Background: The 2021 version of the Standardized Critical Care EEG Terminology published by the American Clinical Neurophysiology Society (ACNS 2021) specifies the diagnostic criteria for non-convulsive status epilepticus (NCSE) using continuous electroencephalographic (cEEG) monitoring. Since few facilities have access to cEEG, routine EEG, which can only be performed during consultation hours, is generally used for emergencies. We examined if the diagnostic ability is enhanced by adding arterial spin labeling (ASL) perfusion imaging to 1.5-Tesla magnetic resonance imaging (MRI). Patients and Methods: Eighty EEGs, performed on patients with neurological emergencies for 2 years, were reviewed which included three patients diagnosed with electrographic seizures (ESz). Results: Based on the ACNS21, EEG could diagnose Esz, but could not diagnose NCSE, being a 30-minute recording. In contrast, ASL clearly identified focal, ictal hyperperfusion. The signal intensity was maximized at a post-labeling delay (PLD) of 1.5-1.75 s. The signal intensity gradually decreased. However, even at a PLD of 2.0 s, the intensity remained strong in areas with a close anatomical relationship to the epileptogenic lesions. Further, the same region showed high signal intensity on diffusion-weighted imaging (DWI). Conclusion: Although ESz can be diagnosed based on the ACNS 2021 using EEG alone, diagnosing NCSE can be challenging. Therefore, our suggestion is to initially perform MRI to capture the hemodynamics of ictal hyperperfusion using ASL with multiple PLDs, and monitor the coupling state of metabolism and blood flow with DWI. Finally, an accurate pathophysiological diagnosis of NCSE should be confirmed by EEG.

Background: We evaluated the usefulness of capturing periictal hyperperfusion for the pathophysiological diagnosis of acute symptomatic seizures (ASS) using 1.5-Tesla (T) arterial spin labeling (ASL) perfusion images and examined the relationship between the time from ASS cessation to ASL imaging and the visualization of periictal hyperperfusion.Patients & Methods: In four patients who presented short ASS, we retrospectively analyzed the performance status and findings of 1.5-T ASL with triple post-labeling delays (PLDs) of 1.5, 1.75 and 2.0 s, as well as routine electroencephalography (EEG).Results: In two patients where ASL imaging was performed 1 or 9 h after ASS, periictal ASL hyperperfusion was markedly visualized. In one patient where images were taken 11 h later, fairly good visualization was obtained. The increase in signal intensity peaked at a PLD of 1.5 s and gradually attenuated with PLDs of 1.75 and 2.0 s. However, the areas where the signal remained intense even at a PLD of 2.0 s had a strong anatomical relationship with the lesion. No clear periictal hyperperfusion was visualized on ASL images taken 13 h later. Although paroxysmal discharges were recorded in one patient where EEG was performed 40 min after ASS, no paroxysms were detected in the other three patients whose EEG was recorded 8 h to 2 days later.Conclusion: We consider it appropriate to first perform ASL within 11 h, and then verify the results with subsequent EEG to accurately diagnose the pathophysiology of ASS.

Purpose: The mechanism underlying sulcal hyperintensity observed on fluid-attenuated inversion recovery magnetic resonance imaging (MRI) (sulcal FLAIR hyperintensity [S-FLAIR-HI]) without apparent abnormalities in the cerebrospinal fluid (CSF) is believed to involve alterations in regional hemodynamics, including venous congestion caused by mass effect, leading to a pathological increase in the blood pool-to-CSF ​​ratio. While S-FLAIR-HI is observed in chronic subdural hematoma (CSDH), its exact incidence, mechanism of occurrence, and relationship with seizures remain unclear.

Methods: Clinical data and MRI findings, including FLAIR and 1.5-Tesla pseudo-continuous arterial spin labeling perfusion imaging performed within 1 day before surgery in 34 patients with CSDH, were retrospectively reviewed. The focus was on the laterality of arterial transit artifact(s) in the sulcus (sulcal ATA [S-ATA]), which are intravascular signals that increase with a delay in arterial transit time, and (peri-)ictal hyperperfusion linked to seizure activity by neurovascular coupling.

Results: S-FLAIR-HI was observed in 12 (35.3%) of the 34 patients with CSDH, 11 of whom exhibited an increase in S-ATA on the ipsilateral side. Increased S-ATA levels were also observed in 10 of the 22 patients without S-FLAIR-HI. However, none of the 12 patients with S-FLAIR-HI developed seizures. In addition, 2 patients who exhibited perioperative seizures did not undergo S-FLAIR-HI.

Discussion: S-FLAIR-HI, observed preoperatively in approximately one-third of patients with CSDH, is a nonspecific finding caused by alterations in regional hemodynamics. Furthermore, there is no evidence supporting the direct involvement of S-FLAIR-HI in the development of seizures.

Purpose: High-frequency oscillations (HFOs) in intracranial electroencephalography (iEEG) are widely investigated as potential biomarkers of epileptogenic tissue. This study aims to propose and evaluate a hybrid deep learning model that combines convolutional neural networks (CNNs) and Transformer architectures for the automatic classification of five types of synthetic iEEG events. Methods: A simulation-based dataset was generated following the framework of Jmail et al. and subsequently processed through preprocessing and data augmentation procedures. The dataset includes five representative event classes: spikes, ripples (80–250 Hz), fast ripples (250–500 Hz), spike–ripple superimposed events, and artifacts. The signals were created under controlled variations of amplitude, oscillation frequency, signal-to-noise ratio (SNR), and overlap rate, providing a reproducible environment for methodological evaluation. Results: The proposed hybrid CNN–Transformer model demonstrated robust discrimination performance across all five classes, achieving an overall accuracy of 97.7%. The model leverages CNN-based spatial–spectral feature extraction and Transformer-based temporal–contextual modeling, enabling effective capture of both local and global signal dependencies. Discussion: Although the simulated frequency range extends beyond the theoretical Nyquist limit of typical EEG recordings, this design intentionally tests model robustness under extended spectral conditions. This proof-of-concept study provides a reproducible and controlled assessment of hybrid attention-based architectures for HFO recognition and establishes a foundation for future validation using real iEEG recordings.

Purpose: In Japan, intravenous (IV) midazolam (MDL) is recommended as first-line therapy for pediatric patients with status epilepticus (SE) if venous access is possible. However, few studies have investigated its use in adults/adolescents with SE. This prospective, uncontrolled, open-label study investigated the efficacy and safety of bolus or continuous IV MDL in adults/adolescents with convulsive SE.Methods: Patients aged ≥15 years who satisfied the diagnostic criteria for SE with convulsive seizures lasting ≥5 min were enrolled. Patients first received bolus IV MDL (0.15 mg/kg). If the seizures continued, additional doses (0.1‒0.3 mg/kg) were administered (maximum cumulative dose: 0.6mg/kg). Patients with a high likelihood of recurrent convulsive seizures were subsequently administered continuous IV MDL (0.1 mg/kg/h). The dose was increased until seizure cessation (maximum: 0.4 mg/kg/h) and administration continued for 24 h from seizure cessation. The primary efficacy endpoint was convulsive seizure cessation after bolus IV. Safety endpoints included adverse events (AEs) and adverse drug reactions (ADRs).Results: Twenty-one patients (aged 18.0‒89.0 years) with SE were enrolled. The convulsive seizure cessation rate after bolus IV MDL was 100.0% (21/21 patients), which was statistically significant (P < 0.001) in one-sample testing (binomial distribution). The most common AE/ADR was hypotension (four patients [19.0%]). There were no deaths, serious AEs/ADRs, or AEs/ADRs leading to discontinuation of MDL. Respiratory depression occurred in two patients (9.5%). None of the patients required mechanical ventilation/endotracheal intubation.Discussion: Bolus IV MDL achieved a high seizure cessation rate in patients with convulsive SE, with minimal effects on respiratory or cardiovascular functions and no major safety issues.

We made a pathophysiological diagnosis of epileptic seizures in a 50-year-old male with congenital unilateral perisylvian syndrome due to right perisylvian polymicrogyria, using routine electroencephalography (EEG) and 1.5-Tesla arterial spin labeling (ASL) magnetic resonance perfusion imaging. No paroxysmal discharges were recorded on EEG performed 1 h after the generalized convulsive seizure. Pseudo-continuous and pulsed ASL images taken 1 h 30 min and 1 h 15 min after the seizure, respectively, captured subtle periictal hyperperfusion linked to seizure activity via neurovascular coupling at the perisylvian area. In particular, the fusion of ASL images with the sagittal view of a three-dimensional T1-weighted image clearly revealed periictal hyperperfusion at the area of polymicrogyria, indicating intrinsic epileptogenicity. This case report details how adding ASL to routine EEG data can be useful in the pathophysiological diagnosis of epilepsy in neurological emergencies.

Perampanel (PER) is a selective, non-competitive alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor antagonist used in the treatment of pediatric epilepsy. We report a case of transient gait disturbance associated with significantly increased serum PER concentration during an infection. A 10-year-old girl with focal epilepsy caused by ulegyria was undergoing treatment with PER, levetiracetam, and lacosamide. She was introduced to our hospital with a sudden onset of gait disturbance. Laboratory findings revealed elevated levels of serum C-reactive protein and PER. Based on these findings, we suspected that the symptoms were caused by PER. The symptoms resolved rapidly and inflammatory markers and the PER concentration eventually returned to normal levels. Infection-related suppression of CYP3A4 activity has been previously suggested to increase serum PER concentration. Patients with epilepsy with structural etiologies may be more susceptible to neurological symptoms triggered by elevated PER levels, particularly during infections. Further research is necessary to elucidate the underlying mechanisms of this phenomenon and explore the role of inflammation in altered pharmacokinetics of antiseizure medications.

Situation-related non-convulsive status epilepticus (SR-NCSE) is a type of NCSE that is associated with various situations, including hyperglycemia. A 67-year-old woman with no prior history of type 2 diabetes mellitus visited our emergency room, experiencing difficulty typing on her mobile phone for approximately 2 h. Her blood glucose level was 334 mg/dL. 1.5-Tesla arterial spin labeling (ASL) perfusion magnetic resonance imaging, performed 40 min after her arrival, revealed presumed ictal hyperperfusion in the left parietal lobe. SR-NCSE associated with hyperglycemia was highly suspected, and she was immediately administered with insulin and antiseizure medications. The patient’s symptoms improved promptly. An electroencephalogram performed approximately 2 days later failed to reveal paroxysmal discharges. During neurological emergencies, ASL has the advantage of taking less time to perform than EEG, and we believe that ASL is useful in diagnosing SR–NCSE as well as structural focal NCSE when EEG cannot be performed.

Although Todd’s palsy is a well-known pathological condition, its pathophysiological mechanisms remain unclear. We evaluated two patients using magnetic resonance imaging (MRI), including 1.5-Tesla pseudo-continuous arterial spin labeling (ASL) perfusion imaging, to observe ictal hyperperfusion and associated hemodynamic changes in the peri-rolandic region. In Patient 1, marked ictal ASL hyperperfusion and cytotoxic edema were observed in the interhemispheric cortex of the right peri-rolandic region. Persistence of this edema was associated with left leg palsy lasting 25 days. In Patient 2, prominent ictal ASL hyperperfusion was observed in the right parieto-occipito-temporal lobes without direct involvement of the precentral gyrus. The palsy and MRI findings improved within one day and on Day 4, respectively. We speculate the palsy was caused by transient hypoperfusion of the precentral gyrus, resulting from blood stealing by ictal hyperperfusion. Todd’s palsy may involve various pathophysiological conditions, and combined use of MRI including ASL and electroencephalography is useful in diagnosing this pathophysiology.