I dug up this article on compensation that was published in 1995 by Prof. Halmagyi here in Sydney. It's 42 page document but I've thrown together a brief summary of what it boils down to in the review. The serotonin information is from more recent research. Halmagyi has really pegged down the vestibular nuclei or the region of the brain where inner ear information is processed as the main site where compensation happens.
Vestibular Compensation: A review of the oculomotor, neural, and clinical consequences of unilateral vestibular loss
Curthoys and Halmagyi
Journal of Vestibular Research, 1995, 5(2):67-107.
Sensory and motor interplay necessary for stable gaze and posture is drastically affected if one labyrinth of the inner ear suffers damage or disease – vertigo, nystagmus, imbalance and ataxia.
Acute symptoms are temporary and rapid recovery is termed “vestibular compensation”. The term is misleading however, because it implies a single process and suggests complete recovery. Neither is correct.
Vestibular compensation is made up of a number of distinct subprocesses that recover at different rates. In many of these subprocesses recovery is not complete. The recovery process that takes place following an injury is never complete although the person may feel 100%.
Exercise speeds compensation (nothing new there).
Failure to compensate
Most patients return to their normal lifestyle and are apparently unaffected by any vestibular symptoms or deficits. Some patients report ongoing distressing postural unsteadiness or oscillopsia (apparent movement of the visual world)…the reason in a relatively small group of patients is unknown. Vestibular testing following injury may reveal no detectable difference in objective measures of vestibular function between patients with excellent or poor recovery. These patients may have some remaining afferents (nerve fibres) that are interfering with the recovery process or the healthier side may also have had some prior deficit. Lastly, they may have cerebellar or other central deficits.
Possibly some event during the early phase after the injury (the critical period) has affected the normal course of vestibular compensation. One would expect to find measurable differences in such individuals but none have been reported.
The most likely possibility holding back compensation are psychological factors causing the remaining vestibular symptoms to become overwhelmingly prominent in these patients’ lives (ie. This could fit a serotonin deficit producing anxiety or perhaps even MAV).
In terms of neural mechanisms involved with compensation, great interest has focused on the vestibular nuclei, because an injury causes substantial changes in the early processing stage. There are approx 18,000 vestibular nerve fibres from each human labyrinth projecting into the vestibular nuclei (part of the brain). At rest they fire at around 1,000,000 times per second (collectively) – even when the head is still! An injury then, silences many of these fibres creating a huge imbalance between the two vestibular nuclei (ie. processing areas for the right and left inner ear in the brain).
Early in recovery, compensation is fragile – nystagmus can reappear precipitated by stress or even an abrupt movement by the observer. Stressful events somehow upset the partially restored balance between the two vestibular nuclei in the brain. The symptoms of decompensation are due to a return of the neuronal imbalance. Even well-compensated patients can decompensate from fatigue, alcohol or drugs.
There are species differences in decompensation: for example rats decompensate easily whereas guinea pigs do not.
Biochemistry of the vestibular nuclei in compensation
Noradrenergic and serotonergic projections to the vestibular nuclei have parallel connections with anxiety pathways. Addition of serotonin into the superior vestibular nucleus induced modifications of the mean firing rate in 87% of the neurons examined. Serotonin exerts various functions throughout the superior vestibular nucleus by various receptors. Dopamine and many other neuro-chemicals are at work in these cells.
The great speed of recovery in most species rules out a number of candidate neural mechanisms. The answer to compensation may be found in a greater understanding of the neurochemistry in the vestibular nuclei.
Vestibular compensation is comprised of a number of different processes that recover at different rates. No single neural mechanism is the cause of compensation.
I had forgotten about that article actually. Gald you brought it back to the top of the pile. Amazing how the nerve fibres all collectively fire at approx 1 million times per second - and with some 18,000 separate nerve fibres leading to the brain on each side. Complexity we can barely understand.
One other thing you need to consider if VRT makes things consistently worse is migraine. For some reason a lot of people with inner ear problems seem to be susceptible to this - whether it comes first or after I don't know but Dr Rauch (videos in the archive) has said that when a patient feels consistently worse from VRT and better without, that he considers this diagnostic for vestibular migraine. This condition can exist even if you've never had a headache.
Do some people truly have rapid compensation from vestibular injury? Has anyone ever heard of someone with that experience? I know the medical texts seem to indicate it happens, but even some of the more public cases of VN (that tennis player for example) seem to go on for months, and I'm sure those folks were getting top medical care/rehab etc.
I also wonder about the "psychological" influences mentioned. I think the vestibular deficit causes the anxiety/other psych issues, perhaps through serotonin depletion or something like that???, and not the other way around. (Not to say that those issues shouldn't be treated and that that won't help the whole situation.)
I know a few people who were really dizzy and sick with this and it all blew over after 6 weeks! Hard to believe but true. One lady here at the uni couldn't walk to the bathroom without falling over. Six weeks later she was back at work as good as gold. Probably depends on which of or how many of those 18,000 neurons get trashed in the initial viral attack - or whether migraine or some other problem (vision problems etc) is at work in the sufferer.
I think you're dead right about the psychological thing in that this illness induces the anxiety state both physiologically and mentally. But it's important to get over it, accept what's happened and look to getting better. Non-stop stressing about this thing has shown to slow recovery. There's studies on this showing that those who believe they will be well again actually got well quicker. They were probably more pro-active and were able to not dwell on it all too muchor they sought out help to kill the anxiety (ie. meds or CBT). Hard not to get stressed out though ... I sure did.
>>> The ENT says the pain in my ears and around my head are not related to the vestibular part of my injury.
Not surprising. Most ENTs don't seem to have a clue about vestibular migraine and would rather come at you with a knife and pliers to remove something. If he told you that, I'd move on for a second opinion. Can you find a migraine clinic somewhere or a neurotologist? Those sorts of people will know this stuff immediately if that's what it is.
>>> One of the hardest things about recovery is that on the outside I look perfectly normal but inside I'm messed up ...
Yup, this is pretty standard for everyone. We look fine but feel lousy. What a piece of work this is eh?
You're right! My ENT already told me that he could remove my inner ear...yikes! He did say that he would only do that if I started to spin (which I have not done as to date). This ENT is the doctor I have to see due to it being a work related injury. However, I will go see a neurotologist. If I could get help for the headaches and pain/pressure in my ears I would be sitting on top of the world! I thought I saw another post that said you get migraines. What do you do for them, if you don't mind me asking?
>>> My ENT already told me that he could remove my inner ear ...
Run in the opposite direction as fast as you can!
>>> I thought I saw another post that said you get migraines. What do you do for them?
I don't get the typical sort of headaches that are outlined by the IHS - things like one-sided throbbing pain, or light sensitivity. Instead I experience it as what conventional docs class as tension type headaches. It wasn't until recently I discovered that these are in fact a form of migraine (check out Heal Your Headache by Dr Buchholtz). The blood vessels in the neck swell and set off the pain and I then feel it as referred pain behind my eyes and in my head not to mention a stiff, sore neck and shoulders when it strikes. If I avoid the migraine triggers it is usually not much of a problem. Taken me years to see the food connection with it. Sometimes I'll have a dizzy episode that will last for 30 minutes or so followed by the pain I described above. The dizziness and pain never happen at the same time. The whole thing was kicked off by VN in August 2003.
Treatment for me has been an SSRI (cipramil) for the last 4 years. I've also tried a bunch other migraine meds without much luck. I always feel much worse on them - meds like propranolol, verapamil, pizotifen, lyrica, topamax and amitriptyline. Tried them all. At the moment I'm trying to stabilise on 10 mg of cipramil plus throwing magnesium at it. Not feeling the best that's for sure. Coming off an SSRI is brutal.
My headaches are classified as tension related also. The doctors do refer to my headaches as migraines so I suspect they are on the right track. My headaches are triggered by anything that requires focusing, putting on my makeup, driving, computer, TV, VRT exercises for the eyes, too much stimulation input such as a day at the shopping mall or crowded places, etc. I feel pain and pressure behind my eyes, in my forehead, back of my head (so much so that I cannot even lay on the back of my head), in and around my ears and yes up the sides of my neck. As far as taking meds. for these headaches, the Midrin prescribed for mine is a nasty little red pill that I have nick named "the mean pill". I take it for pain and it does work but it makes me irritable and snappy..grrrr. Keep up the efforts on getting off the SSRI. My core belief has always been to heal as much as you can without the use of prescription drugs. This isn't always possible. Chiropractic, massage, accupunture, exercise and a clean diet can do wonders. I just watched a program on public TV called Brain Fitness. The number one thing it said you can do to heal and reverse aging of the brain is exercise.
I will check out all the information you have suggested and keep reading these message boards.
I was starting to think that recovering quickly was some kind of a myth! I'm feeling a tad bit better...today anyway! (That means getting closer to 50 percent for me right now.) I wanted to let you know that I did start taking that 5HTP...I'll keep you posted if I have anything of note to report. I do think it is helping me to sleep a little better. (Sleep has been disrupted since onset of dizziness.) Since serotonin plays such a big role in migraine, mood, sleep, etc., I don't think I can go wrong by helping my body make more of it.
>>> I wanted to let you know that I did start taking that 5HTP...I'll keep you posted ...
Please do as I'm getting totally slaughtered by SSRI withdrawal at the moment. Constant headache, spaced out, somewhat dizzy, flu-like symptoms, vivid dreams, waking in the night and not being able to fall asleep again - the whole enchilada. Just hope this doesn't last too much longer ... it's really wearing me out and making work a massive chore. Maybe 5HTP can make this less torturous? Who knows ...
Hi! I just wanted to let you know that there might be some concerns with taking both at the same time...there is something called serotonin syndrome, which can result from too much serotonin. I think this would be highly unlikely in this situation (or in most situations)...on low doses of the ssri and the 5htp it might not be a problem, but I think you should research that first. I'm very sorry that the tapering off process is causing so many symptoms! I wish our bodies didn't feel so funky while they adjust to things. Are you keeping the dose at each level for a while, as you go down? You might also want to try eating tryptophan-rich foods: turkey, chicken, milk, potatoes, turnip/collard greens, eggs, and bananas (migraine trigger?).
I am pretty excited about 5htp and other natural treatments that have been clinically proven to be beneficial...there are others like SAMe and chromium that I am hoping to try soon as well. I feel like a chemistry experiment, but hopefully the results will be good .
Yup, know about serotonin syndrome. I think it's unusual and actually takes a lot of meds to induce it. I'm only on a low-dose of cipramil so not worried about that. In fact, there's a study in the lit where they gave migraineurs both citalopram and amitriptyline! What a nasty cocktail. There were no problems with serotonin syndrome. Can't imagine how bad the side-effects would be on both meds ... and don't want to know.
I'm a little better today but continue to wake feeling very strange/lousy in the morning. I've got 4 days off coming up and am jetting down south to Melbourne to stay with a friend and change the scenery. Should be great to sit on an empty beach away from computers!