Low prevalence of neural autoantibodies in perioperative cerebrospinal fluid samples of epilepsy surgery patients: A multicenter prospective study.

OBJECTIVE: Refractory epilepsy may have an underlying autoimmune etiology. Our aim was to assess the prevalence of neural autoantibodies in a multicenter national prospective cohort of patients with drug-resistant epilepsy undergoing epilepsy surgery utilizing comprehensive clinical, serologic, and histopathological analyses. METHODS: We prospectively recruited patients undergoing epilepsy surgery for refractory focal epilepsy not caused by a brain tumor from epilepsy surgery centers in the Czech Republic. Perioperatively, we collected cerebrospinal fluid (CSF) and/or serum samples and performed comprehensive commercial and in-house assays for neural autoantibodies. Clinical data were obtained from the patients' medical records, and histopathological analysis of resected brain tissue was performed. RESULTS: Seventy-six patients were included, mostly magnetic resonance imaging (MRI)-lesional cases (74%). Mean time from diagnosis to surgery was 21 ± 13 years. Only one patient (1.3%) had antibodies in the CSF and serum (antibodies against glutamic acid decarboxylase 65) in relevant titers; histology revealed focal cortical dysplasia (FCD) III (FCD associated with hippocampal sclerosis [HS]). Five patients' samples displayed CSF-restricted oligoclonal bands (OCBs; 6.6%): three cases with FCD (one with FCD II and two with FCD I), one with HS, and one with negative histology. Importantly, eight patients (one of them with CSF-restricted OCBs) had findings on antibody testing in individual serum and/or CSF tests that could not be confirmed by complementary tests and were thus classified as nonspecific, yet could have been considered specific without confirmatory testing. Of these, two had FCD, two gliosis, and four HS. No inflammatory changes or lymphocyte cuffing was observed histopathologically in any of the 76 patients. SIGNIFICANCE: Neural autoantibodies are a rare finding in perioperatively collected serum and CSF of our cohort of mostly MRI-lesional epilepsy surgery patients. Confirmatory testing is essential to avoid overinterpretation of autoantibody-positive findings.

Experimental Electrophysiological and Pressure Responses of Urinary Bladder Detrusor to Lumbar to Sacral Nerve Rerouting - An Animal Study with Negative Results.

Background/Aims/Objectives: To verify the transfer of evoked potentials through anastomosis of an experimentally created micturition reflex arc and to detect said potentials directly on the detrusor and sphincter of rabbit urinary bladder. METHODS: During 2013-2015, 17 rabbits were operated upon and measurement followed during reoperation 3-16 months later. Suitable ventral spinal roots were electrophysiologically detected following laminectomy, and a somatic-central nervous system-autonomic micturition reflex arc was created. During reoperation, the ventral root was stimulated above and below the anastomosis, the evoked potentials on the bladder detrusor and sphincter were measured, and intravesical pressure was monitored. RESULTS: With stimulation above the anastomosis, 9 animals (53%) displayed a urinary bladder detrusor response and 7 (41%) a sphincter response. Four rabbits (24%) had elevated intravesical pressure. During the control stimulation below the anastomosis, we detected a detrusor response in 7 animals (41%), a sphincter response in 5 (29%), and elevated pressure in 4 (24%). Neither induction of micturition nor decrease in external sphincter activity occurred. CONCLUSIONS: Creation of a somatic-CNS-autonomic reflex arc is technically possible. However reflex activity transferring through the anastomosis is detectable on the detrusor only in some individuals, and is unable to induce a micturition reflex with or without accompanying detrusor-sphincter dyssynergia.

Intracerebral recording of cortical activity related to self-paced voluntary movements: a Bereitschaftspotential and event-related desynchronization/synchronization. SEEG study.

To analyze the distribution of the cortical electrical activity related to self-paced voluntary movements, i.e. the movement-related readiness potentials (Bereitschaftspotential, BP) and the event-related desynchronization (ERD) and synchronization (ERS) of cortical rhythms using intracerebral recordings. EEG was recorded in 14 epilepsy surgery candidates during preoperative video-stereo-EEG monitoring. Subjects performed self-paced hand movements, with their right and left fingers in succession. EEG signals were obtained from a total of 501 contacts using depth electrodes located in primary and nonprimary cortical regions. In accordance with previous studies, BP was found consistently in the primary motor (M1) and somatosensory (S1) cortex, the supplementary motor area (SMA), and in a few recordings also in the cingulate cortex and in the dorsolateral prefrontal and premotor cortex. ERD and ERS of alpha and beta rhythms were also observed in these cortical regions. The distribution of contacts showing ERD or ERS was larger than the distribution of those showing BP. In contrast to BP, ERD and ERS frequently occurred in the lateral and mesial temporal cortex and the inferior parietal lobule. The number of contacts and cortical regions showing ERD and ERS and not BP suggests that the two electrophysiological phenomena are differently involved in the preparation and execution of simple voluntary movements. Substantial differences between BP and ERD in spatial distribution and the widespread topography of ERD/ERS in temporal and higher-order motor regions suggest that oscillatory cortical changes are coupled with cognitive processes supporting movement tasks, such as memory, time interval estimation, and attention.

Cognitive- and movement-related potentials recorded in the human basal ganglia.

Sources of potentials evoked by cognitive processing of sensory and motor activities were studied in 9 epilepsy surgery candidates with electrodes implanted in the basal ganglia (BG), mostly in the putamen. Several contacts were also located in the pallidum and the caudate. The recorded potentials were related to a variety of cognitive and motor activities (attentional, decisional, time estimation, sensory processing, motor preparation, and so on). In five different tests, we recorded P3-like potentials evoked by auditory and visual stimuli and sustained potential shifts in the Bereitschaftspotential and Contingent Negative Variation protocols. All of the studied potentials were generated in the BG. They were recorded from all over the putamen. Various potentials on the same lead or nearby contacts were recorded. A functional topography in the BG was not displayed. We presume that the cognitive processes we studied were produced in clusters of neurons that are organized in the basal ganglia differently than the known functional organization, e.g., of motor functions. The basal ganglia, specifically the striatum, may play an integrative role in cognitive information processing, in motor as well as in nonmotor tasks. This role seems to be nonspecific in terms of stimulus modality and in terms of the cognitive context of the task.

Trends in utilization of antithrombotic therapy in patients with atrial fibrillation before stroke onset in a community-based study, from 1985 through 1997. From scientific evidence to practice.

BACKGROUND: Despite the significant beneficial effects of antithrombotic therapy in primary prevention of stroke in patients with chronic nonvalvular atrial arrhythmia, this prevention therapy is underutilized. We conducted this population-based study to determine the rates and the trends of utilization of antithrombotic therapy for stroke patients with atrial fibrillation before stroke onset, and to evaluate indirectly the impact of medical recommendations on physician practice. Our aim was not to evaluate the efficacy of such prevention therapy. METHODS: From 2,330 men and women of any age registered for a first-ever stroke from 1985 to 1997 in a community-based study, we selected 599 patients admitted for ischemic stroke or TIA, associated with prior atrial fibrillation. Previous antithrombotic treatment before stroke onset was recorded and we evaluated the ratio of stroke patients who had received antithrombotic treatment for atrial fibrillation, from 1985 through 1997. RESULTS: Our study was performed to evaluate the practice of physicians in the prevention of stroke, and not to evaluate the efficacy of the anticoagulants in the prevention of stroke. Atrial fibrillation before stroke onset was identified in 599 patients. Of these, 222 (37%) received no antithrombotic therapy, 65 (10.8%) received an anticoagulant alone, 147 (24.5%) received an antiplatelet agent alone and 10 (1.7%) received both anticoagulation and antiplatelet treatment. From 1985 to 1988, the proportion of treated atrial fibrillation before stroke was small (14.6%). This increased to 21.5% within the period 1989-1991, to 40.3% within the period 1992-1994 and then to 47.6% within the period 1995-1997. It appears that the most significant change occurred within the period 1992-1994 (14.6% of treated atrial fibrillation within the period 1985-1987 constituted to 40.3% within the period 1992-1994) (P < 0.05), with a current rate of utilization of antithrombotic therapy close to 50%. The logistic regression analysis concerning anticoagulant therapy before stroke onset as a dependent variable, found that the factors independently associated with the use of anticoagulants before stroke were the lack of arterial hypertension and a history of smoking. The factors independently associated with the use of aspirin before stroke were arterial hypertension and lower limb peripheral vascular disease. CONCLUSION: For primary prevention of stroke onset in patients with atrial fibrillation, therapeutic trials have changed medical practices although not to ideal levels because close to 50% of patients with atrial fibrillation experiencing an acute stroke or TIA received antithrombotic treatment. Therefore, clinical practice is inconsistent with the guidelines resulting from therapeutic trials. It is necessary to know the reasons for this inconsistency and to improve medical information about the cerebrovascular risk of atrial fibrillation and the efficacy of anticoagulants in stroke prevention in this condition.

Cognitive potentials in the basal ganglia-frontocortical circuits. An intracerebral recording study.

We studied cognitive functions related to processing sensory and motor activities in the basal ganglia (BG), specifically in the putamen and in cortical structures forming the BG-frontocortical circuits. Intracerebral recordings were made from 160 brain sites in 32 epilepsy surgery candidates. We studied P3-like potentials in five different tests evoked by auditory and visual stimuli, and two sustained potentials that are related to cognitive activities linked with movement preparation: BP (Bereitschaftspotential) and CNV (contingent negative variation). We compared the presence of a potential with a phase reversal or an amplitude gradient to the absence of a generator. All of the studied cognitive potentials were generated in the BG; the occurrence in frontal cortical areas was more selective. The frequency of all but one potential was significantly higher in the BG than in the prefrontal and in the cingulate cortices. The P3-like potentials elicited in the oddball paradigm were also more frequent in the BG than in the motor/premotor cortex, while the occurrence of potentials elicited in motor tasks (BP, CNV, and P3-like potentials in the CNV paradigm) in the motor cortex did not significantly differ from the occurrence in the BG. The processing of motor tasks fits with the model by Alexander et al. of segregated information processing in the motor loop. A variable and task-dependent internal organisation is more probable in cognitive sensory information processing. Cognitive potentials were recorded from all over the putamen. The BG may play an integrative role in cognitive information processing.