Saturday, August 7, 2010

Rocks in my Head

That's more or less what the doctor told me.

One of the interesting things about life is that sometimes, your body lets you know how it works by not working properly, hopefully only for a short while. Recently, I had a demonstration of how amazing the human body is and have been learning about the incredible engineering inside us all ever since.

One morning, I woke up and opened my eyes, only to see the room spinning around in circles. When I lay still looking at the ceiling, the spinning would slowly stop, but I spent the next several days feeling generally dizzy and having to avoid looking up or the room would start spinning again.

Its an incredible feeling of weakness. We take our ability to balance for granted. To have to grab onto walls or a desk to avoid falling down in a crumbling pile when suddenly and unexpectedly, the room starts to spin makes you wonder when its going to stop and will you ever be right again.

In my case, its quite an interuption of my active life. At work, I'm under cars on a hoist looking up (spinning) and checking out the suspension. I also drive cars, including evaluating handling, which could bring on the vertigo, as a primary part of my job. At home, I'm either working on projects in the shop (refer to hoist, above) or riding my motorcycles. The thought of having the world spin around while riding the motorcycle has kept me off them since this first occurred.

So I made an appointment with the doctor and he told me I had rocks in my head. More accurately, we all have stones in our inner ear that form part of a balance sensor in each ear. Think of it as an accelerometer that helps our brain figure out which way is up. In my case, one or more of the stones has become displaced so the left ear is sensing gravity differently than the right ear. My brain is reading these two different signals and trying to make sense of it and not doing a very good job, hence the spinning room.

Now the good news is that it should go away over time. The sensor cells that are missing stones will shut down and my brain will reprogram itself for the signals it has available. That alone is amazing.

Look at the design of this tiny accelerometer. The stones are a mass that responds to gravity or other accelerations. The stones float in a damped, flexible layer that supports them and flexes side to side when accelerations move the stones. The hairs flex with the stones and send signals to the nerve cells letting the brain know which way the head is being pulled. Your brain then processes these signals and lets each of us sit, stand, run, jump, or do cartwheels. It also lets us drive or ride a motorcycle by letting us know, in combination with our eyes, which way is up and how fast we are going around a curve.

This system not only lets us know which way is up, but if we are accelerating or braking or, by the difference between left and right ear, turning our head to look left or right. That very key factor lets us know if the tail of our bike or car is sliding out on a corner. It tells us if, in NASCAR terms, the car is pushing or loose.

It has always been clear that some people have more sensitivity to the handling of a car than others. I've always been grateful that I been more sensitive than most as its allowed me to have my career and a lot of enjoyment over the years. Now, I have a subjective understanding of the engineering inside my head and appreciate it all the more. Yes, my body is getting older and breaking down. My days of being the best driver on the track are gone, if they ever were. But the world and our bodies are both an amazing place to live in.


  1. Jac, sorry to hear that your internal gyro is whacked. You've always been one of the most stable people I know (which probably says something scary about my circle of friends and acquaintances).

    I hope the problem passes soon. Will you get some time off work to recoup?

  2. Now. I just toughed it out. Does it matter whether the car is spinning or just my head?

    I'm already much better.