Neurological syndromes and potential triggers associated with antibodies to neuronal surface antigens

BACKGROUND

Autoantibodies against surface neuronal antigens have been associated with specific neurological presentations including autoimmune encephalitis (AE), with variable association with neoplasia and infections.

METHODS

We described the phenotype and environmental associations of patients with neurological syndromes associated with antibodies against neuronal surface antigens who were referred to a tertiary center in the South of Brazil. All patients were tested for neuronal autoantibodies using cell-based assays. Clinical, radiological, and laboratory findings were retrospectively reviewed.

RESULTS

We identified 16 patients, 15 had subacute, and one had a progressive disease course. Among patients with subacute onset, 11 (73 %) were N-Methyl-d-Aspartate receptor (NMDAr-IgG)+, 3 (20 %) were Leucine-rich Glioma-Inactivated-1 (LGI1-IgG)+, and 1 (6 %) was positive for Glycine receptor-IgG. The patient with a progressive disease course had antibodies against IgLON5. Most patients had disease onset in spring and summer suggesting environmental factors for the development of AE. Also, we observed a different pattern of brain lesions when NMDAr-IgG encephalitis followed herpes encephalitis and a previously unreported association with Rosai-Dorfman-Destombe disease. All patients with encephalopathy met criteria for possible AE and all proven NMDAr-IgG+ met criteria for NMDAr-IgG encephalitis. However, only one LGI1-IgG+ patient fulfilled clinical criteria for limbic encephalitis. All but one received high-dose intravenous methylprednisolone, 11 also had intravenous human immunoglobulin, and 4 plasma exchange. Furthermore, all patients received second-line immunotherapy. Importantly, most patients improved with immunotherapy, even when initiated later in the disease course.

CONCLUSION

We identified seasonal variability associated with neuronal surface antibodies suggesting environmental triggers. Also, we described the coexistence of NMDAr-IgG encephalitis with histiocytosis. In our series, most patients received second-line immunotherapy. We observed neurologic improvement after treatment even in cases of delayed diagnosis. Increasing the recognition and availability of tests and treatments for these conditions is of paramount importance in low- and middle-income countries.

Resting-state fMRI in patients with refractory epilepsy with and without drop attacks: exploring the connectivity of sensorimotor cortex

OBJECTIVE

Patients with multifocal or generalized epilepsies manifesting with drop attacks have severe refractory seizures and significant cognitive and behavioural abnormalities. It is unclear to what extent these features relate to network abnormalities and how networks in sensorimotor cortex differ from those in patients with refractory focal epilepsies. Thus, in this study we sought to provide preliminary data on connectivity of sensorimotor cortex in patients with epileptic drop attacks, in comparison to patients with focal refractory epilepsies.

METHODS

Resting-state fMRI (rs-fMRI) data was available for 5 patients with epileptic drop attacks and 15 with refractory focal epilepsies undergoing presurgical evaluation. Functional connectivity was analyzed with a seed-based protocol, with primary seeds placed at the precentral gyrus, the postcentral gyrus and the premotor cortex. For each seed, the subjects' timeseries were extracted and transformed to Z scores. Between-group analysis was then performed using the 3dttest+ + AFNI program.

RESULTS

Two clusters of reduced connectivity in the group with drop attacks (DA group) in relation to those with focal epilepsies were found in the between-group analysis: the precentral seed showed reduced connectivity in the surrounding motor area, and the postcentral seed, reduced connectivity with the ipsilateral posterior cingulate gyrus. In the intra-group analyses, sensorimotor and premotor networks were abnormal in the DA group, whereas patients with focal epilepsies had the usual connectivity maps with each seed.

CONCLUSION

This pilot study shows differences in the cerebral connectivity in the sensorimotor cortex of patients with generalized epilepsies and drop attacks which should be further explored to better understand the biological bases of the seizure generation and cognitive changes in these people.

WNT pathway in focal cortical dysplasia compared to perilesional nonlesional tissue in refractory epilepsies

BACKGROUND

Focal cortical dysplasia (FCD) is a malformation of cortical development that causes medical refractory seizures, and one of the main treatments may be surgical resection of the affected area of the brain. People affected by FCD may present with seizures of variable severity since childhood. Despite many medical treatments available, only surgery can offer cure. The pathophysiology of the disease is not yet understood; however, it is known that several gene alterations may play a role. The WNT/β-catenin pathway is closely related to the control and balance of cell proliferation and differentiation in the central nervous system. The aim of this study was to explore genes related to the WNT/β-catenin pathway in lesional and perilesional brain tissue in patients with FCD type II.

METHODS

Dysplastic and perilesional tissue from the primary dysplastic lesion of patients with FCD type IIa were obtained from two patients who underwent surgical treatment. The analysis of the relative expression of genes was performed by a qRT-PCR array (super array) containing 84 genes related to the WNT pathway.

RESULTS

Our results suggest the existence of molecular alteration in some genes of the WNT pathway in tissue with dysplastic lesions and of perilesional tissue. We call this tissue of normal-appearing adjacent cortex (NAAC). Of all genes analyzed, a large number of genes show similar behavior between injured, perilesional and control tissues. However, some genes have similar characteristics between the perilesional and lesional tissue and are different from the control brain tissue, presenting the perilesional tissue as a molecularly altered material.

CONCLUSION

Our results suggest that the perilesional area after surgical resection of tissue with cortical dysplasia presents molecular changes that may play a role in the recurrence of seizures in these patients. The perilesional tissue should receive expanded attention beyond the somatic mutations described and associated with FCD, such as mTOR, for example, to new signaling pathways that may play a crucial role in seizure recurrence.

Extended resection for seizure control of pure motor strip focal cortical dysplasia during awake craniotomy: illustrative case

BACKGROUND

Focal cortical dysplasias (FCD) represent highly intrinsically epileptogenic lesions that require complete resection for seizure control. Resection of pure motor strip FCD can be challenging. Effective control of postoperative seizures is crucial and extending the boundaries of resection in an eloquent zone remains controversial.

OBSERVATIONS

The authors report a 52-year-old right-handed male with refractory epilepsy. The seizure phenotype was a focal crisis with preserved awareness and a clonic motor onset of right-hemibody. Epilepsy surgery protocol demonstrated a left pure motor strip FCD and a full-awake resective procedure with motor brain mapping was performed. Further resection of surgical boundaries monitoring function along intraoperative motor tasks with no direct electrical stimulation corroborated by intraoperative-neuromonitorization was completed as the final part of the surgery. In the follow-up period of 3-years, the patient has an Engel-IB seizure-control with mild distal lower limb palsy and no gate compromise.

LESSONS

This report represents one of the few cases with pure motor strip FCD resection. In a scenario similar to this case, the authors consider that this variation can be useful to improve seizure control and the quality of life of these patients by extending the resection of a more extensive epileptogenic zone minimizing functional damage.

Selective Posterior Callosotomy for Treatment of Epileptic Drop Attacks: Video Documentation of the Surgical Technique: 2-Dimensional Operative Video

This is a surgical technique video of selective posterior callosotomy (SPC), a novel surgical procedure to alleviate refractory epileptic drop attacks.1 Departing from traditional approaches aiming the anterior half or the entire callosum, SPC sections the posterior half of the callosum sparing prefrontal connectivity.1 Drop attacks are generalized epileptic seizures characterized by sudden falls.1 These seizures are often seen in diffuse brain pathology associated with generalized or multifocal epilepsies, whose electroencephalogram (EEG) "fingerprint" is bilaterally synchronous epileptic discharges.1 Sectioning the callosum to control drop attacks follows the rationale that the rapid synchronization of discharges between motor and premotor regions of both hemispheres is the basis.1 The standard approach to callosotomies always contemplated the anterior fibers of the callosum.2 Literature reports that anterior sections lead to unsatisfactory control of drop attacks, and results are improved when extended into a total callosotomy.2,3 This evidence coupled with diffusion tensor imaging (DTI) findings showing that motor and premotor fibers actually cross through posterior half of the callosum led us to hypothesize that selective section of the posterior half of the callosum would section all relevant motor fibers and control drop attacks to a similar extent to total callosotomies, with the advantage of sparing prefrontal interconnectivity3 and no split-brain syndrome. Both our series, one retrospective, followed by a new prospective study have confirmed SPC to be a safe procedure, leading to complete or greater than 90% control of epileptic falls in 85% of patients.1 The video presented here was recorded during a selective posterior callosotomy performed on a 13-yr-old girl who had hundreds of uncontrollable drop attacks per day. Falls were completely controlled with significant gains in psychomotor development and cognition, after 5 yr of follow-up. The patient provided signed consent to the surgical procedure, video acquisition, photo acquisition, and storage at operations, and the publication of this material.

A novel scale for suspicion of psychogenic nonepileptic seizures: development and accuracy

OBJECTIVE

The differential diagnosis between epileptic and psychogenic nonepileptic seizures (PNES) is challenging, yet suspicion of PNES is crucial to rethink treatment strategies and select patients for diagnostic confirmation through video EEG (VEEG). We developed a novel scale to prospectively suspect PNES.

METHODS

First, we developed a 51-item scale in two steps, based upon literature review and panel expert opinion. A pilot study verified the applicability of the instrument, followed by a prospective evaluation of 158 patients (66.5% women, mean age 33 years) who were diagnosed for prolonged VEEG. Only epileptic seizures were recorded in 103 patients, and the other 55 had either isolated PNES or both types of seizures. Statistical procedures identified 15 items scored between 0 and 3 that best discriminated patients with and without PNES, with a high degree of consistency.

RESULTS

Internal consistency reliability of the scale for suspicion of PNES was 0.77 with Cronbach's Alpha Coefficient and 0.95 with Rasch Item Reliability Index, and performance did not differ according to the patient's gender. For a cut-off score of 20 (of 45) points, area under the curve was 0.92 (95% IC: 0.87-0.96), with an accuracy of 87%, sensitivity of 89%, specificity of 85%, positive predictive value of 77%, and negative predictive value of 94% (95% IC) for a diagnosis of PNES.

CONCLUSIONS

The scale for suspicion of PNES (SS-PNES) has high accuracy to a reliable suspicion of PNES, helping with the interpretation of apparent seizure refractoriness, reframing treatment strategies, and streamlining referral for prolonged VEEG.

Control of drop attacks with selective posterior callosotomy: Anatomical and prognostic data

OBJECTIVE

In a previous proof of concept study, selective posterior callosotomy achieved similar degree of control of drop attacks as total callosotomy, while sparing prefrontal interconnectivity. The present study aims to confirm this finding in a larger cohort and to provide anatomical and prognostic data.

METHODS

Fifty-one patients with refractory drop attacks had selective posterior callosotomy and prospective follow up for a mean of 6.4 years. Twenty-seven patients had post-operative magnetic resonance imaging (MRI) and 18 had tractography (DTI) of remaining callosal fibers. Pre and postoperative falls were quantified and correlated with demographic, clinical and imaging data.

RESULTS

Mean monthly frequency of drop attacks had a 95 % reduction, from 297 before to 16 after the procedure. Forty- one patients (80 %) had either complete or greater than 90 % control of the epileptic falls. Age and duration of epilepsy at surgery correlated with outcome (p values, respectively, 0.042 and 0.005). Mean index of callosal section along the posterior-to-anterior axis was 53.5 %. Extending the posterior section anterior to the midbody of the corpus callosum did not correlate with seizure control (p 0.91), providing fibers interconnecting the primary motor (M1) and caudal supplementary motor areas (SMA) were sectioned. Only one patient had a notable surgical complication which resolved in two days.

CONCLUSIONS

This level III cohort study with objective outcome assessment confirms that selective posterior callosotomy is safe and effective to control epileptic falls. Younger patients with smaller duration of epilepsy have better results. A posterior section contemplating the splenium, isthmus and posterior half of the body (posterior midbody) seems sufficient to achieve complete or almost complete control of drop attacks.

Could the 2017 ILAE and the four-dimensional epilepsy classifications be merged to a new "Integrated Epilepsy Classification"?

Over the last few decades the ILAE classifications for seizures and epilepsies (ILAE-EC) have been updated repeatedly to reflect the substantial progress that has been made in diagnosis and understanding of the etiology of epilepsies and seizures and to correct some of the shortcomings of the terminology used by the original taxonomy from the 1980s. However, these proposals have not been universally accepted or used in routine clinical practice. During the same period, a separate classification known as the "Four-dimensional epilepsy classification" (4D-EC) was developed which includes a seizure classification based exclusively on ictal symptomatology, which has been tested and adapted over the years. The extensive arguments for and against these two classification systems made in the past have mainly focused on the shortcomings of each system, presuming that they are incompatible. As a further more detailed discussion of the differences seemed relatively unproductive, we here review and assess the concordance between these two approaches that has evolved over time, to consider whether a classification incorporating the best aspects of the two approaches is feasible. To facilitate further discussion in this direction we outline a concrete proposal showing how such a compromise could be accomplished, the "Integrated Epilepsy Classification". This consists of five categories derived to different degrees from both of the classification systems: 1) a "Headline" summarizing localization and etiology for the less specialized users, 2) "Seizure type(s)", 3) "Epilepsy type" (focal, generalized or unknown allowing to add the epilepsy syndrome if available), 4) "Etiology", and 5) "Comorbidities & patient preferences".

Regional Amyloid-β Load and White Matter Abnormalities Contribute to Hypometabolism in Alzheimer's Dementia

We investigated the association between amyloid-β deposition and white matter (WM) integrity as a determinant of brain glucose hypometabolism across the Alzheimer's disease (AD) spectrum. We assessed ninety-six subjects (27 cognitively normal, 49 mild cognitive impairment, and 20 AD dementia) who underwent [¹⁸F]FDG and [¹⁸F]Florbetapir positron emission tomography (PET) as well as magnetic resonance imaging (MRI) with diffusion tensor imaging. Among the regions with reduced fractional anisotropy (FA) in the AD group, we selected a voxel of interest in the angular bundle bilaterally for subsequent analyses. Using voxel-based interaction models at voxel level, we tested whether the regional hypometabolism is associated with FA in the angular bundle and regional amyloid-β deposition. In the AD patients, [¹⁸F]FDG hypometabolism in the striatum, mesiobasal temporal, orbitofrontal, precuneus, and cingulate cortices were associated with the interaction between high levels of [¹⁸F]Florbetapir standard uptake value ratios (SUVR) in these regions and low FA in the angular bundle. We found that the interaction between, rather than the independent effects of, high levels of amyloid-β deposition and WM integrity disruption determined limbic hypometabolism in patients with AD. This finding highlights a more integrative model for AD, where the interaction between partially independent processes determines the glucose hypometabolism.

Association between switching antiepileptic drug products and healthcare utilization: A systematic review

AIMS

There is ongoing concern whether switching between different antiepileptic drug (AED) products may compromise patient care. We systematically reviewed changes in healthcare utilization following AED switch.

METHODS

We searched MEDLINE and EMBASE databases (1980-October 2016) for studies that assessed the effect of AED switching in patients with epilepsy on outpatient visits, emergency room visits, hospitalization and hospital stay duration.

RESULTS

A total of 14 articles met the inclusion criteria. All were retrospective studies. Four provided findings for specific AEDs only (lamotrigine, topiramate, phenytoin and divalproex), 9 presented pooled findings from multiple AEDs, and 1 study provided both specific (lamotrigine, topiramate, oxcarbazepine, and levetiracetam) and pooled findings. Three studies found an association between a switch of topiramate and an increase in healthcare utilization. Another three studies found that a brand-to-generic lamotrigine switch was not associated with an increased risk of emergently treated events (ambulance use, ER visits or hospitalization). The outcomes of the pooled AED switch studies were inconsistent; 5 studies reported an increased healthcare utilization while 5 studies did not.

CONCLUSION

Studies that have examined the association between an AED switch and a change in healthcare utilization report conflicting findings. Factors that may explain these inconsistent outcomes include inter-study differences in the type of analysis undertaken (pooled vs individual AED data), the covariates used for data adjustment, and the type of switch examined. Future medical claim database studies employing a prospective design are encouraged to address these and other factors in order to enhance inter-study comparability and extrapolation of findings.

Induced pluripotent stem cells from patients with focal cortical dysplasia and refractory epilepsy

Focal cortical dysplasia (FCD) is caused by numerous alterations, which can be divided into abnormalities of the cortical architecture and cytological variations; however, the exact etiology of FCD remains unknown. The generation of induced pluripotent stem cells (iPSCs) from the cells of patients with neurological diseases, and their subsequent tissue‑specific differentiation, serves as an invaluable source for testing and studying the initial development and subsequent progression of diseases associated with the central nervous system. A total of 2 patients demonstrating seizures refractory to drug treatment, characterized as FCD Type IIb, were enrolled in the present study. Fibroblasts were isolated from residual skin fragments obtained from surgical treatment and from brain samples obtained during surgical resection. iPSCs were generated following exposure of fibroblasts to viral vectors containing POU class 5 homeobox 1 (OCT4), sex determining region Y‑box 2 (SOX2), Kruppel‑like factor 4 and c‑MYC genes, and were characterized by immunohistochemical staining for the pluripotent markers homeobox protein NANOG, SOX2, OCT4, TRA1‑60 and TRA1‑81. The brain samples were tested with antibodies against protein kinase B (AKT), phosphorylated‑AKT, mechanistic target of rapamycin (mTOR) and phosphorylated‑mTOR. Analysis of the AKT/mTOR pathway revealed a statistically significant difference between the cerebral tissues of the two patients, which were of different ages (45 and 12 years old). Clones with the morphological features of embryonic cells were detected on the 13th day and were characterized following three subcultures. The positive staining characteristics of the embryonic cells confirmed the successful generation of iPSCs derived from the patients' fibroblasts. Therefore, the present study presents a method to obtain a useful cellular source that may help to understand embryonic brain development associated with FCD.

Diagnostic utility of invasive EEG for epilepsy surgery: Indications, modalities, and techniques

Many patients with medically refractory epilepsy now undergo successful surgery based on noninvasive diagnostic information, but intracranial electroencephalography (IEEG) continues to be used as increasingly complex cases are considered surgical candidates. The indications for IEEG and the modalities employed vary across epilepsy surgical centers; each modality has its advantages and limitations. IEEG can be performed in the same intraoperative setting, that is, intraoperative electrocorticography, or through an independent implantation procedure with chronic extraoperative recordings; the latter are not only resource intensive but also carry risk. A lack of understanding of IEEG limitations predisposes to data misinterpretation that can lead to denying surgery when indicated or, worse yet, incorrect resection with adverse outcomes. Given the lack of class 1 or 2 evidence on IEEG, a consensus-based expert recommendation on the diagnostic utility of IEEG is presented, with emphasis on the application of various modalities in specific substrates or locations, taking into account their relative efficacy, safety, ease, and incremental cost-benefit. These recommendations aim to curtail outlying indications that risk the over- or underutilization of IEEG, while retaining substantial flexibility in keeping with most standard practices at epilepsy centers and addressing some of the needs of resource-poor regions around the world.

Mother and daughter with adolescent-onset severe frontal lobe dysfunction and epilepsy

Familial cases of early-onset prominent frontal lobe dysfunction associated with epilepsy have not been reported to date. We report a mother and her only daughter with incapacitating behavioral manifestations of frontal lobe dysfunction and epilepsy of variable severity. The possibility of a hitherto undescribed genetic condition is discussed.

Imaging Alzheimer's disease pathophysiology with PET

Alzheimer's disease (AD) has been reconceptualised as a dynamic pathophysiological process characterized by preclinical, mild cognitive impairment (MCI), and dementia stages. Positron emission tomography (PET) associated with various molecular imaging agents reveals numerous aspects of dementia pathophysiology, such as brain amyloidosis, tau accumulation, neuroreceptor changes, metabolism abnormalities and neuroinflammation in dementia patients. In the context of a growing shift toward presymptomatic early diagnosis and disease-modifying interventions, PET molecular imaging agents provide an unprecedented means of quantifying the AD pathophysiological process, monitoring disease progression, ascertaining whether therapies engage their respective brain molecular targets, as well as quantifying pharmacological responses. In the present study, we highlight the most important contributions of PET in describing brain molecular abnormalities in AD.

"Mirror EPC": epilepsia partialis continua shifting sides after rolandic resection in dysplasia

BACKGROUND

Epilepsia partialis continua (EPC) is a life-threatening condition often caused by focal cortical dysplasia (FCD). Resection of the motor cortex is contemplated in the hope that the trade-off between a severe motor deficit and complete seizure control justifies the procedure.

METHODS

Report of 3 patients with EPC due to histologically confirmed FCD, who underwent resection of the motor cortex under acute electrocorticography.

RESULTS

All had re-emergence of medically intractable EPC in the other side of the body after rolandic resection. Two patients died and the third continues with refractory attacks.

CONCLUSION

In some instances, EPC due to FCD may shift sides and re-emerge in the contralateral, previously asymptomatic, hemibody. A mechanism of disinhibition by surgery of a suppressed contralateral and homologous epileptogenic zone is speculated.

Developmental tumors and adjacent cortical dysplasia: single or dual pathology?

Developmental tumors often lead to refractory partial seizures and constitute a well-defined, surgically remediable epilepsy syndrome. Dysplastic features are often associated with these tumors, and their significance carries both practical and conceptual relevance. If associated focal cortical dysplasia (FCD) relates to the extent of the epileptogenic tissue, then presurgical evaluation and surgical strategies should target both the tumor and the surrounding dyslaminated cortex. Furthermore, the association has been included in the recently revised classification of FCD and the epileptogenicity of this associated dysplastic tissue is crucial to validate such revision. In addition to the possibility of representing dual pathology, the association of developmental tumors and adjacent dysplasia may instead represent a single developmental lesion with distinct parts distributed along a histopathologic continuum. Moreover, the possibility that this adjacent dyslamination is of minor epileptogenic relevance should also be entertained. Surgical data show that complete resection of the solid tumors and immediately adjacent tissue harboring satellites may disrupt epileptogenic networks and lead to high rates of seizure freedom, challenging the epileptogenic relevance of more extensive adjacent dyslaminated cortex. Whether the latter is a primary or secondary abnormality and whether dyslaminated cortex in the context of a second lesion may produce seizures after complete resection of the main lesion is still to be proven.

Surgical treatment for epilepsy

Surgical treatment for epilepsy remains highly underutilized: in the United States, there has been no increase in the number of surgical procedures performed annually since 1990¹; for most patients referred, the average duration of epilepsy is 22 years²; and there has been no change in this delay to surgery³, despite two randomized controlled trials^{4, 5} and an American Academy of Neurology practice parameter that recommended surgery as the treatment of choice for medically refractory temporal lobe epilepsy⁶. This session addressed issues relevant to increasing the availability of epilepsy surgery, particularly in countries with limited resources.

Focal malformations of cortical development: a most relevant etiology of epilepsy in children

Malformations of cortical development (MCD) are now well established as a most prevalent and relevant etiology of medically refractory epilepsies in children and adolescents. Focal cortical dysplasia (FCD) and hemimegalencephalies (HMG) occupy a special status because their focality (or in the case of HMG, their unihemispheric distibution) makes them amenable to surgical treatment to attempt seizure control. Since interictal epileptiform discharges and frequent seizures can lead to abnormal development because of brain plasticity during early childhood, the aim of surgical treatment is not only seizure control but also the redirection of development toward more physiological paths. In this review, we propose an "imaging-semiological organization" including (1) patients whose dysplastic lesion surrounds the fronto-rolandic cortex with increased signal and a transmantle sign, (2) multilobar hemispheric lesions, predominating in the anterior or posterior quadrants with large areas of abnormal gyration, increased cortical thickness, and gray-white blurring, (3) anterior temporal dysplasias usually featuring volume reduction combined with blurring of the underlying white matter in the temporal pole, and (4) a very relevant group of patients with refractory seizures, normal or roughly normal intellect, and normal MRI, later shown to harbor microscopic "nidus" of dysplastic cells. Classification takes into account the cortical disorganization, the presence of aberrant cellular elements, and the association with other lesion types.

Anatomy-based reconstruction of FDG-PET images with implicit partial volume correction improves detection of hypometabolic regions in patients with epilepsy due to focal cortical dysplasia diagnosed on MRI

PURPOSE

Detection of hypometabolic areas on interictal FDG-PET images for assessing the epileptogenic zone is hampered by partial volume effects. We evaluated the performance of an anatomy-based maximum a-posteriori (A-MAP) reconstruction algorithm which combined noise suppression with correction for the partial volume effect in the detection of hypometabolic areas in patients with focal cortical dysplasia (FCD).

METHODS

FDG-PET images from 14 patients with refractory partial epilepsy were reconstructed using A-MAP and maximum likelihood (ML) reconstruction. In all patients, presurgical evaluation showed that FCD represented the epileptic lesion. Correspondence between the FCD location and regional metabolism on a predefined atlas was evaluated. An asymmetry index of FCD to normal cortex was calculated.

RESULTS

Hypometabolism at the FCD location was detected in 9/14 patients (64%) using ML and in 10/14 patients (71%) using A-MAP reconstruction. Hypometabolic areas outside the FCD location were detected in 12/14 patients (86%) using ML and in 11/14 patients (79%) using A-MAP reconstruction. The asymmetry index was higher using A-MAP reconstruction (0.61, ML 0.49, p=0.03).

CONCLUSION

The A-MAP reconstruction algorithm improved visual detection of epileptic FCD on brain FDG-PET images compared to ML reconstruction, due to higher contrast and better delineation of the lesion. This improvement failed to reach significance in our small sample. Hypometabolism outside the lesion is often present, consistent with the observation that the functional deficit zone tends to be larger than the epileptogenic zone.

Attention deficit hyperactivity disorder and the behavior of "Che" Guevara

Attention deficit hyperactivity disorder (ADHD) is a childhood onset neuropsychiatric disorder characterized by inattention, hyperactivity and impulsivity. ADHD is related to several co-morbidities, such as opposition defiant disorder, conduct disorder, mood and anxiety disturbances, as well as tics and Tourette's syndrome. The objective of this report is to shed an alternative light on the personality of Ernesto "Che" Guevara, discussing whether he might have had ADHD. Several published biographies of Che Guevara were reviewed. Established ADHD criteria (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), were used as a framework to evaluate Che's behaviour. In addition, we compared the main features of Che's reported behaviour to the set of abnormalities leading to the diagnosis of ADHD in adults proposed by Wender and colleagues and known as the UTAH ADHD criteria. Analysis of the most renowned biographies of Ernesto "Che" Guevara suggests that he may have had ADHD.

Differentiating attention-deficit/hyperactivity disorder inattentive and combined types: a (1)H-magnetic resonance spectroscopy study of fronto-striato-thalamic regions

Despite the implication of fronto-striatal circuits in attention-deficit/hyperactivity disorder (ADHD), there is a lack of information on the role of these regions, especially the thalamus, in the heterogeneity of ADHD. We assessed the (1)H-magnetic resonance spectroscopy profile in ventromedial prefrontal cortex (VMPFC)-thalamic-striatal regions bilaterally in three groups of subjects (age range 18-24 years old): ADHD inattentive type (ADHD-I; n = 9), ADHD combined type (ADHD-C; n = 10) and non-ADHD controls (n = 12). The peaks of N-acetylaspartate, Choline (Cho), myo-inositol (mI), creatine (Cr) and glutamate-glutamine-GABA (Glx) to Cr were calculated. Subjects with ADHD-C showed lower mI/Cr ratio in the right VMPFC than controls, higher Cho/Cr ratio in the left thalamus-pulvinar than the ADHD-I group and higher Glx/Cr ratio in left putamen than individuals with ADHD-I and controls. This metabolic profile suggests a disruption of fronto-striato-thalamic structures in the ADHD-C as a result of lower neuronal energetic metabolism.

Canonical decomposition of ictal scalp EEG reliably detects the seizure onset zone

Long-term electroencephalographic (EEG) recordings are important in the presurgical evaluation of refractory partial epilepsy for the delineation of the irritative and ictal onset zones. In this paper we introduce a new algorithm for an automatic, fast and objective localizing of the ictal onset zone in ictal EEG recordings. We extracted the potential distribution of the ictal activity from EEG using the higher order canonical decomposition method, also referred to as the CP model. The CP model decomposes in a unique way a higher order tensor in a minimal sum of rank-1 'atoms'. We showed that only one atom is related to the seizure activity. Simulation experiments demonstrated that the method correctly extracted the potential distribution of the ictal activity even with low signal-to-noise ratios. In 37 ictal EEGs, the CP method correctly localized the seizure onset zone in 34 (92%) and visual assessment in 21 cases (57%) (p=0.00024). The CP method is a fast method to delineate the ictal onset zone in ictal EEGs and is more sensitive than visual interpretation of the ictal EEGs.

Improving the interpretation of ictal scalp EEG: BSS-CCA algorithm for muscle artifact removal

PURPOSE

To investigate the potential clinical relevance of a new algorithm to remove muscle artifacts in ictal scalp EEG.

METHODS

Thirty-seven patients with refractory partial epilepsy with a well-defined seizure onset zone based on full presurgical evaluation, including SISCOM but excluding ictal EEG findings, were included. One ictal EEG of each patient was presented to a clinical neurophysiologist who was blinded to all other data. Ictal EEGs were first rated after band-pass filtering, then after elimination of muscle artifacts using a blind source separation-canonical correlation analysis technique (BSS-CCA). Degree of muscle artifact contamination, lateralization, localization, time and pattern of ictal EEG onset were compared between the two readings and validated against the other localizing information.

RESULTS

Muscle artifacts contaminated 97% of ictal EEGs, and interfered with the interpretation in 76%, more often in extratemporal than temporal lobe seizures. BSS-CCA significantly improved the sensitivity to localize the seizure onset from 62% to 81%, and performed best in ictal EEGs with moderate to severe muscle artifact contamination. In a significant number of the contaminated EEGs, BSS-CCA also led to an earlier identification of ictal EEG changes, and recognition of ictal EEG patterns that were hidden by muscle artifact.

CONCLUSIONS

Muscle artifacts interfered with the interpretation in a majority of ictal EEGs. BSS-CCA reliably removed these muscle artifacts in a user-friendly manner. BSS-CCA may have an important place in the interpretation of ictal EEGs during presurgical evaluation of patients with refractory partial epilepsy.

Conhecimento sobre o transtorno do déficit de atenção/hiperatividade no Brasil

OBJETIVO: Verificar o conhecimento da população sobre o transtorno do déficit de atenção/hiperatividade (TDAH) e de médicos, psicólogos e educadores sobre aspectos clínicos do transtorno. MÉTODOS: 2.117 indivíduos com idade > 16 anos, 500 educadores, 405 médicos (128 clínicos gerais, 45 neurologistas, 30 neuropediatras, 72 pediatras, 130 psiquiatras) e 100 psicólogos foram entrevistados pelo Instituto Datafolha. A amostra da população foi estratificada por região geográfica, com controle de cotas de sexo e idade. A abordagem foi pessoal. Para os profissionais (amostra aleatória simples), os dados foram coletados por telefone em Belém, Fortaleza, Recife, Salvador, Brasília, Belo Horizonte, Rio de Janeiro, São Paulo, Curitiba e Porto Alegre. resultados: Na população, > 50% acreditavam que medicação para TDAH causa dependência, que TDAH resulta de pais ausentes, que esporte é melhor do que drogas como tratamento e que é viável o tratamento psicoterápico sem medicamentos. Dos educadores, > 50% acreditavam que TDAH resulta de pais ausentes, que tratamento psicoterápico basta e que os esportes substituem os medicamentos. Entre psicólogos, > 50% acreditavam que o tratamento pode ser somente psicoterápico. Dos médicos, > 50% de pediatras e neurologistas acreditavam que TDAH resulta de pais ausentes. CONCLUSÕES: Todos os grupos relataram crenças não respaldadas cientificamente, que podem contribuir para diagnóstico e tratamento inadequados. É urgente capacitar profissionais e estabelecer um programa de informação sobre TDAH para pais e escolas.

Disfunção executiva como uma medida de funcionalidade em adultos com TDAH

Este artigo aborda a presença e a apresentação clínica da disfunção executiva em pacientes com TDAH. Na medida em que sintomas de disfunção executiva determinam as alterações de funcionamento desses pacientes nas atividades do dia-a-dia, torna-se relevante o estudo das relações entre alterações em testes neuropsicológicos formais de funções executivas e a ocorrência desses sintomas. A constatação relativamente recente do papel da disfunção executiva no TDAH tem impulsionado a pesquisa neuropsicológica, mas os dados até agora disponíveis são ainda pouco consistentes. Uma visão atualizada dessas questões sugere que a semiologia neuropsicológica disponível ainda não alcança plenamente a constelação de sintomas práticos do TDAH no dia-a-dia, mostrando a necessidade de avanços na pesquisa dessas relações.

'To do or not to do'? The neurobiology of decision-making in daily life: I. Getting the basics

The constant conflict between decisions leading to immediate pleasurable consequences versus behaviors aiming at long-term social advantages is reviewed here in the framework of the evolutionary systems regulating behavior. The inescapable temporal perspective in decision-making in everyday life is highlighted and integrated with the role of the executive functions in the modulation of subcortical systems. In particular, the representations of the ‘non-existent’ future in the prefrontal cortical regions and how these representations can bridge theory and practice in everyday life are addressed. Relevant discussions regarding the battle between emotions and reasons in the determination of more complex decisions in the realm of neuroeconomics and in moral issues have been reserved for a second essay.

Correlations of interictal FDG-PET metabolism and ictal SPECT perfusion changes in human temporal lobe epilepsy with hippocampal sclerosis

BACKGROUND

The pathophysiological role of the extensive interictal cerebral hypometabolism in complex partial seizures (CPS) in refractory mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS) is poorly understood. Our aim was to study ictal-interictal SPECT perfusion versus interictal fluorodeoxyglucose (FDG)-PET metabolic patterns.

METHODS

Eleven adults with refractory unilateral mTLE-HS, who were rendered seizure free after epilepsy surgery, were included. All had an interictal FDG-PET and an interictal and ictal perfusion SPECT scan. FDG-PET data were reconstructed using an anatomy-based reconstruction algorithm, which corrected for partial volume effects, and analyzed semi-quantitatively after normalization to white matter activity. Using Statistical Parametric Mapping (SPM), we compared interictal metabolism of the patient group with a control group. We correlated metabolic with ictal perfusion changes in the patient group.

RESULTS

Global cerebral grey matter glucose metabolism in patients was decreased 10-25% compared with control subjects. Interictal PET hypometabolism and ictal SPECT hypoperfusion were maximal in the ipsilateral frontal lobe. Ictal frontal lobe hypoperfusion was associated with crossed cerebellar diaschisis. The ipsilateral temporal lobe showed maximal ictal hyperperfusion and interictal hypometabolism, which was relatively mild compared with the degree of hypometabolism affecting the frontal lobes.

CONCLUSION

Interictal hypometabolism in mTLE-HS was greatest in the ipsilateral frontal lobe and represented a seizure-related dynamic process in view of further ictal decreases. Crossed cerebellar diaschisis suggested that there is a strong ipsilateral frontal lobe inhibition during CPS. We speculate that surround inhibition in the frontal lobe is a dynamic defense mechanism against seizure propagation, and may be responsible for functional deficits observed in mTLE.

Painel brasileiro de especialistas sobre diagnóstico do transtorno de déficit de atenção/hiperatividade (TDAH) em adultos

Considerando-se as dificuldades atuais do diagnóstico do transtorno do déficit de atenção/hiperatividade em adultos, foram reunidos especialistas brasileiros que fazem pesquisas nesta área, de modo a produzir diretrizes de consenso para uso no país. Foi realizada uma revisão não-sistemática preliminar e concebido um texto inicial, que foi repetidamente avaliado e editado pelos autores, com acréscimos e correções ao longo de 6 meses, através de correio eletrônico e de uma reunião posterior, patrocinada pela Associação Brasileira do Déficit de Atenção. A versão preliminar foi apresentada publicamente durante o congresso anual da Associação Brasileira de Psiquiatria, com comentários e sugestões dos participantes, para a redação da versão final.

Seizure and memory outcome following temporal lobe surgery: selective compared with nonselective approaches for hippocampal sclerosis

Object

The aim of this study was to compare seizure and memory outcome in patients with medically refractory mesial temporal lobe epilepsy due to hippocampal sclerosis (MTLE/HS) treated using an anterior temporal lobectomy (ATL) or a selective amygdalohippocampectomy (SA).

Methods

Surgical outcome data were prospectively collected for 2 to 11 years in 161 consecutive patients with MTLE/HS. Eighty patients underwent an ATL and 81 an SA. Seizure control achieved with each technique was compared using the Engel classification scheme. Postoperative memory testing was performed in 86 patients (53%). At the last follow up, 72% of the patients who had undergone an ATL (mean follow up 6.7 years) and 71% of those who had undergone an SA (mean follow up 4.5 years) were seizure free (Engle Class IA). Estimated survival in patients in Engel Classes I, IA, and I and II combined did not differ between the two surgical techniques. Preoperatively, 58% of the patients had verbal memory scores one standard deviation (SD) below the normal mean. One third of the patients with preoperative scores in the normal range worsened after surgery, although this outcome was not related to the surgical technique. In contrast, one third of those whose preoperative scores were less than −1 SD experienced improvement after surgery. Nine (18%) of the 50 patients whose left side had been surgically treated improved their verbal memory scores by more than one SD. Seven (78%) of these nine underwent an SA (p = 0.05).

Conclusions

Both ATL and SA can lead to similar favorable seizure control in patients with MTLE/HS. Preliminary data suggest that postoperative verbal memory scores may improve in patients who undergo selective resection of a sclerotic hippocampus in the dominant temporal lobe.

Reflex Seizures in Patients with Malformations of Cortical Development and Refractory Epilepsy

PURPOSE

Malformations of cortical development (MCDs) are usually highly epileptogenic, and their hyperexcitability could facilitate the occurrence of reflex seizures. We sought to characterize reflex seizures in patients with MCDs and refractory epilepsy.

METHODS

Clinical, electrographic, and neuroimaging data were reviewed in eight patients with MCDs who had reflex seizures reproduced during presurgical evaluation.

RESULTS

All eight patients had both reflex and spontaneous seizures. In six, however, drop attacks or axial myoclonic seizures occurred only upon specific sensory stimulation. Reflex seizures were induced by more than one type of stimulus in most patients, but anatomofunctional correlations could usually be invoked. Six patients had significant intellectual impairment. Surgical resection controlled seizures in two patients.

CONCLUSIONS

Reflex seizures in patients with MCDs may be medically refractory and may often manifest as drop attacks or axial myoclonus. Surgical resection of focal lesions can bring reflex seizures under control. Putative mechanisms related to the relatively low frequency of reflex seizures in MCDs are discussed.

Dissociação entre alterações de linguagem e preservação da musicalidade em uma criança com epilepsia refratária

Introdução: Estabelecer uma relação entre epilepsia e linguagem é uma tarefa bastante complexa, visto que existem muitas variáveis envolvidas. Dessa forma, podem ocorrer alterações de linguagem expressiva e compreensiva, e em alguns casos a preservação da musicalidade e da prosódia podem estar presentes. Objetivos: O objetivo deste estudo foi descrever o caso de uma criança com crises epilépticas refratárias multifocais que mostrou uma intrigante dissociação entre o comprometimento de funções de linguagem e a preservação da musicalidade. Métodos: Relato do caso de um menino de 9 anos, internado no Programa de Cirurgia de Epilepsia (PCE) do Hospital São Lucas (HSL) da PUCRS, em novembro de 2004, por apresentar crises epilépticas refratárias. Foram realizados exames clínicos, neurofisiológicos, de neuroimagem e avaliação neuropsicológica. Resultados: Os aspectos lingüísticos do paciente caracterizam uma disfasia, com alterações significativas de expressão e de compreensão da linguagem oral (lobo temporal esquerdo), mas adequação nos aspectos prosódicos da fala e do canto (hemisfério direito). Além disso, a avaliação mostrou um importante atraso global de desenvolvimento neuropsicomotor e alterações comportamentais. Conclusão: Os dados deste trabalho evidenciam a interferência da epilepsia refratária na infância nas habilidades cognitivas, sendo o foco epileptogênico determinante nas alterações lingüísticas. Ressalta-se a importância da avaliação neuropsicológica para mensurar alterações provenientes desta patologia, assim como, identificar áreas da linguagem preservadas, como a musicalidade neste caso, permitindo um elo de ligação para comunicação, avaliação e reabilitação cognitiva.

Survival Analysis of the Surgical Outcome of Temporal Lobe Epilepsy Due to Hippocampal Sclerosis

PURPOSE

Surgical results in patients with mesial temporal lobe epilepsy due to hippocampal sclerosis (MTLE/HS) are often reported in conjunction with other etiologies of TLE.

METHODS

We prospectively collected surgical outcome data for 2 to 11 years for 134 consecutive patients who specifically had MTLE and unilateral HS, according to magnetic resonance imaging (MRI) and confirmed by histopathology. Sixty-five had postoperative neuropsychological testing. Outcome was analyzed by using Engel's classification (a) through Kaplan-Meier estimated survival curves (as a function of the time to seizure recurrence), (b) as percentage of patients in each outcome class on a yearly basis, and (c) at the last updated follow-up.

RESULTS

Kaplan-Meier estimates of complete seizure freedom (Engel's class IA) for years 1, 2, 5, and 10 were 85%, 77%, 74%, and 66%, and of Engel's class I were 89%, 86%, 83%, and 81%. Only nine (6.7%) patients had outcome classes III or IV at any point during follow-up. Of the patients tested, 26% of those operated on the left side and 22% of those operated on the right had postoperative decline of >1 SD in verbal or visual memory, respectively.

CONCLUSIONS

High rates of seizure freedom can be obtained and remain stable over the years in patients operated on for unilateral MTLE/HS, even in countries with limited resources.

Terminology and classification of the cortical dysplasias

BACKGROUND

There have been difficulties in achieving a uniform terminology in the literature regarding issues of classification with respect to focal cortical dysplasias (FCDs) associated with epilepsy.

OBJECTIVE

S: To review and refine the current terminology and classification issues of potential clinical relevance to epileptologists, neuroradiologists, and neuropathologists dealing with FCD.

METHODS

A panel discussion of epileptologists, neuropathologists, and neuroradiologists with special expertise in FCD was held.

RESULTS

The panel proposed 1) a specific terminology for the different types of abnormal cells encountered in the cerebral cortex of patients with FCD; 2) a reappraisal of the different histopathologic abnormalities usually subsumed under the term "microdysgenesis," and suggested that this terminology be abandoned; and 3) a more detailed yet straightforward classification of the various histopathologic features that usually are included under the heterogeneous term of "focal cortical dysplasia."

CONCLUSION

The panel hopes that these proposals will stimulate the debate toward more specific clinical, imaging, histopathologic, and prognostic correlations in patients with FCD associated with epilepsy.

Corpora amylacea in temporal lobe epilepsy associated with hippocampal sclerosis

Hippocampal sclerosis (HS) is the commonest pathology in epileptic patients undergoing temporal lobe epilepsy surgery. Beside, there are an increased density of corpora amylacea (CA) founded in 6 to 63% of those cases. OBJECTIVE: verify the presence of CA and the clinical correlates of their occurrence in a consective series of patients undergoing temporal surgery with diagnosis of HS. METHOD: We reviewed 72 hippocampus specimens from January 1997 to July 2000. Student's t test for independent, samples, ANOVA and Tukey test were performed for statistical analysis. RESULTS: CA were found in 35 patients (49%), whose mean epilepsy duration (28.7 years) was significantly longer than that group of patients without CA (19.5 years, p= 0.001). Besides, when CA were found, duration was also significantly correlated with distribution within hippocampus: 28.7 years with diffuse distribution of CA, 15.4 with exclusively subpial and 17.4 years with distribution subpial plus perivascular (p= 0.001). CONCLUSION: Our findings corroborate the presence of CA in patients with HS and suggest that a longer duration of epilepsy correlate with a more distribution of CA in hippocampus.

The treatment of patients with hypothalamic hamartomas, epilepsy and behavioural abnormalities: facts and hypotheses

The growing interest in the association between hypothalamic hamartomas (HH), epilepsy and behavioural abnormalities witnessed in recent years, has led to significant progress regarding the clinical presentations, pathophysiology and management of this entity. Patients with these lesions may occupy different points within a spectrum of severity of the epileptic and behavioural disorder, and may dynamically progress toward more malignant epilepsies with time. The role of the subcortical lesion in the generation of the gelastic seizures has been established, and encouraging results have been obtained with surgical resection, destruction or disconnection of the hamartoma. The present work highlights several aspects that should be taken into account for the selection of medical and surgical treatment for individual patients. We conclude with a reflection on what we still do not understand as regards in the genesis and surgical management of the neuropsychiatric disabilities related to this disorder.

Functional variability of the human cortical motor map: electrical stimulation findings in perirolandic epilepsy surgery

The purpose of this study was to assess the cortical representation of sensorimotor functions in patients undergoing perirolandic epilepsy surgery, focusing on somatotopy, mosaicism, and variability of function in relation to the classic motor homunculus. The authors studied 36 patients in whom intraoperative or extraoperative electrical cortical stimulation to map motor functions was performed. A computer program was devised to register electrode number, stimulation parameters, and response to each stimulus. Electrode position was represented graphically whenever a stimulus was delivered. A total of 43 maps from 36 patients were analyzed. The authors found variations in the organization of M1 (primary motor cortex) in seven patients (19.4%). Four patients (11.1%) presented mosaicism (overlapping of functional areas), two (5.6%) presented variability (inverted disposition of M1 functional areas), and one (2.8%) had both. The results of this study challenge the notion of orderly topographic relationships between the human sensorimotor functions and their representation in the primary motor cortex. These results confirm those of other studies with animals and humans using novel imaging techniques, suggesting that the motor homunculus may not always be considered a definite and absolute representation of M1.

Subcortical band heterotopia (SBH) in males: clinical, imaging and genetic findings in comparison with females

Subcortical band heterotopia (SBH) or double cortex syndrome is a neuronal migration disorder, which occurs very rarely in males: to date, at least 110 females but only 11 in males have been reported. The syndrome is usually associated with mutations in the doublecortin (DCX) (Xq22.3-q23) gene, and much less frequently in the LIS1 (17p13.3) gene. To determine whether the phenotypic spectrum, the genetic basis and genotype-phenotype correlations of SBH in males are similar to those in females, we compared the clinical, imaging and molecular features in 30 personally evaluated males and 60 previously reported females with SBH. Based on the MRI findings, we defined the following band subtypes: partial, involving one or two cerebral lobes; intermediate, involving two lobes and a portion of a third; diffuse, with substantial involvement of three or more lobes; and pachygyria-SBH, in which posterior SBH merges with anterior pachygyria. Karyo typing and mutation analysis of DCX and/or LIS1 were performed in 23 and 24 patients, respectively. The range of clinical phenotypes in males with SBH greatly overlapped that in females. MRI studies revealed that some anatomical subtypes of SBH, such as partial and intermediate posterior, pachygyria-SBH and diffuse bands with posterior predominance, were more frequently or exclusively present in males. Conversely, classical diffuse SBH and diffuse bands with anterior predominance were more frequent in females. Males had either mild or the most severe band subtypes, and these correlated with the over-representation of normal/borderline intelligence and severe mental retardation, respectively. Conversely, females who had predominantly diffuse bands exhibited mostly mild or moderate mental retardation. Seven patients (29%) had missense mutations in DCX; in four, these were germline mutations, whereas in three there was evidence for somatic mosaicism. A germline missense mutation of LIS1 and a partial trisomy of chromosome 9p were identified in one patient (4%) each. One male each had a possible pathogenic intronic base change in both DCX and LIS1 genes. Our study shows that SBH in males is a clinically heterogeneous syndrome, mostly occurring sporadically. The clinical spectrum is similar to that of females with SBH. However, the greater cognitive and neuroradiological heterogeneity and the small number of mutations identified to date in the coding sequences of the DCX and LIS1 genes in males differ from the findings in females. This suggests other genetic mechanisms such as mutations in the non-coding regions of the DCX or LIS1 genes, gonadal or somatic mosaicism, and finally mutations of other genes.