CONSCIOUS LIVING
Autumn, 2002

Most people know that phantom limb sensation happens after a limb has been amputated. But did you know that individuals born without limbs can also have phantom sensation? Case studies document it. Phantom limb pain is the perception of pain in a limb that does not physically exist. So where does the pain originate from and perhaps more importantly, how does one treat pain in an arm or leg that does not exist? In the last decade, we have been fortunate enough through imaging and diagnostic technology to gain insight into this fascinating but sometimes debilitating phenomenon. 

Let's start with some simple neuroanatomy. First, to understand the concepts it is important to know that an "image" or map of our body exists in our brain. This map in our head is known as a homunculus or "little man." It is important because it shows us how our brain represents or mirrors our body. Our brain's mirror image is nothing like what we see in the mirror each morning. Body parts are represented in a way that is disproportionate to the size of the appendage or body area. For example, our hands and face get just as much cortical/brain representation as our entire torso! Some parts are positioned in the same way as they are in the body while others are not. On our homunculus, our hand is represented next to the thumb which is represented next to the face and our genitals are actually represented next to our toes and feet! What does all of this have to do with the pain or sensation experienced by those missing limbs? You've learned that you have a map of your body in your brain. If one loses an arm, is the representation of the arm in the homunculus eliminated? No, not immediately. It is at this point that the brain gets "confused." The frontal lobe and the cerebellum that tell the missing arm to move do not recognize that it is gone. [This hardwiring is still fully intact!]

However, the parietal lobe that processes any movement or sensation in that arm is not receiving its normal input and the eyes know that that arm is no longer there. Here is the missing piece of the puzzle: before you move your arm, the frontal lobe sends a signal to the parietal lobe letting it know that it should be feeling movement in that arm very soon. When the arm moves as it was told to and sends feedback to the parietal lobe that matches what the frontal lobe told the parietal lobe a moment earlier, all goes well. But because the arm is not there, there is no feedback to the parietal lobe even though the frontal lobe told it to "feel" that arm. And now we have phantom limb sensation. The area of the homunculus representing the arm is activated by the "hardwired" motor areas of the brain, not the arm itself. Does it feel the same? You bet. Imagine the confusion when one perceives that arm the same way even though the eyes tell them it is not there! These patients must continue to protect this area and avoid hitting their phantom arm for fear of increased pain and sensation. So what happens to the arm part of the homunculus? If all goes well, the areas represented on either side, the torso and the face, adopt that area and now have a larger portion of the map. This is known as plasticity or the ability of the brain to grow new connections. However, if new connections are also made with pain areas, it is believed the individual will experience phantom limb pain.This is the most current theory on phantom limb pain/sensation. The key to helping these patients is to assess their brain and central nervous system function of the areas adjacent to the part no longer physically represented, then develop a therapeutic plan that increases or decreases (as needed) the activity of the sensory input to the homunculus. The therapy will consist of afferent stimulation that may include spinal adjustment, olfactory, auditory, visual and tactile stimulation. Mirror image therapy can also be used to "trick" the visual system into observing a limb that functions well. This visual feedback alone has been reported to be enough for some individuals to alleviate their phantom pain/sensations.
Stay tuned to the next issue for information on rehabilitation of nervous system dysfunction that occurs when one has a stroke or movement disorder.

Yes, chiropractic neurology is an appropriate therapy for stroke rehabilitation, especially when other forms of therapy have come up short of desired results. You may be surprised to learn that it is not any different in method than how I work with the back pain or headache patient. Every patient that walks through my door goes through the same comprehensive history and examination including neurologic evaluation. Next, I observe the sub-optimal body/brain patterns that exist that result in symptoms like dizziness/vertigo, muscle weakness or spasticity (dystonia), balance and coordination difficulty, tremors, etc. Lastly, I determine a plan that will positively effect the patient's body/brain patterns. This is when treatment/ therapy must be very specific to the individual patient as each nervous system responds at its own rate. This is to say that the same adjustment on 2 different patients both with left arm sensory/motor deficiencies can result in very different outcomes. For patient A, they may report increased sensation with improved strength immediately, but Patient B may notice worse coordination and more muscle fatigue. I hope you are now asking yourself "what is the difference?" because the answer is exactly what makes chiropractic neurology so special. Specificity. The treatment for these two fictitious stroke patients must be individualized or as you can see from the above example, one-treatment-fits-all comes up short. The goal is the same as with all patients: to stimulate/afferentate the nervous system to allow for optimal body/brain patterns, without fatiguing the nervous system. For one stroke case, strength conditioning may be the key to success. For another, only spinal adjustments may be necessary. For a third patient, eye exercises to strengthen the cerebellum (the coordination center) and intrinsic spinal muscles may be appropriate. There are many options but the right combination, at the right time, is distinctive to each human body.

Treatment is as individual as the personalities of my patients, but all with a common goal: make the body and the brain work well with each other. That is what leads to functional restoration, stroke or no stroke.

Submit your question to the doctor by emailing drtheirl@functionalrestoration.com

Explore the Brain on the Internet
The brain is a fascinating display of the most complex system in our world. Next time you are surfing, visit the following sites for fabulous graphics and interesting facts about brain physiology.

www.hhmi.org/senses
www.brainconnection.net
www.danafoundation.org
www.pbs.org/wnet/brain

If you are interested in learning the pathways, visit your local library or university library and begin with an introduction to neuroanatomy book. Choose something that includes both diagrams and descriptions of the common pathways so that you can both see and read where the pathways begin and end and what they do in between. You may be surprised by how fascinating it is to learn all that must transpire just to move your fingers, not to mention what happens so that you know they actually moved.