1
|
Kwon H, Chinappen DM, Kinard EA, Goodman SK, Huang JF, Berja ED, Walsh KG, Shi W, Manoach DS, Kramer MA, Chu CJ. Impaired sleep-dependent memory consolidation predicted by reduced sleep spindles in Rolandic epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594515. [PMID: 38798414 PMCID: PMC11118409 DOI: 10.1101/2024.05.16.594515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Background and Objectives Sleep spindles are prominent thalamocortical brain oscillations during sleep that have been mechanistically linked to sleep-dependent memory consolidation in animal models and healthy controls. Sleep spindles are decreased in Rolandic epilepsy and related sleep-activated epileptic encephalopathies. We investigate the relationship between sleep spindle deficits and deficient sleep dependent memory consolidation in children with Rolandic epilepsy. Methods In this prospective case-control study, children were trained and tested on a validated probe of memory consolidation, the motor sequence task (MST). Sleep spindles were measured from high-density EEG during a 90-minute nap opportunity between MST training and testing using a validated automated detector. Results Twenty-three children with Rolandic epilepsy (14 with resolved disease), and 19 age- and sex-matched controls were enrolled. Children with active Rolandic epilepsy had decreased memory consolidation compared to control children (p=0.001, mean percentage reduction: 25.7%, 95% CI [10.3, 41.2]%) and compared to children with resolved Rolandic epilepsy (p=0.007, mean percentage reduction: 21.9%, 95% CI [6.2, 37.6]%). Children with active Rolandic epilepsy had decreased sleep spindle rates in the centrotemporal region compared to controls (p=0.008, mean decrease 2.5 spindles/min, 95% CI [0.7, 4.4] spindles/min). Spindle rate positively predicted sleep-dependent memory consolidation (p=0.004, mean MST improvement of 3.9%, 95% CI [1.3, 6.4]%, for each unit increase in spindles per minute). Discussion Children with Rolandic epilepsy have a sleep spindle deficit during the active period of disease which predicts deficits in sleep dependent memory consolidation. This finding provides a mechanism and noninvasive biomarker to aid diagnosis and therapeutic discovery for cognitive dysfunction in Rolandic epilepsy and related sleep activated epilepsy syndromes.
Collapse
Affiliation(s)
- Hunki Kwon
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Dhinakaran M Chinappen
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, USA
| | - Elizabeth A Kinard
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Skyler K Goodman
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jonathan F Huang
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Erin D Berja
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Katherine G Walsh
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Wen Shi
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Dara S Manoach
- Harvard Medical School, Boston, Massachusetts, USA
- Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, USA
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, USA
- Center for Systems Neuroscience, Boston University, Boston, Massachusetts, USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
2
|
Bergamo D, Handjaras G, Petruso F, Talami F, Ricciardi E, Benuzzi F, Vaudano AE, Meletti S, Bernardi G, Betta M. Maturation-dependent changes in cortical and thalamic activity during sleep slow waves: Insights from a combined EEG-fMRI study. Sleep Med 2024; 113:357-369. [PMID: 38113618 DOI: 10.1016/j.sleep.2023.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 11/24/2023] [Accepted: 12/02/2023] [Indexed: 12/21/2023]
Abstract
INTRODUCTION Studies using scalp EEG have shown that slow waves (0.5-4 Hz), the most prominent hallmark of NREM sleep, undergo relevant changes from childhood to adulthood, mirroring brain structural modifications and the acquisition of cognitive skills. Here we used simultaneous EEG-fMRI to investigate the cortical and subcortical correlates of slow waves in school-age children and determine their relative developmental changes. METHODS We analyzed data from 14 school-age children with self-limited focal epilepsy of childhood who fell asleep during EEG-fMRI recordings. Brain regions associated with slow-wave occurrence were identified using a voxel-wise regression that also modelled interictal epileptic discharges and sleep spindles. At the group level, a mixed-effects linear model was used. The results were qualitatively compared with those obtained from 2 adolescents with epilepsy and 17 healthy adults. RESULTS Slow waves were associated with hemodynamic-signal decreases in bilateral somatomotor areas. Such changes extended more posteriorly relative to those in adults. Moreover, the involvement of areas belonging to the default mode network changes as a function of age. No significant hemodynamic responses were observed in subcortical structures. However, we identified a significant correlation between age and thalamic hemodynamic changes. CONCLUSIONS Present findings indicate that the somatomotor cortex may have a key role in slow-wave expression throughout the lifespan. At the same time, they are consistent with a posterior-to-anterior shift in slow-wave distribution mirroring brain maturational changes. Finally, our results suggest that slow-wave changes may not reflect only neocortical modifications but also the maturation of subcortical structures, including the thalamus.
Collapse
Affiliation(s)
- Damiana Bergamo
- MoMiLab, IMT School for Advanced Studies Lucca, Lucca, Italy
| | | | - Flavia Petruso
- MoMiLab, IMT School for Advanced Studies Lucca, Lucca, Italy; Sant'Anna School of Advanced Studies, Pisa, Italy
| | - Francesca Talami
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Dept., Azienda Ospedaliera Universitaria di Modena, Italy
| | | | - Francesca Benuzzi
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Anna Elisabetta Vaudano
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Dept., Azienda Ospedaliera Universitaria di Modena, Italy
| | - Stefano Meletti
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Neurology Dept., Azienda Ospedaliera Universitaria di Modena, Italy
| | - Giulio Bernardi
- MoMiLab, IMT School for Advanced Studies Lucca, Lucca, Italy
| | - Monica Betta
- MoMiLab, IMT School for Advanced Studies Lucca, Lucca, Italy.
| |
Collapse
|
3
|
McLaren JR, Luo Y, Kwon H, Shi W, Kramer MA, Chu CJ. Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy. Ann Clin Transl Neurol 2023; 10:1513-1524. [PMID: 37363864 PMCID: PMC10502632 DOI: 10.1002/acn3.51840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 06/12/2023] [Indexed: 06/28/2023] Open
Abstract
OBJECTIVE Epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: (1) spikes and spindles would be anti-correlated, (2) high-dose diazepam would increase spindles and decrease spikes, and (3) spindle response would be greater in those with cognitive improvement. METHODS Consecutive EE-SWAS patients treated with high-dose diazepam that met the criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. The cognitive response was determined from a chart review. RESULTS Spindle rate was anti-correlated with the spike rate in the channel with the maximal spike rate (p = 0.002) and averaged across all channels (p = 0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment (p ≤ 2e-5, all tests). Spindle rate, duration, and percentage (p ≤ 0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spindle rate but not changes in spike rate distinguished between groups. INTERPRETATION These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.
Collapse
Affiliation(s)
- John R. McLaren
- Department of NeurologyMassachusetts General HospitalBoston02114MassachusettsUSA
- Harvard Medical SchoolBoston02115MassachusettsUSA
| | - Yancheng Luo
- Department of NeurologyMassachusetts General HospitalBoston02114MassachusettsUSA
- Harvard Medical SchoolBoston02115MassachusettsUSA
| | - Hunki Kwon
- Department of NeurologyMassachusetts General HospitalBoston02114MassachusettsUSA
- Harvard Medical SchoolBoston02115MassachusettsUSA
| | - Wen Shi
- Department of NeurologyMassachusetts General HospitalBoston02114MassachusettsUSA
- Harvard Medical SchoolBoston02115MassachusettsUSA
| | - Mark A. Kramer
- Department of Mathematics and Statistics & Center for Systems NeuroscienceBoston UniversityBoston02215MassachusettsUSA
| | - Catherine J. Chu
- Department of NeurologyMassachusetts General HospitalBoston02114MassachusettsUSA
- Harvard Medical SchoolBoston02115MassachusettsUSA
| |
Collapse
|
4
|
McLaren JR, Luo Y, Kwon H, Shi W, Kramer MA, Chu CJ. Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.22.537937. [PMID: 37163098 PMCID: PMC10168273 DOI: 10.1101/2023.04.22.537937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Objective Epileptic encephalopathy with spike wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: 1) spikes and spindles would be anticorrelated, 2) high-dose diazepam would increase spindles and decrease spikes, and 3) spindle response would be greater in those with cognitive improvement. Methods Consecutive EE-SWAS patients treated with high-dose diazepam that met criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. Cognitive response was determined from chart review. Results Spindle rate was anticorrelated with spike rate in the channel with the maximal spike rate ( p =0.002) and averaged across all channels ( p =0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment ( p≤ 2e-5, all tests). Spindle rate, duration, and percentage ( p ≤0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spike rate did not distinguish between groups. Interpretation These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.
Collapse
Affiliation(s)
- John R McLaren
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA 02114
- Harvard Medical School, Boston, MA, USA 02115
| | - Yancheng Luo
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA 02114
- Harvard Medical School, Boston, MA, USA 02115
| | - Hunki Kwon
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA 02114
- Harvard Medical School, Boston, MA, USA 02115
| | - Wen Shi
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA 02114
- Harvard Medical School, Boston, MA, USA 02115
| | - Mark A Kramer
- Department of Mathematics and Statistics & Center for Systems Neuroscience, Boston University, Boston, MA, USA 02215
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA 02114
- Harvard Medical School, Boston, MA, USA 02115
| |
Collapse
|
5
|
Kwon H, Walsh KG, Berja ED, Manoach DS, Eden UT, Kramer MA, Chu CJ. Sleep spindles in the healthy brain from birth through 18 years. Sleep 2023; 46:zsad017. [PMID: 36719044 PMCID: PMC10091086 DOI: 10.1093/sleep/zsad017] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/16/2022] [Indexed: 02/01/2023] Open
Abstract
STUDY OBJECTIVE Sleep spindles are present from birth and reflect cognitive functions across the lifespan, but normative values for this cognitive biomarker across development are lacking. This study aims to establish normative spindle features over development. METHODS All available normal 19-channel electroencephalograms from developmentally normal children between February 2002 and June 2021 in the MGH EEG lab were analyzed. Approximately, 20 000 spindles were hand-marked to train and validate an automated spindle detector across ages. Normative values for spindle rate, duration, frequency, refractory period, and interhemispheric lag are provided for each channel and each age. RESULTS Sleep EEGs from 567 developmentally normal children (range 0 days to 18 years) were included. The detector had excellent performance (F1 = 0.47). Maximal spindle activity is seen over central regions during infancy and adolescence and frontopolar regions during childhood. Spindle rate and duration increase nonlinearly, with the most rapid changes during the first 4 months of life and between ages 3 and 14 years. Peak spindle frequency follows a U-shaped curve and discrete frontal slow and central fast spindles are evident by 18 months. Spindle refractory periods decrease between ages 1 and 14 years while interhemispheric asynchrony decreases over the first 3 months of life and between ages 1 and 14 years. CONCLUSIONS These data provide age- and region-specific normative values for sleep spindles across development, where measures that deviate from these values can be considered pathological. As spindles provide a noninvasive biomarker for cognitive function across the lifespan, these normative measures can accelerate the discovery and diagnosis in neurodevelopmental disorders.
Collapse
Affiliation(s)
- Hunki Kwon
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Katherine G Walsh
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Erin D Berja
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Dara S Manoach
- Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Uri T Eden
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| |
Collapse
|
6
|
Huang Y, Liu Y, Song W, Liu Y, Wang X, Han J, Ye J, Han H, Wang L, Li J, Wang T. Assessment of Cognitive Function with Sleep Spindle Characteristics in Adults with Epilepsy. Neural Plast 2023; 2023:7768980. [PMID: 37101904 PMCID: PMC10125769 DOI: 10.1155/2023/7768980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 05/31/2022] [Accepted: 03/14/2023] [Indexed: 04/28/2023] Open
Abstract
Objective Epilepsy may cause chronic cognitive impairment by disturbing sleep plasticity. Sleep spindles play a crucial role in sleep maintenance and brain plasticity. This study explored the relationship between cognition and spindle characteristics in adult epilepsy. Methods Participants underwent one-night sleep electroencephalogram recording and neuropsychological tests on the same day. Spindle characteristics during N2 sleep were extracted using a learning-based system for sleep staging and an automated spindle detection algorithm. We investigated the difference between cognitive subgroups in spindle characteristics. Multiple linear regressions were applied to analyze associations between cognition and spindle characteristics. Results Compared with no/mild cognitive impairment, epilepsy patients who developed severe cognitive impairment had lower sleep spindle density, the differences mainly distributed in central, occipital, parietal, middle temporal, and posterior temporal (P < 0.05), and had relatively long spindle duration in occipital and posterior temporal (P < 0.05). Mini-Mental State Examination (MMSE) was associated with spindle density (pars triangularis of the inferior frontal gyrus (IFGtri): β = 0.253, P = 0.015, and P.adjust = 0.074) and spindle duration (IFGtri: β = -0.262, P = 0.004, and P.adjust = 0.030). Montreal Cognitive Assessment (MoCA) was associated with spindle duration (IFGtri: β = -0.246, P = 0.010, and P.adjust = 0.055). Executive Index Score (MoCA-EIS) was associated with spindle density (IFGtri: β = 0.238, P = 0.019, and P.adjust = 0.087; parietal: β = 0.227, P = 0.017, and P.adjust = 0.082) and spindle duration (parietal: β = -0.230, P = 0.013, and P.adjust = 0.065). Attention Index Score (MoCA-AIS) was associated with spindle duration (IFGtri: β = -0.233, P = 0.017, and P.adjust = 0.081). Conclusions The findings suggested that the altered spindle activity in epilepsy with severe cognitive impairment, the associations between the global cognitive status of adult epilepsy and spindle characteristics, and specific cognitive domains may relate to spindle characteristics in particular brain regions.
Collapse
Affiliation(s)
- Yajin Huang
- The Second Clinical Medical College, Lanzhou University/Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Yaqing Liu
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Wenjun Song
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Yanjun Liu
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Xiaoqian Wang
- The Second Clinical Medical College, Lanzhou University/Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Juping Han
- The Second Clinical Medical College, Lanzhou University/Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Jiang Ye
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Hongmei Han
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Li Wang
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Juan Li
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| | - Tiancheng Wang
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
| |
Collapse
|
7
|
Electrophysiological markers of memory consolidation in the human brain when memories are reactivated during sleep. Proc Natl Acad Sci U S A 2022; 119:e2123430119. [PMID: 36279460 PMCID: PMC9636913 DOI: 10.1073/pnas.2123430119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sleep contributes to memory consolidation, we presume, because memories are replayed during sleep. Understanding this aspect of consolidation can help with optimizing normal learning in many contexts and with treating memory disorders and other diseases. Here, we systematically manipulated sleep-based processing using targeted memory reactivation; brief sounds coupled with presleep learning were quietly presented again during sleep, producing 1) recall improvements for specific spatial memories associated with those sounds and 2) physiological responses in the sleep electroencephalogram. Neural activity in the hippocampus and adjacent medial temporal cortex was thus found in association with memory consolidation during sleep. These findings advance understanding of consolidation by linking beneficial memory changes during sleep to both memory reactivation and specific patterns of brain activity. Human accomplishments depend on learning, and effective learning depends on consolidation. Consolidation is the process whereby new memories are gradually stored in an enduring way in the brain so that they can be available when needed. For factual or event knowledge, consolidation is thought to progress during sleep as well as during waking states and to be mediated by interactions between hippocampal and neocortical networks. However, consolidation is difficult to observe directly but rather is inferred through behavioral observations. Here, we investigated overnight memory change by measuring electrical activity in and near the hippocampus. Electroencephalographic (EEG) recordings were made in five patients from electrodes implanted to determine whether a surgical treatment could relieve their seizure disorders. One night, while each patient slept in a hospital monitoring room, we recorded electrophysiological responses to 10 to 20 specific sounds that were presented very quietly, to avoid arousal. Half of the sounds had been associated with objects and their precise spatial locations that patients learned before sleep. After sleep, we found systematic improvements in spatial recall, replicating prior results. We assume that when the sounds were presented during sleep, they reactivated and strengthened corresponding spatial memories. Notably, the sounds also elicited oscillatory intracranial EEG activity, including increases in theta, sigma, and gamma EEG bands. Gamma responses, in particular, were consistently associated with the degree of improvement in spatial memory exhibited after sleep. We thus conclude that this electrophysiological activity in the hippocampus and adjacent medial temporal cortex reflects sleep-based enhancement of memory storage.
Collapse
|
8
|
Spencer ER, Chinappen D, Emerton BC, Morgan AK, Hämäläinen MS, Manoach DS, Eden UT, Kramer MA, Chu CJ. Source EEG reveals that Rolandic epilepsy is a regional epileptic encephalopathy. Neuroimage Clin 2022; 33:102956. [PMID: 35151039 PMCID: PMC8844714 DOI: 10.1016/j.nicl.2022.102956] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/10/2022] [Accepted: 02/03/2022] [Indexed: 01/15/2023]
Abstract
Children with RE have fewer spindles but they have typical time–frequency features. Spindle deficits extend to multiple cortical regions in Rolandic epilepsy. Cognitive deficits are predicted by spindle rate in Rolandic epilepsy. Regional spindle rate predicts motor deficits better than Rolandic spindle deficit. Spindle features in RE identify a regional thalamocortical epileptic encephalopathy.
Rolandic epilepsy is the most common form of epileptic encephalopathy, characterized by sleep-potentiated inferior Rolandic epileptiform spikes, seizures, and cognitive deficits in school-age children that spontaneously resolve by adolescence. We recently identified a paucity of sleep spindles, physiological thalamocortical rhythms associated with sleep-dependent learning, in the Rolandic cortex during the active phase of this disease. Because spindles are generated in the thalamus and amplified through regional thalamocortical circuits, we hypothesized that: 1) deficits in spindle rate would involve but extend beyond the inferior Rolandic cortex in active epilepsy and 2) regional spindle deficits would better predict cognitive function than inferior Rolandic spindle deficits alone. To test these hypotheses, we obtained high-resolution MRI, high-density EEG recordings, and focused neuropsychological assessments in children with Rolandic epilepsy during active (n = 8, age 9–14.7 years, 3F) and resolved (seizure free for > 1 year, n = 10, age 10.3–16.7 years, 1F) stages of disease and age-matched controls (n = 8, age 8.9–14.5 years, 5F). Using a validated spindle detector applied to estimates of electrical source activity in 31 cortical regions, including the inferior Rolandic cortex, during stages 2 and 3 of non-rapid eye movement sleep, we compared spindle rates in each cortical region across groups. Among detected spindles, we compared spindle features (power, duration, coherence, bilateral synchrony) between groups. We then used regression models to examine the relationship between spindle rate and cognitive function (fine motor dexterity, phonological processing, attention, and intelligence, and a global measure of all functions). We found that spindle rate was reduced in the inferior Rolandic cortices in active but not resolved disease (active P = 0.007; resolved P = 0.2) compared to controls. Spindles in this region were less synchronous between hemispheres in the active group (P = 0.005; resolved P = 0.1) compared to controls; but there were no differences in spindle power, duration, or coherence between groups. Compared to controls, spindle rate in the active group was also reduced in the prefrontal, insular, superior temporal, and posterior parietal regions (i.e., “regional spindle rate”, P < 0.039 for all). Independent of group, regional spindle rate positively correlated with fine motor dexterity (P < 1e-3), attention (P = 0.02), intelligence (P = 0.04), and global cognitive performance (P < 1e-4). Compared to the inferior Rolandic spindle rate alone, models including regional spindle rate trended to improve prediction of global cognitive performance (P = 0.052), and markedly improved prediction of fine motor dexterity (P = 0.006). These results identify a spindle disruption in Rolandic epilepsy that extends beyond the epileptic cortex and a potential mechanistic explanation for the broad cognitive deficits that can be observed in this epileptic encephalopathy.
Collapse
Affiliation(s)
- Elizabeth R Spencer
- Graduate Program in Neuroscience, Boston University, Boston, MA 02215; Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
| | - Dhinakaran Chinappen
- Graduate Program in Neuroscience, Boston University, Boston, MA 02215; Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
| | - Britt C Emerton
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114
| | - Amy K Morgan
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114
| | - Matti S Hämäläinen
- Harvard Medical School, Boston, MA 02115; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129; Massachusetts General Hospital, Department of Radiology, Boston, MA 02114
| | - Dara S Manoach
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114; Harvard Medical School, Boston, MA 02115; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129
| | - Uri T Eden
- Department of Mathematics and Statistics, Boston University, Boston, MA 02215; Center for Systems Neuroscience, Boston University, Boston, MA 02215
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA 02215; Center for Systems Neuroscience, Boston University, Boston, MA 02215
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114; Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114.
| |
Collapse
|
9
|
Kwon H, Chinappen DM, Huang JF, Berja ED, Walsh KG, Shi W, Kramer MA, Chu CJ. Transient, developmental functional and structural connectivity abnormalities in the thalamocortical motor network in Rolandic epilepsy. NEUROIMAGE: CLINICAL 2022; 35:103102. [PMID: 35777251 PMCID: PMC9251597 DOI: 10.1016/j.nicl.2022.103102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/29/2022] Open
Abstract
Children with active Rolandic epilepsy have increasing thalamocortical functional connectivity in the motor circuit with age. Children with resolved Rolandic epilepsy have increasing thalamocortical structural connectivity in the motor circuit with age. Children with Rolandic epilepsy have no differences in thalamocortical connectivity in the sensory circuit compared to controls. Rolandic thalamocortical structural connectivity does not predict functional connectivity in Rolandic epilepsy or controls.
Rolandic epilepsy (RE) is the most common focal, idiopathic, developmental epilepsy, characterized by a transient period of sleep-potentiated seizures and epileptiform discharges in the inferior Rolandic cortex during childhood. The cause of RE remains unknown but converging evidence has identified abnormalities in the Rolandic thalamocortical circuit. To better localize this transient disease, we evaluated Rolandic thalamocortical functional and structural connectivity in the sensory and motor circuits separately during the symptomatic and asymptomatic phases of this disease. We collected high resolution structural, diffusion, and resting state functional MRI data in a prospective cohort of children with active RE (n = 17), resolved RE (n = 21), and controls (n = 33). We then computed the functional and structural connectivity between the inferior Rolandic cortex and the ventrolateral (VL) nucleus of the thalamus (efferent pathway) and the ventroposterolateral (VPL) nucleus of the thalamus (afferent pathway) across development in children with active, resolved RE and controls. We compared connectivity with age in each group using linear mixed-effects models. We found that children with active RE have increasing thalamocortical functional connectivity between the VL thalamus and inferior motor cortex with age (p = 0.022) that is not observed in controls or resolved RE. In contrast, children with resolved RE have increasing thalamocortical structural connectivity between the VL nucleus and the inferior motor cortex with age (p = 0.025) that is not observed in controls or active RE. No relationships were identified between VPL nuclei and the inferior sensory cortex with age in any group. These findings localize the functional and structural thalamocortical circuit disruption in RE to the efferent thalamocortical motor pathway. Further work is required to determine how these circuit abnormalities contribute to the emergence and resolution of symptoms in this developmental disease.
Collapse
Affiliation(s)
- Hunki Kwon
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Dhinakaran M Chinappen
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Jonathan F Huang
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Erin D Berja
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Katherine G Walsh
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Wen Shi
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA; Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| |
Collapse
|