606 research outputs found
Characterisation of medullary astrocytic populations in respiratory nuclei and alterations in sudden unexpected death in epilepsy
No full textCentral failure of respiration during a seizure is one possible mechanism for sudden unexpected death in epilepsy (SUDEP). Neuroimaging studies indicate volume loss in the medulla in SUDEP and a post mortem study has shown reduction in neuromodulatory neuropeptidergic and monoaminergic neurones in medullary respiratory nuclear groups. Specialised glial cells identified in the medulla are considered essential for normal respiratory regulation including astrocytes with pacemaker properties in the pre-Botzinger complex and populations of subpial and perivascular astrocytes, sensitive to increased pCO2, that excite respiratory neurones. Our aim was to explore niches of medullary astrocytes in SUDEP cases compared to controls. In 48 brainstems from three groups, SUDEP (20), epilepsy controls (10) and non-epilepsy controls (18), sections through the medulla were labelled for GFAP, vimentin and functional markers, astrocytic gap junction protein connexin43 (Cx43) and adenosine A1 receptor (A1R). Regions including the ventro-lateral medulla (VLM; for the pre-Bötzinger complex), Median Raphe (MR) and lateral medullary subpial layer (MSPL) were quantified using image analysis for glial cell populations and compared between groups. Findings included morphologically and regionally distinct vimentin/Cx34-positive glial cells in the VLM and MR in close proximity to neurones. We noted a reduction of vimentin-positive glia in the VLM and MSPL and Cx43 glia in the MR in SUDEP cases compared to control groups (p < 0.05-0.005). In addition, we identified vimentin, Cx43 and A1R positive glial cells in the MSPL region which likely correspond to chemosensory glia identified experimentally. In conclusion, altered medullary glial cell populations could contribute to impaired respiratory regulatory capacity and vulnerability to SUDEP and warrant further investigation.</p
Adenosine kinase and Adenosine receptors A1 and A2A in temporal lobe epilepsy and association with risk factors for SUDEP
No full textSupplemental Material, sj-docx-1-jcn-10.1177_08830738211019576 - Content Validation of Clinician-Reported Items for a Severity Measure for CDKL5 Deficiency Disorder
No full textSupplemental Material, sj-docx-1-jcn-10.1177_08830738211019576 for Content Validation of Clinician-Reported Items for a Severity Measure for CDKL5 Deficiency Disorder by Jacinta Saldaris, Judith Weisenberg, Elia Pestana-Knight, Eric D. Marsh, Bernhard Suter, Rajsekar Rajaraman, Gena Heidary, Heather E. Olson, Orrin Devinsky, Dana Price, Peter Jacoby, Helen Leonard, Tim A. Benke, Scott Demarest and Jenny Downs in Journal of Child Neurology</p
Adenosine kinase and adenosine receptors A1 R and A2A R in temporal lobe epilepsy and hippocampal sclerosis and association with risk factors for SUDEP.
No full textOBJECTIVE: The "adenosine hypothesis of SUDEP" (sudden unexpected death in epilepsy) predicts that a seizure-induced adenosine surge combined with impaired metabolic clearance can foster lethal apnea or cardiac arrest. Changes in adenosine receptor density and adenosine kinase (ADK) occur in surgical epilepsy patients. Our aim was to correlate the distribution of ADK and adenosine A2A and A1 receptors (A2A R and A1 R) in surgical tissue from patients with temporal lobe epilepsy and hippocampal sclerosis (TLE/HS) with SUDEP risk factors. METHODS: In 75 cases, patients were stratified into high-risk (n = 16), medium-risk (n = 11) and low-risk (n = 48) categories according to the frequency of generalized seizures before surgery. Using whole-slide scanning Definiens image analysis we quantified the labeling index (LI) for ADK, A2A R, and A1 R in seven regions of interest: temporal cortex, temporal lobe white matter, CA1, CA4, dentate gyrus, subiculum, and amygdala and relative to glial and neuronal densities with glial fibrillary acidic protein (GFAP) and neuronal nuclear antigen (NeuN). RESULTS: A1 R showed predominant neuronal, A2A R astroglial, and ADK nuclear labeling in all regions but with significant variation. Compared with the low-risk group, the high-risk group had significantly lower A2A R LI in the temporal cortex. In HS cases with severe neuronal cell loss and gliosis predominantly in the CA1 and CA4 regions, significantly higher A1 R was present in the amygdala in high-risk than in low-risk cases. There was no significant difference in neuronal loss or gliosis between the risk groups or differences for ADK labeling. SIGNIFICANCE: Reduced cortical A2A R suggests glial dysfunction and impaired adenosine modulation in response to seizures in patients at higher risk for SUDEP. Increased neuronal A1 R in the high-risk group could contribute to periictal amygdala dysfunction in SUDEP
Psychogenic nonepileptic seizures.
No full textTreatment for PNES must be individualized. A combination of approaches is probably the most beneficial for improvement. Treatment should not simply emphasize removing maladaptive PNES behaviour, but should also focus on learning new coping skills and removing secondary gains. If PNES persist, therapy should be re-evaluated
Multiple task-demands flexibly optimize neural geometry in human ventral temporal cortex
No full textA hallmark of human intelligence is the ability to perform multiple tasks immediately upon instruction. Yet, the neural processes that implement such flexibility remain unclear. Using intracranial electrophysiology in epilepsy patients, we examined how representational geometries evolve as participants switched among three tasks - individuation, categorization, and conceptualization - on a trial-by-trial basis. Although tasks differed in the required representational geometries, neural representations across cortex were not immediately optimized following task cues. Instead, task-tailored geometries emerged gradually over successive stimulus repetitions within a trial. Ventral temporal cortex was the only region to exhibit task-specific adjustments for all three tasks, dynamically transforming within- and between-category distances in line with task demands. Importantly, these gradual representational changes were behaviorally relevant, predicting trial-level performance. Our results show that behavioral flexibility is supported by incremental, task-dependent refinement of representational geometry already within sensory cortex - far earlier in the processing hierarchy than previously thought
The myth of silent cortex and the morbidity of epileptogenic tissue: Implications for temporal lobectomy
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