J.D. Mitchell
[Originally published as Engineering the Human Hand — Part 2]
I recently suffered an ischemic stroke that affected my right hand. The resulting condition left me with no strength in my right hand. I had no control over my fingers, thumb, or any part of my palm. It was as if I had a rag mop suspended at the end of my arm. Being right-handed, this meant I could not even hold a pencil or pen, let alone sign my name.
What I found most amazing was that the stroke did not affect any other part of my body. Thankfully, I had no face drooping, arm or hand numbing, or slurred speech. My wrist, arm, and shoulder all worked normally. I had no loss of touch sense or the ability to feel pressure, pain, or temperature in that hand. I just could not use the hand for any type of grasping, lifting, or movement.
The good news is that after about six weeks of occupational therapy, I had regained almost all of the strength and dexterity in my right hand. While medical personnel involved in my case were aware of the condition and the ability of the body to recover from the condition, they did not share with me how they thought the recovery was accomplished. So, I did my own research, and here is a summary of what I found out about this recovery process.
Hand-Brain Connection
The two primary body parts involved in my condition were the hand and the brain. As I explained in the article “Engineering the Human Hand-Part 1,” an immense amount is known about the structure and detail of the hand. The hand is capable of 58 distinct movements. This amazing dexterity of function is accomplished with the help of muscles in the forearm and the wrist.
In the case of my stroke, I could sense no problem with any of the muscles or tendons in my arm or wrist. It was as if the connection of my arm to my hand had been physically severed at the wrist. Of course, that was not the case at all.
While there are many areas of uncertainty about the brain due to its complexity, one thing we do is that there are areas of the brain that usually control certain aspects and functions of the body. The control center for the right hand is in the left side of the brain. After my stroke, my brain still remembered how to accomplish the 58 movements, it just needed to reconnect the circuitry. The process of recovery was a matter of repetition of motion (exercises) for strength and dexterity. In my case probably half of the recovery took place in the first 7 to 10 days. Then the process became slower with slight improvements each day.
I learned that people who have had their hands amputated even decades previously still could maintain the representation of their hands in their brains. The researchers used an MRI scanner on the brains of two people who had been missing a limb for over 25 years but still experienced phantom sensations of their limbs. They also scanned the brains of eleven volunteers with both arms intact. While inside the MRI machine, the participants were asked to move their fingers one at a time.
The results showed that the primary somatosensory cortex was activated in a similar pattern with both groups. That is, the volunteers who had no hands activated their brain areas the same as those with hands, although to a reduced amount.
The importance of these findings was that they gave researchers valuable information about how future prosthetics might be more effectively engineered. I also found it interesting as it seems to reinforce the fact that the brain has been engineered with an amazing ability to remember and adapt to accidents and diseases that disrupt the original brain control of limbs and hands.
Why would that type of engineering be surprising regarding the amazing Creator God of each human?
For you created my inmost being; you knit me together in my mother’s womb. I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well. My frame was not hidden from you when I was made in the secret place, when I was woven together in the depth of the earth. Your eyes saw my unformed body; all the days ordained for me were written in your book before one of them came to be. (Psalm 139:13-16.)
I thank God for engineering my body with the ability to adapt to this condition, and for providing me with the doctors and other medical personnel who knew how to assist in the process.
Thank you, Lord Jesus!
