Concussion is a common accident experienced by people of all ages. It can be a result of a fall, a hit to the head or any type of traumatic brain injury. Sports related concussions in athletes are among the most common incidents. We discussed about the neurometabolic cascade of concussion in class as it is one of the important areas of neuropsychological diseases. When a traumatic brain injury occurs, the neural cells are overly activated (depolarized and initiation of action potentials) as a result of mass release of excitatory neurotransmitters. When the cells are overly stimulated, there is a massive efflux of potassium, that is potassium molecules going out of the cells in great amounts. As a result, sodium-potassium pump has to work harder to maintain the normal sodium and potassium levels both inside and outside of the cells, called maintaining homeostasis process. The pump is ran by the activity of enzyme ATPase and this ATP is provided from the break down of glucose in the cell, called glycolysis. During the events following the traumatic brain injury, there is a demand for increased ATP to run the pump and hence increase breakdown of glucose called hyperglycolysis occurs. Other important metabolic events include increase lactate accumulation from increased glycolysis, and increased Calcium influx (large amount of Calcium coming into the cells) which leads to impaired metabolism of mitochondria, cell’s main ATP production center. When mitochondrial ATP production is decreased due to impaired metabolism, cell death can occur as a result of energy deficiency and these cell deaths can result in cognitive impairments and amnesic symptoms seen in Concussion.
In this blog, I will discuss the different recovery time required for concussed patients according to the age group. In the mild cases of concussion, the increased release and activities of neurotransmitters can resolve back to normal within a few days due to body’s homeostasis mechanisms. The recovery time differs not only with the age group but also with each individual. Individual differences in recovery time between young or middle-aged concussed patients have been detected in research studies. Elderly concussed patients are found to be affected more and take longer recovery period even with milder brain injuries.
According to the research article by Gagnon,et.al, 2009, a gradual and closely-supervised active rehabilitation program for individual interventions are needed for children who are slow to recover. The article suggested underlying principals for development of intervention according to Montreal Children’s Hospital Rehabilitation After Concussion (MRH-RAC). The MCH-RAC principals include-Aerobic Activity, Coordination/Skill Practice, Visualization of Positive and Successful Activities related to Preferred Physical Activity, and Education and Motivation. The study suggests that children and adolescents who are slow to recover should participate in controlled and closely monitored rehabilitation and individualized intervention is sometimes necessary for concussed children. Exercise is also mentioned to have a positive impact on recovery since it promotes neuroplasticity (the growth of new neurons). Hence, according to Gagnon et.al, active rehabilitation and exercise are recommended recovery interventions for concussion in children.
A study by Mcclincy.et.al, 2005, reports that American athletes suffer approximately 300,000 concussive injuries in a year and 19 percent of participants are athletes who are involved in sports such as football and rugby. The article mentions current recovery measures such as Colorado guidelines, and American Academy of Neurology guidelines, According to the article, these scales diagnose concussion on a three point scale with grade 1 (mild), grade 2 (moderate), and grade 3 (Loss of conscious). For grade 1 injuries, the athletes can return to play on the same day of injury and for grade 2, within 1 weeks of injury. It was also mentioned that all concussion grading scales assume that all athletes should heal from concussive injury within 7 days. However, the study found out that the scales generalize ages, playing levels, gender and individual physiological responses concerned with the recovery process. The study used computerized neuropsychological testing ImPACT which is supposed to provide more accurate individualized results than traditional paper and pencil tests. The results of the study indicated that the cognitive deficits lasted at least 14 days in a sample of collegiate and high school athletes. The study also found out that 5 percent of the grade 1 concussions took 1 week, 34 percent of the grade 2 injuries took 2 weeks, and some of the grade 3 concussions took about a week and some took 2 weeks to recover. Hence, the study points out that traditional grading scales and recovery time according to the grading are not reliable on individual basis of recovery.
Of all the age groups, concussion in elderly patients are believed to take the longest to recover and harder to diagnose due to other neural complications that come with aging. According to the article ‘Outcome after traumatic brain injury: Effects of aging on recovery’ by Testa.et.al, 2005, elderly patients with traumatic brain injury have’ higher mortality and worse functional outcome than younger patients even with less severe injuries. The article states that elderly patients are more likely to suffer mood decline, impaired psychosocial and cognitive functioning and less complete recovery compared to younger patients. This increased vulnerability of the aging brain, the article states, is due to decreased brain reserve to make up for the damaged neural tissues. The article suggests that age is a risk factor in diagnosing and recovery process of concussion in elderly patients. Hence, rehabilitation efforts for these senior patients should consider other factors related to aging and cognitive decline.
By looking at the studies that are mentioned above, it is important to note that recovery time from concussion or traumatic brain injury will vary with the individual’s age, severity of the damage, and physiological responses. Therefore, it is not accurate to generalize the symptoms of children, adolescents, athletes, and elderly patients depending on the popular grading scales and estimate the recovery time according to those scales.