The excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) contribute to epileptogenesis. Thirty patients with epilepsy and 31 healthy controls are scanned using positron emission tomography with our recently developed radiotracer for AMPARs, [11C]K-2, which measures the density of cell-surface AMPARs. In patients with focal-onset seizures, an increase in AMPAR trafficking augments the amplitude of abnormal gamma activity detected by electroencephalography. In contrast, patients with generalized-onset seizures exhibit a decrease in AMPARs coupled with increased amplitude of abnormal gamma activity. Patients with epilepsy had reduced AMPAR levels compared with healthy controls, and AMPARs are reduced in larger areas of the cortex in patients with generalized-onset seizures compared with those with focal-onset seizures. Thus, epileptic brain function can be regulated by the enhanced trafficking of AMPAR due to Hebbian plasticity with increased simultaneous neuronal firing and compensational downregulation of cell-surface AMPARs by the synaptic scaling.
Background Hippocampal sclerosis (HS) is one of the major causes of intractable epilepsy. Astrogliosis in epileptic brain is a peculiar condition showing epileptogenesis and is thought to be different from the other pathological conditions. The aim of this study is to investigate the altered expression of astrocytic receptors, which contribute to neurotransmission in the synapse, and channels in HS lesions. Methods We performed immunohistochemical and immunoblotting analyses of the P2RY1, P2RY2, P2RY4, Kir4.1, Kv4.2, mGluR1, and mGluR5 receptors and channels with the brain samples of 20 HS patients and 4 controls and evaluated the ratio of immunopositive cells and those expression levels. Results The ratio of each immunopositive cell per glial fibrillary acidic protein-positive astrocytes and the expression levels of all 7 astrocytic receptors and channels in HS lesions were significantly increased. We previously described unique astrogliosis in epileptic lesions similar to what was observed in this study. Conclusion This phenomenon is considered to trigger activation of the related signaling pathways and then contribute to epileptogenesis. Thus, astrocytes in epileptic lesion may show self-hyperexcitability and contribute to epileptogenesis through the endogenous astrocytic receptors and channels. These findings may suggest novel astrocytic receptor-related targets for the pharmacological treatment of epilepsy.
Recovery time after corpus callosotomy (CC) is known to be longer in elderly than in younger patients.To evaluate the relationship between patient age and recovery time of activities of daily living (ADL) after 1-stage complete CC.This study included 41 patients (22 women; aged 13 months-34 years, median 7 years) who underwent 1-stage complete CC for medically intractable seizures with drop attacks, infantile spasms, and/or bilaterally synchronized electroencephalographic discharges between August 2009 and April 2019. The timing of restart of competence in 5 ADL categories and surgical outcomes were recorded.Patients (1) restarted speech at 2.2 ± 1.3 (mean ± 2 standard deviations; range 1-5) days, (2) restarted replying with their own name on request at 5.5 ± 8.6 (2-33) days, (3) restarted oral intake at 1.6 ± 1.7 (1-11) days, (5) discontinued intravenous feeding at 6.0 ± 3.0 (2-16) days, and (5) restarted ambulation or wheelchair movement at 5.8 ± 3.4 (2-10) days. Younger patients showed significantly (P < .0223) earlier recovery of ambulation or wheelchair movement, but no age difference was found in the other 4 ADL categories. Overall seizure freedom was achieved in 5 patients, excellent (>80%) seizure reduction in 11, good (50%-80%) seizure reduction in 5, and poor (<50%) seizure reduction in 20.Early ADL recovery after 1-stage complete CC is favorable in both young and adult patients. These findings, with good surgical outcomes, will encourage more positive consideration of 1-stage complete CC in both pediatric and adult patients.
Cognitive risk associated with insular cortex resection is not well understood. The authors reviewed cognitive and developmental outcomes in pediatric patients who underwent resection of the epileptogenic zone involving the insula.
Hull forms of sailing yachts differ considerably from those of general merchant ships. As compared with general merchant ships, sailing yachts are small in L/B and d/B of the main hull and have a fin keel below the surface of the water, that converts the fluid force generated by the sail into thrust. The fin keel and the main hull form a junction, and the flow around the fin keel is a typical juncture flow on a protruded curved surface. It is known that horseshoe vortices are generated around the junction. Since these vortices increase fluid drag, they should be suppressed as much as possible. The fin keel has much effect also on the free surface flow around the sailing yacht. It is recognized that the wavemaking phenomena by the fin keel can not be ignored in the high speed range.In the present paper, experimental studies about the flow field around the fin keel are carried out for the KIT-34 model designed by Masuyannan. Based on these experimental results, possibilities of reducing fluid resistance acting on the sailing yacht are discussed for the condition without yaw angle. In order to suppress horseshoe vortices, a fillet and small bulbs fixed on the junction are tested. For the purpose of reducing wave-making resistance, an inverse taper keel is tested.
Abstract Aim The usefulness of the absolute N‐terminal pro‐brain natriuretic peptide (NT‐ProBNP) concentration and its digit number for screening for cardiac disease was explored in new haemodialysis patients. Methods A cross‐sectional study involving 71 (68 ± 14 years, 83% male) new dialysis patients was conducted. Receiver operator characteristic curve analysis was performed to identify the cutoff level of NT‐proBNP for identifying cardiac disease at the start of dialysis. Results The median NT‐proBNP concentration was 6576 pg/mL just before the first dialysis session and its mean digit number was 4.3 ± 0.6. Overall, 67%, 52%, 9% and 35% of patients had left ventricular ( LV ) hypertrophy, LV dilatation, systolic dysfunction and significant coronary artery disease, respectively. NT‐proBNP levels of about 6000, 10 000 and 14 000 pg/mL were the best cutoff levels for the diagnosis of coronary artery disease ( AUC , 0.754; P < 0.001), LV systolic dysfunction (area under the curve ( AUC) , 0.765, P = 0.001) and LV dilatation ( AUC , 0.685, P = 0.008), respectively. Interestingly, 4.5 was the best digit number cutoff for all cardiac abnormalities. These findings suggest that a digit number of 5 or more means a potentially high risk for cardiovascular disease and a digit number of 3 or less means a relatively low risk. Conclusions The NT‐proBNP concentration just before the first dialysis session is a useful tool for screening for cardiac abnormalities. Considering the wide variation of the NT‐proBNP cutoff levels depending on each cardiac abnormality, the digit number could be potentially easier to use for initial risk stratification for cardiac disease in new dialysis patients.
To the Editor:
We read with interest the article by Pataraia et al.1 who conclude that all patients in whom non-invasive video-EEG (V-EEG) studies are either only partially localizing or non-localizing should have magnetoencephalography (MEG). We feel this is a carefully done study but that the results do not justify the conclusions.
Interictal MEG, the same as interictal EEG, is a technique used to define the irritative zone. The seizure onset zone usually is only a small subset of the irritative zone.2 It is difficult to understand why Pataraia et al lumped the irritative zone and ictal onset zone together and then compared them with the MEG defined irritative zone. A much more meaningful comparison would be to compare the irritative zone defined by EEG and by MEG.3,4 …
