Autonomic Arousal Problems Following Brain Injury

By Dr. Douglas Lee

Autonomic arousal is typically defined by the following symptoms: (1) Palpitations or pounding heart, or accelerated heart rate. (2) Sweating. (3) Trembling or shaking. (4) Dry mouth (not due to medication or dehydration).

This is not a typical outcome of a brain injury but can happen. Such arousal is controlled by the autonomic nervous system, which is made up of the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is responsible for our “fight or flight” activation while the parasympathetic system promotes our “rest and digest” processes.

Bill (pseudonym) was in a car crash. While he suffered only minor long term physical injuries, his major issues were due to a frontal lobe injury resulting in impairments in executive functioning (i.e., planning, impulse control, organizing etc.). I was asked to become involved due to his outbursts of anger.

He had a very skilled 1-1 worker who was able to develop 2-3 clear non-verbal signs to let Bill know that he was starting to get agitated and should move away from the situation.

One of the signs was the worker moving a colorful handkerchief from one pocket to the other, making sure Bill see him do this. 

Such support was necessary as Bill could rarely articulate what he was getting worked up about, even when it was obvious to his worker. 

His worker would explain things to him once they were both out of the situation (e.g., having left the store). Such support allowed Bill much more freedom to be the community in a wide range of everyday activities.

However, Bill still wanted to do some things on his own, typically very familiar routine activities which usually went smoothly. From what we could gather any outbursts were almost always similar to events that the 1-1 worker had also encountered. There were, however, occasional severe outbursts that occurred, at times resulting in police involvement.

These seemed a complete mystery for several months as they seemed completely unexpected and were often the most serious outbursts.

One meeting we had at Bill’s home revealed the underlying issue. While this was a regular update and planning meeting which Bill typically enjoyed, about 15 minutes into the meeting, Bill made a quote from the bible. I asked him about this and over the next 10 minutes the exchange between Bill and I continued to heat up.

Once I saw Bill shift forward in his chair and clench his fists, I diverted the topic and we returned to the regular meeting. For the next hour Bill was engaged, happy and appeared calm. Upon leaving I shuck Bill’s and found his palm to be completely covered in sweat (over and prolonged activation of his sympathetic nervous system). 

This revealed the root cause of the unexplained outbursts. Although infrequent, all the “mystery” outbursts occurred, sometimes up to two hours after an initial problem. Bill’s lack of awareness of his heightened arousal left him completely exposed to minor incidents sending him off into a tirade. 

The solution (not 100%) was for Bill to immediately return home if he had an initial incident (all his independent routines were within walking distance of his apartment) and call either his 1-1 worker or one of his brothers who best understood what was happening. He was to remain in his apartment for a minimum of four hours. Whenever possible either the 1-1 worker or his brother would visit him during this time.

Dr. Lee is a retired clinical psychologist who was also Board Certified in Behavioral and Cognitive Psychology and was a Board-Certified Behavior Analyst.   He has over 30 years experience working with children and adults with moderate to severe brain injury.  He consulted throughout BC and occasionally in Alberta.  His focus was on developing individualized treatment plans for a wide range of behavioral and cognitive issues. Due to the severity of most client’s injuries, he saw them in their local homes and communities. He is currently a board member of Fraser Valley Brain Injury Association.