None listed
Conditions
Brief summary
People with obstructive sleep apnoea (OSA) experience sleep fragmentation and demonstrate impairments in next-day functioning. OSA is associated with an increased risk of developing dementia. While continuous positive airway pressure (CPAP) therapy continues to be the first-line of treatment for OSA, compliance is poor. Hence, alternative interventions are needed to target sleep disturbance and cognitive deficits in OSA. This study aims to evaluate the effects of low current brain stimulation of different brain regions on sleep and sleep-related cognition in a middle to late aged OSA population. Participants will attend three overnight visits at the Woolcock Institute of Medical Research where they will receive either the active frontal, active parietal or sham stimulation condition during sleep in random order. Participants will complete cognitive tasks and have blood samples taken before and after sleep.
Interventions
The overarching aim of this study is to evaluate and compare the effects of high-definition slow-oscillatory transcranial direct current stimulation (so-tDCS), applied to frontal and parietal regions, on slow oscillations during sleep and cognition in middle to late aged adults with obstructive sleep apnoea (OSA). We will recruit 24 participants. Participants will attend three overnight visits at the Woolcock Institute of Medical Research where they will receive either the active frontal (Arm 1
The overarching aim of this study is to evaluate and compare the effects of high-definition slow-oscillatory transcranial direct current stimulation (so-tDCS), applied to frontal and parietal regions, on slow oscillations during sleep and cognition in middle to late aged adults with obstructive sleep apnoea (OSA). We will recruit 24 participants. Participants will attend three overnight visits at the Woolcock Institute of Medical Research where they will receive either the active frontal (Arm 1), active parietal (Arm 2) or sham (Arm 3) stimulation condition in random order, spaced at least 1-day apart. At each overnight visit, participants will complete anthropometric measures and psychometric questionnaires, and memory and attention tasks 30 minutes before and after an 8-hour overnight sleep opportunity. Blood samples will be collected before and after sleep to measure changes in levels of dementia biomarkers. Functional near-infrared spectroscopy will be used to measure overnight brain oxygen and blood flow. Participants will be fitted with a 256 channel high-density electroencephalography (EEG) sensor net cap with the stimulation electrodes nested between the EEG sensors on the cap. Stimulation will be delivered using the Soterix M×N 33/65 High Definition-transcranial Electrical Stimulator using sintered HD electrodes. Active stimulation will consist of an anodal current sinusoidally oscillating at a frequency of 0.75 Hz between zero and 260 µA. The maximum current density will be 0.522 mA/cm2. Channel impedance will be less than 2 kOhms. The low level so-tDCS stimulation will be applied in 5 x 5-minute stimulation blocks by a trained researcher. Participants will be monitored for at least 9 hours following each stimulation while they are asleep and in the morning after they wake up. Stimulation will be delivered by a researcher 4 minutes from the first onset of stable non-rapid eye movement (NREM) (N2 or N3) period. Participant’s sleep EEG will be continuously monitored and visual confirmation of NREM sleep is required before stimulation is applied. If a participant falls out of stable NREM sleep into N1 sleep, wake or REM sleep during the stimulation free period, stimulation will be paused until stable NREM sleep resumes for a period of 2 minutes.
Sponsors
National Health and Medical Research Council (NHMRC) 2021 Investigator Grants Emerging Leadership 2 (EL2) GNT2008001
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
40 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
Participants will be included if they - Are aged 40 to 75 years of age; - Have mild to severe obstructive sleep apnoea (OSA) (polysomnography (PSG) within 1 year with apnoea hypopnea index (AHI) greater than or equal to 5) and the ability to demonstrate stable non-rapid eye movement (NREM) sleep; - Are fluent in English; - Are able to perform cognitive tasks; - Are willing to provide informed consent; - Are willing to participate and comply with the study requirements.
Exclusion criteria
Participants will be excluded if they - Have a history of head injury with associated loss of consciousness >30 minutes; - Have any current or previous diagnosis of psychiatric conditions (other than well managed affective disorders – Patient Health Questionnaire-9 <15 severity and no current feelings of suicidality as determined by item 9, Generalised Anxiety Disorder-7 4 standard drinks on any one day); - Are a current shift-worker or travel overseas within the last 2 weeks; - Have previously used treatment for obstructive sleep apnea (e.g. CPAP) in the last month; - Are currently pregnant; - Have a history of migraine; - Have metallic implants including intracranial electrodes, surgical clips, shrapnel or a pacemaker; - Have history of seizure; - Have had adverse effects to previous brain stimulation methods; - Previous adverse reaction to topical anaesthetic; - Have a diagnosis of another primary sleep disorder (determined via medical screening or Insomnia Severity Index question 1 score greater than or equal 10).
Outcome results
None listed