Post-Traumatic Amnesia: Diagnosis, Testing, and Treatment

Introduction

Post-traumatic amnesia (PTA) is a condition that occurs when an individual suffers an acute brain-damaging injury. Automobile crashes are said to be the most common origin of such injuries and, thus, the fundamental source of this disorder in young adults. The condition may persist for a few minutes or hours after the accident, or may continue for weeks, months, or even years. Post-traumatic amnesia is accompanied chiefly by memory loss and other similar impairments.

This paper begins with an introduction to the disorder, followed by a section on the characteristics that help diagnose PTA. The third section is dedicated to neuropsychological testing and evaluation for identifying behavioral or cognitive shortfalls that a patient might experience with post-traumatic amnesia. The factors for evaluation described include unconsciousness, scores on the Glasgow Coma Scale, and duration of diagnosed post-traumatic amnesia. Treatment techniques for PTA that address sensory, motor, cognitive, and behavioral issues are then addressed. Methods for cognitive rehabilitation are also explained, taking into consideration the role of smells and sounds in sparking memories. The final section addresses general principles that ought to be followed when managing patients with traumatic brain injury.

Post-traumatic amnesia (PTA) is a type of amnesia that occurs after a traumatic incident; it refers to a phase of recuperation from a severe, moderate, or mild brain injury. Patients who suffer from PTA are incapable of processing and retrieving new information or recording new memories. This type of amnesia can be described as a mental disturbance characterized by impaired attention, disorientation, illusions, misidentification of friends, family members, and nursing and medical staff, and by a failure to remember everyday events (Kneafsey, 2003).

The true pathophysiological process of PTA is unknown, but many argue that PTA can be linked with a traumatic injury to the brain and shearing of accelerative or decelerative axons in the brain's temporal and frontal lobes. These forces cause bruising, breakage, and/or inflammation of axons, with message pathways consequently being disrupted and/or damaged. This is commonly described as DAI — Diffuse Axonal Injury. Evidence from magnetic resonance imaging (MRI), however, has shown that some PTA patients do not show any evidence of diffuse axonal injury on their MRI reports (Korinthenberg et al., 2004; Gumm et al., 2014).

The greatest source of traumatic brain injury (TBI) is car crashes. As many as 17% of TBIs are caused by motor vehicle accidents (CDC, 2010). For young males, TBIs remain the leading cause of death. Evidence from numerous severe automobile crashes indicates that the victim's head often strikes the windshield, damaging the brain's prefrontal lobes. This frontal lobe damage may cause long-term memory deficits, problems in planning and organizing, and emotional complications. Damage may also occur in the temporal lobe regions, resulting in additional memory complications. A blow to the back of the head, or counter-coup, may damage the brain's occipital lobe, causing visual deficits as well. A clearer understanding of the nature of memory in the human brain can provide much-needed relief to such individuals. In the meantime, motorists should bear in mind the importance of fastening seat belts and not disabling safety airbags (Schwartz, 2014).

Treatment and care of patients suffering from brain damage falls under the field of clinical neuropsychology. Given that the majority of automobile crash victims tend to be young adults with long lives ahead of them, traumatic brain injury treatment and rehabilitation are of immense social significance in today's auto-centric culture. Clinical neuropsychology concentrates on the restoration and rehabilitation of intellectual skills for car-crash victims. However, because of the regular pattern of extensive damage in auto accidents, victims are rarely used for research examining the relationship between behavior and the brain (Schwartz, 2014).

Traumatic Brain Injury (TBI) Diagnosis

Guidelines have been published by numerous national organizations to define and describe the causes of mild traumatic brain injury (MTBI). These include the Veterans Affairs/Department of Defense (VA/DoD), the Centers for Disease Control and Prevention (CDC, 2010), the 2001 EAST Practice Management Guidelines (PMG), and the American College of Rehabilitation Medicine. All of these definitions concur that the process must comprise a direct external force accompanied by a subsequent physiological alteration in the brain's functioning. Though the language describing the nature of alteration differs among organizations, most agree that presenting Glasgow Coma Scale (GCS) scores ought to be in the range of 13–15 (Barbosa et al., 2012), that any unconsciousness must be under half an hour, and that the duration of post-traumatic amnesia must be less than one day.

Post-traumatic amnesia (PTA) can be distinguished by one or more of the following conditions:

• Disorientation and/or confusion
• Restlessness, a need to wander, thrashing
• Aggressiveness and/or anxiety
• Combativeness, such as pulling at medical tubes and/or devices
• Moaning, "childish" behavior, calling out
• Inappropriate or disinhibited social behavior
• Paranoia and fear
• Over-sensitivity to light
• Fatigue
• Decreased attentiveness and/or focus
• Lack of consistent memory
• Hallucinations
• Confabulation (fabricating stories)
• Repetitive thoughts or movements
• Preoccupation with a single issue
• Disruption of sleeping/waking cycle
• Impulsiveness
• Reduced planning ability or problem-solving skills

The end of PTA may be defined as the disappearance of confusion along with the restored capability of recording new information. PTA can last for periods as short as a few minutes, or as long as days, several weeks, or many months. (Most organizations, such as the VA, describe PTA as ending within one day.) PTA symptoms can vary considerably from one person to another. An individual may be talkative or drowsy, aggressive or docile, irritable or impudent. While some individuals may, after a period of PTA, make a remarkable physical recovery, it is also possible that a range of emotional and cognitive issues might disable these individuals in the long run. The duration of PTA and coma can help predict how severe the total brain injury is (Gumm et al., 2014).

Neuropsychological Testing and Evaluation

A formal neuropsychological examination may identify various behavioral, cognitive, or other deficits. Limited information exists to guide clinicians on which patients to refer for evaluation. Research on this topic is subject to various methodological weaknesses summarized by Sherer et al. (2010), and the influence on patient outcomes remains uncertain. This therapy has been considered more beneficial in cases of mild traumatic brain injury than in cases of moderate to severe traumatic brain injury. However, in research conducted on patients suffering from significant post-concussive syndrome (PCS), neuropsychological therapy was not shown to cause a decrease in symptoms (Barbosa et al., 2012). Through neuropsychological research, clinicians can study the relationships between behavioral and cognitive deficits and their correlation to the locus of injury in the individual's brain. Generally, most brain damage is rather evenly dispersed over large regions of the brain. In some instances, however — often resulting from strokes, bullet wounds, or surgery — damage may be relatively localized, allowing for clearer correlations between brain damage and memory deficits (Schwartz, 2014).

Perhaps the first step taken by healthcare professionals when treating an individual with traumatic brain injury is to evaluate the injury's severity. Severity is determined to facilitate initial triage as well as to assist with treatment planning. Various factors are considered when evaluating injury severity, including loss of consciousness, scores on the Glasgow Coma Scale, and length of post-traumatic amnesia (Struchen et al., 2009).

Loss of Consciousness (LOC)

Individuals may lose consciousness after receiving head injuries (Struchen et al., 2009). In general, the longer the duration of unconsciousness, the greater the severity of the injury. In a hospital setting, the patient's level of consciousness is typically tracked hourly and daily by the medical team, usually using the Glasgow Coma Scale (GCS), described below (O'Donnell et al., 2010).

Glasgow Coma Scale (GCS)

The Glasgow Coma Scale is a measurement tool that assesses the responsiveness of patients after traumatic brain injury. It is widely used in hospitals throughout the United States and around the world. The scale evaluates three responsiveness factors: eye opening (whether the patient is capable of spontaneously opening his or her eyes); motor responses (whether the individual is capable of moving when requested or when reacting to a painful stimulus); and verbal responses (whether the individual is capable of speaking and whether he or she is oriented). Typical GCS scores range from 3 to 15, with 13–15 considered mild injury levels, 9–12 as moderate levels, and 3–8 as severe injury levels. The medical unit generally uses this scale to evaluate the patient at the scene of the accident when the victim is transported through emergency medical services (EMS). The GCS can also be completed upon arrival at a hospital's emergency room. If hospitalization is required, GCS evaluation may be carried out on an hourly basis or multiple times per day until the patient consistently responds as oriented and alert (Struchen et al., 2009).

Post-Traumatic Amnesia (PTA)

The severity of a brain injury may also be estimated by investigating post-traumatic amnesia. After a traumatic brain injury, patients may be disoriented or confused for some period of time. They might not be aware of their surroundings for minutes, hours, or in some cases even days. They might not be capable of accurately stating the time, date, day, month, or year. This period is referred to as post-traumatic confusion or post-traumatic amnesia, and it is common among those with traumatic brain injuries. During this period, individuals may not be capable of forming new memories and may not recall the period later. Generally, a longer PTA duration is associated with a more severe brain injury. In acute hospital and rehabilitation settings, testing of the patient's mental orientation is normally performed at least daily. This may be documented in reports from nursing staff, the treating physician, therapy staff, or a neuropsychologist. One instrument used frequently for assessing orientation following traumatic brain injury is the Galveston Orientation and Amnesia Test, also known as the GOAT (Barbosa et al., 2012; O'Donnell et al., 2010).

The Galveston Orientation and Amnesia Test consists of questions regarding the patient's orientation to time, place, situation, and person. Specific questions are asked, and error points listed alongside each question are used to calculate total scores. A patient's total score at a given time is acquired by subtracting total error points from 100. Scores on the GOAT scale range from -8 to 100. For example, an individual who cannot remember a specific event after suffering the injury, and who is also highly disoriented regarding the date and month, would accrue 30 negative points for an overall score of 70. Scores below 66 are considered defective, while scores ranging from 66 to 75 are deemed borderline. Individuals achieving a score of 76 or above on two successive days are considered "oriented" and are thus no longer regarded as suffering from post-traumatic amnesia (O'Donnell et al., 2010; Struchen et al., 2009).

Conclusion

The understanding of memory in terms of cognitive psychology is becoming increasingly influenced by neuroscience, moving toward the formation of a hybrid field called cognitive neuroscience — a science that examines the relationship of brain anatomy, chemistry, and physiology with cognitive function. Diagnosis and management of veterans with traumatic brain injury and post-traumatic stress disorder (PTSD) is a very challenging clinical task. The relationship between these two conditions and their accompanying comorbidities, such as substance use or chronic pain, has not yet been fully explored; clinicians will frequently face situations in which only a limited body of published research can inform decision-making. Clinical assessment of veterans presenting with mild traumatic brain injuries and PTSD must involve a bio-psychosocial design or a similar model. Some of the treatment options available for cognitive problems related to traumatic brain injury, such as stimulant medication, might be harmful in the presence of comorbid PTSD.

References

Barbosa, R.R., Jawa, R., Watters, J.M., Knight, J.C., Kerwin, A.J., Winston, E.S., Barraco, R.D., Tucker, B., Bardes, J.M., & Rowell, S.E. (2012). Evaluation and management of mild traumatic brain injury: An Eastern Association for the Surgery of Trauma practice management guideline. J Trauma Acute Care Surg, 73(5), Supplement 4.

Capehart, B., & Bass, D. (2012). Review: Managing posttraumatic stress disorder in combat veterans with comorbid traumatic brain injury. JRRD, 49(5).

Centers for Disease Control and Prevention. (2010). Traumatic brain injury in the United States: Emergency department visits, hospitalizations and deaths 2002–2006. U.S. Department of Health and Human Services.

Chung, P., & Khan, F. (2013). Traumatic brain injury (TBI): Overview of diagnosis and treatment. J Neurol Neurophysiol, 5: 182. doi:10.4172/2155-9562.1000182

Gumm, K., Taylor, T., Orbons, K., Carey, L., & PTA Working Party. (2014). Post traumatic amnesia screening and management. The Royal Melbourne Hospital.

Kneafsey, R. (2003). Head injury: Long-term consequences for patients and families and implications for nurses. Journal of Clinical Nursing, 13, 601–608.

Korinthenberg, R., Schreck, J., Weser, J., & Lehmkuhl, G. (2004). Post-traumatic syndrome after minor head injury cannot be predicted by neurological investigations. Brain & Development, 26(2), 113–117.

O'Donnell, M.L., Creamer, M., Holmes, A.C., Ellen, S., McFarlane, A.C., Judson, R., Silove, D., & Bryant, R.A. (2010). Posttraumatic stress disorder after injury: Does admission to intensive care unit increase risk? J. Trauma, 69(3), 627–632.

Schwartz, B. (2014). Memory and the brain (Chapter 2). In Memory: Foundations and applications. London, UK: Sage.

Sherer, M., Roebuck-Spencer, T., & Davis, L.C. (2010). Outcome assessment in traumatic brain injury clinical trials and prognostic studies. J Head Trauma Rehabil, 25, 92–98.

Struchen, M.A., Davis, L.C., McCauley, S.R., & Clark, A.N. (2009). Guidebook for psychologists: Working with clients with traumatic brain injury. University press.

Appendix: Galveston Orientation and Amnesia Test (GOAT)

Source: Struchen, Davis, McCauley, and Clark (2009)

1. What is your name? When were you born? Where do you live?

2. Where are you now? (City? Hospital? — 5 points; unnecessary to state name of hospital)

3. On what date were you admitted to this hospital? How did you get here?

4. What is the first event you can recall after the injury? Can you describe in detail (e.g., date, time, companions) the first event you recall after the injury?

5. Can you describe the last event you recall before the accident? Can you describe in detail (e.g., date, time, companions) the last event you recalled before the injury?

6. What time is it now? (−1 point for each half-hour removed from the correct time, up to a maximum deduction)

7. What day of the week is it? (−1 point for each day removed from the correct one, up to a maximum deduction)

8. What day of the month is it? (−1 point for each date removed from the correct one, up to a maximum deduction)

9. What is the month? (−5 points for each month removed from the correct one, up to a maximum deduction)

10. What is the year? (−10 points for each year removed from the correct one, up to a maximum deduction)