As we talked about in the last blog post, a concussion is a mild traumatic brain injury (mTBI) which can have an impact on so many systems in the body. One of those is the autonomic nervous system, the same area that we see dysfunction in POTS! As a result of a traumatic brain injury, autonomic dysregulation, or dysautonomia, can occur. This results in high sympathetic tone in the body, which can cause anything from exercise intolerance to dizziness to vision impairments.
Let’s review. The autonomic nervous system controls our automatic body processes such as heart rate, blood pressure, body temperature, and digestion to name a few. There are two branches of the autonomic nervous system, the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system (SNS) we can think of as the fight or flight system and the parasympathetic (PNS) is the rest and digest system. We need balance between these two systems to live optimally.
After a mTBI, the brain shifts into an increased sympathetic state. Symptoms of high sympathetic tone include increased heart rate, increased respiratory rate, blood pressure dysregulation, sweating, anxiety, headaches, nausea and GI issues. Exercise intolerance may be one of the first clues that autonomic dysfunction is occurring post concussion, but even vision issues can be a result of dysautonomia.
Let’s dive into the specifics a bit more. Vision changes are one of the most common findings post concussion. Our eyes require a balance between the sympathetic and parasympathetic systems to shift from near, focal vision to a faraway gaze. We need the PNS to activate the near triad response, which is responsible for accommodation, convergence, and pupillary constriction. This is why issues with focus on one object can be difficult post concussion and people may experience double vision or blurred vision. This may also account for light sensitivity experienced post concussion, because the pupils are not able to properly constrict to accommodate for the brighter light.
Also, when we are in the sympathetic state, our vision becomes more like tunnel vision because our brain is only concerned with what is right in front of us and is not worried about things in our periphery or far away. Following a concussion, you may notice increased symptoms when you sense movement in your periphery because your brain is not accommodating to this movement and doesn’t know how to interpret that information since it is stuck in fight or flight. One simple, calming technique for your eyes involves looking at the horizon and noticing things in your periphery. If you are wondering about vision impairments post concussion, make sure you get assessed by an occupational therapist or vision therapist.
Exercise intolerance may be another symptom that pops up post concussion. You may find that your heart rate increases or you become sweaty or dizzy with minimal activity, or even just with standing. If this is the case, getting assessed for postural orthostatic tachycardia syndrome (POTS) may be beneficial. A physical therapist should be able to screen for this and a cardiologist or neurologist may diagnose you with this condition. Physical therapists might perform the Buffalo Concussion Treadmill Test (BCTT), which can screen for autonomic dysfunction. Monitoring heart rate or heart rate variability with change in positions can identify autonomic dysfunction and this may warrant a more formal assessment using the gold standard Tilt Table Test for diagnosis.
Treatment for autonomic dysfunction can come in a variety of forms and is best guided by your practitioner. Lifestyle modifications including increasing fluid and salt intake, wearing compression stockings, eating small, frequent meals, and learning pacing strategies can help manage symptoms. Working with a practitioner familiar with dysautonomia is key to a successful recovery.
Intrinsic Physical Therapy now offers Wellness Coaching to assist you in management of POTS. Schedule a free phone consultation today!