Search Results (8)

The radiological finding of Dark White Matter (DWM)—characteristic diffuse subcortical white matter hypointensity on T2/FLAIR sequences—is underrecognized, but has important clinical implications. Recent systematic evidence shows that over 60% of previously published cases showed seizures in association with DWM findings—it is also particularly predictive of the underlying etiology, particularly non-ketotic hyperglycemic hyperosmolar state (NKH). Based on our previous work, we reinterpret the data, focusing only on patients with seizures and DWM, to summarize the most essential and distinguishing features of these patients. Both cortical and subcortical abnormalities in DWM are more frequently associated with anti-MOG encephalitis. DWM with or without cortical involvement is more commonly found in NKH among patients with seizures. This updated systematic review will describe the proposed pathophysiological mechanisms, clinical associations, and implications for DWM in patients with seizures, and highlight how early recognition of DWM may allow for targeted diagnostic strategies and treatment options. We expanded our previous search with details regarding seizure features, our results show that DWM is associated with repetitive seizures and Status Epilepticus (both convulsive and non), in line with other peri-ictal MRI abnormalities associated with prolonged seizure activity. DWM-associated seizures are mostly focal, rather than generalized. Moreover, the high percentage of clinical recovery at follow-up suggests that DWM may be predictive of a good outcome, especially in NKH cases, although this needs to be confirmed in future studies. Full article

MRI plays an increasingly important role in the diagnosis of status epilepticus (SE). Approximately half of patients with SE do not have pre-existing epilepsy, and the cause of de novo SE is frequently unknown. The role of MRI in the identification of causes of SE is invaluable. MRI is often helpful as a diagnostic tool in cases of non-convulsive status epilepticus (NCSE) with ambiguous EEG findings. Thus, MRI is recommended for all patients presenting with de novo SE, patients with known epilepsy with the first episode of SE and NCSE with equivocal EEG. Different peri-ictal MRI (PMA) alterations may be seen during ongoing SE or briefly after its cessation. They commonly present as peri-ictal hyper-perfusion, diffusion restriction and/or FLAIR-hyperintensity affecting specific brain areas such as the cortex, hippocampus, pulvinar of the thalamus, splenium of the corpus callosum, claustrum or cerebellum, frequently in combination, suggesting the existence of a “status epilepticus network”. MRI sequences, which are necessary for detecting PMA, include diffusion-weighted imaging, fluid attenuated inversion recovery, T1-weighted imaging with and without contrast application, as well as perfusion sequences such as arterial spin labeling. Recent research suggests that they may serve as biomarkers for predicting an outcome in SE. Patients with PMA seem to have a higher mortality rate compared to those without PMA. However, there is still a substantial knowledge gap and there are many open questions related to imaging in SE. Further prospective quantitative MRI studies with uniform protocols, timing and follow-up periods are needed to answer these important and clinically relevant questions. Full article

Background/Objectives: Brain magnetic resonance imaging (MRI) often reveals acute peri-ictal abnormalities (PMAs) during or shortly after status epilepticus (SE) but also following single seizures (SiS) or clusters of seizures (CS). However, the incidence, characteristics, and progression remain not clearly known. This study aimed to investigate incidence, clinical correlations, and evolution of PMAs in SE, CS, and SiS patients. Methods: This prospective observational study enrolled patients with SE, CS, and SiS who underwent MRI within 120 h of the ictal event. Demographic, clinical, EEG, and MRI data were collected. Patients with PMAs (PMAs+) underwent serial follow-up MRI. Incidence, association with clinical characteristics, and progression of PMAs were analyzed across the three groups. Results: Among 76 patients (30 SE, 22 CS, 24 SiS), PMAs were observed in 31 (41%), with a significant difference between groups (p = 0.011), as PMAs were less frequent in SiS (17%) compared to SE (57%) and CS (45%) patients. Acute symptomatic SE/seizures were significantly more common in PMAs+ compared to PMAs− in the overall cohort (52% vs. 29%; p = 0.045) and in the SiS group (100% vs. 25%; p = 0.031). History of epilepsy was less frequent in PMAs+ in the whole cohort (13% vs. 40%; p = 0.011) and in SE in particular (12% vs. 46%, p = 0.049). No association between PMAs and seizure type, SE duration, etiology, time to MRI, and EEG findings (p > 0.005) was found. The temporal cortex and hippocampus were most frequently affected by PMAs. Follow-up MRI performed in 16 patients showed resolution of PMAs in 75% (5/7 SE, 3/6 CS, 3/3 SiS) within a median time of 24 days (IQR: 8–39). Conclusions: PMAs were more common in SE and CS than in SiS. Acute underlying pathology was frequently associated with PMAs. While duration of ictal activity is an important factor, it was not the sole determinant. Most PMAs resolved, particularly in SiS. Further studies are needed to clarify the pathophysiological mechanism and clinical implications of PMAs. Full article

Epilepsy is a common neurological disorder; 1% of people worldwide have epilepsy. Differentiating epileptic seizures from other acute neurological disorders in a clinical setting can be challenging. Approximately one-third of patients have drug-resistant epilepsy that is not well controlled by current antiepileptic drug therapy. Surgical treatment is potentially curative if the epileptogenic focus is accurately localized. Diffusion-weighted imaging (DWI) is an advanced magnetic resonance imaging technique that is sensitive to the diffusion of water molecules and provides additional information on the microstructure of tissue. Qualitative and quantitative analysis of peri-ictal, postictal, and interictal diffusion images can aid the differential diagnosis of seizures and seizure foci localization. This review focused on the fundamentals of DWI and its associated techniques, such as apparent diffusion coefficient, diffusion tensor imaging, and tractography, as well as their impact on epilepsy in terms of differential diagnosis, epileptic foci determination, and prognosis prediction. Full article

Mesial temporal lobe epilepsy (mTLE) is a life-threatening condition characterized by recurrent hippocampal seizures. mTLE can develop after exposure to risk factors such as febrile seizure, trauma, and infection. Within the latent period between exposure and onset of epilepsy, pathological remodeling events occur that contribute to epileptogenesis. The molecular mechanisms responsible are currently unclear. We used the mouse intrahippocampal kainite model of mTLE to investigate transcriptional dysregulation in the ipsilateral and contralateral dentate gyrus (DG), representing the epileptogenic zone (EZ) and peri-ictal zone (PIZ). DG were analyzed after 3, 7, and 14 days by RNA sequencing. In both the EZ and PIZ, transcriptional dysregulation was dynamic over the epileptogenic period with early expression of genes representing cell signaling, migration, and proliferation. Canonical Wnt signaling was upregulated in the EZ and PIZ at 3 days. Expression of inflammatory genes differed between the EZ and PIZ, with early expression after 3 days in the PIZ and delayed expression after 7–14 days in the EZ. This suggests that critical gene changes occur early in the hippocampal seizure network and that Wnt signaling may play a role within the latent epileptogenic period. These findings may help to identify novel therapeutic targets that could prevent epileptogenesis. Full article

Epilepsy is a common clinical manifestation and a source of significant morbidity in patients with brain tumors. Neuroimaging has a pivotal role in neuro-oncology practice, including tumor detection, differentiation, grading, treatment guidance, and posttreatment monitoring. In this review, we highlight studies demonstrating that imaging can also provide information about brain tumor-associated epileptogenicity and assist delineation of the peritumoral epileptic cortex to optimize postsurgical seizure outcome. Most studies focused on gliomas and glioneuronal tumors where positron emission tomography (PET) and advanced magnetic resonance imaging (MRI) techniques can detect metabolic and biochemical changes associated with altered amino acid transport and metabolism, neuroinflammation, and neurotransmitter abnormalities in and around epileptogenic tumors. PET imaging of amino acid uptake and metabolism as well as activated microglia can detect interictal or peri-ictal cortical increased uptake (as compared to non-epileptic cortex) associated with tumor-associated epilepsy. Metabolic tumor volumes may predict seizure outcome based on objective treatment response during glioma chemotherapy. Advanced MRI, especially glutamate imaging, can detect neurotransmitter changes around epileptogenic brain tumors. Recently, developed PET radiotracers targeting specific glutamate receptor types may also identify therapeutic targets for pharmacologic seizure control. Further studies with advanced multimodal imaging approaches may facilitate development of precision treatment strategies to control brain tumor-associated epilepsy. Full article

Background: Though Todd’s phenomenon (TP) is a relatively rare occurrence, its correct identification is of key diagnostic and therapeutic importance as a stroke mimic. Here we describe a case of isolated gaze palsy as a manifestation of TP, discuss periictal gaze abnormalities as lateralizing sign involving the frontal eye field (FEF), and present a narrative literature review. Methods: We reviewed the main features of the case and conducted a structured literature search of TP and gaze palsy using PubMed. We restricted the search to publications in English, Spanish, French, and German. Case presentation: A 71-year-old male with a history of right frontotemporal subarachnoid hemorrhage was admitted to the Emergency Department of our institution after suffering a first unprovoked focal to bilateral tonic-clonic seizure with ictal gaze deviation to the left. Cranial imaging showed no signs of ischemia, intracerebral hemorrhage, or tumor. The patient presented the following postictal features: involuntary eye deviation to the right due to left-sided gaze palsy and disorientation in time with preserved responsiveness. Eye movements were normal three days later. We concluded that the patient suffered from new-onset epilepsy due to sequelae following the right frontotemporal subarachnoid hemorrhage, affecting the FEF with contralateral ictal gaze deviation, and postictal gaze palsy with ipsilateral eye deviation as an unusual Todd’s phenomenon. Conclusion: Unusual manifestations of TP are uncommon but clinically highly relevant, as they can mimic stroke or epileptic status and are decisive in the diagnostic and therapeutic decision-making process. Though postictal gaze palsy has been reported associated with other deficits, this constitutes, to our knowledge, the first report of isolated gaze palsy as a form of TP. Further research into the underlying causes is needed. Ictal contralateral gaze and head deviation, and probably postictal ipsilateral gaze deviation if present, are very helpful for the lateralization of the seizure-onset zone. Full article

There are a number of reports that perceptual, electrophysiological and imaging measures can track migraine periodicity. As the electrophysiological and imaging research requires specialist equipment, it has few practical applications. This study sought to track changes in performance on four visual tasks over the migraine cycle. Coherence thresholds were measured for two motion and two orientation tasks. The first part of the study confirmed that the data obtained from an online study produced comparable results to those obtained under controlled laboratory conditions. Thirteen migraine with aura, 12 without aura, and 12 healthy controls participated. The second part of the study showed that thresholds for discriminating vertical coherent motion varied with the migraine cycle for a majority of the participants who tested themselves multiple times (four with aura, seven without). Performance improved two days prior to a migraine attack and remained improved for two days afterwards. This outcome is as expected from an extrapolation of earlier electrophysiological research. This research points to the possibility of developing sensitive visual tests that patients can use at home to predict an impending migraine attack and so take steps to try to abort it or, if it is inevitable, to plan their lives around it. Full article