Aerobic exercise may help
reduce the symptoms of concussion in post concussive patients, according to a new
study. The finding challenges the traditional recommendation of complete rest
(both physically and mentally) and suggests that daily low level activity,
10-15 minutes, may diminish prolonged symptoms of concussion.
For the study, “Exercise Intolerance in Individuals With
Postconcussion Syndrome”, which
was published last fall in the Journal of Athletic Training, researchers at
Canisius College recruited 34 concussed males and females, ages 25.9 + 10.9
yrs. On average, the participants had suffered a concussion 226 days earlier.
Postconcussive syndrome (PCS)
is a diagnosis that is given when concussion symptoms are still present and not
subsiding, at least three weeks after a concussion occurs. According to the World Health Organization
PCS includes a history of traumatic brain injury with at least three self
reported symptoms. Symptoms of concussion include: headache, fatigue,
dizziness, difficulty concentrating, intolerance of stress or light, feeling in
a fog, and insomnia.
The study participants
were tested by walking on a treadmill. Blood pressure measurements were taken
every two minutes and heart rate was recorded every minute. The test ended as
soon as any concussion symptoms grew worse. The control group in this study was
made up of individuals who had no history of traumatic brain injury. PCS
participants were unable to exercise as long as the uninjured control group.
For some time, researchers have
known that small amounts of exercise that do not increase symptoms and
treadmill testing are safe and effective in the evaluation of concussion in
athletes and determining when they can
return to sports (Leddy
et al. 2010). Clinicians have access to tangible data like
heart rate, blood pressure while carefully monitoring concussion symptoms such
as headache while patients are on a treadmill, similar to a cardiac stress test
evaluation. An asymptomatic response to
graded exercise can be and is a key decisive factor for determining return to
sport and recovery from concussion.
Noticeably different than its
predecessors, the Zurich
Guidelines are a stepwise approach that recommends return to
play guidelines should progress in 24 hour increments. The athlete should be
asymptomatic before advancing to the next level of exertion, if symptoms are
exacerbated, the athlete returns to the previous level (Guskiewicz & Valovich McLeod, 2011). The Zurich stepwise
return-to-play guidelines are based on consensus and not evidence based
studies; they are subjective and vague about intensity and duration.
Cobb &
Battin, (2004) suggested that current return to play guidelines may be
“too lenient to protect a student from Second Impact Syndrome (SIS)”. Second Impact Syndrome is also called “second
impact”, “subsequent head injury”, and “recurrent traumatic brain injury” in
the literature. Second Impact Syndrome is a rapid swelling of the brain that
can occur hours, days, or weeks after the first brain injury (Cobb & Battin, 2004). Cantu
(1996) suggests, “athletes that sustain a concussion are four times more likely
to sustain another concussion than those who never had a concussion”. The subject of SIS is currently controversial
among researchers but they agree that edema is more likely in the younger brain
rather than the more mature brain (Guskiewicz & Valovich McLeod, 2011).
It is agreed that patients must
rest mentally and physically during the acute phase of concussion, 1-3
weeks. Beyond three weeks complete rest
even “cocooning” may not be the best approach.
Karl Kozlowski, PhD, the lead researcher of this study, is developing an
individually tailored intervention for athletes to stay in condition, without
exacerbating symptoms, while recovering from PCS.
According to researchers,
moderate physical activity actually restores the brain’s auto regulation
mechanism, which increases blood flow, and simulates neurogenesis in the
hippocampus, the memory center, which stimulates the growth of new neurons, or
nerve cells. Cerebral auto regulation, the system that maintains cerebral blood
flow, may be dysfunctional in people with concussion and may return to normal
with controlled exercise.
Regulated exercise allowed for
recovery of participants in the study. All but two concussed participants were
free of symptoms at follow up. Athletes recovered more quickly (11-36 days)
than non athletes (41-112 days). A limitation in this study is the small sample
size.
Daily moderate exercise, in a
controlled or clinical environment may not only be helpful in the monitoring
and recovery from PCS, but a more accurate screening tool for determining
return to play. Additionally, controlled
graded treadmill testing may be a valuable therapy for depression, cognitive
function, neurodegenerative diseases such as Alzheimer’s (Smith et al., 2011), and may help differentiate PCS from other diagnoses
such as migraine, post traumatic stress disorder, and depression which share
similar symptoms.
