By Dr. Ken Manges, Ph.D. | Forensic Psychologist
As a forensic psychologist and wage loss expert I frequently receive referrals that overlap both medical and psychological issues. In a recent matter, a claimant’s life was fortunately saved by emergency room personnel who were able to successfully re-start her heart after a cardiac arrest, in the emergency room!
The good news was, she survived. The bad news is, she had to have her heart re-started 10+ times, which subsequently resulted in some cognitive impairment and traumatic brain injury.
The referral question asked of me was:
Is the injured worker now capable of returning to her former job as an assistant manager, post cardiac arrest?
I was not asked to diagnose the cause of the brain dysfunction but rather the damages or aftermath of the impairment.
My research was informative and I thought it was spot on regarding the injured worker’s clinical presentation, so I am sharing it here for others who may have similar cases dealing with traumatic brain injury.
The brain requires a constant flow of oxygen to function normally. In this woman’s situation she experienced a disrupted flow of blood to her brain as a consequence of her multiple cardiac arrests, diagnosed in this case as a hypoxic-anoxic injury (HAI).
HAI occurs when blood flow is disrupted. The brain is essentially starved of nutrients and prevented from performing vital biochemical processes.
Hypoxic refers to a partial lack of oxygen; anoxic means a total lack. As you might suspect, the more complete the deprivation, the more severe the harm to the brain and the worse the consequences.
By way of history in this claimant’s case, the injured worker was complaining of chest pain and went to the emergency room. While being interviewed she actually went into cardiac arrest! She received CPR for 30+ minutes and was then transferred to another area of the hospital where she received 10+ shock/defibrillation procedures to her chest wall, along with medications to revive her.
Her condition was later diagnosed with a total occlusion of the left anterior descending coronary artery and a low 35% to 40% ejection fraction or EF (EF is a measurement of the percentage of blood leaving your heart each time it contracts). A normal EF is between 55 and 70. A measurement under 40 may be evidence of heart failure or cardiomyopathy. An EF between 40 and 55 indicates probable damage.
During each heartbeat cycle, the heart contracts and relaxes. When your heart contracts, it ejects blood from the two pumping chambers (ventricles). When your heart relaxes, the ventricles refill with blood. No matter how forceful the contraction, it doesn’t empty all of the blood out of a ventricle. The term “ejection fraction” refers to the percentage of blood that’s pumped out of a filled ventricle with each heartbeat.
Diminished oxygen supply to the brain can cause serious impairments in cognitive skills, as well as, physical, and psychological functions. Recovery can occur in many cases, but it depends largely on the parts of the brain affected, and its pace and extent are unpredictable. Some persons may have a diffuse, overall deterioration, others may have more a specific loss (vision, hearing etc.).
Causes of Hypoxic-Anoxic Injury
In my research I learned that the brain consumes about a fifth of the body’s total oxygen supply, and needs constant energy to transmit electrochemical impulses between cells and to maintain the ability of neurons to receive and respond to these signals.
Cells of the brain will start to die within a few minutes if they are deprived of oxygen. The result can result in a cascade of problems. The disruption of the transmission of electrochemical impulses impacts the production and activity of our neurotransmitters, which regulate many cognitive, physiological and emotional processes.
Not to get too far off the path, there are many neurotransmitters, and in combination they perform a wide variety of important functions. Although the specific ways neurotransmitters work is not fully understood Some, such as serotonin, dopamine and norepinephrine, play an important role in regulating moods. Endorphins are critical for controlling pain and enhancing pleasure, while acetylcholine is important for memory functions.
A variety of disease processes and injuries can cause HAI. The most common is called hypoxic ischemic injury, also known as HII or stagnant anoxia. This occurs when some internal event prevents enough oxygen-rich blood from reaching the brain. While strokes and cardiac arrhythmia can both result in HII, the most frequent cause is cardiac arrest. Occasionally, HAI is caused by anoxic anoxia, which is when the air itself does not contain enough oxygen to be absorbed and used by the body.
Symptoms of Hypoxic-Anoxic Injury HAI is generally marked by an initial loss of consciousness or coma. The period of unconsciousness, whether short or long, might be followed by a persistent vegetative state (where a person is neither comatose nor responsive to external stimuli). This state is sometimes called “wakeful unresponsiveness.”
Even when a person has fully recovered consciousness, he or she might suffer from a long list of symptoms. In many ways, these symptoms are similar to those commonly seen after a blow to the head/TBI/traumatic brain injury/mild brain trauma.
The effects can vary widely depending upon the part of the brain that has been injured and the extent of the damage. Some of the major cognitive (thought) problems are:
- Short-term memory loss. This is the most common cognitive symptom, especially among those who have HII. The reason is that the part of the brain that is believed to be responsible for learning new information, called the hippocampus, has neurons that are highly sensitive to oxygen deprivation.
- Decline in executive functions. Disruption of such critical tasks as reasoning, making judgments, and synthesizing information. This can lead to impulsive behavior, poor decision-making, inability to direct, divide, or switch attention.
- Difficulty with words, also known as anomia. These linguistic problems include not being able to remember the right word, selecting the wrong word, confusing similar words, or not understanding commonly used words.
- Visual disturbances. Difficulty processing visual information can occur in some cases. One rare disorder is called cortical blindness, in which the area of the brain responsible for vision becomes disconnected from the rest of the brain. Because the brain cannot tell that this part is damaged, people may appear to act as though they can see even though they display no ability to identify or recognize objects, shapes or colors.
The person I saw for her vocational evaluation exhibited a loss of memory for visual and auditory (verbal) information. I evaluated her using the Wechsler series (both intellectual and memory) along with a validity test (a measure to assess if she was malingering or faking the results.
She was genuine in her responses but showed a diminished level of memory and other cognitive losses causing her to be unable to complete even routine tasks on a reliable basis, much less the demanding work she did as an assistant manager.
I hope others are helped by my research.