removed 10 human cadaveric brains (20 sides) from their crania, noted relationships between the lateral temporal neocortex and underlying hippocampus, and measured the distance between the hippocampus and superficial landmarks.Results:Mean distances were as follows: 3.8 cm from the tip of the temporal lobe to the head of the hippocampus; 6.5 cm from the tip of the temporal lobe to the junction of the fornix and hippocampus; and 3.5 cm between the tail and head of the hippocampus. The head of the hippocampus ranged from 0 to 5 mm inferior to the inferior temporal sulcus. The tail of the hippocampus ranged from 2.2 to 7 mm superior to the inferior temporal sulcus. In two specimens, the tail was deep to the superior temporal sulcus. Generally the length of the hippocampus was along the inferior temporal sulcus and inferior aspect of the middle temporal gyrus. The hippocampus tended to be more superiorly located and shorter in females and left sides, but this was not statistically significant.Conclusions:Additional landmarks for localizing the underlying hippocampus may be helpful in temporal lobe surgery. Our study showed relatively constant anatomic landmarks between the hippocampus and overlying temporal cortex that may help localize the hippocampus during amygdalohippocampectomy and depth electrode implantation, verify the accuracy of image-guided methods, and used as adjuvant methodologies when these latter technologies are unavailable.

Dichotic perception in patients with and without medial temporal sclerosis

BackgroundMedial temporal lobe epilepsy causes widespread damage to the central nervous system, thereby impairing the auditory processing mechanisms.AimTo study the dichotic perception skills in patients with medial temporal lobe epilepsy with and without medial lobe sclerosis.DesignThe study employed a prospective cross-sectional behavioral design. The dichotic digits test (DDT) performance of 100 patients with medial temporal lobe epilepsy (50 patients with medial temporal lobe sclerosis and 50 patients with normal magnetic resonance imaging) was compared to that of 50 normal controls. These patients were enrolled for the study while they were undergoing pre-surgical evaluation for epilepsy management.ResultsPatient groups performed significantly poorer than the normal control group. The test did not show any lateralization effect. Further, 60% of patients in both groups exhibited poor performance with reference to normal cut-off values.ConclusionPatients with medial temporal lobe epilepsy both with and without medial temporal lobe sclerosis exhibited affected auditory processing skill on DDT. However DDT failed to differentiate the patients' subgroups.

Chapter 16 - Human herpesvirus 6 and the nervous system

Human herpesvirus (HHV)-6 is a β-herpesvirus that infects most infants by 2 years of age and persists in a variety of host cells after primary infection, with intermittent reactivation typically during periods of immunosuppression. HHV-6 has two closely related species, HHV-6A and B, which are both neurotropic and can be detected in up to 85% of brain samples at autopsy. This pleiotropic virus has been implicated in many central nervous system (CNS) diseases, including febrile seizures (FS), epilepsy due to medial temporal lobe sclerosis, multiple sclerosis, encephalomyelitis, progressive multifocal leukoencephalopathy, chronic fatigue syndrome, and cognitive dysfunction. The significance of HHV-6 infection is often controversial due to the challenge implicit in attributing disease to a commensal virus of the brain. Studies have used a variety of unstandardized techniques on an array of sample sources to detect HHV-6, making direct comparisons problematic. In addition, many detection methods do not distinguish between latent and active infection. However, there is accumulating evidence implicating HHV-6 as a cause of CNS pathology, especially in FS and encephalitis. Treatment options are limited, fraught with side-effects, and poorly studied. Whether HHV-6 is a commensal pathogen of the brain, marker of immune dysregulation, trigger of autoimmunity, or directly neurotoxic mediator of CNS disease will remain uncertain for many CNS diseases until more refined studies are performed.

Simulating memory outcome before right selective amygdalohippocampectomy

In this paper we present the case of a left-sided speech dominant patient with right medial temporal sclerosis (RMTS) and pharmacoresistant epilepsy who showed improved verbal memory during intracarotid amobarbital test (IAT) at his right hemisphere as compared with his own performance before the drug injection (baseline), as well as after right selective amygdalohippocampectomy. We suggest that the defective verbal memory shown by this patient is due to abnormal activity of his right hippocampus that interfered with the function of his left hippocampus. This hypothesis was demonstrated by the fact that disconnection of the two hippocampi, either by anesthetisation or by resection of the right hippocampus, disengaged the left hippocampus and, consequently improved its function. This paper main objective is twofold: first to contribute to the field of neuropsychology of epilepsy surgery by emphasising on postoperative memory outcomes in right medial temporal lobe epilepsy (RMTLE) patients, particularly those undergoing amygdalohippocampectomy, as the pattern of memory changes after resection of the right temporal lobe is less clear; second, by focusing on memory performance asymmetries during IAT, and comparatively considering them with neuropsychological memory performance, because of their possible prognostic-simulating value.

EEG-fMRI findings in late seizure recurrence following temporal lobectomy: A possible contribution of area tempestas.

Late seizure relapses following temporal lobectomy for drug-resistant temporal lobe epilepsy occur in 18–30% of operated-on cases, and recent evidence suggests that a significant proportion of them are due to maturation and activation of proepileptic tissue having defied initial resection and located at the vicinity of or at a short distance from its borders, usually over the posterior medial, basal temporal-occipital, and lateral temporal regions. Experimental studies in animals and functional imaging studies in humans suggest that the area tempestas, a particular region of the basal-frontal piriform cortex, is critical for kindling and initiation and propagation of seizure activity arising from different cortical foci, especially limbic ones. This case report of a patient with late seizure relapse, three years following an initially successful right temporal lobectomy for ipsilateral medial temporal sclerosis, is the first one in the literature to demonstrate interictal EEG–fMRI evidence of significant BOLD signal changes over the inferior, basal and lateral temporal and temporooccipital cortices posterior to the resection margin, plus a significant BOLD signal change over the ipsilateral basal frontal region, closely corresponding to the piriform cortex/area tempestas. Our case study provides further functional imaging evidence in support of maturation/activation of proepileptic tissue located at the vicinity of the initial temporal lobe resection in cases of late seizure relapses and suggests, in addition, a possible role for the piriform cortex/area tempestas in the relapsing process.

Extratemporal surface EEG features do not preclude successful surgical outcomes in drug‐resistant epilepsy patients with unitemporal MRI lesions

Of 47 patients with onset of intractable partial seizures and temporal lobe MRI lesions, subjected to presurgical evaluation and temporal lobe surgery, we identified eight (mean age: 24 years; range: 7-52 years) demonstrating surface interictal and/or ictal EEG features suggestive of an extratemporal localisation. All eight patients underwent surgery aiming to predominantly resect the lesion, without extending to the extratemporal region. The patients were prospectively followed (mean follow-up duration: 38 months; range: 12-66 months) and all achieved excellent postoperative seizure control. Extratemporal surface interictal/ictal EEG features were more often encountered in tumoural and focal cortical dysplasia cases, compared with medial temporal sclerosis cases, and were most frequently localised over frontopolar and suprasylvian-pericentral locations. We postulate that propagation of interictal/ictal activity from the epileptogenic region of the temporal lobe to extratemporal neocortical areas, perhaps utilising the temporal pole and insula as intermediary nodes of a common epileptogenic network, accounts for the presence of our cohort's discordant lesion and EEG features.

Yield from Neuroimaging in Migraine

Introduction: Increasing numbers of children with chronic headaches are referred from primary care due to uncertainty of diagnosis or for symptom control. Although the diagnosis of migraine is essentially clinical, neuroimaging may be performed if there are worrying neurological symptoms or signs, or poor response to treatment. Aim: To determine the indications and yield from neuroimaging in migraine. Methods: We identified 31 children (19 boys and 12 girls) with migraine who either had Magnetic resonance imaging (MRI) or computed tomography (CT) scans of the brain. Mean age at onset of migraine symptoms was 11.8 ± 2.56 (7-16) yrs. Mean age at neuroimaging was 12.9 ± 3.03 (8-17) yrs. The indications for neuroimaging could be categorised as follows: increasing frequency or severity of headaches (n=12) reported vision abnormality (n=5), suspected raised intracranial pressure (n=5) co-existent epilepsy (n=4L) 'dizzy /collapse' (n=2) and other neurological symptoms (n=3). The MRI scans were abnormal in 7 of 28 cases. Abnormalities included sinusitis in four, demyelination in one, distorted anatomy of cochlea/vestibule in one and medial temporal lobe sclerosis in one. CT scan in one of three cases revealed sinusits. Following negative neuroimaging 5/23 had dramatic improvement of symptoms which facilitated discharge from clinic. Conclusion: Radiological evidence of sinusitis co-existed in 5 children with migraine but was suspected in only one patient. It is important to consider sinusitis in chronic headaches. Normal neuroimaging may relieve parental anxiety and we speculate that this aided resolution of symptoms and facilitated discharge from clinic in 5/31 patients.