ABSTRACT
Humans form lasting memories of stimuli that were only encountered once. This naturally occurs when listening to a story, however it remains unclear how and when memories are stored and retrieved during story-listening. Here, we first confirm in behavioral experiments that participants can learn about the structure of a story after a single exposure and are able to recall upcoming words when the story is presented again. We then track mnemonic information in high frequency activity (70-200 Hz) as patients undergoing electrocorticographic recordings listen twice to the same story. We demonstrate predictive recall of upcoming information through neural responses in auditory processing regions. This neural measure correlates with behavioral measures of event segmentation and learning. Event boundaries are linked to information flow from cortex to hippocampus. When listening for a second time, information flow from hippocampus to cortex precedes moments of predictive recall. These results provide insight on a fine-grained temporal scale into how episodic memory encoding and retrieval work under naturalistic conditions.
Subject(s)
Cerebral Cortex/physiology , Electrocorticography/methods , Hippocampus/physiology , Learning/physiology , Mental Recall/physiology , Adolescent , Adult , Algorithms , Brain Mapping/methods , Female , Humans , Male , Middle Aged , Models, Neurological , Young AdultABSTRACT
Drug-resistant focal epilepsy (DRFE) in children can impair cognition and behavior, and lead to premature death. Increased pediatric epilepsy surgery numbers reflect the improvements in seizure control and long-term developmental outcomes. Yet, many children with DRFE are not candidates for surgical resection due to overlap of the seizure network with eloquent cortex or multiple seizure-onset zones, making surgery dangerous or ineffective. In adults, responsive neurostimulation (RNS System) therapy is safe and effective treatment for DRFE with one or two seizure foci, especially when the seizure focus is in eloquent cortex. We present six pediatric patients with DRFE who underwent RNS implantation. Our outcomes demonstrate safety, decreased clinical seizure frequency, as well as improved functional status and quality of life. Changes in the clinical seizure semiology and frequency occurred in conjunction with adjustments to the stimulation parameters, supporting the efficacy of responsive neuromodulation in children.
Subject(s)
Deep Brain Stimulation , Drug Resistant Epilepsy , Epilepsy , Adult , Cerebral Cortex , Child , Drug Resistant Epilepsy/therapy , Epilepsy/therapy , Humans , Quality of LifeABSTRACT
OBJECTIVE: Refractory status epilepticus (RSE) requires aggressive management with multiple antiepileptic drugs (AEDs) often requiring the initiation of continuous infusions of propofol, midazolam, or pentobarbital to achieve adequate control in addition to intermittent agents. Ketamine has been implicated in several case reports as a successful agent for treating RSE given that it blocks the N-methyl-D-aspartate receptor, which is overexpressed in prolonged status epilepticus. CASE SUMMARY: We describe a previously healthy 27-year-old woman who presented with prolonged RSE requiring the initiation of multiple AEDs, including high-dose propofol and midazolam continuous infusions. As a result of hypotension from propofol and inadequate seizure control with midazolam, the patient was successfully transitioned to a pentobarbital infusion in combination with multiple AEDs. Although the patient achieved control of her RSE, her course was complicated by the development of an anticonvulsant hypersensitivity syndrome (AHS) with transaminitis. Limited with the options of AED that could have been used, it was decided to initiate the patient on a continuous ketamine infusion plus midazolam and slowly wean the patient off pentobarbital as well as to avoid further use of phenytoin and phenobarbital. DISCUSSION: The patient was successfully transitioned off pentobarbital to a ketamine infusion plus midazolam with complete seizure control after several dose escalations. Her AHS and transaminitis resolved on a ketamine infusion for a total of 12 days, and she was successfully discharged from the hospital after 60 days in the ICU. CONCLUSION: This is the first case report to describe a successful transition to a ketamine infusion in a patient with AHS and transaminitis.
