Dyspnea
Conditions
Keywords
Air Hunger
Brief summary
The purpose of this study is to see if the front part of the brain called the "Dorsolateral Prefrontal Cortex" (DLPFC) has a role in our ability to feel breathlessness. The experiment will use a device that sits on the top of the head which produces a magnetic field that penetrates the scalp and excites the brain tissue directly under it. This procedure is called repetitive transcranial magnetic stimulation (rTMS), it is a painless procedure and known to be safe in healthy individuals. Previous research has shown that the pain felt when capsaicin, the active ingredient in 'chilli' powder, is applied to the hand is reduced by applying the rTMS on the scalp directly above the DLPFC part of the brain. In this experiment we want to see if breathlessness is also reduced. We will use a breathing task that will generate a moderate amount of breathlessness by adding a small amount of carbon dioxide to the inhaled air, while preventing the increase in the amount of breathing we would normally see in response to this. If we find that breathlessness produced by this breathing task is reduced after rTMS over the DLPFC, this may lead to new drugs that target this part of the brain in patients suffering from breathlessness due to heart or lung disease. The study will also improve our knowledge of how the brain enables us to feel breathlessness
Interventions
DEVICErTMS-L-DLPFC
5 Hz rTMS applied using an actual coil over the left DLPFC
DEVICErTMS-R-DLPFC
5Hz rTMS applied using actual coil over Right DLPFC
DEVICESham rTMS-DLPFC
5Hz rTMS applied using sham coil over left or right DLPFC
Sponsors
Oxford Brookes University
University of Oxford
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Masking will only be applied to the participants in relation to whether they receive sham or actual rTMS.
Intervention model description
Following a practice session, there will be 3 intervention arms presented in random order on 3 separate days. The three arms will be: (i) 10-20mins of 5Hz rTMS over left DLPFC (Arm 1), (ii) 5Hz rTMS over right DLPFC (Arm 2), (iii) sham rTMS (Arm 3). A standard steady state air hunger test will be conducted before and immediately after each intervention.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
healthy individuals, over 18 years old, with no history of heart, lung or neurological conditions
Exclusion criteria
* Any history of respiratory problems (including Asthma that involves regular use of inhalers) * Any history of heart or circulatory problems (e.g. palpitations, arrhythmias, angina, BP) * Any history of epilepsy, convulsions or seizures, migraines, or fainting * Any history of anxiety disorders (e.g. panic attacks) * Any history of serious head injury or brain surgery * Any metal parts in the head (except dental wire) * Any implants (e.g. pacemaker, insulin pump, neurostimulator) * Pregnancy or problems with alcohol or drug abuse.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Air hunger | Average of 4 steady state ratings in the last minute of air hunger tests | Ratings of air hunger on a 100mm Visual analog scale with the extremes defined as 'non' and 'tolerable limit' |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Bond Lader Mood questionnaire scores | Questionnaire administered immediately following pre and post intervention air hunger tests for how participants were feeling at that moment in time. | Ratings provided on a 100mm visual analogue scale anchored by a negative mood descriptor at one extreme and the opposing positive mood descriptor at the other extreme. The average scores for 'sedation' descriptors, 'discontentment' descriptors, and 'relaxation' descriptors are each expressed as %maximum |
| Spielberger's state-trait anxiety inventory (STAI form Y-1 and form Y2) scores | Form Y-2 (trait anxiety) administered once on the initial practice day. Form Y-1 (state anxiety) administered immediately following pre and post intervention air hunger tests on test days. | 20 is the lowest score and 80 is the highest score for both state (form Y-1) and trait (Form Y-2) anxiety |
| Dyspnoea-12 total, physical and emotion scores | Administered immediately following pre and post intervention air hunger tests in relation to the "test just completed" | For Total score; zero indicates no dyspnoea and 36 indicates worst possible dyspnoea (expressed as %fullscale). For Physical score; zero indicates no dyspnoea in the physical domain and 21 indicates worst possible dyspnoea in physical domain (expressed as %fullscale). For Emotion score; zero indicates no dyspnoea in emotion domian and 15 indicates worst possible dyspnoea in emotion domain (expressed as %fullscale). |
Countries
United Kingdom
Contacts
PRINCIPAL_INVESTIGATORShakeeb H Moosavi, PhD
Oxford Brookes University
Outcome results
None listed