An Anatomy Lesson

I believe it would be helpful to provide some basic anatomical information to provide you with a better understanding to what a vestibular system is and why it’s so important to our connection to our surroundings, our center and, to gravity.  After all, I had no idea something like this existed in my body so how can I expect you to know either.  Let’s start with an illustration of the vestibular system that is the major area of damage from ototoxity (ear poisoning) which my case, was a result of a side effect from the use of the antibiotic gentamicin.  The vestibular system is located in the inner ear:

Image

Image from Google Images

When gentamicin is eliminated in the body, as all things are like liquids, solids, and yes, medications, for some reason gentamicin is eliminated through the kidneys and strangely enough, the inner ear.  Through this elimination the hair cells in the vestibular mechanism of the inner ear are damaged and can no longer pick up the signal of the body’s movement, or provide the connection to the sense of gravity.

Image

Image from Google Images

What this illustration demonstrates are the inner working components of the vestibular system.  Keep in mind, these parts are microscopic in nature but is how information of balance gets to the brain.  It all begins with the otoliths at the top of this illustration.  These cause a movement in the otolithic membrane which is a Jello like substance that moves in correspondence to the many ways our body moves around.  This shift in this membrane tickles the hair cells which send signals to the vestibular nerve fibers that movement has taken place.  The vestibular nerve corresponds to the eight cranial nerve of the brain that sends signals that movement has occurred.  Without this signal, there are no messengers telling the brain, or the body, where it is in space.  There is a complete disconnection between the body and its ability to perceive what is up, down or sideways, much like zero gravity in outer space.

 

Image

Photo from Google Images

Only thing wrong with this photo is when one has vestibular damage, this feeling isn’t all that fun…. You feel this way all the time..

ImageImage from Google Images

Because there is a direct correlation between the vestibular system and the visual, or ocular system, an corresponding side effect of a damaged vestibular system is a visual condition called, oscillopsia, or bouncy and blurry vision.  Here’s a great illustration from YouTube of what that looks like:

http://www.youtube.com/watch?v=fsD3RDUqgJU

Here’s a pretty good picture of what it looks like to see with oscillopsia:

 Image

Image from Google Images

           The vestibular and ocular systems work together because of the connection that travels from the vestibular organ in the inner are to the optical system.  Weird, huh?

          I hope this gives you a better understanding of why I lost my sense of balance and what oscillopsia looks like.  Put the two together and wow, what a mixed up world it becomes…  and really, really hard to live with…

 

This entry was posted in Disability, Gentamicin, Gravity, Independent Living, Inspiration, Motivation, Non Fiction, Oscillopsia, Ototoxicity, Perception, Rehabilitation, Research, Self Help, Transition, Vestibular System, Vocational Rehabilitation and tagged , , , , , , , , , , , , , , , . Bookmark the permalink.

2 Responses to An Anatomy Lesson

  1. docpmk says:

    Just to add a little bit to the excellent discussion of the vestibular system and what happens when things go wrong in that system: First, a little bit on my background I have a course in sensory physiology at the master’s degree level, a yearlong course in neuroscience at the PhD level and again in medical school (they make you do stupid things in medical school — I aced it twice! Oh well, it was good review!). Several other courses at the PhD level on various aspects of neurophysiology and a rotation in neurology in medical school seeing patients — and I was on the consult service so I saw all kinds of patients all over the hospital. I also have a law degree and have written on the quality and potential liability involved in medically-related sites on the internet. The quality varies greatly from total misinformation to excellent sites with loads of good information. This blog gives an excellent view of the results of ototoxicity from a drug, Gentamicin. It would be very hard to improve on what is described here! One’s ability to maintain equilibrium is dependent on vision, the vestibular system, sensory receptors in most of the muscles of the body called proprioceptors and a complex neural network between the cerebellum, the midbrain, the brainstem and visual centers at a conscious level in the cerebrum as well as visual centers at a lower level of the brain. Under some circumstances the brain can and does essentially ignore portions of this system. However, the human body does not tolerate confusing inputs to the system, especially from the vestibular system — that tends to make one feel very, very ill! This results in a form of dizziness and imbalance called vertigo. This can cause someone to bump into things or fall. This is often accompanied by nausea and even vomiting. A variety of conditions can cause a disturbance in vestibular function — motion sickness, various inflammatory processes in the head like colds, flu, otitis (infection in the ear), skull fractures, concussion, Meniere’s syndrome (the exact cause of this syndrome is unknown), and as here certain antibiotics like Gentamicin and other drugs. With the exception of drugs and in a few cases of Meniere’s syndrome, most of these go away with time. But they are nevertheless disturbing. While the brain can and does ignore the vestibular system at times, ignoring some of the subconscious systems can be very dangerous at times — i.e. that’s why test pilots have sometimes flown their planes upside-down straight into the ocean, relying on vision they were confused into thinking they were going up! However, for someone who has a chronic disturbance of the vestibular system as a result of drugs or other problems, to some extent the ability to compensate is based on this fact that the brain can depend on vision and other aspects of this complex system.

    Unlike a camera which must be held steady, the eyes must constantly make small movements to see properly. The vestibular system is very important in coordinating these movements of the eyes and during sudden changes of directions and especially during angular motion — i.e. while spinning! Even during small movements of the head, the vestibular system helps keep the eyes focused on what you are looking at. It is also involved in tracking a moving object.

    Except for the fact that all of this operates at a subconscious level, the vestibular system is like many of the gauges on the dashboard of your car like engine temperature and oil pressure. Much of the time you can ignore those gauges, but if anything goes wrong …. The vestibular system becomes important when the inputs from the inner ear, vision, and proprioceptors conflict and especially with abrupt changes in motion and while spinning. That is when symptoms of imbalance, vertigo, and nausea occur. Philip M. Kober, JD, MD, PhD

    • Thank you Phil for your fabulous comments. I appreciate your verification of getting it right when describing the vestibular system! I found learning as much as I could about what had happened to me to really help me understand, and better control, the unbelievable side effects from my vestibular damage. It is fascinating how such a tiny little part of anatomy can have such devastating effects on so many different areas of the the body when damaged. Thank you again for your clear, detailed and professional comments, I appreciate that. Enjoy your day, Cheryl

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s