Delayed Amnesia Can’t Be Found without Later Inquiry
Delayed Amnesia Requires Thorough and Continuing Investigation
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Delayed amnesia is a more significant indicator of injury severity than amnesia which only last a few seconds. By delayed amnesia I mean amnesia that doesn’t start until the emotional turmoil of the accident itself has passed. Yet, serious diagnostic mistakes are made because of failure to do the following:
- Distinguishing between confusion and amnesia; and
- Not accounting for memory pockets around the time of the accident.
The result is a serious under-reporting of amnesia. Without that reporting, it is extremely difficult to diagnose all brain injuries. More importantly, failure to document delayed amnesia, means a failure to identify those individuals who are at risk for long term brain damage. The most important important predictor of injury severity after concussion is the length of amnesia. If no questions are asked about memory for any period after the accident, if the possibility of a delayed amnesia is not considered, then many of the more potentially serious injuries, will be missed.
That the medical establishment is flawed in its current protocols for identifying amnesia is demonstrated by the following case study of TM. This in an extreme case, (and only possibly a case of delayed amnesia) but shows how medical diagnosis can be so distracted by other medical issues, that no documentation of amnesia ever makes it way into the medical records.
This 49 year old man was kicked in the face by a cow, which resulted in his being thrown to the ground rather violently and landing on his head on a very hard surface. He suffered a loss of consciousness lasting somewhere between 3 and 5 minutes. He had a GCS score of 14 for the next two hours, meaning that he was awake but unable to engage in meaningful communication. When he reached the ER, the focus of attention was on his facial injuries, which required close to 80 stitches to repair. He was anesthetized for six hours of surgery, so nothing was expected of his mental status for some time. He was hospitalized for a week.
In what turned out to be a critical decision for further evaluation, the mirrors were removed from the room lest he become too alarmed by his appearance. Thus, he had nothing to remind him what occurred. He had no recollection at all of the accident or his facial injuries. His medical record notes repeatedly described him as “alert, oriented and in no apparent distress.” His social skills were excellent and he could routinely get perfect scores on the Mini Mental Status Exam.
At the same time, when his wife would visit, and they were alone, he would ask where he was and why he was there. She started to bring a Polaroid camera with her and each time he asked, she would take a photo of his face to demonstrate. She did this three or four times per day for a week before his memory recovered enough to keep in his mind what had happened.
What is noteworthy here is that a TBI that caused an obliteration of his ability to retain memory for a week, was never identified in his hospital course. How does a memory defect this apparent evade documentation by a hospital staff that treated this man for an entire week?
Two things must be done to change the under-reporting of amnesia:
- Better questions must be asked that elucidate whether new memories are being encoded past the layer of immediate memory; and
- The better questions need to be repeated in successive days until the amnesia or other acute brain injury symptoms have cleared.
Delayed Amnesia Requires Better Questions
I have reviewed a number of standardized measures for identifying amnesia. That these measures are more sensitive to spot the disorder in the survivors of severe brain injury is clear. The bulk of these measures are little more than an elongated test for confusion.
What kind of questions should be asked to spot amnesia, especially delayed amnesia? In order to be sensitive to a dysfunction in a complex memory mechanism, the questions need to be open ended. The inquiry must include complex questions that the answers to will not fit neatly on the questionaire. My background as a lawyer who spends a significant proportion of time in the questioning of adverse expert witnesses may make me better at asking quesitons. But getting to the truth involves more than writing down the answer to yes and no and multiple choice questions. In reviewing amnesia questionnaires, I am continually reminded of the inexperienced lawyer who writes out of all his questions of a witness before hand and seems to lack the capacity to ask the followup question.
To diagnose delayed amnesia, the examiner must become a listener, and most importantly, an interactive listener. To determine whether someone has amnesia, you must know something about what it is that they are having difficulty remembering. Further, it is key to engage in conversation. This should improve the familiarity with a patient like TM above so that you might learn about the need for the Polaroids. But in conversation, the next question flows from the previous response.
To determine whether there is amnesia, the professional must engage the crashed mind in a task that would be potentially impaired.
While I would never want to limit the areas of examination the curious inquirer might ask, we can presume that what might not be remember could fit into these categories of inquiry:
Transportation to and Time in ER. For the individual who is seen in the Emergency Room, find out how they got there. Find out what they remember about the process of leaving the scene and getting to the hospital. Find out what they remember about the intake process in the hospital. Find out what they remember about waiting in the Emergency Room to be treated. If this is a busy Emergency Room, have them tell you about someone else who was waiting with them. Perhaps have the patient describe the most seriously hurt other patient, the most inpatient other person in the ER.
Ask About the Rest of the Game. If the person is injured in a game and did not leave the scene immediately, ask them how the game went after they got hurt.
Compare Notes Between Intake, Nurses and Doctors. If this ER is anything like the ER’s I have been in, there will be more than one professional who is asking these kind of questions. If the index of suspicion is raised that there might have been a concussion, the different examiners should compare notes. Even checking with the person who took the insurance information, might yield interesting inconsistencies in what was remembered. Remember, that unless someone is beckoning for the bed or space, there is no harm holding the person a little longer and asking some of these same questions again. If a person is sent for a CT scan, repeat the inquiry when they return. A differential memory may be as significant indicator as absence of memory.
One does not need to be a doctor to identify amnesia. What one needs to do is listen interactively and record what is said. A simple check in a box that says: __ LOC, oriented times three – won’t identify delayed amnesia. Further, if and when amnesia is identified, then the diagnosis of brain injury must be affirmatively ruled out before the injured person can be sent out into the world without the knowledge of that diagnosis.
 One theme of this book is that just recognition of a risk for disability can soften the synergistic negative plasticity which we believe is a major component to persistent disability post concussion. Yet, we also believe that as we improve at prioritize this spotting those at risk for disability, we will also increase our research and our commitment to treatment to prevent that negative plasticity and to address the other symptoms associated with MTBI.
 Two issue to flush out in this footnote. The ACRM comment about other serious injuries and the difficulties in using the GCS with someone who gets anesthetized.
 See Michael McCrea, Ph.D., James P. Kelly, M.D.,Christopher Randolph, Ph.D., Ron Cisler, Ph.D., Lisa Berger, M.S.W Neurosurgery, Vol. 50, No. 5, May 2002 Immediate Neurocognitive Effects of Concussion
“All injured subjects in this study sustained concussion according to standard definitions accepted by the American Academy of Neurology (3) and the American Congress of Rehabilitation Medicine (4). Subjects who experienced “ding” injuries (concussion without LOC or PTA) exhibited significant deterioration from their preinjury baseline levels of cognitive functioning. These findings are consistent with earlier research suggesting that neurocognitive functioning is the component of neurological status that is most susceptible to change after MTBI (30), thus indicating the need for detailed mental status testing to detect subtle abnormalities, even in cases without documented LOC or PTA. As indicated by the current findings, sensitive testing of orientation, concentration, and memory is critical for assessment of subtle mentalstatus changes after concussion.” P. 1037
The infrequent occurrence of LOC and PTA limits our interpretation of the rate and trajectory of recovery by the three clinical groups and highlights the need for very large multisite research initiatives to accrue enough head injuries of varying severity for study. The design of this study unfortunately does not provide more detailed data on the dynamics of cognitive recovery by subjects with PTA and LOC between 15 minutes and 48 hours after injury. Our findings demonstrate the need for further study of recovery during the first 24 hours after concussion. P. 1039 (Emphasis added.)