This post is not about the recent movie on brain damage discovered in (American) football players by Dr. Bennet Omalu. It is about my own recent journey.
I rarely share personal information over the internet. However, I want to give those of you who follow AllSignalProcessing.com some context for my reduced level of activity on the site over the past months. The short story is that I was in a bicycle accident that resulted in a mild traumatic brain injury (mTBI) or concussion. I expect to fully recover and get back to my goal of regularly adding content to this site, although the timeframe is likely to be measured in months, not weeks.
It would be great to have an epic story around the accident - like I rode in front of an oncoming beer delivery truck to rescue a child and the truck hit my rear wheel, knocking me to the pavement.
The truth is that the accident involved one of those otherwise embarrassing moments where gravity won and I lost. For some unknown reason I lost my balance in the midst of a U-turn. I couldn't get my foot out of the pedal binding and simply tipped over while attached to the bike. I was wearing a helmet.
I bike about 3000 miles a year and often balance on the bike while stopped for a traffic light or stop sign. It was a freak accident where many things happened just right, or I should say, "just wrong," to lead to an injury.
I have learned a few things about mTBI that are relevant to signal processing. First, there are no existing imaging methods for evaluating mTBI. MRI and CT can be used to detect bleeding, but typical damage to the neurons cannot be seen with current clinical imaging technology. I have found a couple very recent research papers that attempt to measure changes in functional connectivity as a result of mTBI, but those methods are a long way from the clinic.
One of my research interests is developing network models for brain function. Many of the symptoms of mTBI appear to be a consequence of disrupted network connectivity. One mTBI theory is that the impact damages the myelin sheath surrounding the axons, and breaks dendritic connections between neurons. Axons are like transmission lines connecting one nerve to distant others and comprise the white matter of the brain. Damage to the myelin sheath impacts the transmission characteristics of the axons and results in neural signals (action potentials) not arriving at the right time at other points in the network. Dendrites are local connections, so damaging those also interrupts normal connectivity. The sophisticated capabilities of our brains result from the immense network of interactions amongst 80 billion or so neurons. Disrupting the network leads to impaired function.
The good news is that the brain is incredibly plastic. That is, it makes new connections readily through neurogenesis, and can even recruit new areas to replace functions lost due to localized damage. But that reconfiguration and rebuilding process takes time. Each mTBI is unique and the duration of the recovery process is difficult to predict. If we had better technologies for imaging the brain, and a better understanding of how the brain works, we likely would be able to better understand mTBI and a host of other brain diseases. Developing those technologies and understanding is an outstanding challenge and opportunity for scientists and engineers.
Please enjoy the existing content while I continue healing. I have a lot of ideas and plans to extend the range of topics covered on this site. I am eager to implement those plans as soon as I'm able.
Also, please wear a helmet when biking, skiing, motorcycling, and so on. Stay safe and be well.
