December 15, 2022
As the holiday season approaches, concussion recovery can become especially challenging. The hustle and bustle of the holidays often bring increased social expectations and overwhelming schedules that can cause additional…
In short, the answer to this question is that we don’t totally know. What we do know is that physically, mentally and emotionally things can go wrong when people don’t get enough sleep. Sleep is not just a downtime of “nonexistence.” There are actually many important physiological things that happen during this period.
Slow wave sleep is a time for the brain to clean and renew itself. It actually flushes out toxins and proteins that don’t need to be – and shouldn’t be – in there. In fact, with excessive buildup of some of these components, we see the typical pattern of an Alzheimer’s brain.
While we don’t know for certain the exact link between a lack of restorative sleep and neurodegenerative conditions like Parkinson’s and Alzheimer’s (it’s a bit of a ‘chicken and egg’ scenario), we do see unique patterns of sleep abnormalities years before the onset of certain conditions.
For example, people that develop Parkinson’s Disease can be seen with REM sleep behavior disorder 10 years prior to any clinical symptoms of the disease process. Despite this, discussion remains as to whether sleep disturbances contribute to the illness or the reverse, if the process that caused the disease is impacting parts of the brain that control sleep. This currently remains unclear.
In addition, we know that heart rate and blood pressure should decrease somewhat during the stages of sleep. But if sleep is disturbed we often see a persistence in daytime elevated heart rate and blood pressure, which can lead to cardiovascular disease.
Proper sleep is necessary for the production and release of important hormones, including Human Growth Hormone (HGH). Proper regulation of this hormone is particularly important for children to progress through puberty, though it is also important for adults throughout life to maintain homeostasis in terms of muscle and bone.
And finally, good rhythmic breathing patterns are important during sleep because when we have drops in oxygen levels, as happens with sleep apnea, it is a trigger for inflammation. And as we are now learning, chronic inflammation is the root cause of most modern disease.
So, the reality is that sleep, along with diet and exercise, is an overarching element that impacts your health and well-being.
We know that behaviorally and cognitively, if you don’t sleep enough, you’re more emotionally unstable. So, your boss and kids and commuter traffic are going to annoy you that much more. You also don’t have the same attention span, you don’t have the ability to multitask, and even your reflexes are affected.
You can take an otherwise healthy young person and deprive them completely of sleep for just a few nights and in some more extreme cases, cause psychotic breaks. In a lesser degree this can contribute to car accidents and lots of learning difficulties. So while many students think pulling all-nighters studying is the right way to go, they’re actually shooting themselves in the foot as proper sleep is required for memory consolidation and the ability to learn the next day.
Sleep or lack thereof affects everything; cardiovascular health, brain health, next day brain function, and emotional function to name a few. When you sleep poorly, it also impacts how you eat the next day, your food choices, hormone production and ultimately your microbiome and general gut health. It is all tied into a regular and cyclical pattern of wakefulness and rest.
So we’ve just seen how important sleep is for our mental and physical health. Now let’s take a look at how a concussion can disrupt a person’s sleep patterns. Later, we’ll talk about how concussion patients can maintain proper sleep hygiene for better health outcomes.
What typically happens to someone who has sustained a concussion is they are told by well-meaning doctors to go home, sit in a dark room for X number of days, and not do anything. And so this person very suddenly changes their schedule and begins “free sleeping” so to speak. They no longer set an alarm to get up for school or work and they nap throughout the day because, they no longer have anywhere to be, what else are they going to do? In short, their sleep schedule gets completely out-of-whack.
They also can’t really continue their exercise program, or don’t feel well enough to eat well or shop, perhaps they start eating more comfort foods. Body pains or medications used can disrupt the ability to maintain deep, restorative sleep at night. And, all these major changes can cause depressive symptoms, and we know mood can impact sleep as well.
In addition, the brain has experienced a trauma and so there may be a disruption in hormone production and even a breakdown in the blood-brain barrier. Now things are leaking into the brain that shouldn’t be, which triggers an inflammatory response. Even though a concussion does not present as a structural change on an MRI, you still get changes in how the neurons function chemically and hormonally due to this perpetuating inflammation.
Many concussion patients also develop a disruption in their breathing patterns, breathing shallow and more rapidly. And as we saw, this impacts sleep and your body’s ability to clear inflammation.
One of the big reasons so many concussion patients have trouble sleeping is because the concussion causes them to be more sensitive to light. So they tend to avoid light by either drawing the curtains in their home or wearing sunglasses all day. But it is this exposure to light that helps the body to maintain its circadian rhythm.
The human body functions on a 24-hour pattern. This is why it has been said that we each have an internal clock. When you are exposed to sunlight in the early morning hours, it sets your internal clock by saying “My day begins NOW.” Your clock then programs itself from that initial start time and says, “In about 12 to 16 hours, we’re going to start feeling sleepy.” This internal conversation works in conjunction with adenosine buildup and melatonin secretion.
The problem is that historically, concussion patients have been told to avoid bright lights and wear sunglasses, for fear light would provoke unpleasant symptoms. This results in the patient not getting the proper exposure to light in the morning to regulate their sleep/wake cycle.
Admittedly, it’s a bit of a catch 22. If a patient exposes themselves to blue light, it may indeed provoke symptoms. But if they don’t expose themselves to blue light, they are messing with their natural circadian rhythm and sleep cycle and their ability to clear inflammation. And the more inflammation they have, the more sleep issues they will develop, and on and on. It is for this reason that we ultimately tell our patients to get as much exposure to light as they can at the same time each morning, without causing themselves pain or triggering symptoms.
New data suggests there is an increased rate of sleep apnea among people who have sustained a concussion. The interesting thing is that in these cases we are dealing with obstructive, not central sleep apnea.
Central apnea is where the brain does not send the signal to the body to take a breath. Whereas in obstructive apnea, the brain sends the signal, but the airway has collapsed and has closed and therefore you cannot draw down air in an effective manner.
We don’t necessarily have a good explanation why an obstructive mechanism would be more prevalent in concussion patients. Having said that, some of the risk factors that go along with developing obstructive sleep apnea tend to occur. For example, gaining weight is a risk factor for obstructive sleep apnea. In concussion patients, a lack of exercise and eating more can lead to sudden weight gain.
At the end of the day, it’s still neural pathways that control the pattern of breathing, and the maintenance of tone in muscles. So, have we disrupted that pathway in some way, whether directly through impact or the subsequent inflammation that is happening in the brain? More studies will need to be conducted for us to have any solid understanding of the mechanisms that may be occurring here.
Blog content adapted from ACD Podcast Episode 129 with Dr Adit Margaliot (Neurologist) – to listen to the full podcast click (here)
Doctor Margaliot is a Canadian trained neurologist with a fellowship in neuromuscular disorders and further specialization in sleep medicine.
She has practiced in both hospital and community settings. She now also practices Functional Medicine, an approach to treating individuals as a whole and addressing root causes of chronic illness.
She views sleep as a very important component of an individual’s care and also recognizes the impact that other health issues have on sleep.
She presently practices in Toronto, and is pleased to sit on the board of Complete Concussions.
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