A Wobbler’s Story

This is the blog post I promised about the woman who lost her sense of balance & then recovered it. This is one of my most favorite case studies. It is remarkable in what it demonstrates in our resilience.

Cheryl always feels like she is falling. There is never a moment in her life that she does not experience the sensation of falling. When she is lying flat in bed, she feels as if she is falling. When she is sitting in a chair, she feels as if she is falling. When she stands, she feels as if she is falling. And when she falls and is lying in a heap on the ground, she still feels like she is falling.

Not only does she constantly have the sensation of falling, but when she moves, everything moves. She describes it as eve

Vestibular System

Inner ear, showing semi-circular canals Image via Wikipedia

rything seeming to be made of Jell-O or being wiggly. Moving objects seem to bounce. Rooms spin.

She can not be still because she is constantly trying to catch her balance. Walking is nearly impossible. Standing more so.

Cheryl lost her sense of balance when she was given the antibiotic gentamicin for a post-operative infection.  Gentamicin is cheap & effective, but when taken for too long of a period of time, it will destroy the inner ear causing hearing loss, ringing in the ears, & a loss of balance

. Cheryl can still hear, but she has ringing in her ears & no sense of balance. She was 39 years old. People who suffer a loss of balance due to gentamicin call themselves Wobblers.

Balance relies on two separate sets of inputs. First are the signals that come from our semicircular canals. These tell us which way is up and how badly we’ve gotten off of perpendicular. They are responsible for that lingering disquieting spinning sensation after having been spun around.Cheryl’s semi-circular canals were destroyed by the gentamicin.

The second source of balance information is from the eyes. When we can see the horizon and other horizontal lines, we can tell if we’re upright or not. Motion sickness comes from this source. Oddly, Cheryl’s visual support for her balance is easily disturbed by looking at zig-zagging lines or other designs that are not square or imitate depth. Consequently, Cheryl is constantly fatigued. Her brain is working overtime to keep her relatively balanced taking away resources used for calculating, reasoning, or even communicating.

Luckily, Cheryl found out about a neuroplastician named, Paul Bach-y-Rita. He had developed ways of retraining the brain to use other cortical areas to compensate for deficits. His has helped people who have had strokes, accidents, and birth defects. And, he had a

Paul Bach-y-Rita (1934 - 2006)

possible solution for Cheryl.

His idea was to help her bypass the semi-circular canals & the cortical area that interpreted their input. He realized that she probably was still getting signals from the canals, but that it was “noisy” filled with bad information and perhaps some good information. The problem was that the brain didn’t know which was which, & then when she tried to match her faulty information from her semi-circular canals up with the accurate information from her eyes, her brain didn’t know which to believe. So, Bach-y-Rita created a helmet that was lined with sensors. These sensors would detect the position of her head. He fed this information into a small thin device that she would press to her tongue. It was covered with electrodes. When her head tilted one way, that area on her tongue with tingle with gentle electrical energy. When it tilted another, her tongue would tingle in another place. In this way, her brain could start to learn which signals were accurate and which were not, & then begin to match up the accurate information and ignore the inaccurate.

It took her only a couple of hours to get the hang of it. She was able to maintain her balance while the helmet was on her head & the tongue tingler was in her mouth. She was even able to maintain her balance for a few minutes afterward. So, she began to wear it for a couple of hours everyday, & the length of time that she could maintain her balance increased… exponentially. It soon began to stretch into days.

They sent her home with the device. She wore it whenever the effect began to wear off, & soon it lasted weeks. Then, it was months. Now, she hasn’t needed it for years. In essence, she was cured. Her brain had adapted to her new sensory input for balance! It was a miracle.

A tongue sensor that is similar to the one Cheryl wore.

An apparatus similar to the one Cheryl used

Brain Dissection!

I am so proud of y’all! I cannot believe what a GREAT job each of you did with today’s dissection! I couldn’t believe how well it went. Everyone was able to find olfactory bulbs, medulla, the Pons, the thalamus & hypothalamus, hippocampi, & the amygdala! Amazing! We even had a great example of dura matter, pig hair, & a bit of bone. No one threw up — only slightly disappointing, but Mr. Sharp wasn’t there enough to make it likely that he would’ve been vomited on. You know what I always say, why waste a good vomit? Vomit on someone. And we I got pranked by Shinie & Mr. Sharp. A perfect dissection lab.

My only regret is that I didn’t have a camera to photograph it all.

Thanks again.

Pig Brain Dissection 2

Howdy y’all!

I have two documents that I want you to have access to online:

  1. The Pre-Dissection Worksheet: This worksheet was put together using pictures of pig brain dissections from years past. It gives you a good idea of what you’ll find on Friday. It also will help you find and label the various structures that we will be finding.
  2. The Pig Brain Dissection Guide: You will use this guide on Friday as you dissect the pig brain. I ask you to make sketches of what you see & check boxes of what you find. It will help you stay on track, do things in order, and remember what you saw and found. Unfortunately, it will get some pig brain and blood on it.

Week 2 (24 – 28 Oct): Dissection Preparation

Howdy y’all!

Notice some of the changes I’ve posted here:

  1. Links to each of your blogs. This was done from the “Appearance” menu using the widget, “links.” I had to create (a) a link category (from the “Links” menu), (b) enter each link, and (c) check off the link category to get it to show up. Just drag and drop the widget into the area of the page you want it.
  2. Links to dissection guides. You’ll notice that these are all for sheep brains. That is the standard brain dissection, but we cannot get them as cheaply as we can pig brains. So, our brain will be slightly different. Remember, also, that our brains are not prepped for dissection. They have not been preserved in formaldehyde. Ours are fresh and have been prepped by a butcher for sale for consumption.
  3. Some of the dissection links are to worksheets in a variety of formats (pdf & ppt). In addition, I have this worksheet here: Sheep Dissection Guide as a word document. Each of the guides & worksheets cover a lot of the same ground. Look over them all and choose one or two to read in detail. Base your choice on what your comfortable with in terms of difficulty, pictures, etc.

Week 1 (17 – 21 Oct): Blogging for the AP

Howdy y’all!

Blogging is a good way of casually & informally formulating & focusing your thoughts on a topic. Of course, the topic that concerns us all is the AP Psychology exam in May 2012. I will be blogging my thoughts on the topics that we are studying in class & those that are coming up.

Pig Brain Dissection

I love dissecting the brains. I’m always freaked out a little given the brain‘s central position in our functioning. I mean it is an animal’s brain! Not its heart, stomach, eyes, or lungs. But, it is fascinating, too. I love it because you can find so many of the structures that we study in class.

One of my favorite things to do is look at how closely the cerebellum & the brain stem, especially the Pons & the medulla, are connected. This is easily seen if your carefully and slowly separate the cerebellum from the rest of the brain. Also, the corpus callosum is amazingly big. The illustrations in the textbook don’t do it justice.

Other Stuff

Well, this is a good start. I’ll try & post some dissection pictures later in the week. I’ll also be putting up model vocabulary pages, too.

Looking forward to it!

Mr M.