Could you explain in layman terms how the pathways of short term and long term brain damage differ? Also what are some of the differences in the treatment of short and long term trauma?
I can do my best, it's a bit complicated and there's a lot that researcher don't know, yet. There is some overlap between the two as well.
Basically, long term damage is late stage neurological degeneration. More akin to Alzheimers or Parkinson, with changes in brain metabolism, cerebral blood flow, brain atrophy and build up of plaque like the tau protein. This is where CTE would be. The environmental risk factors for developing this are mostly in line with the OP, as well a high volume of sustained (sub)concussive trauma over a long duration of years or decades.
Short term damage is concussive damage with immediate changes in brain metabolism, blood flow, autonomic function, mood, cognitive function and often accompanied by cervical pathology/whiplash syndrome. Roughly 10-15% will experience long term symptoms which is defined as post-concussion syndrome (PCS). This can become chronic and last for months or even years, and in some cases indefinitely. Environmental risk factors are not really well understood, however previous concussions and being female, as well as having had psychosocial difficulties prior to the initial trauma, may elevate risk. A concussion is classified as a mild traumatic brain injury, with moderate to severe traumatic brain injuries have similar but more severe injury mechanisms, often with macro damage to the brain akin to that of a stroke. This often results in an additional loss of cognition, sensory input and motor function.
In regards to the rehabilitation of long term damage like Alzheimers or CTE, compared to PCS, as I said initially there is an overlap there but the way in which the treatment is administered can be very different. Considering exercise and cognitive stimulation, for example. Exercise is good for both, as it normalises cerebral blood flow as well as autonomic regulation, however many PCS patients have what is called exercise intolerance. Any physical exertion makes them experience symptom exacerbation. Here you would have to use a very strict and sub-maximal aerobic protocol to improve exercise tolerance. In regards to cognitive stimulation, higher levels of cognitive activity can actually prolong the duration of recovery in PCS patients, which is seemingly not the case for late stage neurological degeneration. Which is why rest and activity has to be managed thoughfully, and it's here that stress reducing activities as well as meditation, mindfulness, stretching, breathing exercises or otherwise, come into play. This is applicable to both, I'd say. Stress is not good for the brain.
Anyway, that's a small example. I'm currently co-authoring a paper on PCS in physical therapy, but it's geared towards healthcare professionals and it's not completely encompassing. I'll have a thorough section on PCS pathology, risk factors and recovery strategies on my website when I finally get time to sit down and do it over the next few months. I will most likely be posting both here when it's done, for anyone who wants to read it.
