Avatar universal

Brain fog caused by OSA or by another sleep disorder?

I have been diagnosed with mild obstructive sleep apnea (sleep study results are below), however, it's not clear to me that sleep apnea is causing my problem.  My primary problem is brain fog (a feeling like I have not completely awakened from sleep with an inability to focus and concentrate).  This is intermittent, however.  On some days I am very alert (about 20% of the time), on most days I am somewhat alert and functional (about 50% of the time) and on some days I can barely function at all (about 30% of the time).

I have been using a CPAP (7 cm H2O) machine for about 1 month.  For a week prior to using CPAP I felt alert and energetic (typical of the intermittent nature of the problem).  When I started using CPAP I continued to feel good for about a week and I felt adjusted to sleeping with it.  Then, my intermittent brain fog returned for several days.  As I continue to use CPAP I feel good on some days and on some days I have brain fog, just like it has been for many years.  Note: the CPAP transmits data to the doctor’s office and to the company that leases the machine.  Both have indicated that it appears to be working properly.

My sleep doctor has not been particularly creative or challenged by my problem.  He told me to continue to use CPAP and see him in 6 months.

The fact that the brain fog continues with the use of CPAP makes me think that sleep apnea is not the cause of my brain fog.  Maybe I have some other type of sleep disorder.  During the sleep study I had 119 non-REM spontaneous arousals.  That seems like a lot to me.

What do you think?

Any help would be greatly appreciated.


I have had a problem with brain fog (inability to focus and concentrate) for at least 15 years, but only recently had a sleep study done.  On bad days I am moody, cannot concentrate and feel like I am still partially asleep.  The brain fog is intermittent, however.  There have been periods for as long as several weeks in duration when I have felt very good during the day.  Sometimes there are long periods when I have brain fog daily.   For many years I have kept a journal, but I have been unable to determine any patterns or reasons for my brain fog based on physical activity, non-activity, food, lack of food, eating times, amount of food, various diet changes, sleep times, amount of sleep, allergies, health problems and other factors.

Neither I nor doctors thought that I had a sleep problem, but, eventually proceeded with a sleep study.  I am in reasonably good health: 56 years old, no medications, 6 feet tall, 155 pounds, I exercise.  My wife and I do not think I am a loud snorer.  I go to bed at around 9:30 to 10:30 at night and I wake up around 5:30 to 6:30 in the morning, although I often wake up during the night and use the bathroom and then go back to sleep.

Several doctors automatically diagnosed depression, however, I never felt like I had depression and I do not believe that I have many of the symptoms.  I am not under a lot of stress, I do not have family problems, I am in relatively good health, I have a good appetite, I have many interests, etc.  Regardless, I went to see a psychiatrist.  After trying St. John's Wort, Wellbutrin and Pristiq, the psychiatrist pretty much ruled out depression and any emotional disorder.

The psychiatrist gave me Adderall (amphetamine salts) to use when I could not concentrate.  It was the first medication that actually did anything for me.  On bad brain fog days, after taking Adderall, I was able to concentrate, but it only lasted for a few hours and I did not care for the after effects.  On a bad day, multiple cups of coffee does not help me at all.  Nuvigil works for me, similar to Adderall, but I don’t like the after effects and it does not last long.

I am able to recognize that the airflow obstruction is not in the throat region.  It is somewhere in the airway beyond the nostrils, but before the throat.  I am able to feel the obstruction sometimes when I startle just at the point of falling asleep in the supine position.

1st sleep study report:
AHI: 12.5
RDI: 12.5
REM&Supine AHI: 23.1
13 Non-REM oxygen desaturation events (index 3.4)
28 REM oxygen desaturation events (index 23.5)
% time oxygen saturation below 90%: 5.6%
No oxygen saturation below 87%
Heart rate max 84 bpm, min 45 bpm
No cardiac events
No limb movements
Total recording time: 435 minutes
Sleep period: 6:50
Total sleep time: 298 minutes
Sleep efficiency: 68.5%
Sleep latency: 25:56
Total stage changes after sleep: 208
Awakenings after sleep onset: 31
WASO: 111
Stage N1: 22.3%
Stage N2: 47.4%
Stage N3: 6.4%
Stage REM: 24%
REM periods: 4
REM latency: 56:30
REM latency less wake time: 50:30
Supine position as percent of total sleep time: 54%
Prone position as percent of total sleep time: 0%
Left side position as percent of total sleep time: 36%
Right side position as percent of total sleep time: 10%
Upright position as percent of total sleep time: 0%
Obstructive apneas: 7 (non-supine)
Central apneas: 1 (supine)
Hypopneas: 33 (supine), 21 (non-supine)
Arousals: 25 non-REM respiratory (index 6.6), 36 REM resp. (index 30.2), 119 non-REM spontaneous (index 31.5), 12 REM spontaneous (index 10.1)

2nd sleep study:
CPAP setting at 7 cm H2O
Arousals: 3 non-REM respiratory (index .7), 2 REM resp. (index 1.7), 136 non-REM spontaneous (index 33.9), 18 REM spontaneous (index 15.4)
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Avatar universal
Thank you for your detailed comments.

I'm sure that I have a very mild form of OSA, but I'm still not convinced that it is causing my brain fog.  It seems that most people with OSA have the problem every night.  I don't have OSA every night and I don't have brain fog every day.  My pulse oximeter shows levels under 95% at times, but that's not real low.  For the past several days the pulse oximeter levels were mostly above 95%.
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1423357 tn?1511085442
Interesting data.  The only data I received was my AHI was 61.  "Very severe OSA".  My condition was so bad, that I had developed secondary polycythemia; excessive red blood cells.  I spent most of the night, with pulse ox levels in the low 70%.

I believe I experienced a "brain fog" during the 3 years or so that I spent in this condition.  I liken it to the feeling you may have when you get a bad sinus infection, but without the stuffiness or pain.  One of the things I remember most was the ringing sensation I had in my ears while listening to music or loud voices such as a noisy room or a public address system.  Every loud sound produced a ringing sound similar to feedback.  The sensation was terrible, and I lived on daily doses of Avdil in an attempt to make it go away.  I had this constant feeling of just being out of it all the time.  I stopped skating during this period as I was just too tired!  I began to gain weight from lack of exercise.  I remember on bad days driving the 50 mile home from work and just hoping I'd make it home and not driving off the road. On those days, I fall on the sofa and sleep, sometimes for 2 or 3 hours right through dinner.  I've had supra ventricular tachycardia all of my life, and during this period I experienced an increase in the number of monthly SVT events, and increased skipping of the heart known as PVC's.  A very bad night would produce several days of skipping heart beat.  My wife was aware of something very wrong.  Besides the horrendous snoring, snoring that was more like a gurgling gasp that could be heard one floor below, she said I had periods of silence where my chest would go up and down, but there was no obvious sign of exchange of air.  This would last for up to a minute when I would suddenly bolt upright in bed and give a huge gasp.  This became a source of fright for my wife, and ammusement to me, the fact that I would startle her.  I'd lay back down chuckling, but little did I know the danger I was playing with.  Eventually my wife moved into another bedroom due to the snoring.

It wasn't until I complained to my physician of waking up with a pounding puse, combined with the observed polycythemia in a blood test that he suggested a sleep study.  I was immediately placed on CPAP (7 cm H2O, same as you).  "7" is very low, but has no corelation to the severity of the OSA.  Within a week, there was a remakable difference in my demeanor, and alertness in work.  I immediately stopped snoring, and of course got my wife back in bed to snuggle with. Blood tests every 6 months showed a gradual reduction in red blood cells, and slowly the stuffy, ringing noise in my ears diminished. There's no doubt in my mind that CPAP saved me from a slow unpleasant death from stroke, or enlarged heart.  I apologize if I've provided more than a direct answer to your question, but so many people suffer from undiagnosed OSA, that I hope my contribution here will spark somebody to do something about it.
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Avatar universal
Thank you for sharing your experience.

I have considered inflammation as a cause of my problem and I am still considering it.  It's possible that when I am  in a lower inflammation condition that I do not experience the apnea; when I am in a higher condition of inflammation I experience apnea and, also, the brain fog as a result of the apnea.

What would be causing the inflammation?  I don't know.  I have felt very good for the past five days and I have not changed my diet. (Note: I am not currently using CPAP.)  For just about the whole month of January I had brain fog.  For most of October I did not have brain fog.  Over the many years that I have been dealing with brain fog I have not been able to determine any patterns related to foods or seasonal allergies.

Maybe you've discovered your personal problem and solution.  I wouldn't declare victory, however, until a lot of time passes without the symptoms -- like 3 months, at least.
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Avatar universal
Possible help:  I was diagnosed with mild obstructive sleep apnea in early 2012. I was given a cpap machine and had used it for a few months. Some time during the fall I started getting pretty bad brain fog. I could barely do my work, wanted to sleep all the time, and on top of that I had a sensation that something was stuck in my throat.

I started seeing a physical trainer to see if the exercise would help but symptoms only got worse and I physically looked worse. I followed up with a new doctor about a month ago to get a second opinion. He suggested I continue using the cpap machine, take an antihistamine for post nasal drip that I had issues with since I was having lots of phlegm, and gave me a prescription for anxiety since I was stressing about my issues. I had inquired about seeing an allergist but my doctor didn't want to do so and asked that we try the antihistamine and to sleep better.

After a week and a half my symptoms were the same and at times worse. I couldn't stand it any longer and to a point I didn't want to eat anymore.

Desperately, I decided I to go on a diet. For the past 2 weeks I have been eating at home. Since reading some articles about the hazards of GMOs I decided to purchase non GMO products from Whole Foods and make my meals. Along with that I added Omega 3 fish oil and kefir to my regimen. There are other diet changes that I made that I can share. After 2 or 3 days I started to feel a little better.

This past week is the best I have felt in months. The sensation in my throat has just about disappeared. My trainer has noticed that my top portion of my body has become really lean after struggling for months. I haven't been working out any harder than the past months. I also noticed that I have no problem sleeping without my cpap machine. My throat obstruction is nearly gone. I am able to multi-task at work with either no brain fog or very mild and I no longer feel like sleeping during the day.

It seems as something that I had been eating before my diet causes severe inflammation inside my body. The inflammation is probably causing the brain fog among other symptoms. Whether it's GMO or not I don't really know. Feels like I am slowly getting back to my normal self. Hope this helps some of you. Good luck and don't give up finding out what is causing your symptoms.
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Avatar universal
Re: Surgery -- I know somebody who had surgery to fix a deviated septum and he was very unhappy with it.  I also read a post in a different forum about another surgery, but now I realize that both surgeries are not the same as the one that you described.

I have not noticed any effects on my brain fog related to food consumption (certain foods, food quantities, eating times, etc.) nor have I noticed any effects from certain weather events or seasons.

I have noticed that I am likely to get brain fog after a day of moderate to heavy exercise.  It could be sleep related in that I believe that I sleep more soundly and longer after a day of exercise.  But, then again, it could be sinus related.  It's possible that there could be more sinus related inflammation after doing heavy breathing from exercise.

Have you had that experience?
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Avatar universal
Thank you for the very interesting comments and suggestions.  I'll write some more in a day or two, but for now I just wanted to thank you.  You've given me more things to try and ponder.
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Avatar universal
Very interesting. I didn't mention it before, because I'm not sure how much it helped, but I too had food allergy testing, and also cleaned up my diet.
I had an ELISA IGG food allergy test, and tested positive (off the scale) for milk and egg, so I haven't eaten any for a few years. After I made the switch, my digestion improved and my breathing passages opened up noticeably, but I still have the brain fog. I also eat a low-sugar diet with lots of organic veggies, healthy fats and meats, and some grains and beans. I cook a lot at home. I'm 6'1" and about 150 lbs, FYI. The only thing I've noticed is that if I eat too much insoluble whole grain fiber, it made my brain fog worse, but the breathe-right strips have minimized this effect.

As far as the surgery goes, according to my ENT, my sinus infection is not going anywhere until I get that polyp removed, because the polyp is blocking the entrance to my maxillary sinus. I've basically got a closed bottle of infection in my head. So I'm definitely going to go ahead with that part of the surgery. As far as the septum goes, can you tell me about the negative results you've heard of? My understanding was that septoplasty was a procedure with a very low incidence of negative side effects.

I think what we both need is an ENT who specializes in sleep disturbances, and a sleep doctor who specializes in UARS. My ENT clinic is getting a sleep specialist in a couple months, but I haven't found a sleep doc who specializes in UARS yet.

a couple more things:
        --did you get a copy of your sinus CT so you could look at it yourself? Maybe there's something there that your ENT missed? It seems to me like even though you now get fewer sinus infections, the fact that you still get them means something could be amiss in your upper airway.
        --have you done any type of saline irrigation? I started using a neti pot a couple of years ago and it has helped lessen my symptoms. There's also something called a 'flip-turn' nasal flush that hasn't worked for me, but has gotten a lot of positive buzz online for resolving/preventing sinus infections.

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Avatar universal
I appreciate the response.

Your condition does, in fact, sound very similar to mine, however, I have a few experiences which are different than yours.

I used to get about 3 or 4 sinus infections per year and I thought my brain fog was somehow related to allergies or sinus problems.  I went to an alternative medicine doctor who did some allergy testing and he suggested that I change my diet.  The allergy tests indicated some allergies, but not anything significant.  I also have a deviated septum (I know many people have deviated septums)

I changed my diet and took some homeopathic medicines as prescribed, but I didn't get any immediate relief from the brain fog and the sinus infections and eventually I stopped seeing that doctor.

I did, however, continue with the diet changes.  I significantly reduced my consumption of simple carbohydrates such as cereals, breads, sodas, fruit juices, deserts, alcoholic beverages.  Mostly, I eat whole foods, not processed foods.  I'll eat whole potatoes with the skin (mashed, baked, etc.), but not potato chips.  I do not eat pasta except a few times per year.  I also significantly reduced my consumption of dairy products.  Mostly, I eat vegetables, fruits, nuts, meats.  I eat whole grain cereal such as slow cooked oatmeal for breakfast.  I drink about 30 to 45 ounces of water per day.  I've been eating this way for about 10 years.

Although I wasn't overweight to begin with (I am six feet tall and I used to weigh 165 pounds), now I weigh 150 pounds.  I EAT OFTEN AND LARGE QUANTITIES OF FOOD, but I stick with the plan.  For example, I only eat pizza, cookies, ice cream and potato chips just a few times per year.  So far this year I haven't eaten any ice cream, cookies or potato chips.  I haven't eaten a single donut in 10 years.

At some point after I had changed my way of eating, maybe after a year or year and a half, I started to notice that I wasn't getting sinus infections.  I cannot specifically attribute it to the significant reduction of any one food (maybe dairy products? I'm really not sure).  I won't say that I have never had a sinus infection in the past 15 years.  Instead of 3 sinus infections per year now I get one sinus infection about every 3 years.

Unfortunately, however, this did not stop my brain fog.

About 8 years ago I had allergy tests done by an ENT and I had a CT scan.  I still thought there was a sinus or allergy issue causing the brain fog.  The doctor basically told me that I didn't have any major sinus or allergy problems.

Based on my more recent recognition of sleep problems and airflow obstruction, despite the ENT's diagnosis, I still think that I have polyps or something causing an obstruction like you described for yourself.

Are you sure you want to do the surgery?  I know one person who got the surgery and he was not happy with the results.  I have read other posts about sinus surgery and they have not been very positive.
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Avatar universal
Not entirely. But I've made some progress, enough to restart my career.

I'm just going to describe the parts of my treatment that have been the most helpful, and for which I have the strongest, most objective evidence that they've helped...

About 4 years ago, I was tested for environmental allergies, and began sublingual immunotherapy for multiple allergies (dust mites, tree pollen, cats, etc.).
The immunotherapy has been quite successful; I feel like my allergies have significantly decreased and the skin-***** allergy tests agree. And my brain fog has decreased. But it is still there.

After reading about UARS about 2 months ago, I noticed how perfectly it matched my symptoms (I eat well, am thin, exercise regularly, have a positive attitude about life, but still have debilitating brain fog, low blood pressure, cold hands and feet, and digestive problems).
So I tried using Breathe-Right strips, and my digestive problems disappeared within a couple of days!
So that was a clue that I was on the right track. Plus, it makes sense that if UARS is my problem, that allergy treatment would help somewhat.

So about a month ago I had an appointment with an ENT, who looked around in my nose, saw that some things were not right, and ordered a sinus CT. The CT shows that I have a big nasal polyp, a deviated septum, and a very old chronic sinus infection!

So I'm having sinus surgery in about a month to fix all these things, and hopefully after that, I'll be a lot better.

Also, by the way, I had a sleep study about 6 years ago, and my results are look pretty similar to yours. I had a lot of RERAs and not very many apneas, and my percentage of deep sleep was quite low, just like you. So, at the time, they told me I had mild sleep apnea, which I now think was a misdiagnosis. At that time, I tried CPAP as well, and I had about the same results that you did. From my reading about UARS on the internet, the opinion seems to be that if you titrate the CPAP only enough to fix the apneas, you won't be getting enough pressure to address the RERAs. And, of course, if you have some physical blockage in the nose, it limits how effective CPAP can be.

One more thing: it feels like whatever is blocking my breathing is in the same place you described in your initial post.

I hope you find this helpful!
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Avatar universal
Thank you for your response.  I recently heard about UARS.  Did you get a resolution to your problem?
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Avatar universal
Hi Yumm,
I rarely post, and I'm not a medical care professional, but I just had to respond to you, because I have very similar symptoms to yours and have spent years seeking a solution. I think I've finally figured out what's going on with me, and perhaps we're in the same boat....

Have you and your medical care provider(s) considered the possibility of UARS (Upper Airway Resistance Syndrome), as opposed to OSA? Your symptoms and your sleep study seem to match UARS very well. Also, have you been to an ENT that specializes in sleep issues?

Rather than go on about UARS and/or my own history, I'll keep this post short and can write more later if you'd like.
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Avatar universal
currysue -
I appreciate your response and comments.  Its good that you found a good GP.  
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Avatar universal
I am not a doctor, but I can relate my experience with tiredness and brain fog. I had been telling doctors that I was very tired for years. Yes I also was diagnosed with depression. Last year I asked my GP for a referral to a sleep doctor. I was diagnosed with severe OSA and started CPAP at 15 cm H2O. The technicians told me that I should feel better once my sleep debt was resolved.

After several weeks of Cpap I was still extremely tired. The Sleep Doctor put me through the Multiple Sleep Latency Test (MSLT) which indicated Ideopathic hypersomnia (IH). It is similar to narcolepsy in that both are characterised by excessive daytime sleepiness. The differences are that after a short nap narcoleptics will feel energised but are soon tired again. People with IH are constantly tired, they do not feel refreshed after a nap. And as mentioned above narcoleptics can experience sleep paralysis and cataplexy. IH does not have symptoms of sleep paralysis or cataplexy. The medication for both is the same and only treat the symptoms not the cause.

OK, so now I have 2 sleep disorders and both are being treated. But I am still so tired ... Back to the sleep doctor I go. Her comment was "there is a difference between sleepiness and fatigue." That was the end of appointment. She suggested I come back in 6 months or a year for a review.

Thankfully, I lucked into a young GP who treats the whole person. After many tests, I has diagnosed with Chronic Fatigue (CF) and deconditioning (extremely unfit due to extended bed rest from CF, OSA and IH). CF is another condition that I would describe as causing daytime sleepiness. But then, I didn't know sleepiness and fatigue were different things. CF can be a symptom of many different illnesses. But it is also an illness in itself. CF is characterised by different symptoms in different people. My symptoms are mostly sleepiness/fatigue, physical exhaustion and brain fog. The symptoms wax and wain, come and go at no set pattern that I can determine. But emotion, concentration or physical activity will exhaust me, leaving me trembling, brain fogged and non-functioning... sometimes for a week or more. My GP is treating me with current best practice for CF. But I keep my eye on current research and bring to his attention anything that seems appropriate.

I believe my condition is much worse than it needed to be because I was not diagnosed and treated when the condition was relatively minor. But I was not confident / assertive in managing my own health. I eventually gave up and accepted the opinion of certain doctors. That is... until I was in a brain fog 100% of the time and was unable to function at work or force myself out of bed.

Yumm, You know how you feel. You know it isn't right. Keep searching for answers and for appropriate medical support. Don't Give Up! God bless
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Avatar universal
Thank you very much for the response.  I will consider narcolepsy, however, it does not appear that I have many of the symptoms or conditions:  There is no family history of narcolepsy, I do not have periods of extreme drowsiness and usually do not feel refreshed after naps, I have not experienced sleep paralysis nor cataplexy.
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Avatar universal
Hello and hope you are doing well.

The sleep study does not reflect any obstructive apneas. The brain fog could be due to excessive sleepiness and this could be the symptom of a sleep disorder Narcolepsy. This sleep disorder is mainly characterized by excessive daytime sleepiness. In addition there are sleep paralysis, cataplexy where the person has episodes of loss of muscle function while awake and automatic behavior.

Narcolepsy is diagnosed by the sleep onset REM episodes (SOREMs), wherein the person goes into the dream phase or REM cycle soon after sleep onset. This is evident in the Multiple Sleep Latency Test (MSLT). It can however be regulated with medications. Discuss the possibilities with your consulting doctor.

Hope this helped and do keep us posted.
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