In rehab, we can see a lot of different types of complicated conditions. Brain injury, spinal cord impairment, multiple trauma and chronic illnesses… these impairments can lead to their own host of complicated side effects. And one of the most intimidating issues that can rear its ugly head is sympathetic dysfunction or overactivity. This can be challenging to deal with, and even to understand- I have heard (and been guilty of!) mixing up autonomic dysreflexia and sympathetic storming in rehab, when I have encountered them. Here, we want to examine- what is the difference between these two conditions? What should I know? And how best can I deal with it as a rehab clinician?
First- a quick review that will help understand the reasons that these conditions can occur! Let’s revise the sympathetic system.
The sympathetic nervous system
The sympathetic nervous system (SNS) is a part of the autonomic (unconscious) nervous system. When we try to explain the SNS, the concept of ‘fight-or-flight’ is often brought up- an involuntary bodily response to protect us from perceived danger. The lack of conscious control of the SNS is key to its protective function- by producing its localized reactions to stimuli (internal or external), it prepares the body to deal with a potentially dangerous situation. The SNS will cool the body in response to external heat, by sweating; increase adrenaline to the muscles in response to stress; and narrow the focus/concentration of the mind in response to fear.
When triggered by a stressor, the SNS will kick into high gear- releasing a high level of epinephrine, increasing heart rate and cardiac output, pupillary dilation, skeletal muscle vasodilation and gastrointestinal vasoconstriction.
These functions of the SNS cause a cascade effect, and in an unimpaired system- sustained SNS overactivity can cause a variety of physiological consequences, such as hyperglycemia (which may lead to Type 2 Diabetes) and hypertension, which can lead to cardiovascular disease,
The effect of an overstimulated SNS system in a person with spinal cord or brain injury, however, can lead to an uncontrolled and dangerous response.
Autonomic Dysreflexia (AD) is considered a Medical Emergency in Rehab Medicine- and for good reason. It is defined as a life-threatening condition, that can occur in patients with a spinal cord injury at the level of T6 (or above) because of unchecked sympathetic response.
The prevalence of Autonomic Dysreflexia is variously reported to range from 20 to 70%- in other words, an essential condition to be able to recognize, treat and manage, if you work in the rehab field!
Luckily for most people- AD can easily be prevented and treated if it occurs!
Let’s have a look at how this condition presents in those post spinal cord injury. Some the symptoms of AD can include: high blood pressure, pounding headache, flushed face and sweating above the level of the injury, goosebumps, stuffy nose, and a slowed pulse (<60bpm). Normal Blood pressure in those with a SCI above T6 runs lower than the average, with systolic in the 90-110 mm range. Therefore, if your patient is presenting with headache and a BP of 140 systolic, you should be very concerned about the possibility of AD.
These symptoms can vary based in the individual- but can lead to a serious event, such as a stroke, if not addressed immediately.
Autonomic dysreflexia is caused by a noxious stimulant below the level of the injury. This could be bladder related, as in (commonly) a kink in the catheter tubing, UTI, or other bladder irritation; bowel-related, such as pain from infections/hemorrhoids, distended bowel; other skin irritation like ingrown toenails, sunburn, overly tight clothing, or bruising/abrasions; or other stimulation such as menstrual cramps, sexual activity, labor, or bone injury/fracture.
Knowing the symptoms of Autonomic Dysreflexia for those who are at risk, the rehab clinicians treating them, and their caregivers- is paramount. The correct action must be taken quickly in order to avoid serious consequence.
What should a rehab clinician do?
|Educate your patient about the signs/symptoms of AD.|
|Learn the person’s ‘typical’ resting BP, and explain that a reading of 20-40 mm HG above baseline is cause for concern (which may read like a ‘normal’ BP in a person without SCI!).|
|Move to a position that will cause blood to flow to your feet. Sit your patient up to 90 degrees, and lower the legs.|
|Loosen or remove tight clothing and socks/shoes.|
|Check the catheter (if applicable), and ensure that there is no visible blockage/distended bladder.|
|Examine for other noxious or painful stimuli.|
|Check the BP reading every 5 minutes to ensure that the readings are not worsening.|
|Certain medications can be used to manage the mixed signals with regard to blood pressure; and may require administration if removal of the visible noxious stim does not stabilize the patient- such as vasodilators, nitroglycerine, nitrates, and so on.|
|The majority of the role of the clinician, however, should be focused on prevention! Ensure that a bladder and bowel program/schedule is established and adhered to, educate your patient about protecting and examining the skin and limbs below the waist level.|
Officially known as Paroxysmal Sympathetic Hyperactivity, which describes the sudden onset and recurrence of these ‘storms’; as well as the sympathetic system involvement and function, in the moment of attack. The paroxysms cause an increase (hyperactivity) of the circulating corticoids and catecholamines- or a stress response.
Sympathetic storming, or PSH is reported to affect 15 to 33 percent of people who have sustained a TBI, with symptom onset occurring within hours or even months of injury. It is most frequently associated with severe traumatic brain injuries, and even with non-traumatic injuries such as hydrocephalus, intracranial tumors, severe hypoxia and Intracerebral hemorrhage.
How does sympathetic storming present? PSH is a diagnosis by exception- a conglomeration of symptoms can be present, which may include: hypertension, tachycardia, tachypnea, hyperthermia, posturing, dystonia, and diaphoresis. Once any other metabolic or infections have been ruled out as causational, a positive diagnosis of PSH can be made.
Sympathetic storming can also be triggered by infections, unrecognized injuries, and other medical conditions, so evaluation and identification of triggers such as these are paramount to providing the correct response.
Just as discussed previously with AD, there is a strong need to focus on management of PSH, as there may be a risk of increased morbidity if left unaddressed. Secondary brain injury from hyperthermia, posturing that may result in energy expenditure and cardiac/skeletal muscle damage, brain bleeds from hypertension are examples of the adverse effects that may occur if PSH is left untreated.
As a clinician, recognizing the symptoms and signs of a sympathetic storming event is going to be crucial to getting the care they need.
What can a rehab clinician do?
Hypertension—increased blood pressure Tachycardia—abnormally rapid heart rate
Tachypnea—abnormally rapid breathing Dystonia—state of abnormal muscle tone
Hyperthermia—abnormally high body temperature, of central origin
Posturing—abnormal muscle stiffness/body positioning Diaphoresis—abnormal/excessive degree of sweating
|Check your patient for cause- noxious stimuli and external triggers- and remove if applicable|
|Educate and empower caregivers and family members to spot an event|
|Address hydration, manage temperature, and increase comfort during an episode|
|Provide calming input: cool cloths, quiet conversation, soothing music and massage|
|Analyze triggers and avoid (once identified)|
|Treatment is largely pharmacological- alert physician, seek medical management|
Why can these two conditions be confused?
So why and how can these two conditions be confused? Well, as these conditions are both related to dysfunction of the sympathetic system, they can be easily confused. In rehab, we often encounter patients who have had a spinal cord injury- a TBI- or sometimes, in the case of severe multi-trauma: both. It is incumbent on all in patient rehab clinicians who are working with the neurological population to be aware of the complications that may arise as a secondary impact of their condition- and sympathetic dysfunction can be one that we frequently encounter!
In order to provide best service, you should: familiarize yourself with the presentation of these dysfunctions; educate patients, family and caregivers about these conditions and how to recognize them; and develop a protocol for managing and addressing these complications as they arise.
Some useful resources that you may want to have in hand in YOUR rehab department:
Remember- we may be very likely to see these condition in in-patient rehab, when clients are newly presenting with a brain injury, spinal cord injury, or other insult to the sympathetic nervous system- but these issues can continue (or begin!) to occur in home care and in outpatient care as well. Hence, educating patient and family to recognize and act quickly is going to be of the utmost priority, at every stage of rehab and recovery!
Interested in learning more about the management of brain injury, autonomic dysreflexia and other rehab topics? Consider becoming a Certified Brain Injury Specialist (CBIS)! Check out our offering: the Certified Brain Injury Specialist Training Prep Course for training and credentialing, and set yourself apart by obtaining this certificate in 2 days!
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