[Show abstract][Hide abstract] ABSTRACT: Malformations of cortical development (MCD) are an increasingly recognized cause of medically intractable epilepsy. We assessed the role of fMRI in evaluating the motor and somatosensory cortices, as well as if there is possible reorganization of these vital areas in patients with polymicrogyria.
Clinical neurology and neurosurgery. 07/2014; 122C:29-33.
[Show abstract][Hide abstract] ABSTRACT: We compared clinical characteristics of seizures at ischemic stroke presentation (SSP) to seizures during hospitalization post ischemic stroke (SDH), and their impacts on stroke outcome, using the Registry of the Canadian Stroke Network (RCSN) database.
This cohort study included consecutive patients from the RCSN who had an acute ischemic stroke between July 2003 and March 2008. Outcome measures included morbidity, mortality, length of hospital stay, and discharge disposition. Clinical variables for either SSP or SDH were investigated and the stroke outcome was stratified by stroke severity.
The study included 10,261 patients with ischemic strokes: 157 patients (1.53%) had SSP and 208 patients (2.03%) had SDH. Compared to stroke patients without seizures, patients with SSP and SDH were younger, had more severe strokes (p < 0.001), a higher admission rate to the intensive care unit (p < 0.001), higher morbidity, and higher mortality (p < 0.05). SSP was associated with female sex and less limb weakness, while SDH was associated with pneumonia and the presence of hemineglect. Importantly, patients with less severe strokes had higher morbidity and mortality (p < 0.005) if SDH occurred. Variables predicting overall mortality were SDH, older age, higher Charlson-Deyo index, more severe strokes, and nonalert status on arrival (all p < 0.001).
SSP and SDH have different characteristics. SDH indicates a poorer prognosis in patients. Increased awareness of SSP and efforts to prevent SDH may be important in improving outcomes following clinical stroke care.
[Show abstract][Hide abstract] ABSTRACT: Objective
Malformations of cortical development (MCD) are an increasingly recognized cause of medically intractable epilepsy. We assessed the role of fMRI in evaluating the motor and somatosensory cortices, as well as if there is possible reorganization of these vital areas in patients with polymicrogyria.
We included 2 patients with polymicrogyria and epilepsy. Somatosensory and motor cortices were assessed with a 4 T fMRI. These findings were compared with direct cortical stimulation.
Localization of the sensorimotor cortices was adequately identified by fMRI. These vital areas did not reorganize outside the malformation of cortical development.
fMRI is a tool that can allow identification of these vital areas of the brain in a non-invasive manner.
Adequate localization of the sensorimotor cortices is important for optimal patient selection, surgical strategy, and to determine the maximal extent of the resection. The clinical implications for such understanding are not limited to it; these findings should help researchers understand more of the neurobiology of MCDs and even possibly clues to the mechanisms of epileptogenesis associated with such malformations.
Clinical Neurology and Neurosurgery. 01/2014; 122:29–33.
[Show abstract][Hide abstract] ABSTRACT: Seizure recurrence after epilepsy surgery has been classified as either early or late depending on the recurrence time after operation. However, time of recurrence is variable and has been arbitrarily defined in the literature. We established a mathematical model for discriminating patients with early or late seizure recurrence, and examined differences between these two groups.
A historical cohort of 247 consecutive patients treated surgically for temporal lobe epilepsy was identified. In patients who recurred, postoperative time until seizure recurrence was examined using an receiver-operating characteristic (ROC) curve to determine the best cutoff for predicting long-term prognosis, dividing patients in those with early and those with late seizure recurrence. We then compared the groups in terms of a number of clinical, electrophysiologic, and radiologic variables.
Seizures recurred in 107 patients (48.9%). The ROC curve demonstrated that 6 months was the ideal time for predicting long-term surgical outcome with best accuracy, (area under the curve [AUC] = 0.761; sensitivity = 78.8%; specificity = 72.1%). We observed that patients with seizure recurrence during the first 6 months started having seizures at younger age (odds ratio [OR] = 6.03; 95% confidence interval [CI] = 1.06-11.01; p = 0.018), had a worse outcome (OR = 6.85; 95% CI = 2.54-18.52; p = 0.001), needed a higher number of antiepileptic medications (OR = 2.07; 95% CI = 1.16-9.34; p = 0.013), and more frequently had repeat surgery (OR = 9.59; 95% CI = 1.18-77.88; p = 0.021). Patients with late relapse more frequently had seizures associated with trigger events (OR = 9.61; 95% CI = 3.52-26.31; p < 0.01).
Patients with early or late recurrence of seizures have different characteristics that might reflect diversity in the epileptogenic zone and epileptogenicity itself. These disparities might help explain variable patterns of seizure recurrence after epilepsy surgery.
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: To review the evidence base for different treatment strategies in intraparenchymal neurocysticercosis in adults and children. METHOD: A literature search of Medline, EMBASE, LILACS, and the Cochrane Database from 1980 to 2008, updated in 2012, resulted in the identification of 10 Class I or Class II trials of cysticidal drugs administered with or without corticosteroids in the treatment of neurocysticercosis. RESULTS: The available data demonstrate that albendazole therapy, administered with or without corticosteroids, is probably effective in decreasing both long-term seizure frequency and the number of cysts demonstrable radiologically in adults and children with neurocysticercosis, and is well-tolerated. There is insufficient information to assess the efficacy of praziquantel. RECOMMENDATIONS: Albendazole plus either dexamethasone or prednisolone should be considered for adults and children with neurocysticercosis, both to decrease the number of active lesions on brain imaging studies (Level B) and to reduce long-term seizure frequency (Level B). The evidence is insufficient to support or refute the use of steroid treatment alone in patients with intraparenchymal neurocysticercosis (Level U).
[Show abstract][Hide abstract] ABSTRACT: Neurocysticercosis (NCC) is the main risk factor for late-onset seizures in many Taenia solium endemic countries and is also increasingly recognized in high income countries, where it was once thought to have been eliminated. The course and outcome of NCC-associated seizures and epilepsy are poorly understood. Substrates underlying NCC-associated seizures and epilepsy are unknown. Another unknown is if there is an association between NCC and hippocampal sclerosis (HS) and if it leads to intractable epilepsy. We review evidence regarding the structural basis of seizures and epilepsy in NCC and its association with HS. There are only a limited number of prospective studies of NCC-associated seizures and epilepsy. From these, it can be inferred that the risk of seizure recurrence is high following a first seizure, even though seizures are well-controlled with antiepileptic drugs. The single most important risk factor for ongoing or recurrent seizures is the persistence of either degenerating or residual calcified cysticercus cysts in the brain parenchyma on follow-up imaging studies. Medically intractable epilepsy requiring surgical treatment appears to be rare in people with NCC. In few cases that have been operated, gliosis around the cysticerci is the principal pathologic finding. Reports of the association between NCC and HS might be categorized into those in which the calcified cysticercus is located within the hippocampus and those in which the calcified cysticercus is located remote from the hippocampus. The former are convincing cases of medically intractable epilepsy with good seizure control following hippocampal resection. In the remaining, it is unclear whether a dual pathology relationship exists between HS and the calcified cysticercus. Carefully planned, follow-up studies incorporating high-resolution and quantitative imaging are desirable in order to clarify the outcome, the structural basis of NCC-associated epilepsy, and also its association with HS.
[Show abstract][Hide abstract] ABSTRACT: We report the achievements obtained, over a period of 4years, by the collaborative partnering effort of the Epilepsy Program at Western University in Canada and the Instituto of Ciencias Neurologicas in Lima, Peru, building an epilepsy program in Peru.
[Show abstract][Hide abstract] ABSTRACT: We developed novel methodology for investigating the use of quantitative relaxometry (T1, T2) and diffusion tensor imaging (DTI) for lateralization in temporal lobe epilepsy. Patients with mesial temporal sclerosis confirmed by pathology (N = 8) and non-MTS unilateral temporal lobe epilepsy (N = 6) were compared against healthy controls (N = 19) using voxel-based analysis restricted to the anterior temporal lobes, and laterality indices for each MRI metric (T1, T2, fractional anisotropy (FA), mean diffusivity, axial and radial diffusivity) were computed based on the proportion of significant voxels on each side. The diffusivity metrics were the most lateralizing MRI metrics in MTS and non-MTS subsets, with significant differences also seen with FA, T1 and T2. Patient-specific multi-modal laterality indices were also computed and were shown to clearly separate the left-onset and right-onset patients. Marked differences between left-onset and right-onset patients were also observed, with left-onset patients exhibiting stronger laterality indices. Finally, neocortical abnormalities were found to be more common in the non-MTS patients. These preliminary results on a small sample size support the further investigation of quantitative MRI and multi-modal image analysis in clinical determination of seizure onset. The presence of more neocortical abnormalities in the non-MTS group suggests a role in seizure onset or propagation and motivates the investigation of more sensitive histopathological analysis to detect and delineate potentially subtle neocortical pathology.
[Show abstract][Hide abstract] ABSTRACT: ABSTRACT: Epilepsy surgery is a highly effective and durable treatment for specific types of drug
resistant epilepsy such as temporal lobe epilepsy. assessment of outcomes is essential in epilepsy
surgery, which is an irreversible intervention for a chronic condition. Excellent short-term results of
resective epilepsy surgery have been established. In the last years more information regarding long term
outcomes have been published. This article reviews the best available evidence about the best measures
to assess outcomes and the most important evidence. The outcomes reviewed in this article are the
following: seizure outcome, social and psychiatric outcomes, complications and mortality
The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 12/2012; 36(6):S25-29. · 1.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVES: Despite evidence that epilepsy surgery is more effective than medical therapy, significant delays between seizure intractability and surgery exist. We aimed to develop a new Web-based methodology to assist physicians in identifying patients who might benefit from an epilepsy surgery evaluation. METHODS: The RAND/UCLA appropriateness method was used. Clinical scenarios were developed based on eligibility criteria from previously published surgical series. Thirteen national experts rated the scenarios for their appropriateness for an epilepsy surgery evaluation based on published evidence. All scenarios were rerated after a face-to-face meeting following a modified Delphi process. Appropriate scenarios were rerated for necessity to determine referral priority. RESULTS: Of the final 2646 scenarios, 20.6% (n = 544) were appropriate, 17.2% (n = 456) uncertain, and 61.5% (n = 1626) inappropriate for a surgical evaluation. Of the appropriate cases, 55.9% (n = 306) were rated as very high priority. Not attempting AED treatment was always rated as inappropriate for a referral. Trial of 2 AEDs was usually rated as appropriate unless seizure-free or not fully investigated Based on these data, a Web-based decision tool (www.epilepsycases.com) was created. CONCLUSIONS: Using the available evidence through 2008 and expert consensus, we developed a Web-based decision tool that provides a guide for determining candidacy for epilepsy surgery evaluations. The tool needs clinical validation, and will be updated and revised regularly. This rendition of the tool is most appropriate for those over age 12 years with focal epilepsy. The Rand/UCLA appropriate methodology might be considered in the development of guidelines in other areas of epilepsy care.
[Show abstract][Hide abstract] ABSTRACT: In déjà vu, a phenomenological impression of familiarity for the current visual environment is experienced with a sense that it should in fact not feel familiar. The fleeting nature of this phenomenon in daily life, and the difficulty in developing experimental paradigms to elicit it, has hindered progress in understanding déjà vu. Some neurological patients with temporal-lobe epilepsy (TLE) consistently experience déjà vu at the onset of their seizures. An investigation of such patients offers a unique opportunity to shed light on its possible underlying mechanisms. In the present study, we sought to determine whether unilateral TLE patients with déjà vu (TLE+) show a unique pattern of interictal memory deficits that selectively affect familiarity assessment. In Experiment 1, we employed a Remember-Know paradigm for categorized visual scenes and found evidence for impairments that were limited to familiarity-based responses. In Experiment 2, we administered an exclusion task for highly similar categorized visual scenes that placed both recognition processes in opposition. TLE+ patients again displayed recognition impairments, and these impairments spared their ability to engage recollective processes so as to counteract familiarity. The selective deficits we observed in TLE+ patients contrasted with the broader pattern of recognition-memory impairments that was present in a control group of unilateral patients without déjà vu (TLE-). MRI volumetry revealed that ipsilateral medial temporal structures were less broadly affected in TLE+ than in TLE- patients, with a trend for more focal volume reductions in the rhinal cortices of the TLE+ group. The current findings establish a first empirical link between déjà vu in TLE and processes of familiarity assessment, as defined and measured in current cognitive models. They also reveal a pattern of selectivity in recognition impairments that is rarely observed and, thus, of significant theoretical interest to the memory literature at large.
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: To identify the perceived practice among Canadian epileptologists regarding discontinuation of antiepileptic drugs (AEDs) following successful resective surgery for temporal and extratemporal surgery. METHODS: We performed a survey of pediatric and adult epileptologists in Canada, using a 77-item questionnaire to explore attitudes, timing, rate of withdrawal, and factors contributing to the decision to withdraw AEDs after successful epilepsy surgery. Surveys were mailed with a postage-paid return envelope. Two subsequent surveys were mailed to non-respondents at 15 days intervals. All procedures received institutional review board approval. RESULTS: Surveys were sent to 82 epileptologists in all the Canadian provinces. Sixty-six physicians answered the survey (80.5%), representing all epilepsy centers across Canada. The minimum seizure free period required after epilepsy surgery before withdrawing AEDs, varied substantially among responders: <6 months in 10%, 6-11 months in 21%, >1 year in 50%, >2 years in 12%, >2 years in 3% after. The most important factors influencing the decision to withdraw AEDs a negative EEG before discontinuation (71%), patients' preferences (78%) and the presence of unilateral mesial temporal sclerosis (70%). The most important factors against reduction were the following: patients' wishes to resume driving (67%), focal (65%) or generalized (78%) epileptiform activity on EEG after surgery, persistent isolated auras (78%), any seizures after hospital discharge (81%), and presurgical multifocal/bilateral/diffuse findings (78%). DISCUSSION: Canadian epileptologists indicated that AED levels, EEG and MRI are typically done before discontinuing AEDs. Generally, a good candidate for stopping AEDs has focal pathology, is completely seizure free, had an anterior temporal lobe resection, complete resection of seizure focus, and has no epileptiform discharges on postoperative EEG. The data pertaining to self-reported practice styles, and actual practice may differ.
[Show abstract][Hide abstract] ABSTRACT: Diagnosing and treating neurological infectious diseases are often difficult for both neurologists and infectious disease
specialists. Treatment of neurological infectious diseases is frequently based on anecdotal or experiential evidence rather
than on evidence from controlled trials. Although studies are lacking for many specific neurological infectious diseases,
good evidence exists to support the treatment of bacterial meningitis, herpes encephalitis, neurocysticercosis, and fungal
meningitis. This chapter evaluates the available literature and presents treatment options based on those data.
KeywordsBacterial meningitis-Herpes encephalitis-Neurocysticercosis-Fungal meningitis-Treatment-Diagnosis