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Agger MP, Danielsen ER, Carstensen MS, Nguyen NM, Horning M, Henney MA, Jensen CBR, Baandrup AO, Kjær TW, Madsen KH, Miskowiak K, Petersen PM, Høgh P. Safety, Feasibility, and Potential Clinical Efficacy of 40 Hz Invisible Spectral Flicker versus Placebo in Patients with Mild-to-Moderate Alzheimer's Disease: A Randomized, Placebo-Controlled, Double-Blinded, Pilot Study. J Alzheimers Dis 2023; 92:653-665. [PMID: 36776073 DOI: 10.3233/jad-221238] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND Recent studies suggested induction of 40 Hz neural activity as a potential treatment for Alzheimer's disease (AD). However, prolonged exposure to flickering light raises adherence and safety concerns, encouraging investigation of tolerable light stimulation protocols. OBJECTIVE To investigate the safety, feasibility, and exploratory measures of efficacy. METHODS This two-stage randomized placebo-controlled double-blinded clinical trial, recruited first cognitive healthy participants (n = 3/2 active/placebo), and subsequently patients with mild-to-moderate AD (n = 5/6, active/placebo). Participants were randomized 1:1 to receive either active intervention with 40 Hz Invisible Spectral Flicker (ISF) or placebo intervention with color and intensity matched non-flickering white light. RESULTS Few and mild adverse events were observed. Adherence was above 86.1% of intended treatment days, with participants remaining in front of the device for >51.3 min (60 max) and directed gaze >34.9 min. Secondary outcomes of cognition indicate a tendency towards improvement in the active group compared to placebo (mean: -2.6/1.5, SD: 6.58/6.53, active/placebo) at week 6. Changes in hippocampal and ventricular volume also showed no tendency of improvement in the active group at week 6 compared to placebo. At week 12, a potential delayed effect of the intervention was seen on the volume of the hippocampus in the active group compared to placebo (mean: 0.34/-2.03, SD: 3.26/1.18, active/placebo), and the ventricular volume active group (mean: -0.36/2.50, SD: 1.89/2.05, active/placebo), compared to placebo. CONCLUSION Treatment with 40 Hz ISF offers no significant safety or adherence concerns. Potential impact on secondary outcomes must be tested in larger scale clinical trials.
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Affiliation(s)
- Mikkel Pejstrup Agger
- Department of Neurology, Zealand University Hospital, Denmark
- Department of Clinical Medicine, University of Copenhagen, Denmark
| | | | | | | | - Maibritt Horning
- Department of Neurology, Zealand University Hospital, Denmark
- Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Mark Alexander Henney
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Denmark
| | | | | | - Troels Wesenberg Kjær
- Department of Neurology, Zealand University Hospital, Denmark
- Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Kristoffer Hougaard Madsen
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Denmark
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Kamilla Miskowiak
- Neurocognition and Emotion in Affective Disorders (NEAD) Group, Copenhagen Affective Disorder Research Centre (CADIC), Psychiatric Centre Copenhagen, Copenhagen University Hospital, Rigshospitalet, Denmark
| | | | - Peter Høgh
- Department of Neurology, Zealand University Hospital, Denmark
- Department of Clinical Medicine, University of Copenhagen, Denmark
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Abstract
BACKGROUND 40 Hz light flicker is a well-known non-invasive treatment that is thought to be effective in treating Alzheimer's disease. However, the effects of 40 Hz visual stimulation on neural networks, synaptic plasticity, and learning and memory in wild-type animals remain unclear. OBJECTIVE We aimed to explore the impact of 40 Hz visual stimulation on synaptic plasticity, place cell, and learning and memory in wild-type mice. METHODS c-Fos+ cell distribution and in vivo electrophysiology was used to explore the effects of 40 Hz chronic visual stimulation on neural networks and neuroplasticity in wild-type mice. The character of c-Fos+ distribution in the brain and the changes of corticosterone levels in the blood were used to investigate the state of animal. Place cell analysis and novel location test were utilized to examine the effects of 40 Hz chronic visual stimulation on learning and memory in wild-type mice. RESULTS We found that 40 Hz light flicker significantly affected many brain regions that are related to stress. Also, 40 Hz induced gamma enrichment within 15 min after light flickers and impaired the expression of long-term potentiation (LTP), while facilitated the expression of long-term depression (LTD) in the hippocampal CA1. Furthermore, 40 Hz light flicker enhanced the expression of corticosterone, rendered well-formed place cells unstable and improved animal's learning and memory in novel local recognition test, which could be blocked by pre-treatment with the LTD specific blocker Glu2A-3Y. CONCLUSION These finding suggested that 40 Hz chronic light flicker contains stress effects, promoting learning and memory in wild-type mice via LTD.
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Affiliation(s)
- Tian Tian
- The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Xin Qin
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Yali Wang
- Key Laboratory for the Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
| | - Yan Shi
- Faculty of Laboratory Medicine, School of Medicine, Hunan Normal University, Changsha, China
| | - Xin Yang
- The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
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Jones M, McDermott B, Oliveira BL, O'Brien A, Coogan D, Lang M, Moriarty N, Dowd E, Quinlan L, Mc Ginley B, Dunne E, Newell D, Porter E, Elahi MA, O' Halloran M, Shahzad A. Gamma Band Light Stimulation in Human Case Studies: Groundwork for Potential Alzheimer's Disease Treatment. J Alzheimers Dis 2020; 70:171-185. [PMID: 31156180 PMCID: PMC6700637 DOI: 10.3233/jad-190299] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background: It is known that proteins associated with Alzheimer’s disease (AD) pathogenesis are significantly reduced by 40 Hz entrainment in mice. If this were to translate to humans, verifying that such a light stimulus can induce a 40 Hz entrainment response in humans and harnessing insights from these case studies could be one step in the development of a multisensory device to prevent and treat AD. Objective: Verify the inducement of a 40 Hz response in the human brain by a 40 Hz light stimulus and obtain insights that could potentially aid in the development of a multisensory device for the prevention and treatment of AD. Methods: Electroencephalographic brain activity was recorded simultaneously with application of stimulus at different frequencies and intensities. Power spectral densities were analyzed. Results: Entrainment to visual stimuli occurred with the largest response at 40 Hz. The high intensity 40 Hz stimulus caused widespread entrainment. The number of electrodes demonstrating entrainment increased with increasing light intensity. Largest amplitudes for the high intensity 40 Hz stimulus were consistently found at the primary visual cortex. There was a harmonic effect at double the frequency for the 40 Hz stimulus. An eyes-open protocol caused more entrainment than an eyes-closed protocol. Conclusion: It was possible to induce widespread entrainment using a 40 Hz light stimulus in this sample cohort. Insights gleaned from these case studies could potentially aid in the development of a multisensory medical device to prevent and treat AD.
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Affiliation(s)
- Marggie Jones
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - Barry McDermott
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - Bárbara Luz Oliveira
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland
| | - Aoife O'Brien
- School of Psychology, National University of Ireland Galway, Ireland
| | - Declan Coogan
- School of Psychology, National University of Ireland Galway, Ireland
| | - Mark Lang
- School of Physics, National University of Ireland Galway, Ireland
| | - Niamh Moriarty
- Discipline of Pharmacology, National University of Ireland Galway, Ireland
| | - Eilis Dowd
- Discipline of Pharmacology, National University of Ireland Galway, Ireland
| | - Leo Quinlan
- Discipline of Physiology, National University of Ireland Galway, Ireland
| | - Brian Mc Ginley
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,Departments of Computer Science & Applied Physics, Galway-Mayo Institute of Technology, Ireland
| | - Eoghan Dunne
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - David Newell
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - Emily Porter
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - Muhammad Adnan Elahi
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - Martin O' Halloran
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
| | - Atif Shahzad
- Translational Medical Device Lab (TMD Lab), National University of Ireland Galway, Ireland.,School of Electrical & Electronic Engineering, National University of Ireland Galway, Ireland
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Zibrandtsen IC, Agger M, Kjaer TW. Gamma Entrainment in a Large Retrospective Cohort: Implications for Photic Stimulation Therapy for Alzheimer's Disease. J Alzheimers Dis 2020; 75:1181-1190. [PMID: 32390632 DOI: 10.3233/jad-200083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Studies on mice models of Alzheimer's disease (AD) have suggested potential therapeutic benefits of intermittent photic stimulation at 40 Hz. OBJECTIVE We examined the physiological response of 40 Hz intermittent photic stimulation (IPS) on routine EEG in a large retrospective cohort to investigate the effects of age on induced gamma oscillations by intermittent photic stimulation. Since most AD patients are elderly, it is important for future research to know if age affects photic stimulation. METHODS Retrospective data from 1,464 subjects aged 0- 91. We performed frequency analysis and automatic peak detection and used regression analysis to investigate the effects of age and sex on peak frequencies and amplitude changes. To investigate the spread of the induced gamma oscillations, we assessed averaged topographies of 40 Hz band power. RESULTS There was a statistically significant but very minor effect of age on amplitude change (- 0.002 normalized power per year, p < 0.0001) but not for sex (p = 0.728). Detection probability of induced peaks was significantly predicted by both age (OR = 0.988, CI 95 % [0.984, 0.993], p < 0.00001) and sex (OR = 0.625, CI 95 % [0.496, 0.787>], p < 0.0001). The induced 40 Hz gamma entrainment is spatially confined to the occipital area. CONCLUSION There is a significant effect of age on induced gamma activity, but advanced age does not fundamentally change the behavior of the response in either magnitude or spatial distribution. This fact is important regarding future research into the possible therapeutic effects of photic stimulation in patients with AD.
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Affiliation(s)
| | - Mikkel Agger
- Department of Neurology, Zealand University Hospital, Roskilde, Denmark
| | - Troels W Kjaer
- Department of Neurology, Zealand University Hospital, Roskilde, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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