Publications by authors named "John S Duncan"

EEG slowing is reported in various neurological disorders including Alzheimer's, Parkinson's and Epilepsy. Here, we investigate alpha rhythm slowing in individuals with refractory temporal lobe epilepsy compared with healthy controls, using scalp EEG and magnetoencephalography. We retrospectively analysed data from 17 (46) healthy controls and 22 (24) individuals with temporal lobe epilepsy who underwent scalp EEG and magnetoencephalography recordings as part of presurgical evaluation.

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Objective: Magnetic resonance imaging (MRI) is a crucial tool for identifying brain abnormalities in a wide range of neurological disorders. In focal epilepsy, MRI is used to identify structural cerebral abnormalities. For covert lesions, machine learning and artificial intelligence (AI) algorithms may improve lesion detection if abnormalities are not evident on visual inspection.

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  • Hippocampal sclerosis (HS) is a major cause of temporal lobe epilepsy (TLE) but can be hard to detect on MRI, leading to surgical delays, so researchers created open-source software to improve diagnosis.
  • The study involved 365 participants, using the software HippUnfold to analyze MRI scans and develop a logistic regression model that accurately identifies and localizes HS.
  • The classifier showed high accuracy in detecting HS in both initial and independent patient cohorts, proving effective for individual assessments by comparing patient data with normative growth patterns.
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Introduction: Epilepsia Partialis Continua (EPC) is a challenging condition in which repetitive transcranial magnetic stimulation (rTMS) can induce a neuromodulation effect of potential diagnostic and therapeutic value.

Methods: A comprehensive literature search was conducted using Pubmed and Web of Science databases to identify cases of EPC who underwent rTMS, including children and adults. Additionally, we present two patients from our centre who underwent rTMS at a low frequency (0.

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Vagus nerve stimulation (VNS) is an established therapy for drug-resistant epilepsy. However, there is a lack of reliable predictors of VNS response in clinical use. The identification of factors predictive of VNS response is important for patient selection and stratification as well as tailored stimulation programming.

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  • White matter changes in temporal lobe epilepsy (TLE) are linked to cognitive impairments and possible neurodegenerative processes, with a study examining surgical resections from 44 patients.
  • The research found increased arteriolosclerosis and alterations in microvascular structure, including reduced vessel size and higher pericyte coverage, particularly in deeper white matter, independent of age and linked to epilepsy duration.
  • Additionally, there were significant changes in glial and myelin cell densities, with gene expression analysis indicating stronger myelination reductions in patients with hippocampal sclerosis, highlighting a relationship between imaging abnormalities and cognitive decline.
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Chronobiological rhythms, such as the circadian rhythm, have long been linked to neurological disorders, but it is currently unknown how pathological processes affect the expression of biological rhythms in the brain. Here, we use the unique opportunity of long-term, continuous intracranially recorded EEG from 38 patients (totalling 6338 hours) to delineate circadian (daily) and ultradian (minute to hourly) rhythms in different brain regions. We show that functional circadian and ultradian rhythms are diminished in pathological tissue, independent of regional variations.

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Background And Objectives: Neuroimaging studies have so far identified structural changes in individuals with juvenile myoclonic epilepsy (JME) when compared with controls. However, the underlying mechanisms of drug-resistant JME remain unknown. In this study, we aimed at characterizing the structural underpinnings of drug-resistant JME using MRI-derived cortical morphologic markers.

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  • The study aimed to explore abnormalities in the mesial temporal lobe of patients with mesial temporal lobe epilepsy (MTLE) by analyzing seizure-onset patterns identified through stereotactic electroencephalography (SEEG).
  • Fifty-one MTLE patients were divided into two groups (hypersynchronous (HYP) and low-voltage fast (LVF)) and their brain structures were compared to a control group using MRI and F-FDG-PET imaging.
  • Results showed distinct brain changes—LVF patients had amygdala enlargement and contralateral hippocampus hypermetabolism, while HYP patients showed significant hippocampal atrophy linked to worse outcomes; identifying these abnormalities could enhance diagnosis and treatment planning for MTLE
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Background: Juvenile myoclonic epilepsy (JME) is associated with cortical thinning of the motor areas. The relative contribution of antiseizure medication to cortical thickness is unknown. We aimed to investigate how valproate influences the cortical morphology of JME.

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Objective: Anterior temporal lobe resection (ATLR) effectively controls seizures in medically refractory temporal lobe epilepsy but risks significant episodic memory decline. Beyond 1 year postoperatively, the influence of preoperative clinical factors on episodic memory and long-term network plasticity remain underexplored. Ten years post-ATLR, we aimed to determine biomarkers of successful memory network reorganization and establish presurgical features' lasting impact on memory function.

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  • Researchers studied how important it is to fully remove areas of the brain that cause seizures during surgery for patients who can't control their epilepsy with medicine.
  • They looked at data from 63 patients and found that most had a lot of the problem areas taken out, but it didn't seem to help them avoid seizures afterward.
  • The study concluded that just removing the seizure areas isn't enough to guarantee no more seizures, suggesting that there might be other reasons for seizures after surgery.
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Normative models of brain structure estimate the effects of covariates such as age and sex using large samples of healthy controls. These models can then be applied to e.g.

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  • The decision to have epilepsy surgery is different for everyone and needs to be discussed carefully between the patient and their doctors.
  • Virginia had epilepsy since she was 1 and faced challenges, including weakness on her left side.
  • After many tests, they decided to perform surgery that made her seizure-free after a year, even though it affected her ability to use her left hand.
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Purpose: P-glycoprotein (P-gp) has been hypothesized to be involved in drug-resistance of epilepsy by actively extruding antiseizure medications (ASMs) from the brain. The P-gp inhibitor tariquidar (TQD) has been shown to effectively inhibit P-gp at the human blood-brain barrier, improving brain entry of several ASMs. A potential strategy to overcome drug-resistance is the co-administration of P-gp inhibitors such as TQD to ASMs.

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  • After having a stroke, some people might have seizures, which can affect their ability to drive safely.
  • Researchers studied over 4,400 stroke survivors to figure out their risk of having a seizure in the next year using the SeLECT model.
  • The results showed that people without seizures right after their stroke have a lower risk, while those with seizures have a much higher risk, and tools like apps can help decide if they can drive safely.
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  • - This study investigates how using language fMRI-guided tractography can predict naming difficulties after surgery in patients with temporal lobe epilepsy (TLE).
  • - It involved 20 patients who underwent fMRI tasks to assess brain activation and track white matter language pathways; results indicated that larger volumes of these tracts were linked to greater naming decline post-surgery.
  • - The findings suggest that analyzing white matter tract volumes can help predict surgical outcomes and potentially reduce the risk of language deficits in TLE patients.
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Objectives: Temporal lobe epilepsy (TLE) is commonly associated with mesiotemporal pathology and widespread alterations of grey and white matter structures. Evidence supports a progressive condition although the temporal evolution of TLE is poorly defined. This ENIGMA-Epilepsy study utilized multimodal magnetic resonance imaging (MRI) data to investigate structural alterations in TLE patients across the adult lifespan.

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Objective: The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current corticocentric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural magnetic resonance imaging in 1602 adults with epilepsy and 1022 healthy controls across 22 sites from the global ENIGMA-Epilepsy working group.

Methods: A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions.

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Extra temporal lobe epilepsy (eTLE) may involve heterogenous widespread cerebral networks. We investigated the structural network of an eTLE cohort, at the postulated epileptogenic zone later surgically removed, as a network node: the resection zone (RZ). We hypothesized patients with an abnormal connection to/from the RZ to have proportionally increased abnormalities based on topological proximity to the RZ, in addition to poorer post-operative seizure outcome.

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Objective: The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current cortico-centric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural MRI in 1,602 adults with epilepsy and 1,022 healthy controls across twenty-two sites from the global ENIGMA-Epilepsy working group.

Methods: A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions.

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Intracranial EEG is the gold standard technique for epileptogenic zone localization but requires a preconceived hypothesis of the location of the epileptogenic tissue. This placement is guided by qualitative interpretations of seizure semiology, MRI, EEG and other imaging modalities, such as magnetoencephalography. Quantitative abnormality mapping using magnetoencephalography has recently been shown to have potential clinical value.

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Background: When investigating suitability for epilepsy surgery, people with drug-refractory focal epilepsy may have intracranial EEG (iEEG) electrodes implanted to localise seizure onset. Diffusion-weighted magnetic resonance imaging (dMRI) may be acquired to identify key white matter tracts for surgical avoidance. Here, we investigate whether structural connectivity abnormalities, inferred from dMRI, may be used in conjunction with functional iEEG abnormalities to aid localisation of the epileptogenic zone (EZ), improving surgical outcomes in epilepsy.

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