Optimizing and simplifying post-traumatic amnesia testing after moderate-severe traumatic brain injury despite common confounders in routine practice

The duration of post-traumatic amnesia (PTA) following traumatic brain injury (TBI) is a key diagnostic and outcome indicator. However, concerningly, different PTA paradigms record different PTA durations: some over-estimate, others under-estimate, PTA. Thus, a compromise is implied. The potential effect of in-hospital confounders including opioids is unknown. Three clinical groups were prospectively recruited. Group-1: in-patients with moderate-severe-TBI (MS-TBI), considered likely ‘in-PTA’. Group-2: patients rehabilitating after recent MS-TBI, considered ‘out-of-PTA’. Group-3: orthopaedic in-patients without TBI undergoing elective surgery. Only Groups 1&3 were taking opioids. All were administered the Westmead Post-traumatic Amnesia Scale (WPTAS) and the Galveston Orientation and Amnesia Test (GOAT). Results were obtained in n = 56 (Group-1:n = 18, Group-2:n = 13 and Group-3:n = 25). On WPTAS, Groups 1&3 scored similarly, but significantly lower than, Group-2 (χ² = 8.2, P = 0.017). Contrariwise, on GOAT, Group-1 scored significantly lower than Groups 2&3 (χ² = 23.99, P < 0.001): however, no patient scored GOAT <75. WPTAS showed moderate sensitivity (72%) but poor specificity (40%) in distinguishing Group-1 from Groups 2&3. Contrariwise, GOAT showed 100% specificity but 0% sensitivity. WPTAS ‘day of week’ and ‘pictures’ combined with GOAT ‘transport medium to hospital’, ‘anterograde amnesia’ and ‘retrograde amnesia’ maximized sensitivity (100%), specificity (85–88%), PPV (77–83%) and NPV (100%) in distinguishing Group-1 from Groups 2&3.ConclusionsConfounders including opioids likely affected WPTAS overall, but not GOAT specificity. A merger, whereby WPTAS sensitivity augmented GOAT specificity, was therefore sought. Favourable items from WPTAS (4/12) and GOAT (3/10) together optimized, and yet simplified, PTA testing; despite prevalent clinical confounders. Less, not more, ‘PTA’ items would benefit both patients and staff alike.     

Post-traumatic amnesia

Of patients hospitalised for traumatic brain injury (TBI), most pass through a state of altered consciousness known as “post-traumatic amnesia” (PTA). Despite the lack of a consistent definition, PTA is widely used as a construct in neurosurgical practice to guide decision-making and prognosis. Accurate PTA assessment is important, because over-evaluation leads to excess social, financial and opportunity costs, whilst under-evaluation risks patient welfare. Whilst anterograde memory is certainly disrupted in PTA, PTA in fact involves a far more extensive memory disturbance. More instructively, the complete “post-TBI syndrome” also comprises an extensive cognitive deficit which includes a confusional state, as well as a behavioural disturbance characterised by acute agitation. Recently, impairments in attention and executive functioning have also been emphasised; indeed, some consider these the primary disturbance with PTA. Although all of these features were fully described (or implied) by the earliest pioneers, most current PTA scores do not assess the complete “post-TBI syndrome”. Currently, the Westmead PTA scale (WPTAS) directs most in-hospital TBI management throughout Australasia: however, in addition to general defects, specific limitations have been identified in the levels of evidence for WPTAS validity. We review the literature regarding PTA and, in particular, the continued role of the WPTAS in directing neurosurgical practice.     

Traumatic brain injury produces impairments in long-term and recent memory

Traumatic brain injury (TBI) in humans typically produces neurological suppression and a longer lasting impairment of memory clinically defined as post-traumatic amnesia. An animal model that reliably reproduces the physiological changes associated with TBI was used to assess the memory deficits following brain injury. Prior to TBI, rats were trained to perform one of four tasks that assessed either motor performance, long-term or recent memory. Rats were randomly assigned to one of three groups (anesthesia only, sham operation or fluid percussion). Following fluid percussion, used to produce TBI, rats were tested for 6 test sessions. The first session occurred 1–2 min after the experimental manipulation. The next 5 sessions followed the training schedule maintained prior to experimental manipulation. Differences in long-term memory occurred only in the first post-operative test session. Differences in recent memory performance were found across all 6 test sessions. The memory deficits were clearly dissociated from motor deficits. The similar memory deficits observed following human head injury and the experimentally produced TBI injury demonstrate that fluid percussion is a useful approach to examine underlying neurobiological mechanisms involved in head injury and possible clinical interventions.     

Longitudinal study of objective and subjective cognitive performance and psychological distress in OEF/OIF Veterans with and without traumatic brain injury

Objective: To describe changes in post-deployment objective and subjective cognitive performance in combat Veterans over 18 months, relative to traumatic brain injury (TBI) status and psychological distress. Method: This prospective cohort study examined 500 Veterans from Upstate New York at four time points, six months apart. TBI status was determined by a structured clinical interview. Neuropsychological instruments focused on attention, memory, and executive functions. Subjective cognitive complaints were assessed with the Neurobehavioral Symptom Inventory (NSI). A psychological distress composite included measures of post-traumatic stress disorder (PTSD), depression, and generalized anxiety. Results: Forty-four percent of the sample was found to have sustained military-related TBI, 97% of which were classified as mild (mTBI), with a mean time since injury of 41 months. Veterans with TBI endorsed moderate cognitive symptoms on the NSI. In contrast to these subjective complaints, mean cognitive test performance was within normal limits at each time point in all domains, regardless of TBI status. Multilevel models examined effects of TBI status, time, and psychological distress. Psychological distress was a strong predictor of all cognitive domains, especially the subjective domain. Substantial proportions of both TBI+ and TBI? groups remained in the clinically significant range at the initial and final assessment for all three distress measures, but the TBI+ group had higher proportions of clinically significant cases. Conclusions: Objective cognitive performance was generally within normal limits for Veterans with mTBI across all assessments. Psychological distress was elevated and significantly related to both objective and subjective cognitive performance.     

Long-term outcome following traumatic brain injury: A comparison of subjective reports by those injured and their relatives

Many long-term outcome studies have documented changes following injury using subjective reports from TBI patients and close others. It is known that factors such as self-awareness and emotional adjustment can influence subjective reports, but there has been limited research comparing reports by those injured with those of their close others at longer periods post-injury. The aims of the present study were to compare TBI participants' and close others' subjective reports of cognitive and behavioural problems 10 years following TBI and to investigate the relationship between subjective reports of cognitive impairments and TBI participants' performances on cognitive tests. Fifty-four participants who had sustained mild to very severe TBI were followed up a mean of 10 years post-injury and 54 close others also participated. Measures included the Neurobehavioural Functioning Inventory (NFI), the Hospital Anxiety and Depression Scale (HADS), and cognitive measures of attention, memory and executive function. TBI participants and close others showed strong agreement in their reporting of problems on the NFI. However, there was no strong relationship between subjective reports of cognitive problems and test performances. Much stronger relationships were found between subjective reports of cognitive change and emotional state. This study highlights the importance of assessing emotional state when utilising subjective report data, as well as the need to use objective measures of cognitive impairment.     

A multicentre, randomised trial examining the effect of test procedures measuring emergence from post-traumatic amnesia

Background

Post‐traumatic amnesia (PTA) tests that record different PTA durations in the same patient, thereby raising measurement accuracy issues, have been reported previously. A major problem lies in determining the end point of PTA.

Aims

To delineate areas of discrepancy in PTA tests and to provide independent verification for a criterion signalling emergence from PTA.

Methods

In a randomised design, two related PTA procedures were compared, one purportedly more difficult (Westmead PTA Scale, WPTAS) than the other (Modified Oxford PTA Scale, MOPTAS). Eighty two patients in the early stages of PTA were examined daily until emergence, by using the Galveston Orientation and Amnesia Test (GOAT) and the WPTAS/MOPTAS. A short battery of cognitive and behavioural measurements was made on three occasions: at the early stage of PTA (time 1), towards the end of PTA when the maximum score (12/12) was first obtained (time 2) and at the traditional criterion for emergence (scoring 12/12 for 3 consecutive days; time 3).

Results

No significant difference was recorded in PTA duration between the MOPTAS and WPTAS. Both scales recorded longer PTA durations than the GOAT. By using Kaplan–Meier survival analyses, the WPTAS was found to show a more protracted pattern of emergence at the end stage of PTA than the MOPTAS. A time lag of ⩾1 week in the resolution of disorientation as compared with amnesia was observed in 59% cases. Significant improvements occurred on all independent measurements between time 1 and time 2, but on only 2 of 5 cognitive measurements between time 2 and time 3.

Conclusions

Although no significant differences in the duration of PTA on the MOPTAS/WPTAS were recorded, emergence from the late stages of PTA occurred more promptly with the MOPTAS. The need for inclusion of both orientation and memory items in PTA tests is highlighted by the frequency of disorientation–amnesia dissociations. The patterns of results on the independent measures suggest that patients who are in PTA for > 4 weeks have probably emerged from PTA when they first score 12/12 on the MOPTAS/WPTAS, and this criterion can replace the traditional criterion.Post‐traumatic amnesia (PTA) is a transitory state between coma and return of full consciousness defined as “an interval during which the patient is confused, amnesic for ongoing events and likely to evidence behavioral disturbance”.¹ It is a characteristic feature of traumatic brain injury, present in about 70% of admissions to brain injury rehabilitation units.^2,3 Duration of PTA is extremely variable, ranging from minutes to months. Although the early stages of PTA are easily recognised, identifying the end point is difficult and complex.^4,5,6 In some cases, the end of PTA cannot be determined because of chronic memory impairment;^7,8 in others, everyday behaviours at the ward level may indicate resolution of PTA, although the criterion on PTA tests cannot be achieved.⁹ Additionally, differences in recorded PTA duration in the same patient have been shown by using different PTA tests.^10,11,12,13 Such problems raise validity issues regarding the capacity of PTA tests to accurately measure PTA duration.More specifically, in comparing two similar scales, Tate et al¹³ found greater difficulty in measuring emergence from the end stages of PTA with the Westmead PTA Scale (WPTAS)^14,15 than with the Modified Oxford PTA Scale (MOPTAS; unpublished). The maximum score (12/12) was obtained on a significantly larger number of occasions on the WPTAS before reaching the criterion for emergence from PTA (first of three consecutive days scoring 12/12). We describe one case where the maximum score first occurred on day 14 post trauma, but the first of three consecutive maximum scores required an additional 17 days of testing (to day 31 post trauma); the patient scored 12/12 on seven separate occasions in the interim. The more demanding method of measuring the picture recognition‐memory component was mooted as responsible, but a definitive conclusion could not be drawn. An implication of the findings was that the criterion score for emergence from PTA on the WPTAS needed reconsideration. No empirical study has been conducted for either scale to establish such a criterion. On the basis of data from Tate et al,¹³ an earlier time point (first occasion scoring 12/12) was a possible alternative. We reasoned that if there were no improvements on independent neurobehavioural measures between the first and third consecutive days of scoring 12/12, then a revised criterion for the end of PTA (namely, first 12/12) was justified. As the case described above shows, not all patients can immediately sustain the maximum score for three consecutive days.Results from that study also indicated that further investigation on dissociations in resolution of disorientation and amnesia was required. Discrepancies among reports^13,16 may be resolved by examining the time lag between resolution of these PTA components. If the latencies are not significant, it is not important to measure both disorientation and amnesia, and PTA tests can be simplified, as is the current trend.^12,17 If large dissociations exist, however, the composition of PTA tests requires inclusion of both orientation and memory items to have any claims of accuracy.These issues formed the aims of the study. It was hypothesised that (1) recorded duration of PTA is longer on the WPTAS than on the MOPTAS, (2) sustaining the maximum score is more difficult on the WPTAS than on the MOPTAS, and (3) differences occur on the picture recognition‐memory but not on orientation items. Sustaining the maximum score was taken to be an index of the efficiency of measuring emergence from PTA (see Method section for operational definition). The second aim was to further examine the end point of PTA with independent measures and compare three time points: at the early stage of PTA (time 1), towards the end of PTA (time 2) and at the end of PTA (time 3). As examination occasions were linked to the level of recovery (measured by PTA score) rather than time post trauma, group differences were not anticipated. Marked differences were expected between time 1 and time 2, but not between time 2 and time 3.     

Resolution of disorientation and amnesia during post-traumatic amnesia

OBJECTIVES: Despite the growing number of instruments for the prospective measurement of post-traumatic amnesia (PTA) after traumatic brain injury, fundamental issues about the natural history of its resolution and methods of examination remain unresolved. The aims of the present study were to: (1) examine the sequence of resolution of disorientation and amnesia, and (2) determine if the method of measuring the memory component affected the duration of PTA. METHODS: The sample comprised 31 severely injured patients admitted to a brain injury rehabilitation unit who were examined daily until they emerged from PTA. They were administered a composite PTA scale, covering orientation and memory items from standard PTA scales. Patients were consecutively allocated to one of two groups according to the method of measuring the memory component. Each group was administered identical materials with a different procedure. RESULTS: The most common sequence for resolution of disorientation in both groups was person, followed by place, then time. Overall, amnesia resolved before disorientation in 94% of cases. Correlation coefficients between return of components of orientation and memory were all highly significant, ranging from r=0. 81 to 0.93. Significant variability occurred in the number of days to emerge from PTA according to the scale used. There was evidence that the method of measuring memory influenced the patient's capacity to consistently sustain criterion scores on the scale. CONCLUSIONS: These results are contrary to findings in mildly injured patients, in whom orientation usually returns before memory. They also demonstrate that the duration of PTA will be dictated by the method used. These findings raise validity issues with respect to the prospective measurement of PTA, and in particular determining when an individual patient has emerged from PTA, which require further investigation.     

Posttraumatic amnesia and recall of a traumatic event following traumatic brain injury

The relationship between posttraumatic amnesia (PTA) and symptoms of posttraumatic stress disorder (PTSD) was examined in 282 outpatients at a mean of 53 days after traumatic brain injury (TBI). Patients were assessed for TBI severity, intrusive and avoidant PTSD-type symptoms, and psychological distress, and were stratified into four comparison groups by duration of PTA. Levels of PTSD-type symptoms and psychological distress did not differ significantly between groups. Even patients with PTA >1 week reported intrusive and avoidant PTSD-type symptoms. However, when patients were stratified into those with PTA of <1 hour or >1 hour, the former were more likely to report such symptoms. TBI patients with brief PTA are more likely to experience PTSD-type reactions, but severe TBI with prolonged PTA is not incompatible with such reactions in a subset of patients. Possible mechanisms that could account for this finding are discussed.     

Centralized rehabilitation after severe traumatic brain injury--a population-based study

OBJECTIVES: To present results from the first 3 years of centralized subacute rehabilitation after very severe traumatic brain injury (TBI), and to compare results of centralized versus decentralized rehabilitation. MATERIAL AND METHODS: Prospectively, the most severely injured group of adults from an uptake area of 2.4 million in Denmark were included at admission to a regional brain injury unit (BIU), on average 19 days after injury. Patients in the retrospective study used for comparison were randomly chosen from the national hospital register. RESULTS AND CONCLUSIONS: Out of 117 patients in the prospective study, six died, and 92 (1.27 per 100,000 population per year) survived after a post-traumatic amnesia (PTA) period of at least 28 days. All 19 patients with PTA 7-27 days and 48% of survivors with PTA at least 4 weeks were discharged directly home. The incidence of patients vegetative at 1 month post-trauma was 0.29, and at 1 year 0.055 per 100,000 population. By comparison of 39 patients from the centralized unit injured in 2000-2003 with 21 patients injured in 1982, 1987 or 1992 and with similar PTA- and age distributions and male/female ratio, Glasgow Outcome Scale score at discharge was significantly better for the former group.     

Extensive temporally graded retrograde amnesia for personal-episodic facts in transient global amnesia

Abstract

Transient global amnesia (TGA) is characterized by an impairment of episodic memory resulting both in anterograde and retrograde amnesia. Few studies have assessed retrograde amnesia in TGA. Only Evans et al. (Journal of Neurology, Neurosurgery and Psychiatry 1993; 56: 1227-30) have distinguished between the episodic and semantic components of autobiographical memory, suggesting a disturbance of autobiographical incident recollection. A patient was tested during the acute phase of TGA with a sophisticated autobiographical event interview [derived from Kopelman et al. (Journal of Clinical and Experimental Neuropscyhology 1989; 11: 724-44) and Borrini et al. (Psychological Medicine 1989; 19: 215-24)], designed to replicate and extend this study of autobiographical memory. The autobiographical event interview disclosed an extensive disturbance in recalling memories with a temporal gradient, sparing earliest memories compared to more recent ones.     

Subjective ratings of cognitive and emotional functioning in patients with mild cognitive impairment and patients with subjective memory complaints but normal cognitive functioning

In a retrospective chart review, 39 patients referred for a clinical neuropsychological examination were identified as showing either mild cognitive impairment of the amnestic type (MCI-A; N = 21) or subjective memory complaints but with normal memory function (SMC; N = 18). During the clinical interview, patients and informants were routinely asked to make subjective ratings regarding the patient’s cognitive and affective functioning in everyday life. The purpose of this study was to determine whether these two patient groups (and their informants) significantly differed in their subjective reports about level of cognitive and affective difficulties. It was predicted that SMC patients would report higher levels of cognitive and emotional dysfunction than MCI-A patients. It was further predicted that MCI-A patients would underreport cognitive difficulties (compared to informant reports); SMC patients would demonstrate the opposite pattern. Results supported these predictions and suggest that routine assessment of subjective experiences of patients in conjunction with informant ratings may aid clinical diagnosis, particularly when the primary complaint is a decline in memory.     

Personal semantic and episodic autobiographical memories in Korsakoff syndrome: A comparison of interview methods

Objective: The temporal gradient in patients with Korsakoff’s syndrome has been of particular interest in the literature, as many studies have found evidence for a steep temporal gradient, but others have observed more uniform remote memory impairment across all past time periods. Inconsistencies might be the result of the nature of remote memory impairment under study (i.e., nonpersonal or autobiographical memory) and of methodological differences in the examination of remote memory loss. The aim of this study was to examine whether differences between autobiographical memory interview (AMI) and autobiographical interview (AI) procedures influence the presence of a temporal gradient in semantic and episodic autobiographical memory in Korsakoff patients. Method: The procedure used in the present study combined the AMI and AI into one study session. We compared the performance of 20 patients with Korsakoff’s syndrome and 27 healthy controls. First, participants were asked to recall knowledge from different life periods. Second, participants were asked to recall memories from five life periods. Thirdly, participants were asked to rate their subjective experience of each event recalled on a 5-point scale. Finally, we analyzed the findings in terms of all the memories recalled versus the first memory from each life-period only. Results: Both the AMI and the AI showed a temporally graded retrograde amnesia in the Korsakoff patients for personal semantic and episodic autobiographical memories. The pattern of amnesia in Korsakoff patients was not affected by examining only one event per life-period. Subjective ratings of recalled memories were largely comparable between the groups. Conclusions: The findings were generally consistent across the AMI and AI. Varying the number of events did not affect the pattern of the gradient. Hence, the temporal gradient in Korsakoff patients is not an artefact of either the AMI or the AI method.     

Factor analysis of the everyday memory questionnaire in persons with traumatic brain injury

Objectives: To investigate the factor structure of the Everyday Memory Questionnaire (EMQ) in persons with traumatic brain injury (TBI). Method: This was a secondary analysis of baseline data from two clinical trials targeting memory impairment after TBI. Participants were 169 persons with complicated mild, moderate, or severe TBI at an average of 41 months post-injury. They completed the EMQ via clinical interview. Exploratory factor analysis was conducted using a three-factor principal axis factoring estimation method with a polychoric correlation matrix and oblique rotation. Results: The three factors accounted for 49.2% of the variance, with moderate correlations observed among the factors. The three factors appeared to represent general everyday memory (prospective and episodic), conversational memory, and spatial or action memory. The three factors added significantly to the variance in age-corrected objective learning test scores predicted by injury severity, education, and sex. Conclusions: The three factors of the EMQ are consistent with the heterogeneity of memory impairments observed after TBI. The factor scores may be used to target treatments for impaired memory and to evaluate their effectiveness.     

Long-term amnesia: a review and detailed illustrative case study

Long-term amnesia is a slowly developing form of anterograde amnesia accompanied by retrograde amnesia of variable severity (Kapur, 1996; 1997) often associated with damage to the anterior temporal neocortex and epileptic seizures. The precise neural and functional deficits that underlie this condition are unknown. A patient, JL, who has this condition following a closed-head injury, is described in detail. Her injury caused bilateral anterior temporal neocortex damage that was more extensive on the left and right-sided damage to the perirhinal and orbitofrontal cortices. The hippocampus appeared to be intact bilaterally. Epilepsy developed within two years of JL's injury. Apart from her memory impairments, JL's cognitive functions, including high-level visual perception, attention, semantic memory and executive functions were well preserved. Her memory also seemed well preserved for at least 30 minutes following encoding. The one exception was the patient's relatively greater impairment at difficult visual recognition tests for which verbalization may not have been an effective strategy. This problem may have been caused by JL's right-sided perirhinal and orbitofrontal cortex damage. Her recall and recognition was clearly impaired after a three-week delay. She also showed a retrograde amnesia, which appeared to be milder than her remote post-morbid memory deficit. JL's remote memory was preserved for information first encountered in either the pre- or post-morbid period provided the information had received sufficient rehearsal over long periods of time. Her long-term amnesia may have been caused by anterior temporal neocortex damage, possibly in association with her epileptic seizures. Whether the condition is heterogeneous, involves a deficit in slow consolidation, disruption of unconsolidated memories, or blockage of maintenance or disruption of insufficiently rehearsed memories whether or not these have been slowly consolidated is discussed.     

A case of persistent retrograde amnesia following a dissociative fugue: neuropsychological and neurofunctional underpinnings of loss of autobiographical memory and self-awareness

Autobiographical memory relies on complex interactions between episodic memory contents, associated emotions and a sense of self-continuity over the course of one's life. This paper reports a study based upon the case of the patient NN who suffered from a complete loss of autobiographical memory and awareness of identity subsequent to a dissociative fugue. Neuropsychological, behavioral, and functional neuroimaging tests converged on the conclusion that NN suffered from a selective retrograde amnesia following an episode of dissociative fugue, during which he had lost explicit knowledge and vivid memory of his personal past. NN's loss of self-related memories was mirrored in neurobiological changes after the fugue whereas his semantic memory remained intact. Although NN still claimed to suffer from a stable loss of autobiographical, self-relevant memories 1 year after the fugue state, a proportionate improvement in underlying fronto-temporal neuronal networks was evident at this point in time. In spite of this improvement in neuronal activation, his anterograde visual memory had been decreased. It is posited that our data provide evidence for the important role of visual processing in autobiographical memory as well as for the efficiency of protective control mechanisms that constitute functional retrograde amnesia.     

Autobiographical memory, the sense of recollection and executive functions after severe traumatic brain injury

Residual disorders of autobiographical memory long after trauma resulting from head injury are rarely assessed, even though they may affect social adjustment and the resumption of daily life. We conducted a thorough study of autobiographical memory in severe traumatic brain injury (TBI) patients, examined at least one year post-trauma. Twenty-five patients were submitted to a novel and controlled autobiographical procedure specially designed to measure episodic memories (i.e., unique, specific in time and space, and detailed) from their entire life span with two kinds of self-remembering experience. The ability to mentally travel back through time and re-experience the source of acquisition, i.e. autonoetic consciousness, was assessed via the "Remember/Know" paradigm and a checking procedure of sense of remembering. Self-perspective in visual imagery, which is also critically involved in episodic recollection, was assessed by the "Field/Observer perspective" paradigm. In addition, the patients underwent a battery of standardized neuropsychological tests to assess episodic and semantic memory, orientation and executive functions. The results showed that the patients, compared with healthy controls, were significantly impaired in recalling episodic autobiographical memories. This impairment was not related to the life period tested or the patients' ages nor the intellectual impairment. Deficits involved disturbances in sense of remembering, visual imagery self-perspective and recollection of spatiotemporal details. Stepwise-regression analyses carried out in the TBI patients revealed a significant relationship between an abnormal sense of remembering and executive dysfunction covering both anterograde and retrograde components. The novel assessment used in this study provides the first detailed evidence of a more fine-grained deficit of autobiographical memory in TBI patients. Indeed, the results suggest that these patients, long after trauma, present autonoetic consciousness and self-perspective disorders, which include sense of identity (the self) as a continuous entity across time, probably related to frontal dysfunction.     

Autobiographical memory in long-term survivors of severe traumatic brain injury

The aim of this study was to examine the ability of persons who had sustained a severe traumatic brain injury (TBI) at least 6 years previously to recall memories associated with famous names. Each of 19 persons with TBI was matched with a healthy control of the same age, gender, and occupational-educational background. A list of 115 names of famous people was compiled, 25 of whom came to prominence in each decade from 1960 to 1999, and 15 in the period 2000 to 2005. Participants were first asked whether they recognized each name as being of a famous person and to state the reason for the individual's fame. For those names they correctly identified, they were asked to recall a memory associated with the person; each memory produced was categorized as a context-specific memory or a general memory. The ability to recognize and identify famous names was well preserved in the TBI group; however, they showed a consistent impairment in the ability to recall specific episodic memories acquired before and after the date of the TBI. This inability to generate personal and specific information is likely to have an impact on the ability of the person with TBI to participate in interpersonal interactions and problem solve in complex social situations.     

Music evoked autobiographical memory after severe acquired brain injury: Preliminary findings from a case series

Music evoked autobiographical memories (MEAMs) have been characterised in the healthy population, but not, to date, in patients with acquired brain injury (ABI). Our aim was to investigate music compared with verbal evoked autobiographical memories. Five patients with severe ABI and matched controls completed the experimental music (MEAM) task (a written questionnaire) while listening to 50 “Number 1 Songs of the Year” (from 1960 to 2010). Patients also completed the Autobiographical Memory Interview (AMI) and a standard neuropsychological assessment. With the exception of Case 5, who reported no MEAMs and no autobiographical incidents on the AMI and who also had impaired pitch perception, the range of frequency and type of MEAMs in patients was broadly in keeping with their matched controls. The relative preservation of MEAMs in four cases was particularly noteworthy given their impaired verbal and/or visual anterograde memory, and in three cases, autobiographical memory impairment. The majority of MEAMs in both cases and matched controls were of a person/people or a period of life. In three patients music was more efficient at evoking autobiographical memories than the AMI verbal prompts. This is the first study of MEAMs after ABI. The findings suggest that music is an effective stimulus for eliciting autobiographical memories, and may be beneficial in the rehabilitation of autobiographical amnesia, but only in patients without a fundamental deficit in autobiographical recall memory and intact pitch perception.