Subclinical focal seizures as a sign of progression in gliomas

Background. Subclinical seizures are ictal electrographic discharges lacking signs of clinical seizures, behavioural alteration or subjective symptoms. The diagnosis and detection of this type of non‐convulsive seizures remain challenging, and information is scarce regarding this electroclinical picture in subjects with gliomas. The aim of this report is to describe two patients with gliomas who, after treatment with surgery and radiotherapy, exhibited subclinical seizures on video‐EEG monitoring, as a manifestation of recurrence or progression of their brain tumour. Methods. Case report and video‐EEG monitoring analysis. Results. Two patients with gliomas were admitted to our neurosurgical unit after a generalized tonic‐clonic seizure. Brain MRI revealed a recurrence of their tumour. The use of video‐EEG monitoring allowed the detection and characterization of subclinical seizures in both patients that otherwise would have gone undetected. In both cases, subclinical seizures arose from the frontal lobe and were not associated with motor manifestations or subjective symptoms. Conclusions. We emphasize that the existence of subclinical seizures in patients with gliomas is likely to be underestimated, and can occur in advanced progressive tumours. It is important to carry out continuous video‐EEG monitoring in brain tumour patients who have had recent clinical seizures in order to be able to detect subclinical seizures and make appropriate diagnosis.     

Delta–alpha ratio correlates with level of recovery after neurorehabilitation in patients with acquired brain injury

ObjectiveTo explore the relationship between three QEEG global indexes and their association with functional outcome after neurorehabilitation in non-acute acquired brain injury (ABI) patients (traumatic brain injury and stroke).MethodsTwenty-one adult ABI patients in post-acute phase were studied. Delta–alpha ratio (DAR), Power Ratio Index (PRI) and Mean Brain Symmetry Index (mBSI) were calculated from resting-state EEG taken at admission. These indexes and other clinical variables were correlated with functional recovery achieved after six months of neurorehabilitation.ResultsDAR showed the highest strength of association with the functional outcome measure (ρ = −0.65, P = 0.002). The other QEEG indexes and clinical variables showed modest non-significant correlations. A posteriori group analysis showed higher DAR in patients with poor recovery as compared to good recovery patients.ConclusionsFunctional recovery after neurorehabilitation appears to be associated with a number of clinical and neurophysiological variables. Among the latter, the ratio between delta and alpha may play a significant role in predicting and monitoring functional rehabilitation outcome.SignificanceNeurophysiological assessment of ABI patients may be an important tool in monitoring and predicting outcomes after neurorehabilitation.     

Can diffusion‐weighted imaging be used as a tool to predict seizures in patients with PLEDS?

It is unclear which patients with PLEDs will have associated seizures and therefore will need to be treated aggressively with antiepileptic medications. We present a prospective observational study of ten consecutive non‐anoxic patients with PLEDs based on continuous 24‐hour EEG monitoring. According to the EEG, five of the patients had seizures associated with PLEDs and five had PLEDs but no seizures. The aetiology included: neoplasm (n=1), cortical dysplasia (n=1), acute head trauma (n=1), encephalomalacia related to healed abscess (n=1), intra‐parenchymal haemorrhage (n=1), and no structural lesion (n=5). All patients underwent brain MRI using diffusion‐weighted imaging (DWI). We found that the five patients who had seizures with PLEDs on continuous EEG had restricted diffusion on DWI. In contrast, the five patients who had PLEDs but no seizures on continuous EEG did not show a restricted diffusion pattern on DWI. We will continue to prospectively assess DWI findings in this group of patients and encourage other centres to also review similar data. If our observation is replicated, this would indicate that restricted diffusion on brain MRI may be a useful marker to identify patients with PLEDs on their EEG who are likely to have associated seizures.     

EEG-NeuroBioFeedback Treatment of Patients with Brain Injury: Part 2: Changes in EEG Parameters versus Rehabilitation

ABSTRACT

Background. A sample of 27 patients with brain injury distributed in five clinical classes was examined for pre- and post-treatment symptoms and associated power spectra.

Methods. Changes in electroencephalographic (EEG) compressed spectral arrays were analyzed with respect to the rate of rehabilitation and correlated with a checklist of symptoms for each patient and the group as a whole.

Results. Targeted decreases in slower (3–7 Hz) and higher (24–32 Hz) frequencies, and EMG (70–90 Hz), and increases of alpha (8–12 Hz) and mid-range beta frequencies (15–18 Hz) were achieved following Neuro-BioFeedback (NBF) treatment using positive reward tones and a simultaneous visual reward. The impact of gender and age class influence was assessed against treatment results. Single lead EEG power spectra changes were analyzed for hemispherectomized patients, stroke, car accident and trauma patients. A common EEG pattern was observed for a group of patients exhibiting vertigo with two subgroups in which vertigo resolved or did not resolve showing EEG differences.

Conclusions. EEG NeuroBioFeedback can successfully treat patients with brain injury with highly clinically-meaningful clinical results. Changes in Cz power spectra generally occur, but do not always immediately follow resolution of symptoms. Since EEG-NBF is limited to recording cortical surface potentials, it is possible that changes induced by the treatment which result in clinical changes may not always be reflected at the cortical surface and hence may not be available for recording and analysis there, despite subcortical integration.     

Transient epileptic amnesia diagnosed using long‐term electroencephalography

Transient epileptic amnesia (TEA) is a distinct syndrome affecting middle‐aged persons without concurrent brain disease or disposition to epileptic seizures. Seizures are characterized by amnesia, usually lasting less than one hour, and interictal memory deficits that are common. Effective antiseizure treatment is usually rapid in patients with TEA, which underlines the need for prompt diagnosis. Here, we report a 58‐year‐old male patient with recurrent episodes of antero‐ and retrograde amnesia. MRI was normal and diagnosis was made using long‐term EEG (27 hours), revealing 10 right‐sided temporal lobe seizures with subtle clinical symptoms lasting up to 86 seconds. Details of the video‐EEG are presented. Treatment with levetiracetam resulted in complete recovery and seizure freedom that was confirmed on a second long‐term EEG. Given the favourable outcome with antiseizure treatment, our case study illustrates the role of long‐term EEG monitoring in patients with recurrent transient amnesia to establish a correct diagnosis [Published with video sequence].     

Epileptic and nonepileptic features in patients with early onset epileptic encephalopathy and STXBP1 mutations

Purpose: STXBP1 (MUNC18‐1) mutations have been associated with various types of epilepsies, mostly beginning early in life. To refine the phenotype associated with STXBP1 aberrations in early onset epileptic syndromes, we studied this gene in a cohort of patients with early onset epileptic encephalopathy. Methods: STXBP1 was screened in a multicenter cohort of 52 patients with early onset epilepsy (first seizure observed before the age of 3 months), no cortical malformation on brain magnetic resonance imaging (MRI), and negative metabolic screening. Three groups of patients could be distinguished in this cohort: (1) Ohtahara syndromes (n = 38); (2) early myoclonic encephalopathies (n = 7); and (3) early onset epileptic encephalopathies that did not match any familiar syndrome (n = 7). None of the patients displayed any cortical malformation on brain MRI and all were screened through multiple video–electroencephalography (EEG) recordings for a time period spanning from birth to their sixth postnatal month. Subsequently, patients had standard EEG or video‐EEG recordings. Key Findings: We found five novel STXBP1 mutations in patients for whom video‐EEG recordings could be sampled from the beginning of the disease. All patients with a mutation displayed Ohtahara syndrome, since most early seizures could be classified as epileptic spasms and since the silent EEG periods were on average shorter than bursts. However, each patient in addition displayed a particular clinical and EEG feature: In two patients, early seizures were clonic, with very early EEG studies exhibiting relatively low amplitude bursts of activity before progressing into a typical suppression‐burst pattern, whereas the three other patients displayed epileptic spasms associated with typical suppression‐burst patterns starting from the early recordings. Epilepsy dramatically improved after 6 months and finally disappeared before the end of the first year of life for four patients; the remaining one patient had few seizures until 18 months of age. In parallel, EEG paroxysmal abnormalities disappeared in three patients and decreased in two, giving place to continuous activity with fast rhythms. Each patient displayed frequent nonepileptic movement disorders that could easily be mistaken for epileptic seizures. These movements could be observed as early as the neonatal period and, unlike seizures, persisted during all the follow‐up period. Significance: We confirm that STXBP1 is a major gene to screen in cases of Ohtahara syndrome, since it is mutated in >10% of the Ohtahara patients within our cohort. This gene should particularly be tested in the case of a surprising evolution of the patient condition if epileptic seizures and EEG paroxysmal activity disappear and are replaced by fast rhythms after the end of the first postnatal year.     

The Improvement of Severe Psychomotor and Neurological Dysfunctions Treated with the Tomatis Audio-Psycho-Phonology Method Measured with EEG Brain Map and Auditory Evoked Potentials

Background. Pioneering research of Tomatis led to the introduction of the Audio-Psycho-Phonology (APP), to treat, improve, or remediate severely neurologically impaired individual.

Method. Here we present for the first time independent data on the APP method with auditive evoked potentials and electroencephalographically based brain mapping.

Results. The improvement of these 4 patients by undergoing APP treatment is shown in their listening curves as well as in the results of the EEG based brain maps and the auditory evoked potentials.

Conclusion. 1. APP method seems to be an effective and harmless treatment for patients with severe psychomotor and/or neurological dysfunctions.

2. Auditory evoked potentials and electroencephalographically based brain mapping seems to be an appropriate examination to demonstrate neurological changes after APP therapy.

Besides the presentation of the four cases, a short overview of the method is presented.     

Carotid endarterectomy without shunt: the role of cerebral metabolic protection

Abstract

Background: The optimal method to protect the brain from hemodynamic ischemia during carotid endarterectomy (CEA) remains controversial. This study reports our experience with induced arterial hypertension and selective etomidate cerebral protection in a cohort of patients who underwent CEA without shunting and continuous electroencephalography (EEG) monitoring.

Methods: We reviewed retrospectively 102 consecutive CEAs performed in 102 patients with routine EEG monitoring and general anesthesia between March 1998 and October 2002. There were 65 (66%) symptomatic and 37 (34%) asymptomatic individuals. A protocol of induced arterial hypertension against EEG ischemic changes during carotid artery cross clamping was followed. Only patients with EEG changes refractory to induced hypertension went into etomidate-induced burst suppression.

Results: EEG changes were classified as mild, moderate and severe. Twenty patients (19.6%) developed asymmetric EEG changes, of which the great majority were mild and moderate (75%, p< 0.05). Seven patients with moderate (n=3) and severe (n=4) EEG changes needed etomidate cerebral protection. There were no mortalities and only one stroke (0.98%) is reported in the series. The morbidity rate was 6.8% and included transient cranial nerve palsies (n=5) and wound hematoma (n=1).

Conclusions: Carotid endarterectomy can be safely performed with EEG monitoring and selective induced arterial hypertension and etomidate cerebral protection. Our results suggest that this method may be a good alternative for shunting and its inherent risks.     

Drug‐resistant parietal lobe epilepsy: clinical manifestations and surgery outcome

Aim. We reviewed a large surgical cohort to investigate the clinical manifestations, EEG and neuroimaging findings, and postoperative seizure outcome in patients with drug‐resistant parietal lobe epilepsy (PLE). Methods. All drug‐resistant PLE patients, who were investigated for epilepsy surgery at Jefferson Comprehensive Epilepsy Center between 1986 and 2015, were identified. Demographic data, seizure data, EEG recordings, brain MRI, pathological findings, and postsurgical seizure outcome were reviewed. Results. In total, 18 patients (11 males and seven females) were identified. Sixteen patients (88%) had tonic‐clonic seizures, 12 (66%) had focal seizures with impaired awareness, and 13 (72%) described auras. Among 15 patients who had brain MRI, 14 patients (93%) had parietal lobe lesions. Only three of 15 patients (20%) who had interictal scalp EEG recordings showed parietal interictal spikes. Of 12 patients with available ictal surface EEG recordings, only three patients (25%) had parietal ictal EEG onset. After a mean follow‐up duration of 8.6 years, 14 patients (77.7%) showed a favourable postoperative seizure outcome. Conclusion. In patients with PLE, semiology and EEG may be misleading and brain MRI is the most valuable tool to localize the epileptogenic zone. Postsurgical seizure outcome was favourable in our patients with drug‐resistant parietal lobe epilepsy.     

Tramadol-associated seizures in Egypt: Epidemiological,clinical, and radiological study

BackgroundTramadol intake related seizures have emerged as a common cause of seizures in Egypt affecting mainly young men.ObjectiveThis study aimed to determine the percentage of tramadol induced seizures, and to compare the clinical, neurophysiological, and radiological features of tramadol induced seizures group with idiopathic epilepsy group.MethodsTwo phases study; at first phase, data analysis for all Kasr-Alainy epilepsy clinic patients in Cairo during the period from January 2012 through June 2014, then at second phase a group of tramadol induced seizures’ patients were compared with a matching group of idiopathic epilepsy patients. Detailed history and examination, laboratory tests, electroencephalogram (EEG), Magnetic Resonance Imaging (MRI) of the brain, and Hamilton depression rating scale (HAM-D) were performed for both groups.ResultsTramadol induced seizures represented 7% of all patients (103 out of 1480) and 12% of male patients. All cases were males. Occupational driving was the most common job. Seizures were generalized tonic clonic (GTCs) in 86%. Seventy-seven percent of tramadol induced seizures developed with toxic tramadol dose (>400 mg/day). Inter-ictal EEG was normal in most patients (87.5%). Depression and EEG abnormalities were significantly less than idiopathic epilepsy patients. MRI brain for both groups was normal.ConclusionTramadol induced seizures represented 7% of cases. This deviates the attention to the problem of tramadol addiction in Egypt and raises our awareness of tramadol induced seizures.     

A comparison of continuous video‐EEG monitoring and 30‐minute EEG in an ICU

Aim. To determine whether there is added benefit in detecting electrographic abnormalities from 16–24 hours of continuous video‐EEG in adult medical/surgical ICU patients, compared to a 30‐minute EEG. Methods. This was a prospectively enroled non‐randomized study of 130 consecutive ICU patients for whom EEG was requested. For 117 patients, a 30‐minute EEG was requested for altered mental state and/or suspected seizures; 83 patients continued with continuous video‐EEG for 16–24 hours and 34 patients had only the 30‐minute EEG. For 13 patients with prior seizures, continuous video‐EEG was requested and was carried out for 16–24 hours. We gathered EEG data prospectively, and reviewed the medical records retrospectively to assess the impact of continuous video‐EEG. Results. A total of 83 continuous video‐EEG recordings were performed for 16–24 hours beyond 30 minutes of routine EEG. All were slow, and 34% showed epileptiform findings in the first 30 minutes, including 2% with seizures. Over 16–24 hours, 14% developed new or additional epileptiform abnormalities, including 6% with seizures. In 8%, treatment was changed based on continuous video‐EEG. Among the 34 EEGs limited to 30 minutes, almost all were slow and 18% showed epileptiform activity, including 3% with seizures. Among the 13 patients with known seizures, continuous video‐EEG was slow in all and 69% had epileptiform abnormalities in the first 30 minutes, including 31% with seizures. An additional 8% developed epileptiform abnormalities over 16–24 hours. In 46%, treatment was changed based on continuous video‐EEG. Conclusion. This study indicates that if continuous video‐EEG is not available, a 30‐minute EEG in the ICU has a substantial diagnostic yield and will lead to the detection of the majority of epileptiform abnormalities. In a small percentage of patients, continuous video‐EEG will lead to the detection of additional epileptiform abnormalities. In a sub‐population, with a history of seizures prior to the initiation of EEG recording, the benefits of continuous video‐EEG in monitoring seizure activity and influencing treatment may be greater.     

Continuous EEG monitoring in comatose intensive care patients

Introduction: It is unclear whether patients or subpopulations of patients might benefit from EEG monitoring. Methods: We conducted a prospective trial of continuous electroencephalogram monitoring (CEEG; 48 hours). Results: Eleven of 55 (20%) patients who underwent CEEG monitoring recorded seizures. Of patients with acute structural brain lesions (ASBLs), 10 of 31 (32%) patients experiences recorded seizures, whereas only 24 (4%) patients with metabolic encephalopathies experienced recorded seizures (p<0.01). Six patients with ASBLs (11%) and one patient with metabolic encephalopathy (4%) had spikes/interictal epileptiform discharges (p=0.087). Conclusion: Our study suggests that CEEG monitoring may be more valuable for detection of seizures in patients with ASBLs than in patients with metabolic encephalopathies.     

Cortical network dysfunction in musicogenic epilepsy reflecting the role of snowballing emotional processes in seizure generation: an fMRI‐EEG study

Aim. Patients suffering from musicogenic epilepsy have focal seizures triggered by auditory stimuli. In some of these patients, the emotions associated with the music appear to play a role in the process triggering the seizure, however, the significance of these emotions and the brain regions involved are unclear. In order to shed some light on this, we conducted fMRI and EEG in a case of musicogenic epilepsy. Methods. In a 32‐year‐old male patient with seizures induced by a specific piece of Russian music, we performed video‐EEG monitoring as well as simultaneous fMRI and EEG registration. Results. Video‐EEG monitoring revealed a left temporo‐frontal epileptogenic focus. During fMRI‐EEG co‐registration, BOLD signal alterations were not only found in the epileptogenic focus but also in areas known for their role in the processing of emotions. Prior to a seizure in some of these areas, BOLD contrasts exponentially increased or decreased. Conclusion. These results suggest that in our case, dysfunction of the regulation processes of the musically‐induced emotions, and not the musical stimulus itself, led to the seizures.     

Neuroimaging characterization of recovery of impaired consciousness in patients with disorders of consciousness

Elucidation of critical brain areas or structures that are responsible for recovery of impaired consciousness in patients with disorders of consciousness is important because it can provide information that is useful when developing therapeutic strategies for neurorehabilitation or neurointervention in patients with disorders of consciousness.In this review,studies that have demonstrated brain changes during recovery of impaired consciousness were reviewed.These studies used positron emission tomography,electroencephalography/transcranial magnetic stimulation,diffusion tensor tractography,and diffusion tensor tractography/electroencephalography.The majority of these studies reported on the importance of supratentorial areas or structures in the recovery of impaired consciousness.The important brain areas or structures that were identified were the prefrontal cortex,basal forebrain,anterior cingulate cortex,and parietal cortex.These results have a clinically important implication that these brain areas or structures can be target areas for neurorehabilitation or neurointervention in patients with disorders of consciousness.However,most of studies were case reports;therefore,further original studies involving larger numbers of patients with disorders of consciousness are warranted.In addition,more detailed information on the brain areas or structures that are relevant to the recovery of impaired consciousness is needed.     

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.     

EEG and video-EEG seizure monitoring has limited utility in patients with hypothalamic hamartoma and epilepsy

Purpose: Hypothalamic hamartomas (HHs) are a malformation of the ventral hypothalamus and tuber cinereum, associated with gelastic seizures and epilepsy. We sought to determine the spectrum of electroencephalography (EEG) abnormalities in a large cohort of HH patients. Methods: Data was collected for HH patients undergoing evaluation between 2003 and 2007. Data included seizure history, prior treatment, and results of diagnostic studies. After informed consent, data were entered into a database. Key Findings: We reviewed 133 HH patients. Mean age at time of data analysis was 15.7 years (59.4% male). Most patients had gelastic (77%) and/or complex partial seizures (58%). Records for 102 EEG studies on 73 patients were reviewed. Interictal epileptiform abnormalities were seen in 77%, localizing predominately to the temporal and frontal regions. Records for 104 video‐EEG (VEEG) studies on 65 patients were reviewed. Of 584 gelastic seizures (GS) captured, no ictal EEG change was noted in 438 (75%). Of GS with localizing features, 89% suggested onset from the temporal and/or frontal regions. There were 160 complex partial seizures (CPS). For those with localizing features, 100% localized to the temporal and/or frontal head regions. EEG and VEEG findings correlated with the side of HH attachment. VEEG did not influence outcome. Significance: EEG features in HH patients are diverse. The majority of gelastic seizures fail to demonstrate change in the EEG. The lack of EEG changes with many clinical seizures, and the false localization seen in those events with an ictal change suggest the utility of EEG is limited in the evaluation of these patients.     

Infrared Imaging and Neurofeedback: Initial Reliability and Validity

Introduction. The neurological correlates underlying positive treatment outcomes for neurofeedback have been either unavailable or difficult to demonstrate. Assessment of brain-related changes associated with neurofeedback is needed to further establish its empirical basis. Infrared (IR) imaging is a noninvasive assessment of brain activity with high spatial and temporal resolution.

Method. Study 1, a reliability study, assessed the test-retest stability of IR imaging. In Validity Study 2 and 3, IR imaging assessed brain-related changes prior to and following neurofeedback and passive infrared hemoencephalography (pir HEG) training, respectively.

Results. In Study 1, high correlations occurred in pre-post comparisons for IR measures unrelated to treatment. Lower correlation between measures of IR imaging indicated changes in brain activation associated with thermoregulation following neurofeedback training. In Study 2, changes in thermal regulation occurred both within and across sessions. The change in metabolic regulation was enduring and associated with a reduction in core Autistic Spectrum Disorder symptomatology and improved cerebral connectivity. In Study 3, a significant percentage of patients with Traumatic Brain Injury increased thermal readings following pir HEG training and the change in thermal readings was associated with EEG connectivity.

Conclusion. Findings indicated that IR imaging may be a reliable and valid measure of treatment outcomes with clinical utility and sensitivity.     

Real-Time Changes in Connectivities During Neurofeedback

Introduction. Changes in quantitative EEG during and in response to neurofeedback (NF) training was explored in patients with traumatic brain injury (TBI). Data from 19 adults with a TBI of moderate mechanical nature, non-drug-related, and without severe posttraumatic stress disorder or seizure disorder were analyzed (14 male and 5 female).

Methods. EEG was evaluated before, during, and after ROSHI NF training. Data were collected as duplicate samples of 6 min each during eyes open and eyes closed conditions, but only the eyes closed condition was analyzed.

Results. Significant changes in connectivity occurred during and in response to NF training.

Conclusion. Results showed significant changes in real-time QEEG connectivity. An evaluation of a larger subject population will clarify gender differences in connectivity responses to NF training.     

Functional Connectivity and Aging: Comodulation and Coherence Differences

Introduction. Misconceptions about coherence and comodulation has hindered their simultaneous use in assessing electroencephalography (EEG). Coherence refers to phase synchrony, whereas comodulation refers to magnitude synchrony. Child and adult EEG data were analyzed for age functions to demonstrate coherence and comodulation differences.

Method. Eyes closed resting EEG was analyzed for 101 children and adults between ages of 5 and 35 years (34 female, 67 male; M age = 17.5 years). Spectral analysis focused on site-centered connectivity of 10 frequency bands. Site-centered connectivity refers to averaged coherence or comodulation associated with a site, an estimate of its network traffic.

Results. Site-centered coherence and comodulation increased with age for frequencies below 30 Hz in most sites. Age-related changes in anterior connectivity occurred for adults but not for children. The strongest age function was found for alpha comodulation at electrode site T5. Differences in coherence and comodulation results are also reported.

Conclusion. Functional connectivity increases steadily with age. Anterior EEG connectivity increased during adulthood but not during childhood. This finding parallels previous research on anterior callosal myelination and suggests that EEG connectivity measures may in part reflect myelination patterns. A model that associates coherence and comodulation with feedforward and feedback activity of the brain is proposed. A Periodicity Table for creating new and potentially relevant psychophysiological coefficients was described.