Clinical Course May Be Independent from Neuroimaging in DEPDC-5-Related Epilepsy.

DEPDC5 is an upstream repressor of the mechanistic target of rapamycin pathway via the GATOR-1 complex. Pathogenic variants causing loss of function typically result in familial focal epilepsy with variable foci. Neuroimaging may either be normal or show brain malformations. Lesional and nonlesional cases may be present within the same family. Here, we describe a parent-child dyad affected by a truncating DEPDC5 pathogenic variant (c.727C > T; p.Arg243*), analyze the epilepsy clinical course, and describe neuroimaging characteristics from a 3T brain magnetic resonance imaging. Despite sharing the same variant, patients diverged both in terms of epilepsy severity and neuroimaging features. Surprisingly, the mother is still suffering from drug-resistant seizures and has normal neuroimaging, while the child has been experiencing prolonged seizure freedom notwithstanding a bottom-of-sulcus focal cortical dysplasia. An increasing gradient of severity has been proposed for families with GATOR1-related epilepsies. We confirm clinical and neuroradiological expressivities are variable and also suggest the prognostication of epilepsy outcome may be particularly difficult. The epilepsy outcome could partially be independent from brain structural abnormalities.

The Central Noradrenergic System in Neurodevelopmental Disorders: Merging Experimental and Clinical Evidence.

The aim of this article is to highlight the potential role of the locus-coeruleus-noradrenergic (LC-NA) system in neurodevelopmental disorders (NdDs). The LC is the main brain noradrenergic nucleus, key in the regulation of arousal, attention, and stress response, and its early maturation and sensitivity to perinatal damage make it an interesting target for translational research. Clinical data shows the involvement of the LC-NA system in several NdDs, suggesting a pathogenetic role in the development of such disorders. In this context, a new neuroimaging tool, LC Magnetic Resonance Imaging (MRI), has been developed to visualize the LC in vivo and assess its integrity, which could be a valuable tool for exploring morphological alterations in NdD in vivo in humans. New animal models may be used to test the contribution of the LC-NA system to the pathogenic pathways of NdD and to evaluate the efficacy of NA-targeting drugs. In this narrative review, we provide an overview of how the LC-NA system may represent a common pathophysiological and pathogenic mechanism in NdD and a reliable target for symptomatic and disease-modifying drugs. Further research is needed to fully understand the interplay between the LC-NA system and NdD.

A systems-level analysis highlights microglial activation as a modifying factor in common epilepsies.

AIMS: The causes of distinct patterns of reduced cortical thickness in the common human epilepsies, detectable on neuroimaging and with important clinical consequences, are unknown. We investigated the underlying mechanisms of cortical thinning using a systems-level analysis. METHODS: Imaging-based cortical structural maps from a large-scale epilepsy neuroimaging study were overlaid with highly spatially resolved human brain gene expression data from the Allen Human Brain Atlas. Cell-type deconvolution, differential expression analysis and cell-type enrichment analyses were used to identify differences in cell-type distribution. These differences were followed up in post-mortem brain tissue from humans with epilepsy using Iba1 immunolabelling. Furthermore, to investigate a causal effect in cortical thinning, cell-type-specific depletion was used in a murine model of acquired epilepsy. RESULTS: We identified elevated fractions of microglia and endothelial cells in regions of reduced cortical thickness. Differentially expressed genes showed enrichment for microglial markers and, in particular, activated microglial states. Analysis of post-mortem brain tissue from humans with epilepsy confirmed excess activated microglia. In the murine model, transient depletion of activated microglia during the early phase of the disease development prevented cortical thinning and neuronal cell loss in the temporal cortex. Although the development of chronic seizures was unaffected, the epileptic mice with early depletion of activated microglia did not develop deficits in a non-spatial memory test seen in epileptic mice not depleted of microglia. CONCLUSIONS: These convergent data strongly implicate activated microglia in cortical thinning, representing a new dimension for concern and disease modification in the epilepsies, potentially distinct from seizure control.

Drug-resistant epilepsy at the age extremes: Disentangling the underlying etiology.

The incidence of epilepsy is highest at the extreme age ranges: childhood and elderly age. The most common syndromes in these demographics - self-limited epilepsies of childhood and idiopathic generalized epilepsies in pediatric age, focal epilepsy with structural etiology in older people - are expected to be drug responsive. In this work, we focus on such epilepsy types, overviewing the complex clinical background of unexpected drug-resistance. For self-limited epilepsies of childhood and idiopathic generalized epilepsies, we illustrate drug-resistance resulting from syndrome misinterpretation, reason on possible unexpected courses of epilepsy, and explicate the influence of inappropriate treatments. For elderly-onset epilepsy, we show the challenges in differential diagnosis possibly leading to pseudoresistance and analyze how drug-resistant epilepsy can arise in stroke, neurocognitive disorders, brain tumors, and autoimmune encephalitis. In children and senior people, drug-resistance can be regarded as a hint to review the diagnosis or explore alternative therapeutic strategies. Refractory seizures are not only a therapeutic challenge, but also a cardinal sign not to be overlooked in syndromes commonly deemed to be drug-responsive.

Hyperosmolar hyperglycaemic state causing atypical status epilepticus with hippocampal involvement.

Diabetes mellitus may arise abruptly and decompensate suddenly, leading to a hyperglycaemic hyperosmolar state. Coma often ensues, although this usually reverses after the metabolic abnormalities have resolved. Acute symptomatic seizures can also occur in patients who are conscious, although these usually resolve after osmolarity and glycaemia have normalised. We describe an elderly woman who failed to regain vigilance despite prompt treatment; the cause was an unusual non-convulsive status epilepticus arising from the mesial temporal lobe and promoting a progressive and selective hippocampal involvement. During follow-up, her seizures recurred after stopping antiseizure medication and she developed hippocampal sclerosis, although she subsequently became seizure-free with antiseizure medications. Patients who are unresponsive in a hyperglycaemic hyperosmolar state may be having subclinical epileptiform discharges and risk developing permanent brain damage and long-term epilepsy.

Brivaracetam as add-on treatment in focal epilepsy: A real-world time-based analysis.

The study assessed the clinical response to add-on brivaracetam (BRV) in real-world practice by means of time-to-baseline seizure count methodology. Patients with focal epilepsy who were prescribed add-on BRV were identified. Primary endpoint was the time-to-baseline seizure count defined as the number of days until each patient experienced the number of focal seizures that occurred in the 90 days before BRV initiation. Subgroup analysis was performed according to levetiracetam (LEV) status (naive vs prior use). Three-hundred eighty-seven patients were included. The overall median time-to-baseline seizure count was 150 (95% confidence interval [CI] = 130-175) days. The median time-to-baseline seizure count was 198 (lower limit of 95% CI = 168) days for LEV-naive patients, 126 (95% CI = 105-150) days for patients with prior LEV use and withdrawal due to insufficient efficacy, and 170 (95% CI = 128-291) days for patients who discontinued LEV due to adverse events (P = .002). The number of prior antiseizure medications (adjusted hazard ratio [adj HR] = 1.07, 95% CI = 1.02-1.13, P = .009) and baseline monthly seizure frequency (adj HR = 1.004, 95% CI = 1.001-1.008, P = .028) were independently associated with the primary endpoint. Add-on BRV improved seizure control in LEV-naive and LEV-prior patients. The time-to-baseline seizure count represents an informative endpoint alongside traditional study outcomes and designs.

White matter abnormalities across different epilepsy syndromes in adults: an ENIGMA-Epilepsy study.

The epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy. Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analysed from 1069 healthy controls and 1249 patients: temporal lobe epilepsy with hippocampal sclerosis (n = 599), temporal lobe epilepsy with normal MRI (n = 275), genetic generalized epilepsy (n = 182) and non-lesional extratemporal epilepsy (n = 193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fibre tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at P < 0.001). Across 'all epilepsies' lower fractional anisotropy was observed in most fibre tracts with small to medium effect sizes, especially in the corpus callosum, cingulum and external capsule. There were also less robust increases in mean diffusivity. Syndrome-specific fractional anisotropy and mean diffusivity differences were most pronounced in patients with hippocampal sclerosis in the ipsilateral parahippocampal cingulum and external capsule, with smaller effects across most other tracts. Individuals with temporal lobe epilepsy and normal MRI showed a similar pattern of greater ipsilateral than contralateral abnormalities, but less marked than those in patients with hippocampal sclerosis. Patients with generalized and extratemporal epilepsies had pronounced reductions in fractional anisotropy in the corpus callosum, corona radiata and external capsule, and increased mean diffusivity of the anterior corona radiata. Earlier age of seizure onset and longer disease duration were associated with a greater extent of diffusion abnormalities in patients with hippocampal sclerosis. We demonstrate microstructural abnormalities across major association, commissural, and projection fibres in a large multicentre study of epilepsy. Overall, patients with epilepsy showed white matter abnormalities in the corpus callosum, cingulum and external capsule, with differing severity across epilepsy syndromes. These data further define the spectrum of white matter abnormalities in common epilepsy syndromes, yielding more detailed insights into pathological substrates that may explain cognitive and psychiatric co-morbidities and be used to guide biomarker studies of treatment outcomes and/or genetic research.

Drugs for patients with epilepsy and excessive daytime sleepiness.

Excessive daytime sleepiness (EDS) and attentional deficits are often observed in people with epilepsy. They may be the consequence of seizures and subclinical discharges as well as of comorbid conditions as obstructive sleep apnea/hypopnea syndrome (OSAS), attention deficit hyperactivity disorder (ADHD), or other less frequent disorders. Excessive daytime sleepiness may also be caused or worsened by antiseizure medications (ASMs). Several meta-analyses suggested that lamotrigine, lacosamide, and perhaps eslicarbazepine are less sedative than other traditional and new ASMs and, in patients prone to somnolence, might be preferred over ASMs with more sedative properties. In patients with severe EDS and/or ADHD, advantages and risks of a treatment with a psychostimulant need to be considered. Methylphenidate, modafinil, armodafinil, pitolisant, and solriamfetol are authorized for use in ADHD and EDS in patients with narcolepsy and some of them also in OSAS. These agents are off-label for the treatment of EDS associated with epilepsy. They do not have proconvulsant effects, although there are several possible risks for patients with epilepsy. The risks of cardiovascular events and psychiatric symptoms should be carefully evaluated as such disorders can coexist with epilepsy and be triggered by these agents. Finally, combination of psychostimulants with ASMs may be associated with several pharmacokinetic drug-drug interactions.

Climate change and epilepsy: Insights from clinical and basic science studies.

Climate change is with us. As professionals who place value on evidence-based practice, climate change is something we cannot ignore. The current pandemic of the novel coronavirus, SARS-CoV-2, has demonstrated how global crises can arise suddenly and have a significant impact on public health. Global warming, a chronic process punctuated by acute episodes of extreme weather events, is an insidious global health crisis needing at least as much attention. Many neurological diseases are complex chronic conditions influenced at many levels by changes in the environment. This review aimed to collate and evaluate reports from clinical and basic science about the relationship between climate change and epilepsy. The keywords climate change, seasonal variation, temperature, humidity, thermoregulation, biorhythm, gene, circadian rhythm, heat, and weather were used to search the published evidence. A number of climatic variables are associated with increased seizure frequency in people with epilepsy. Climate change-induced increase in seizure precipitants such as fevers, stress, and sleep deprivation (e.g. as a result of more frequent extreme weather events) or vector-borne infections may trigger or exacerbate seizures, lead to deterioration of seizure control, and affect neurological, cerebrovascular, or cardiovascular comorbidities and risk of sudden unexpected death in epilepsy. Risks are likely to be modified by many factors, ranging from individual genetic variation and temperature-dependent channel function, to housing quality and global supply chains. According to the results of the limited number of experimental studies with animal models of seizures or epilepsy, different seizure types appear to have distinct susceptibility to seasonal influences. Increased body temperature, whether in the context of fever or not, has a critical role in seizure threshold and seizure-related brain damage. Links between climate change and epilepsy are likely to be multifactorial, complex, and often indirect, which makes predictions difficult. We need more data on possible climate-driven altered risks for seizures, epilepsy, and epileptogenesis, to identify underlying mechanisms at systems, cellular, and molecular levels for better understanding of the impact of climate change on epilepsy. Further focussed data would help us to develop evidence for mitigation methods to do more to protect people with epilepsy from the effects of climate change.

The ENIGMA-Epilepsy working group: Mapping disease from large data sets.

Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smaller-scale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care. Through the infrastructure and concepts now well-established by the ENIGMA Consortium, ENIGMA-Epilepsy was established to strengthen epilepsy neuroscience by greatly increasing sample sizes, leveraging ideas and methods established in other ENIGMA projects, and generating a body of collaborating scientists and clinicians to drive forward robust research. Here we review published, current, and future projects, that include structural MRI, diffusion tensor imaging (DTI), and resting state functional MRI (rsfMRI), and that employ advanced methods including structural covariance, and event-based modeling analysis. We explore age of onset- and duration-related features, as well as phenomena-specific work focusing on particular epilepsy syndromes or phenotypes, multimodal analyses focused on understanding the biology of disease progression, and deep learning approaches. We encourage groups who may be interested in participating to make contact to further grow and develop ENIGMA-Epilepsy.

Epilepsy and brain channelopathies from infancy to adulthood.

Genetic brain channelopathies result from inherited or de novo mutations of genes encoding ion channel subunits within the central nervous system. Most neurological channelopathies arise in childhood with paroxysmal or episodic symptoms, likely because of a transient impairment of homeostatic mechanisms regulating membrane excitability, and the prototypical expression of this impairment is epilepsy. Migraine, episodic ataxia and alternating hemiplegia can also occur, as well as chronic phenotypes, such as spinocerebellar ataxias, intellectual disability and autism spectrum disorder. Voltage-gated and ligand-gated channels may be involved. In most cases, a single gene may be associated with a phenotypical spectrum that shows variable expressivity. Different clinical features may arise at different ages and the adult phenotype may be remarkably modified from the syndrome onset in childhood or adolescence. Recognizing the prominent phenotypical traits of brain channelopathies is essential to perform appropriate diagnostic investigations and to provide the better care not only in the paediatric setting but also for adult patients and their caregivers. Herein, we provide an overview of genetic brain channelopathies associated with epilepsy, highlight the different molecular mechanisms and describe the different clinical characteristics which may prompt the clinician to suspect specific syndromes and to possibly establish tailored treatments.

Transcranial color-coded sonography may indirectly reveal an intracranial meningioma.

Meningiomas are extra-axial tumors with a long-standing indolent clinical course. Sphenoid wing meningiomas may slowly grow, spreading toward the orbitofrontal and temporal regions as well as encasing the middle cerebral artery (MCA). Herein, we report the incidental finding of a sphenoid wing meningioma compressing the MCA in a patient who undergone a transcranial sonography study for recurrent speech disorders. We illustrate the associated sonographic "red flags" which should prompt to suspect an underlying compressive space-occupying lesion.

Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study.

Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen's d = -0.24 to -0.73; P < 1.49 × 10-4), and lower thickness in the precentral gyri bilaterally (d = -0.34 to -0.52; P < 4.31 × 10-6). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = -1.73 to -1.91, P < 1.4 × 10-19), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = -0.36 to -0.52; P < 1.49 × 10-4). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = -0.29 to -0.54; P < 1.49 × 10-4). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = -0.27 to -0.51; P < 1.49 × 10-4). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < -0.0018; P < 1.49 × 10-4). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed.

Dealing with the storm: An overview of seizure precipitants and spontaneous seizure worsening in drug-resistant epilepsy.

In drug-resistant epilepsy, periods of seizure stability may alternate with abrupt worsening, with frequent seizures limiting the individual's independence and physical, social, and psychological well-being. Here, we review the literature focusing on different clinical scenarios related to seizure aggravation in people with drug-resistant epilepsy. The role of antiseizure medication (ASM) changes is examined, especially focusing on paradoxical seizure aggravation after increased treatment. The external provocative factors that unbalance the brittle equilibrium of seizure control are reviewed, distinguishing between unspecific triggering factors, specific precipitants, and 'reflex' mechanisms. The chance of intervening surgical or medical conditions, including somatic comorbidities and epilepsy surgery failure, causing increased seizures is discussed. Spontaneous exacerbation is also explored, emphasizing recent findings on subject-specific circadian and ultradian rhythms. Awareness of external precipitants and understanding the subject-specific spontaneous epilepsy course may allow individuals to modify their lifestyles. It also allows clinicians to counsel appropriately and to institute suitable medical treatment to avoid sudden loss of seizure control.

The application of artificial intelligence to understand the pathophysiological basis of psychogenic nonepileptic seizures.

Psychogenic nonepileptic seizures (PNES) are episodes of paroxysmal impairment associated with a range of motor, sensory, and mental manifestations, which perfectly mimic epileptic seizures. Several patterns of neural abnormalities have been described without identifying a definite neurobiological substrate. In this multicenter cross-sectional study, we applied a multivariate classification algorithm on morphological brain imaging metrics to extract reliable biomarkers useful to distinguish patients from controls at an individual level. Twenty-three patients with PNES and 21 demographically matched healthy controls (HC) underwent an extensive neuropsychiatric/neuropsychological and neuroimaging assessment. One hundred and fifty morphological brain metrics were used for training a random forest (RF) machine-learning (ML) algorithm. A typical complex psychopathological construct was observed in PNES. Similarly, univariate neuroimaging analysis revealed widespread neuroanatomical changes affecting patients with PNES. Machine-learning approach, after feature selection, was able to perform an individual classification of PNES from controls with a mean accuracy of 74.5%, revealing that brain regions influencing classification accuracy were mainly localized within the limbic (posterior cingulate and insula) and motor inhibition systems (the right inferior frontal cortex (IFC)). This study provides Class II evidence that the considerable clinical and neurobiological heterogeneity observed in individuals with PNES might be overcome by ML algorithms trained on surface-based magnetic resonance imaging (MRI) data.

Limb Shaking Transient Ischemic Attacks with Normal Neurovascular Ultrasound may Herald Cardioembolic Stroke: A Case Report.

Our objective is to highlight that the rare occurrence of limb shaking in transient ischemic attacks may be underpinned by etiologies other than critical internal carotid stenosis/occlusion. We describe a 74 year-old woman with abrupt left arm jerking and normal urgent computed tomography scan, electroencephalography (EEG) as well as carotid and transcranial ultrasound. Two days later she developed an overt ischemic stroke, with left mesencephalon and left cerebellar hemisphere lesions at brain magnetic resonance imaging and paroxysmal atrial fibrillation at Holter-EKG. Transient ischemic attacks should be considered in the differential diagnosis of limb shaking even in patients with normal carotid and transcranial ultrasonography.

Fast Progression of Cerebellar Atrophy in PLA2G6-Associated Infantile Neuronal Axonal Dystrophy.

Infantile neuronal axonal dystrophy (INAD) is characterized by progressive cerebellar atrophy. MRI has been recommended as a marker of disease progression in cerebellar diseases. We performed a longitudinal brain volumetry study in a couple of bicorial twins with PLA2G6-positive INAD. Brain volumetry was calculated with FreeSurfer software on 3T T1-weighted images acquired at age 28 (t 0) and 36 months (t 1) in patient 1 and at age 22 (t 0) and 31 months (t 1) in patient 2. Data at t 0 were compared to those obtained in 18 control children aged 14-44 months with normal MRI. At t 0, both patients showed markedly lower cerebellar volume compared to controls. At t 1, both patients exhibited a remarkable decrease of cerebellar volume (-25.8% in patient 1; -16.5% in patient 2) and of frontal (-6.8% in patient 1 and -3.3% in patient 2) and occipital (-9.8% in patient 1 and -9.1% in patient 2) cortical GM volume. Our MRI morphometry study indicates that INAD is characterized by a remarkably fast progression of cerebellar atrophy and mild atrophy of the frontal and occipital cortex presumably secondary to deafferentation in the cortical-pons-cerebellum-rubro-thalamus-cortical circuit and visual pathways.

7T MRI in focal epilepsy with unrevealing conventional field strength imaging.

OBJECTIVE: To assess the diagnostic yield of 7T magnetic resonance imaging (MRI) in detecting and characterizing structural lesions in patients with intractable focal epilepsy and unrevealing conventional (1.5 or 3T) MRI. METHODS: We conducted an observational clinical imaging study on 21 patients (17 adults and 4 children) with intractable focal epilepsy, exhibiting clinical and electroencephalographic features consistent with a single seizure-onset zone (SOZ) and unrevealing conventional MRI. Patients were enrolled at two tertiary epilepsy surgery centers and imaged at 7T, including whole brain (three-dimensional [3D] T1 -weighted [T1W] fast-spoiled gradient echo (FSPGR), 3D susceptibility-weighted angiography [SWAN], 3D fluid-attenuated inversion recovery [FLAIR]) and targeted imaging (2D T2*-weighted dual-echo gradient-recalled echo [GRE] and 2D gray-white matter tissue border enhancement [TBE] fast spin echo inversion recovery [FSE-IR]). MRI studies at 1.5 or 3T deemed unrevealing at the referral center were reviewed by three experts in epilepsy imaging. Reviewers were provided information regarding the suspected localization of the SOZ. The same team subsequently reviewed 7T images. Agreement in imaging interpretation was reached through consensus-based discussions based on visual identification of structural abnormalities and their likely correlation with clinical and electrographic data. RESULTS: 7T MRI revealed structural lesions in 6 (29%) of 21 patients. The diagnostic gain in detection was obtained using GRE and FLAIR images. Four of the six patients with abnormal 7T underwent epilepsy surgery. Histopathology revealed focal cortical dysplasia (FCD) in all. In the remaining 15 patients (71%), 7T MRI remained unrevealing; 4 of the patients underwent epilepsy surgery and histopathologic evaluation revealed gliosis. SIGNIFICANCE: 7T MRI improves detection of epileptogenic FCD that is not visible at conventional field strengths. A dedicated protocol including whole brain FLAIR and GRE images at 7T targeted at the suspected SOZ increases the diagnostic yield.

Diffuse Brain Hypoperfusion in Advanced Leukoencephalopathy with Calcifications and Cysts.

Leukoencephalopathy with calcifications and cysts (LCC) is an uncommon condition of unknown etiology occurring in children and adults. Pathological findings include obliterative hyalinosis of the small vessels, myelin loss, intense gliosis, Rosenthal fiber formation, microcalcifications, and hemosiderin deposits. Herein we report a 55-year-old man with LCC documented 10 years ago, in whom we examined brain perfusion by pseudocontinuous arterial spin labeling technique. We demonstrated diffused hypoperfusion of the affected white matter (WM) and of the subcortical gray matter (GM) and cortical GM in the patient in comparison to a group of healthy control subjects, using both qualitative evaluation and region of interest analysis. WM and subcortical GM hypoperfusion reflects the known distribution of LCC microangiopathy. We speculate that cortical hypoperfusion may be related to cerebral atrophy or may reflect deafferentation secondary to severe leukoencephalopathy, and may possibly contribute to severe motor and cognitive impairment. Further studies addressing cerebral blood flow in LCC are necessary.

Abnormal response to photic stimulation in juvenile myoclonic epilepsy: an EEG-fMRI study.

OBJECTIVE: Juvenile myoclonic epilepsy (JME) is a young-onset electroclinical syndrome, characterized by myoclonic, generalized tonic-clonic, and possibly typical absence seizures. Interictal electroencephalography (EEG) displays 3-6 Hz spike/polyspike and wave pattern. Photosensitivity is common. Our aim was to explore the blood oxygen level-dependent (BOLD) response evoked by a highly provocative photic stimulus in a cohort of people with JME compared to a group of nonphotosensitive healthy controls, and to investigate the hemodynamic phenomena seen in patients with photosensitive JME. METHODS: We studied 13 JME patients and 18 healthy controls using EEG-functional magnetic resonance imaging (fMRI) performed during low luminance intermittent photic stimulation (IPS). The BOLD response to IPS was investigated both in JME and control groups. In photosensitive JME subjects, we also performed a dynamic evaluation of BOLD signal changes evoked by the photoparoxysmal response (PPR) in a time frame ranging from 10 s before the onset of the EEG paroxysm up until 10 s afterward. RESULTS: The IPS evoked a positive BOLD response in striate and extrastriate visual areas, which was less in JME patients than in controls. Moreover, people with JME had a reduced positive BOLD response in the frontoparietal areas and putamen but a stronger negative BOLD response in the primary sensorimotor cortex (SM1) and in cortical regions belonging to the default mode network (DMN). In JME, the dynamic evaluation of BOLD signal changes related to PPR revealed an early positive response in the putamen and SM1, followed by BOLD signal decrements in the putamen, caudate nuclei, thalami, and SM1. SIGNIFICANCE: Our results confirm the hypothesis that people with JME might have an altered interaction between the motor circuit and other neuronal networks, with prominent involvement of basal ganglia circuitry. The PPR could be a final expression of pathogenic phenomena occurring in the striato-thalamocortical system, possibly a core feature of system epilepsy JME.