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Paprocka J, Coppola A, Cuccurullo C, Stawicka E, Striano P. Epilepsy, EEG and chromosomal rearrangements. Epilepsia Open 2024; 9:1192-1232. [PMID: 38837855 PMCID: PMC11296106 DOI: 10.1002/epi4.12951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 03/17/2024] [Accepted: 04/10/2024] [Indexed: 06/07/2024] Open
Abstract
Chromosomal abnormalities are associated with a broad spectrum of clinical manifestations, one of the more commonly observed of which is epilepsy. The frequency, severity, and type of epileptic seizures vary according to the macro- and microrearrangements present. Even within a single chromosomal anomaly, we most often deal with a phenotypic spectrum. The aim of the study was to look for chromosomal rearrangements with a characteristic electroencephalographic pattern. Only a few disorders have peculiar electroclinical abnormalities: 1p36, 4p16, 6q terminal or trisomy 12p, Angelman syndrome, inv dup 15, 15q13.3 deletions, ring 20, Down syndrome, or Xp11.22-11.23 duplication. We also reviewed studies on epileptic seizures and typical electroencephalographic patterns described in certain chromosomal rearrangements, focusing on the quest for potential electroclinical biomarkers. The comprehensive review concludes with clinical presentations of the most common micro and macro chromosomal rearrangements, such as 17q21.31 microdeletion, 6q terminal deletion, 15q inv dup syndrome, 2q24.4 deletion, Xp11.22-11.23 duplication, 15q13.3 microdeletion, 1p36 terminal deletion, 5q14.3 microdeletion, and Xq28 duplication. The papers reviewed did not identify any specific interictal electroencephalographic patterns that were unique and significant biomarkers for a given chromosomal microrearrangement. The types of seizures described varied, with both generalized and focal seizures of various morphologies being reported. Patients with chromosomal anomalies may also meet the criteria for specific epileptic syndromes such as Infantile Epilepsy Spasms Syndrome (IESS, West syndrome): 16p13.11, 15q13.3 and 17q21.31 microdeletions, 5q inv dup. syndrome; Dravet syndrome (2q24.4 deletion), Lennox-Gastaut syndrome (15q11 duplication. 1q13.3, 5q inv dup.); or Self-Limited Epilepsy with Autonomic Features (SeLEAS, Panayiotopoulos syndrome: terminal deletion of 6q.n), Self-Limited Epilepsy with Centrotemporal Spikes (SeLECT): fragile X syndrome. It is essential to better characterize groups of patients to more accurately define patterns of epilepsy and EEG abnormalities. This could lead to new treatment strategies. Future research is required to better understand epileptic syndromes and chromosomal rearrangements. PLAIN LANGUAGE SUMMARY: This paper presents EEG recording abnormalities in patients with various gene abnormalities that can cause epilepsy. The authors summarize these EEG variations based on a literature review to see if they occur frequently enough in other chromosomal abnormalities (in addition to those already known) to be a clue for further diagnosis.
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Affiliation(s)
- Justyna Paprocka
- Pediatric Neurology Department, Faculty of Medical SciencesMedical University of SilesiaKatowicePoland
| | - Antonietta Coppola
- Epilepsy Centre, Neurology Department of Neurology, Reproductive and OdontostomatologyFederico II UniversityNaplesItaly
| | - Claudia Cuccurullo
- Epilepsy Centre, Neurology Department of Neurology, Reproductive and OdontostomatologyFederico II UniversityNaplesItaly
| | - Elżbieta Stawicka
- Clinic of Paediatric NeurologyInstitute of Mother and ChildWarsawPoland
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthIRCCS Istituto Giannina GasliniGenoaItaly
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversity of GenoaGenoaItaly
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Medina J, Zhou Z. Unlock the potential: Auditory-evoked event-related potential (ERP) as a treatment-responsive biomarker for Rett syndrome. Neurotherapeutics 2024; 21:e00389. [PMID: 38944637 DOI: 10.1016/j.neurot.2024.e00389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Accepted: 06/15/2024] [Indexed: 07/01/2024] Open
Affiliation(s)
- Joanna Medina
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhaolan Zhou
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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Dong HW, Weiss K, Baugh K, Meadows MJ, Niswender CM, Neul JL. Potentiation of the muscarinic acetylcholine receptor 1 modulates neurophysiological features in a mouse model of Rett syndrome. Neurotherapeutics 2024; 21:e00384. [PMID: 38880672 DOI: 10.1016/j.neurot.2024.e00384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/07/2024] [Accepted: 06/09/2024] [Indexed: 06/18/2024] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder primarily caused by mutations in the X chromosome-linked gene Methyl-CpG Binding Protein 2 (MECP2). Restoring MeCP2 expression after disease onset in a mouse model of RTT reverses phenotypes, providing hope for development of treatments for RTT. Translatable biomarkers of improvement and treatment responses have the potential to accelerate both preclinical and clinical evaluation of targeted therapies in RTT. Studies in people with and mouse models of RTT have identified neurophysiological features, such as auditory event-related potentials, that correlate with disease severity, suggesting that they could be useful as biomarkers of disease improvement or early treatment response. We recently demonstrated that treatment of RTT mice with a positive allosteric modulator (PAM) of muscarinic acetylcholine subtype 1 receptor (M1) improved phenotypes, suggesting that modulation of M1 activity is a potential therapy in RTT. To evaluate whether neurophysiological features could be useful biomarkers to assess the effects of M1 PAM treatment, we acutely administered the M1 PAM VU0486846 (VU846) at doses of 1, 3, 10 and 30 mg/kg in wildtype and RTT mice. This resulted in an inverted U-shaped dose response with maximal improvement of AEP features at 3 mg/kg but with no marked effect on basal EEG power or epileptiform discharges in RTT mice and no significant changes in wildtype mice. These findings suggest that M1 potentiation can improve neural circuit synchrony to auditory stimuli in RTT mice and that neurophysiological features have potential as pharmacodynamic or treatment-responsive biomarkers for preclinical and clinical evaluation of putative therapies in RTT.
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Affiliation(s)
- Hong-Wei Dong
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, USA; Vanderbilt University Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kelly Weiss
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Warren Center for Neuroscience Drug Discovery, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Kathryn Baugh
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, USA
| | - Mac J Meadows
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Warren Center for Neuroscience Drug Discovery, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Colleen M Niswender
- Vanderbilt University Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Warren Center for Neuroscience Drug Discovery, School of Medicine, Vanderbilt University, Nashville, TN, USA; Vanderbilt Institute for Chemical Biology, Nashville, TN, USA; Vanderbilt Brain Institute, Nashville, TN, USA.
| | - Jeffrey L Neul
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, USA; Vanderbilt University Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, TN, USA; Vanderbilt Brain Institute, Nashville, TN, USA.
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Brima T, Beker S, Prinsloo KD, Butler JS, Djukic A, Freedman EG, Molholm S, Foxe JJ. Probing a neural unreliability account of auditory sensory processing atypicalities in Rett Syndrome. J Neurodev Disord 2024; 16:28. [PMID: 38831410 PMCID: PMC11149250 DOI: 10.1186/s11689-024-09544-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 05/21/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND In the search for objective tools to quantify neural function in Rett Syndrome (RTT), which are crucial in the evaluation of therapeutic efficacy in clinical trials, recordings of sensory-perceptual functioning using event-related potential (ERP) approaches have emerged as potentially powerful tools. Considerable work points to highly anomalous auditory evoked potentials (AEPs) in RTT. However, an assumption of the typical signal-averaging method used to derive these measures is "stationarity" of the underlying responses - i.e. neural responses to each input are highly stereotyped. An alternate possibility is that responses to repeated stimuli are highly variable in RTT. If so, this will significantly impact the validity of assumptions about underlying neural dysfunction, and likely lead to overestimation of underlying neuropathology. To assess this possibility, analyses at the single-trial level assessing signal-to-noise ratios (SNR), inter-trial variability (ITV) and inter-trial phase coherence (ITPC) are necessary. METHODS AEPs were recorded to simple 100 Hz tones from 18 RTT and 27 age-matched controls (Ages: 6-22 years). We applied standard AEP averaging, as well as measures of neuronal reliability at the single-trial level (i.e. SNR, ITV, ITPC). To separate signal-carrying components from non-neural noise sources, we also applied a denoising source separation (DSS) algorithm and then repeated the reliability measures. RESULTS Substantially increased ITV, lower SNRs, and reduced ITPC were observed in auditory responses of RTT participants, supporting a "neural unreliability" account. Application of the DSS technique made it clear that non-neural noise sources contribute to overestimation of the extent of processing deficits in RTT. Post-DSS, ITV measures were substantially reduced, so much so that pre-DSS ITV differences between RTT and TD populations were no longer detected. In the case of SNR and ITPC, DSS substantially improved these estimates in the RTT population, but robust differences between RTT and TD were still fully evident. CONCLUSIONS To accurately represent the degree of neural dysfunction in RTT using the ERP technique, a consideration of response reliability at the single-trial level is highly advised. Non-neural sources of noise lead to overestimation of the degree of pathological processing in RTT, and denoising source separation techniques during signal processing substantially ameliorate this issue.
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Affiliation(s)
- Tufikameni Brima
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience & Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Shlomit Beker
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA
| | - Kevin D Prinsloo
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience & Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - John S Butler
- School of Mathematical Sciences, Technological University Dublin, Kevin Street Campus, Dublin 8, Ireland
| | - Aleksandra Djukic
- Rett Syndrome Center, Department of Neurology, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA
| | - Edward G Freedman
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience & Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Sophie Molholm
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience & Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA
| | - John J Foxe
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience & Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics and Neuroscience, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA.
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Brima T, Beker S, Prinsloo KD, Butler JS, Djukic A, Freedman EG, Molholm S, Foxe JJ. Probing a neural unreliability account of auditory sensory processing atypicalities in Rett Syndrome. RESEARCH SQUARE 2024:rs.3.rs-3863341. [PMID: 38352397 PMCID: PMC10862956 DOI: 10.21203/rs.3.rs-3863341/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Background In the search for objective tools to quantify neural function in Rett Syndrome (RTT), which are crucial in the evaluation of therapeutic efficacy in clinical trials, recordings of sensory-perceptual functioning using event-related potential (ERP) approaches have emerged as potentially powerful tools. Considerable work points to highly anomalous auditory evoked potentials (AEPs) in RTT. However, an assumption of the typical signal-averaging method used to derive these measures is "stationarity" of the underlying responses - i.e. neural responses to each input are highly stereotyped. An alternate possibility is that responses to repeated stimuli are highly variable in RTT. If so, this will significantly impact the validity of assumptions about underlying neural dysfunction, and likely lead to overestimation of underlying neuropathology. To assess this possibility, analyses at the single-trial level assessing signal-to-noise ratios (SNR), inter-trial variability (ITV) and inter-trial phase coherence (ITPC) are necessary. Methods AEPs were recorded to simple 100Hz tones from 18 RTT and 27 age-matched controls (Ages: 6-22 years). We applied standard AEP averaging, as well as measures of neuronal reliability at the single-trial level (i.e. SNR, ITV, ITPC). To separate signal-carrying components from non-neural noise sources, we also applied a denoising source separation (DSS) algorithm and then repeated the reliability measures. Results Substantially increased ITV, lower SNRs, and reduced ITPC were observed in auditory responses of RTT participants, supporting a "neural unreliability" account. Application of the DSS technique made it clear that non-neural noise sources contribute to overestimation of the extent of processing deficits in RTT. Post-DSS, ITV measures were substantially reduced, so much so that pre-DSS ITV differences between RTT and TD populations were no longer detected. In the case of SNR and ITPC, DSS substantially improved these estimates in the RTT population, but robust differences between RTT and TD were still fully evident. Conclusions To accurately represent the degree of neural dysfunction in RTT using the ERP technique, a consideration of response reliability at the single-trial level is highly advised. Non-neural sources of noise lead to overestimation of the degree of pathological processing in RTT, and denoising source separation techniques during signal processing substantially ameliorate this issue.
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Brima T, Beker S, Prinsloo KD, Butler JS, Djukic A, Freedman EG, Molholm S, Foxe JJ. Probing a neural unreliability account of auditory sensory processing atypicalities in Rett Syndrome. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.25.24301723. [PMID: 38343802 PMCID: PMC10854351 DOI: 10.1101/2024.01.25.24301723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/26/2024]
Abstract
Background In the search for objective tools to quantify neural function in Rett Syndrome (RTT), which are crucial in the evaluation of therapeutic efficacy in clinical trials, recordings of sensory-perceptual functioning using event-related potential (ERP) approaches have emerged as potentially powerful tools. Considerable work points to highly anomalous auditory evoked potentials (AEPs) in RTT. However, an assumption of the typical signal-averaging method used to derive these measures is "stationarity" of the underlying responses - i.e. neural responses to each input are highly stereotyped. An alternate possibility is that responses to repeated stimuli are highly variable in RTT. If so, this will significantly impact the validity of assumptions about underlying neural dysfunction, and likely lead to overestimation of underlying neuropathology. To assess this possibility, analyses at the single-trial level assessing signal-to-noise ratios (SNR), inter-trial variability (ITV) and inter-trial phase coherence (ITPC) are necessary. Methods AEPs were recorded to simple 100Hz tones from 18 RTT and 27 age-matched controls (Ages: 6-22 years). We applied standard AEP averaging, as well as measures of neuronal reliability at the single-trial level (i.e. SNR, ITV, ITPC). To separate signal-carrying components from non-neural noise sources, we also applied a denoising source separation (DSS) algorithm and then repeated the reliability measures. Results Substantially increased ITV, lower SNRs, and reduced ITPC were observed in auditory responses of RTT participants, supporting a "neural unreliability" account. Application of the DSS technique made it clear that non-neural noise sources contribute to overestimation of the extent of processing deficits in RTT. Post-DSS, ITV measures were substantially reduced, so much so that pre-DSS ITV differences between RTT and TD populations were no longer detected. In the case of SNR and ITPC, DSS substantially improved these estimates in the RTT population, but robust differences between RTT and TD were still fully evident. Conclusions To accurately represent the degree of neural dysfunction in RTT using the ERP technique, a consideration of response reliability at the single-trial level is highly advised. Non-neural sources of noise lead to overestimation of the degree of pathological processing in RTT, and denoising source separation techniques during signal processing substantially ameliorate this issue.
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Affiliation(s)
- Tufikameni Brima
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory Ernest J. Del Monte Institute for Neuroscience &Department of Neuroscience University of Rochester School of Medicine and Dentistry Rochester, New York 14642, USA
| | - Shlomit Beker
- The Cognitive Neurophysiology Laboratory Departments of Pediatrics and Neuroscience Albert Einstein College of Medicine & Montefiore Medical Center Bronx, New York 10461, USA
| | - Kevin D. Prinsloo
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory Ernest J. Del Monte Institute for Neuroscience &Department of Neuroscience University of Rochester School of Medicine and Dentistry Rochester, New York 14642, USA
| | - John S. Butler
- School of Mathematical Sciences Technological University Dublin Kevin Street Campus, Dublin 8, Ireland
| | - Aleksandra Djukic
- Rett Syndrome Center Department of Neurology Albert Einstein College of Medicine & Montefiore Medical Center Bronx, New York 10467, USA
| | - Edward G. Freedman
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory Ernest J. Del Monte Institute for Neuroscience &Department of Neuroscience University of Rochester School of Medicine and Dentistry Rochester, New York 14642, USA
| | - Sophie Molholm
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory Ernest J. Del Monte Institute for Neuroscience &Department of Neuroscience University of Rochester School of Medicine and Dentistry Rochester, New York 14642, USA
- The Cognitive Neurophysiology Laboratory Departments of Pediatrics and Neuroscience Albert Einstein College of Medicine & Montefiore Medical Center Bronx, New York 10461, USA
| | - John J. Foxe
- The Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory Ernest J. Del Monte Institute for Neuroscience &Department of Neuroscience University of Rochester School of Medicine and Dentistry Rochester, New York 14642, USA
- The Cognitive Neurophysiology Laboratory Departments of Pediatrics and Neuroscience Albert Einstein College of Medicine & Montefiore Medical Center Bronx, New York 10461, USA
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Rahn RM, Yen A, Chen S, Gaines SH, Bice AR, Brier LM, Swift RG, Lee L, Maloney SE, Culver JP, Dougherty JD. Mecp2 deletion results in profound alterations of developmental and adult functional connectivity. Cereb Cortex 2023; 33:7436-7453. [PMID: 36897048 PMCID: PMC10267622 DOI: 10.1093/cercor/bhad050] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 03/11/2023] Open
Abstract
As a regressive neurodevelopmental disorder with a well-established genetic cause, Rett syndrome and its Mecp2 loss-of-function mouse model provide an excellent opportunity to define potentially translatable functional signatures of disease progression, as well as offer insight into the role of Mecp2 in functional circuit development. Thus, we applied widefield optical fluorescence imaging to assess mesoscale calcium functional connectivity (FC) in the Mecp2 cortex both at postnatal day (P)35 in development and during the disease-related decline. We found that FC between numerous cortical regions was disrupted in Mecp2 mutant males both in juvenile development and early adulthood. Female Mecp2 mice displayed an increase in homotopic contralateral FC in the motor cortex at P35 but not in adulthood, where instead more posterior parietal regions were implicated. An increase in the amplitude of connection strength, both with more positive correlations and more negative anticorrelations, was observed across the male cortex in numerous functional regions. Widespread rescue of MeCP2 protein in GABAergic neurons rescued none of these functional deficits, nor, surprisingly, the expected male lifespan. Altogether, the female results identify early signs of disease progression, while the results in males indicate MeCP2 protein is required for typical FC in the brain.
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Affiliation(s)
- Rachel M Rahn
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Allen Yen
- Department of Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Siyu Chen
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Seana H Gaines
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Annie R Bice
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Lindsey M Brier
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Raylynn G Swift
- Department of Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - LeiLani Lee
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Susan E Maloney
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Intellectual and Developmental Disabilities Research Center, 660 South Euclid Avenue, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Joseph P Culver
- Department of Radiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Physics, Washington University School of Arts and Sciences, 1 Brookings Drive, St. Louis, MO 63130, United States
- Department of Biomedical Engineering, Washington University School of Engineering, 1 Brookings Drive, St. Louis, MO 63130, United States
| | - Joseph D Dougherty
- Department of Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, United States
- Intellectual and Developmental Disabilities Research Center, 660 South Euclid Avenue, Washington University School of Medicine, St. Louis, MO 63110, United States
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Goodspeed K, Armstrong D, Dolce A, Evans P, Said R, Tsai P, Sirsi D. Electroencephalographic (EEG) Biomarkers in Genetic Neurodevelopmental Disorders. J Child Neurol 2023; 38:466-477. [PMID: 37264615 PMCID: PMC10644693 DOI: 10.1177/08830738231177386] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/17/2022] [Accepted: 04/28/2023] [Indexed: 06/03/2023]
Abstract
Collectively, neurodevelopmental disorders are highly prevalent, but more than a third of neurodevelopmental disorders have an identifiable genetic etiology, each of which is individually rare. The genes associated with neurodevelopmental disorders are often involved in early brain development, neuronal signaling, or synaptic plasticity. Novel treatments for many genetic neurodevelopmental disorders are being developed, but disease-relevant clinical outcome assessments and biomarkers are limited. Electroencephalography (EEG) is a promising noninvasive potential biomarker of brain function. It has been used extensively in epileptic disorders, but its application in neurodevelopmental disorders needs further investigation. In this review, we explore the use of EEG in 3 of the most prevalent genetic neurodevelopmental disorders-Angelman syndrome, Rett syndrome, and fragile X syndrome. Quantitative analyses of EEGs, such as power spectral analysis or measures of connectivity, can quantify EEG signatures seen on qualitative review and potentially correlate with phenotypes. In both Angelman syndrome and Rett syndrome, increased delta power on spectral analysis has correlated with clinical markers of disease severity including developmental disability and seizure burden, whereas spectral power analysis on EEG in fragile X syndrome tends to demonstrate abnormalities in gamma power. Further studies are needed to establish reliable relationships between quantitative EEG biomarkers and clinical phenotypes in rare genetic neurodevelopmental disorders.
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Affiliation(s)
- Kimberly Goodspeed
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Dallas Armstrong
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Alison Dolce
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Patricia Evans
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rana Said
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Peter Tsai
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Deepa Sirsi
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Saby JN, Peters SU, Benke TA, Standridge SM, Swanson LC, Lieberman DN, Olson HE, Key AP, Percy AK, Neul JL, Nelson CA, Roberts TPL, Marsh ED. Comparison of evoked potentials across four related developmental encephalopathies. J Neurodev Disord 2023; 15:10. [PMID: 36870948 PMCID: PMC9985257 DOI: 10.1186/s11689-023-09479-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/23/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Developing biomarkers is a priority for drug development for all conditions, but vital in the rare neurodevelopmental disorders where sensitive outcome measures are lacking. We have previously demonstrated the feasibility and tracking of evoked potentials to disease severity in Rett syndrome and CDKL5 deficiency disorder. The aim of the current study is to characterize evoked potentials in two related developmental encephalopathies, MECP2 duplication syndrome and FOXG1 syndrome, and compare across all four groups to better understand the potential of these measures to serve as biomarkers of clinical severity for the developmental encephalopathies. METHODS Visual and auditory evoked potentials were acquired from participants with MECP2 duplication syndrome and FOXG1 syndrome across five sites of the Rett Syndrome and Rett-Related Disorders Natural History Study. A group of age-matched individuals (mean = 7.8 years; range = 1-17) with Rett syndrome, CDKL5 deficiency disorder, and typically-developing participants served as a comparison group. The analysis focused on group-level differences as well as associations between the evoked potentials and measures of clinical severity from the Natural History Study. RESULTS As reported previously, group-level comparisons revealed attenuated visual evoked potentials (VEPs) in participants with Rett syndrome (n = 43) and CDKL5 deficiency disorder (n = 16) compared to typically-developing participants. VEP amplitude was also attenuated in participants with MECP2 duplication syndrome (n = 15) compared to the typically-developing group. VEP amplitude correlated with clinical severity for Rett syndrome and FOXG1 syndrome (n = 5). Auditory evoked potential (AEP) amplitude did not differ between groups, but AEP latency was prolonged in individuals with MECP2 duplication syndrome (n = 14) and FOXG1 syndrome (n = 6) compared to individuals with Rett syndrome (n = 51) and CDKL5 deficiency disorder (n = 14). AEP amplitude correlated with severity in Rett syndrome and CDKL5 deficiency disorder. AEP latency correlated with severity in CDKL5 deficiency disorder, MECP2 duplication syndrome, and FOXG1 syndrome. CONCLUSIONS There are consistent abnormalities in the evoked potentials in four developmental encephalopathies some of which correlate with clinical severity. While there are consistent changes amongst these four disorders, there are also condition specific findings that need to be further refined and validated. Overall, these results provide a foundation for further refinement of these measures for use in future clinical trials for these conditions.
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Affiliation(s)
- Joni N Saby
- Division of Radiology Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sarika U Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, TN, USA
| | - Timothy A Benke
- Department of Pediatrics, Neurology,, Pharmacology and Otolaryngology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, USA
| | - Shannon M Standridge
- Division of Neurology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, , USA
| | - Lindsay C Swanson
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - David N Lieberman
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Heather E Olson
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Alexandra P Key
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, TN, USA
| | - Alan K Percy
- Department of Pediatrics (Neurology), University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jeffrey L Neul
- Department of Pediatrics, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, TN, USA
| | - Charles A Nelson
- Laboratories of Cognitive Neuroscience, Boston Children's Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Graduate School of Education, Harvard University, Cambridge, MA, USA
| | - Timothy P L Roberts
- Division of Radiology Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Eric D Marsh
- Division of Child Neurology, Children's Hospital of Philadelphia, Abramson Research Building- Room 502E, 3615 Civic Center Boulevard, Philadelphia, PA, 19104, USA.
- Orphan Disease Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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10
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Hypoventilation and sleep hypercapnia in a case of congenital variant-like Rett syndrome. Ital J Pediatr 2022; 48:167. [PMID: 36071486 PMCID: PMC9450235 DOI: 10.1186/s13052-022-01359-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 08/30/2022] [Indexed: 11/18/2022] Open
Abstract
Background Breathing disturbances are often a primary clinical concern especially during wakefulness of the classic form of Rett syndrome, but data for atypical forms are lacking. Case presentation We report the case of a 20-month-old female affected by Rett syndrome with congenital variant-like onset, characterized by severe hypotonia and neurodevelopment impairment. She presented hypoventilation, persistent periodic breathing, and sustained desaturation during sleep, without obstructive or mixed events. Pulse oximetry and capnography during wakefulness were strictly normal. To the best of our knowledge, this is the first case of a patient affected by a congenital variant of Rett syndrome presenting sleep hypercapnia. Hypotonia may play a major role in the genesis of hypoventilation and hypoxemia in our patient. Non-invasive ventilation led to quality-of-life improvements. Conclusions Thus, we suggest screening patients with congenital-like Rett syndrome through transcutaneous bedtime carbon dioxide and oxygen monitoring. Moreover, assisted control mode was a breakthrough to achieve adequate ventilation in our case.
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11
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Wilde M, Constantin L, Thorne PR, Montgomery JM, Scott EK, Cheyne JE. Auditory processing in rodent models of autism: a systematic review. J Neurodev Disord 2022; 14:48. [PMID: 36042393 PMCID: PMC9429780 DOI: 10.1186/s11689-022-09458-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 08/07/2022] [Indexed: 11/19/2022] Open
Abstract
Autism is a complex condition with many traits, including differences in auditory sensitivity. Studies in human autism are plagued by the difficulty of controlling for aetiology, whereas studies in individual rodent models cannot represent the full spectrum of human autism. This systematic review compares results in auditory studies across a wide range of established rodent models of autism to mimic the wide range of aetiologies in the human population. A search was conducted in the PubMed and Web of Science databases to find primary research articles in mouse or rat models of autism which investigate central auditory processing. A total of 88 studies were included. These used non-invasive measures of auditory function, such as auditory brainstem response recordings, cortical event-related potentials, electroencephalography, and behavioural tests, which are translatable to human studies. They also included invasive measures, such as electrophysiology and histology, which shed insight on the origins of the phenotypes found in the non-invasive studies. The most consistent results across these studies were increased latency of the N1 peak of event-related potentials, decreased power and coherence of gamma activity in the auditory cortex, and increased auditory startle responses to high sound levels. Invasive studies indicated loss of subcortical inhibitory neurons, hyperactivity in the lateral superior olive and auditory thalamus, and reduced specificity of responses in the auditory cortex. This review compares the auditory phenotypes across rodent models and highlights those that mimic findings in human studies, providing a framework and avenues for future studies to inform understanding of the auditory system in autism.
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Affiliation(s)
- Maya Wilde
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Lena Constantin
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Peter R Thorne
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Section of Audiology, School of Population Health, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Ethan K Scott
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.,Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Juliette E Cheyne
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand.
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12
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CDKL5 deficiency disorder: molecular insights and mechanisms of pathogenicity to fast-track therapeutic development. Biochem Soc Trans 2022; 50:1207-1224. [PMID: 35997111 PMCID: PMC9444073 DOI: 10.1042/bst20220791] [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: 05/30/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 12/02/2022]
Abstract
CDKL5 deficiency disorder (CDD) is an X-linked brain disorder of young children and is caused by pathogenic variants in the cyclin-dependent kinase-like 5 (CDKL5) gene. Individuals with CDD suffer infantile onset, drug-resistant seizures, severe neurodevelopmental impairment and profound lifelong disability. The CDKL5 protein is a kinase that regulates key phosphorylation events vital to the development of the complex neuronal network of the brain. Pathogenic variants identified in patients may either result in loss of CDKL5 catalytic activity or are hypomorphic leading to partial loss of function. Whilst the progressive nature of CDD provides an excellent opportunity for disease intervention, we cannot develop effective therapeutics without in-depth knowledge of CDKL5 function in human neurons. In this mini review, we summarize new findings on the function of CDKL5. These include CDKL5 phosphorylation targets and the consequence of disruptions on signaling pathways in the human brain. This new knowledge of CDKL5 biology may be leveraged to advance targeted drug discovery and rapid development of treatments for CDD. Continued development of effective humanized models will further propel our understanding of CDD biology and may permit the development and testing of therapies that will significantly alter CDD disease trajectory in young children.
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13
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Improving clinical trial readiness to accelerate development of new therapeutics for Rett syndrome. Orphanet J Rare Dis 2022; 17:108. [PMID: 35246185 PMCID: PMC8894842 DOI: 10.1186/s13023-022-02240-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 02/06/2022] [Indexed: 12/16/2022] Open
Abstract
Rett syndrome is associated with severe functional impairments and many comorbidities, each in urgent need of treatments. Mutations in the MECP2 gene were identified as causing Rett syndrome in 1999. Over the past 20 years there has been an abundance of preclinical research with some studies leading to human clinical trials. Despite this, few viable therapeutic options have emerged from this investment of effort. Reasons for this lack of success as they relate both to preclinical research and the clinical trial landscape are discussed. Considering what needs to be done to promote further success in the field, we take a positive and constructive approach and introduce the concept of clinical trial readiness and its necessary ingredients for Rett syndrome. These include: listening to the needs of families; support from advocacy groups; optimising use of existing clinic infrastructures and available natural history data; and, finally, the validation of existing outcome measures and/or the development and validation of new measures. We conclude by reiterating the need for a collaborative and coordinated approach amongst the many different stakeholder groups and the need to engage in new types of trial design which could be much more efficient, less costly and much less burdensome on families.
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14
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Ramirez JM, Karlen-Amarante M, Wang JDJ, Huff A, Burgraff N. Breathing disturbances in Rett syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:139-151. [PMID: 36031301 PMCID: PMC10029146 DOI: 10.1016/b978-0-323-91532-8.00018-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Rett Syndrome is an X-linked neurological disorder characterized by behavioral and neurological regression, seizures, motor deficits, and dysautonomia. A particularly prominent presentation includes breathing abnormalities characterized by breathing irregularities, hyperventilation, repetitive breathholding during wakefulness, obstructive and central apneas during sleep, and abnormal responses to hypoxia and hypercapnia. The condition and pathology of the respiratory system is further complicated by dysfunctions of breathing-motor coordination, which is reflected in dysphagia. The discovery of the X-linked mutations in the MECP2 gene has transformed our understanding of the cellular and molecular mechanisms that are at the root of various clinical phenotypes. However, the genotype-phenotype relationship is complicated by various factors which include not only X-inactivation but also consequences of the intermittent hypoxia and oxidative stress associated with the breathing abnormalities.
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Affiliation(s)
- Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States; Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, United States.
| | - Marlusa Karlen-Amarante
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Jia-Der Ju Wang
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Alyssa Huff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Nicholas Burgraff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
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15
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Saby JN, Mulcahey PJ, Zavez AE, Peters SU, Standridge SM, Swanson LC, Lieberman DN, Olson HE, Key AP, Percy AK, Neul JL, Nelson CA, Roberts TPL, Benke TA, Marsh ED. Electrophysiological biomarkers of brain function in CDKL5 deficiency disorder. Brain Commun 2022; 4:fcac197. [PMID: 35974796 PMCID: PMC9374482 DOI: 10.1093/braincomms/fcac197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/05/2022] [Accepted: 08/02/2022] [Indexed: 11/14/2022] Open
Abstract
CDKL5 deficiency disorder is a debilitating developmental and epileptic encephalopathy for which no targeted treatment exists. A number of promising therapeutics are under development for CDKL5 deficiency disorder but a lack of validated biomarkers of brain function and clinical severity may limit the ability to objectively assess the efficacy of new treatments as they become available. To address this need, the current study quantified electrophysiological measures in individuals with CDKL5 deficiency disorder and the association between these parameters and clinical severity. Visual and auditory evoked potentials, as well as resting EEG, were acquired across 5 clinical sites from 26 individuals with CDKL5 deficiency disorder. Evoked potential and quantitative EEG features were calculated and compared with typically developing individuals in an age- and sex-matched cohort. Baseline and Year 1 data, when available, were analysed and the repeatability of the results was tested. Two clinician-completed severity scales were used for evaluating the clinical relevance of the electrophysiological parameters. Group-level comparisons revealed reduced visual evoked potential amplitude in CDKL5 deficiency disorder individuals versus typically developing individuals. There were no group differences in the latency of the visual evoked potentials or in the latency or amplitude of the auditory evoked potentials. Within the CDKL5 deficiency disorder group, auditory evoked potential amplitude correlated with disease severity at baseline as well as Year 1. Multiple quantitative EEG features differed between CDKL5 deficiency disorder and typically developing participants, including amplitude standard deviation, 1/f slope and global delta, theta, alpha and beta power. Several quantitative EEG features correlated with clinical severity, including amplitude skewness, theta/delta ratio and alpha/delta ratio. The theta/delta ratio was the overall strongest predictor of severity and also among the most repeatable qEEG measures from baseline to Year 1. Together, the present findings point to the utility of evoked potentials and quantitative EEG parameters as objective measures of brain function and disease severity in future clinical trials for CDKL5 deficiency disorder. The results also underscore the utility of the current methods, which could be similarly applied to the identification and validation of electrophysiological biomarkers of brain function for other developmental encephalopathies.
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Affiliation(s)
| | | | - Alexis E Zavez
- Orphan Disease Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarika U Peters
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Shannon M Standridge
- Cincinnati Children’s Hospital Medical Center, Division of Neurology and University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Lindsay C Swanson
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - David N Lieberman
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Heather E Olson
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Alexandra P Key
- Department of Hearing and Speech Sciences, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alan K Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Jeffrey L Neul
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Charles A Nelson
- Laboratories of Cognitive Neuroscience, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics, Harvard Medical School, Cambridge, MA 02115, USA
- Graduate School of Education, Harvard University, Cambridge, MA 02115, USA
| | - Timothy P L Roberts
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Timothy A Benke
- Department of Pediatrics, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
- Department of Neurology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
- Department of Pharmacology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
- Department of Otolaryngology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Eric D Marsh
- Correspondence to: Eric D. Marsh, MD Division of Child Neurology Abramson Research Building, Room 502E 3615 Civic Center Boulevard Philadelphia, PA 19104, USA E-mail:
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16
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Terzic B, Davatolhagh MF, Ho Y, Tang S, Liu YT, Xia Z, Cui Y, Fuccillo MV, Zhou Z. Temporal manipulation of Cdkl5 reveals essential postdevelopmental functions and reversible CDKL5 deficiency disorder-related deficits. J Clin Invest 2021; 131:143655. [PMID: 34651584 DOI: 10.1172/jci143655] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 08/05/2021] [Indexed: 12/23/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is an early onset, neurodevelopmental syndrome associated with pathogenic variants in the X-linked gene encoding cyclin-dependent kinase-like 5 (CDKL5). CDKL5 has been implicated in neuronal synapse maturation, yet its postdevelopmental necessity and the reversibility of CDD-associated impairments remain unknown. We temporally manipulated endogenous Cdkl5 expression in male mice and found that postdevelopmental loss of CDKL5 disrupts numerous behavioral domains, hippocampal circuit communication, and dendritic spine morphology, demonstrating an indispensable role for CDKL5 in the adult brain. Accordingly, restoration of Cdkl5 after the early stages of brain development using a conditional rescue mouse model ameliorated CDD-related behavioral impairments and aberrant NMDA receptor signaling. These findings highlight the requirement of CDKL5 beyond early development, underscore the potential for disease reversal in CDD, and suggest that a broad therapeutic time window exists for potential treatment of CDD-related deficits.
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Affiliation(s)
| | - M Felicia Davatolhagh
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | - Marc V Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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17
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Armstrong C, Marsh ED. Electrophysiological Biomarkers in Genetic Epilepsies. Neurotherapeutics 2021; 18:1458-1467. [PMID: 34642905 PMCID: PMC8609056 DOI: 10.1007/s13311-021-01132-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2021] [Indexed: 02/04/2023] Open
Abstract
Precision treatments for epilepsy targeting the underlying genetic diagnoses are becoming a reality. Historically, the goal of epilepsy treatments was to reduce seizure frequency. In the era of precision medicine, however, outcomes such as prevention of epilepsy progression or even improvements in cognitive functions are both aspirational targets for any intervention. Developing methods, both in clinical trial design and in novel endpoints, will be necessary for measuring, not only seizures, but also the other neurodevelopmental outcomes that are predicted to be targeted by precision treatments. Biomarkers that quantitatively measure disease progression or network level changes are needed to allow for unbiased measurements of the effects of any gene-level treatments. Here, we discuss some of the promising electrophysiological biomarkers that may be of use in clinical trials of precision therapies, as well as the difficulties in implementing them.
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Affiliation(s)
- Caren Armstrong
- Division of Neurology and Pediatric Epilepsy Program, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Eric D Marsh
- Division of Neurology and Pediatric Epilepsy Program, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
- Department of Pediatrics and Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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18
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Singh J, Lanzarini E, Santosh P. Autonomic Characteristics of Sudden Unexpected Death in Epilepsy in Children-A Systematic Review of Studies and Their Relevance to the Management of Epilepsy in Rett Syndrome. Front Neurol 2021; 11:632510. [PMID: 33613425 PMCID: PMC7892970 DOI: 10.3389/fneur.2020.632510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 12/28/2020] [Indexed: 01/21/2023] Open
Abstract
Aim: To systematically identify and critically appraise studies that investigate the autonomic characteristics of Sudden Unexpected Death in Epilepsy (SUDEP) in the pediatric population. We also wanted to explore how this information would be relevant to the management of epilepsy in patients with Rett Syndrome. Method: Using PRISMA guidelines, a systematic review of PubMed, Scopus, Cochrane, PsycINFO, Embase, and Web of Science databases was performed to identify eligible studies. After extracting data from the included studies, a thematic analysis was undertaken to identify emerging themes. A quality appraisal was also done to assess the quality of the included studies. Results: The systematic search revealed 41 records, and 15 full-text articles on the autonomic characteristics of SUDEP in children were included in the final analysis. Following thematic analysis, three themes were identified (I) modulation in sympathovagal tone, (II) pre- and post-ictal autonomic changes, and (III) other markers of autonomic dysregulation in children with epilepsy. Modulation in sympathovagal tone emerged as the theme with the highest frequency followed by pre- and post-ictal autonomic changes. While the themes provide additional insight into the management of epilepsy in the Rett Syndrome population, the quality of evidence concerning the autonomic characteristics of SUDEP in the pediatric population was low and underscores the importance of much needed research in this area. Conclusion: The mechanism of SUDEP in the pediatric population is complex and involves an interplay between several components of the autonomic nervous system. While direct clinical inferences regarding pediatric SUDEP could not be made, the thematic analysis does suggest that in vulnerable populations such as Rett Syndrome, where there is already a pervasive autonomic dysregulation, pro-active surveillance of the autonomic profile in this patient group would be useful to better manage epilepsy and reduce the SUDEP risk.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, United Kingdom.,Centre for Personalised Medicine in Rett Syndrome, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Evamaria Lanzarini
- Child and Adolescent Neuropsychiatry Unit, Infermi Hospital, Rimini, Italy
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, United Kingdom.,Centre for Personalised Medicine in Rett Syndrome, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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19
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Dong HW, Erickson K, Lee JR, Merritt J, Fu C, Neul JL. Detection of neurophysiological features in female R255X MeCP2 mutation mice. Neurobiol Dis 2020; 145:105083. [PMID: 32927061 PMCID: PMC7572861 DOI: 10.1016/j.nbd.2020.105083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/11/2020] [Accepted: 09/08/2020] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder (NDD) that is nearly always caused by loss of function mutations in Methyl-CpG-binding Protein 2 (MECP2) and shares many clinical features with other NDD. Genetic restoration of Mecp2 in symptomatic mice lacking MeCP2 expression can reverse symptoms, providing hope that disease modifying therapies can be identified for RTT. Effective and rapid clinical trial completion relies on well-defined clinical outcome measures and robust biomarkers of treatment responses. Studies on other NDD have found evidence of differences in neurophysiological measures that correlate with disease severity. However, currently there are no well-validated biomarkers in RTT to predict disease prognosis or treatment responses. To address this, we characterized neurophysiological features in a mouse model of RTT containing a knock-in nonsense mutation (p.R255X) in the Mecp2 locus. We found a variety of changes in heterozygous female Mecp2R255X/X mice including age-related changes in sleep/wake architecture, alterations in baseline EEG power, increased incidence of spontaneous epileptiform discharges, and changes in auditory evoked potentials. Furthermore, we identified association of some neurophysiological features with disease severity. These findings provide a set of potential non-invasive and translatable biomarkers that can be utilized in preclinical therapy trials in animal models of RTT and eventually within the context of clinical trials.
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Affiliation(s)
- Hong-Wei Dong
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Kirsty Erickson
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jessica R Lee
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jonathan Merritt
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Cary Fu
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jeffrey L Neul
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
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20
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Functional Network Mapping Reveals State-Dependent Response to IGF1 Treatment in Rett Syndrome. Brain Sci 2020; 10:brainsci10080515. [PMID: 32756423 PMCID: PMC7465931 DOI: 10.3390/brainsci10080515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 01/20/2023] Open
Abstract
Rett Syndrome (RTT) is a neurodevelopmental disorder associated with mutations in the gene MeCP2, which is involved in the development and function of cortical networks. The clinical presentation of RTT is generally severe and includes developmental regression and marked neurologic impairment. Insulin-Like growth factor 1 (IGF1) ameliorates RTT-relevant phenotypes in animal models and improves some clinical manifestations in early human trials. However, it remains unclear whether IGF1 treatment has an impact on cortical electrophysiology in line with MeCP2’s role in network formation, and whether these electrophysiological changes are related to clinical response. We performed clinical assessments and resting-state electroencephalogram (EEG) recordings in eighteen patients with classic RTT, nine of whom were treated with IGF1. Among the treated patients, we distinguished those who showed improvements after treatment (responders) from those who did not show any changes (nonresponders). Clinical assessments were carried out for all individuals with RTT at baseline and 12 months after treatment. Network measures were derived using statistical modelling techniques based on interelectrode coherence measures. We found significant interaction between treatment groups and timepoints, indicating an effect of IGF1 on network measures. We also found a significant effect of responder status and timepoint, indicating that these changes in network measures are associated with clinical response to treatment. Further, we found baseline variability in network characteristics, and a machine learning model using these measures applied to pretreatment data predicted treatment response with 100% accuracy (100% sensitivity and 100% specificity) in this small patient group. These results highlight the importance of network pathology in RTT, as well as providing preliminary evidence for the potential of network measures as tools for the characterisation of disease subtypes and as biomarkers for clinical trials.
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