In order to keep this blog relevant I like to review academic and mainstream articles related to traumatic brain injury (TBI). I regularly read the journal “Nature“- considered a premier journal in all areas of scientific research- the best of the best for important new discoveries in science.
So I recently read an interesting article in a May 2018 issue in Nature describing new approaches in brain repair. The problem in Traumatic Brain Injury is even though we are getting better at identifying its presence, we haven’t made much progress in treatment. Drug trials have so far been a failure. Brain tissue does not easily repair itself. All sorts of important neurologic diseases are up against many of the same frustrations. Alzheimer’s, Parkinson’s, and Amyotrophic lateral sclerosis (ALS) are also short on remedies. TBI does not exist in a vacuum and shares many similarities to these other major chronic neurologic disorders.
Rescue or reprogramming are highlighted in this recent article. One must either rescue brain cells that are injured but not yet dead, or teach brain cells to bypass broken bridges and establish new neural highways for important neurologic function. Most of the brain does not actually consist of neurons- the cells that actually conduct electric impulses. Most of the cells are supporting cells (astrocytes for example) which help maintain the health of neurons but might do quite a bit more. We tend to think of the brain as a tight matrix of electric wires (neurons with their axon arms), but this ignores the supporting cast of cellular characters.
Enhancing regeneration of the brain can be done by restoring damaged cells. This usually involves the delivery of neurotrophic factors which can be delivered by cell based treatments. Thus, grafted cells (such as stem cells) could used to protect or rejuvenate damaged cells. Replacing dead neurons with new functional neurons still seems a long way off but would be the ideal treatment.
Interestingly, rehabilitation exercises frequently employed in treatment of TBI have been shown in experimental models to facilitate the endogenous production of brain growth factors. Cognitive therapy probably helps by allowing the brain to heal itself on a psychological as well as biochemical basis.
Unfortunately, the use of such growth factors to treat ALS or Parkinson’s disease has been disappointing in research going back nearly 20 years. These are brain diseases that are more clearly defined than TBI. This is not encouraging news.
Stem cells have been promoted as a possible answer to many human diseases. Experimentally, it has been possible to get stem cells and other cells to differentiate into neurons. Introducing them, even by direct implantation in the brain, does not mean they will do anything useful. Again, in animal models these cells can be shown to integrate into local preexisting neural networks. The road to integration into human brains with actual overt clinical improvement has been difficult to achieve.
Direct reprogramming of the brain with existing brain cells has made progress in recent years and would be less invasive and less risky than introducing external cells. The purpose of this blog is not to communicate information that is so technical that it makes the explanations unclear. This is perhaps my first attempt to dig a little deeper in my presentations.
One important take away message is that TBI is not alone in neurologic disorders of the brain. Progress in treating these disorders may have profound implications on therapy for TBI. One hopeful element in TBI is we often know the approximate date of onset and can intervene earlier in the disease process. By the time we diagnose Alzheimer’s or Parkinson’s, the destruction of brain tissue has been going on a long time. Intervening early is a key theme in effective medical therapy for illness in general. The potential to intervene early exists in TBI.
Steven H. Rauchman, M.D. is an eye physician and surgeon who has been in private practice for 30 years. He has served as a Traumatic Brain Injury (TBI) medical/legal expert for the last 6 years specializing in the area of personal injury and related traumatic brain injuries.