The human body is a delicate balance of electrical and mechanical functions.
Like any machine, the body can malfunction when the balance is disrupted. The neurovascular system involves functions of both the nervous and cardiovascular systems, which are bridged by the vagus nerve.
There are a lot “moving parts” to account for in a neurovascular assessment, making it difficult to map a symptom to its root cause. This presents challenges when you’re trying to address a patient’s symptoms, especially in functional medicine where the goal is to treat underlying causes. Masking pain or numbness won’t ultimately help your patient live a better, healthier life.
Because we’re looking for that root cause, conducting a better assessment of your patient’s neurovascular health is less about the equipment you use, or tests you order, and more about cultivating and maintaining a holistic perspective of your patient’s body.
The Basics of a Neurovascular Assessment
The purpose of a neurovascular assessment is to determine whether your patient’s nervous and vascular systems are properly functioning in tandem.
At its most basic, the assessment is distilled down to 5 Ps: pain, pallor, pulse, paresthesia, and paralysis.
You’ll often evaluate these elements of the extremity that is linked to whatever symptom your patient is experiencing. In both natural and traditional medicine approaches, the assessment takes place along the extremities because that’s where vascular trauma and injuries are most commonly experienced.
If your patient is experiencing symptoms like chronic pain, or paresthesia (like numbness, tingling, or prickling sensation when touched), it could be a sign that a nerve or blood vessel has been compressed.
Heart Rate Variability and the Vagal Tone
The brain, the heart, and the cardiovascular system are discreet networks that are woven together by the vagus nerve. A neurovascular assessment helps you pinpoint the potential causes of your patient’s discomfort, but there’s additional value to be found in analyzing the vagal tone and the heart rate variability of your patient.
The mechanism that determines your heart rate and the one that directs the vagal tone are both part of the patient’s autonomic system. Vagal tone is largely a function of the vagus nerve, which is a cranial nerve that has a down-regulatory effect on the heart rate.
The vagal tone can reduce the heart rate, relaxing vessels so they are more patient, more open. However, a decreased vagal tone can lead to abnormal heart rate variability (HRV). This has been linked to conditions like obesity, insulin resistance, high blood pressure, anxiety, GI problems, and heart failure. Keeping an eye on the vagal tone and heart rate variability can reveal abnormal function as the underlying cause or an influencing factor in a variety of health problems.
Any of these symptoms or conditions would be cause for a neurovascular assessment.
As a natural medicine practitioner, you’ve been trained to look at the body holistically and determine how environmental factors align to produce symptoms in your patients. HRV is a useful data point with the potential for insight that you can use in developing care plans for the aforementioned conditions. HRV gives a reading of the patient’s health at the intersection of the electrical and mechanical systems in the body. Abnormal HRV would indicate a disproportionate response to internal or external stimuli.
According to Harvard Medical School, “If a person’s system is in more of a fight-or-flight mode, the variation between subsequent heartbeats is low. If one is in a more relaxed state, the variation between beats is high.”
Obviously, we want to avoid staying in a perpetual fight-or-flight mode. Our bodies aren’t built to endure stress for extended periods of time, which is why studies have found a link between low HRV and depression and cardiovascular disease.
By using the neurovascular assessment to seek issues beyond 5 Ps, you can expand the impact of your work with a patient.
Beyond the Symptoms
It’s easy to treat a neurovascular assessment as the end itself rather than a means to a good patient outcome. Approaching the patient’s health holistically and using that top-down direction to find areas where there might be neurovascular issues at play will help realign focus on positive patient outcome rather than assessment data.
Emerging findings about HRV demonstrate how sensitive we are to environmental changes like lack of sleep or chronic situational stress.
There’s an old saying, “When all you have is a hammer, everything looks like a nail.” If you approach the neurovascular assessment only as a means to uncovering vascular damage, you’re limiting the scope of your impact. Remind yourself that the body’s systems are interconnected, and that any sort of abnormality or misalignment can have wide-ranging effects on your patient’s quality of life and overall health.
Our goal is to push medicine beyond simply treating the symptom. To do so, we must understand how the body functions as a system.