Episodic and semantic memory after traumatic brain injury in a child]

In an early-life, a memory disturbance affects the learning and school record directly. Furthermore, it may cause the problem of maltreatment or adaptation difficulty for school life. We report a child amnesia caused by a traumatic brain injury when she was 9 years old. We examined her episodic and semantic memory. We developed 3-steps tasks of recognition and recall for the post-accident episodic memory. First, the examiner presented the patient with four words orally including a label of her episode, and asked her to choose one that she felt familiar with (the recognition of the episodic label). Second, if the word she selected was correct, she was required to recall the episode related to the word (the recall of the episode). Third, if she could not recall the episode herself correctly, she was required to choose a correct sentence about the episode (the recognition of the episode). She could not recall episodes correctly, but produced confabulation instead. She showed, however, good recognition of each episode. Furthermore, we performed recognition tests of time, person, and place about the same post-accident episodes, which were poor especially for time. In semantic memory tasks, we examined about kanji characters (ideogram) learned from the first grade to the sixth grade and mathematical knowledge learned from the second grade to the sixth grade at elementary school ("What centimeters is equal to one meter?" or "Tell me the formula of the size of a circle." etc). We found that she showed a retrograde impairment for about one year. For both episodic and semantic memory, she showed an anterograde impairment. Because of the anterograde amnesia she could not acquire new facts, and also showed para-amnesia or confabulation. In a child with brain damage, neuropsychological assessment is important in predicting effect of rehabilitation and recovery of school performance.     

Impaired response inhibition in veterans with post-traumatic stress disorder and mild traumatic brain injury

Combat veterans with post-traumatic stress disorder (PTSD) can show impairments in executive control and increases in impulsivity. The current study examined the effects of PTSD on motor response inhibition, a key cognitive control function. A Go/NoGo task was administered to veterans with a diagnosis of PTSD based on semi-structured clinical interview using DSM-IV criteria (n = 40) and age-matched control veterans (n = 33). Participants also completed questionnaires to assess self-reported levels of PTSD and depressive symptoms. Performance measures from the patients (error rates and reaction times) were compared to those from controls. PTSD patients showed a significant deficit in response inhibition, committing more errors on NoGo trials than controls. Higher levels of PTSD and depressive symptoms were associated with higher error rates. Of the three symptom clusters, re-experiencing was the strongest predictor of performance. Because the co-morbidity of mild traumatic brain injury (mTBI) and PTSD was high in this population, secondary analyses compared veterans with PTSD+mTBI (n = 30) to veterans with PTSD only (n = 10). Although preliminary, results indicated the two patient groups did not differ on any measure (p > .88). Since cognitive impairments could hinder the effectiveness of standard PTSD therapies, incorporating treatments that strengthen executive functions might be considered in the future. (JINS, 2012, 18, 1-10).     

Episodic and semantic memory in mild cognitive impairment

Little is known about episodic and semantic memory in the early predementia stage of Alzheimer's disease (AD), which is referred to as mild cognitive impairment (MCI). To explore person knowledge, item recognition and spatial associative memory, we designed the Face Place Test (FPT). A total of 75 subjects participated: 22 patients with early AD, 24 with MCI and 29 matched controls. As predicted, AD patients showed significant deficits in person naming, item recognition and recall of spatial location (placing). Surprisingly, subjects with MCI were also impaired on all components. There was no significant difference between AD and MCI except on the placing component. Analysis of the relationship between semantic (naming) and episodic (recognition and placing) components of the FPT revealed a significant association between the two episodic tasks, but not between episodic and semantic performance. Patients with MCI show deficits of episodic and semantic memory. The extent of impairment suggests dysfunction beyond the medial temporal lobe. The FPT might form the basis of a sensitive early indicator of AD.     

ERPs elicited by a cognitive incongruity paradigm: a semantic memory study

The cognitive incongruity paradigm consists in presenting congruous or incongruous factual information to subjects, who are instructed to judge the truth of this information by comparing it with the factual knowledge stored in their semantic long-term memory. The factual information tested was whether a city presented after the name of a country, belongs (congruity) or not (incongruity) to that country. Results revealed that the recognition of incongruous factual information is characterized by a negative wave (N400), while the processing of congruous factual knowledge is characterized by a positive wave (P300) about 600 ms post-stimulus. In addition, these two components were sensitive to subject performance and subject confidence levels. The neurophysiological brain pattern observed during the cognitive incongruity paradigm reveals that the N400 and P300 are jointly affected by the task and reflect the recognition processes of factual knowledge.     

Norepinephrine and traumatic brain injury: a possible role in post-traumatic edema

Unilateral cerebral contusion is associated with an early (30 min) increase in norepinephrine (NE) turnover followed by a later (6–24 h) depression of turnover which is bilateral and widespread throughout the brain. Blockade of NE function during the first few hours after traumatic brain injury (TBI) impedes subsequent recovery of function without enlarging the size of the lesion. The current studies were carried out to characterize further the timing of the switch from increased to decreased NE turnover and to investigate the pathogenesis of the delayed recovery of function associated with blocking NE function. Adult male rats had unilateral somatosensory cortex contusions made with a 5 mm diameter impact piston. They were killed after 2 h and their brains analyzed for NE turnover by HPLC with electrochemical detection. In general, NE turnover (the ratio of 3-methoxy-4-hyroxyphenylglycol to NE levels) had returned to sham-lesion control levels in most brain regions by 2 h after either left or right sided contusions. The only exceptions were a persistent 87% increase at the lesion site after right-sided contusions and 22% and 32% increases in the contralateral cerebellum after right- and left-sided contusions, respectively. Blockade of α₁-adrenoceptors by treatment with prazosin (3 mg/ kg, i.p.) 30 min prior to TBI produced edema in the striatum and hippocampus at 24 h which was not seen saline-treated rats nor in rats where NE reuptake was blocked with desmethylimipramine (DMI; 10 mg/kg, i.p.). DMI increased edema at the lesion site at 24 h, however. These data suggest that the early increase in NE release following unilateral cerebral contusion is protective and that this may act to stabilize the blood–brain barrier in areas adjacent to the injury site. Drugs that interfere with this enhanced noradrenergic function might enhance the damage caused by TBI.     

Prediction of brain age and cognitive age: Quantifying brain and cognitive maintenance in aging

The concept of brain maintenance refers to the preservation of brain integrity in older age, while cognitive reserve refers to the capacity to maintain cognition in the presence of neurodegeneration or aging‐related brain changes. While both mechanisms are thought to contribute to individual differences in cognitive function among older adults, there is currently no “gold standard” for measuring these constructs. Using machine‐learning methods, we estimated brain and cognitive age based on deviations from normative aging patterns in the Whitehall II MRI substudy cohort (N = 537, age range = 60.34–82.76), and tested the degree of correspondence between these constructs, as well as their associations with premorbid IQ, education, and lifestyle trajectories. In line with established literature highlighting IQ as a proxy for cognitive reserve, higher premorbid IQ was linked to lower cognitive age independent of brain age. No strong evidence was found for associations between brain or cognitive age and lifestyle trajectories from midlife to late life based on latent class growth analyses. However, post hoc analyses revealed a relationship between cumulative lifestyle measures and brain age independent of cognitive age. In conclusion, we present a novel approach to characterizing brain and cognitive maintenance in aging, which may be useful for future studies seeking to identify factors that contribute to brain preservation and cognitive reserve mechanisms in older age.     

Anatomical functional and cognitive determinants of semantic memory disorders

Contemporary debates on the 'semantic memory' construct revolve around three main topics: (1) the functional and anatomical relationships between episodic and semantic memory; (2) the format of semantic representations and their relationships with the underlying sensory-motor processes; (3) the categorical organization of semantic memory. The aim of the present review is to demonstrate that there is a common thread linking these different aspects of semantic memory. This thread is represented by the interdependence of mechanisms involved in the construction of semantic memory and the content of semantic representations. In particular, I suggest there is a continuity between: (a) the mechanisms of acquisition of episodic and semantic memory; (b) semantic representations and sensory-motor processes preliminary to the acquisition of these representations. This continuity has important implications for the format of semantic representations and the brain structures subserving the organisation of various categories of knowledge.     

Factors associated with remission of post-traumatic brain injury fatigue in the years following traumatic brain injury (TBI): a TBI model systems module study

ABSTRACT

Post-traumatic brain injury fatigue (PTBIF) is a major problem in the years after traumatic brain injury (TBI), yet little is known about its persistence and resolution. The objective of the study was to identify factors related to PTBIF remission and resolution. TBI Model System registrants at five centres participated in interviews at either one and two years post-injury (Y1-2 Cohort), or two and five years post-injury (Y2-5 Cohort). Characteristics of participants with PTBIF remission were compared to those with PTBIF persistence. Variables studied included the presence of and changes in disability, sleep dysfunction, mood, and community participation. The Functional Independence Measure did not differ significantly between groups or over time. In the Y1-2 Cohort the Fatigue Resolved group scored significantly better on the Disability Rating Scale and Pittsburgh Sleep Quality Index. In the Y2-5 Cohort the Fatigue Resolved group scored significantly higher on a measure of community participation. It was concluded that fewer than half of the sample in each cohort experienced a remission of PTBIF between time points. Persistence of PTBIF 1–2 years post-injury is associated with disability, sleep disturbance, and depression while persistence of fatigue beyond 2 years post-injury appears to be related to participation level, underscoring the potential impact of effective surveillance, assessment, and treatment of this condition in optimising life after TBI. Differences in fatigue progression may point to the presence of different types of PTBIF.     

Measuring recovery in new learning and memory following traumatic brain injury: a mixed-effects modeling approach

Patterns of recovery from traumatic brain injury (TBI) vary greatly across individuals. Using archival data from the Traumatic Brain Injury Model Systems, recovery of memory following TBI as measured by scores on the Rey Auditory Verbal Learning Test (RAVLT) through 5 years postinjury was examined via mixed-effects modeling. Individual-level variables of age and posttraumatic amnesia duration were significant predictors of 1-year RAVLT total score. None of the variables examined predicted the trajectory of memory recovery after 1 year. Mixed-effects analyses can be helpful in determining the effect of intervention while allowing for missing data across time points.     

Google Calendar: a new memory aid to compensate for prospective memory deficits following acquired brain injury

Prospective memory impairment is common following acquired brain injury (ABI) and intervention has proved challenging. The current treatment of choice involves using external memory aids as a method of compensation, with those incorporating active reminders proving most successful. In this paper we report findings of an investigation into the effectiveness of a novel external memory aid, Google Calendar. This aid incorporates active reminders and overcomes some of the limitations associated with existing aids. Twelve participants with ABI took part in the study incorporating a randomised control crossover within-subjects design, consisting of a 5-week baseline phase, followed by two 5-week intervention phases where either Google Calendar or a standard diary were used. Participants identified activities to target during the study and a family member monitored their success. Google Calendar was more effective than the diary in enhancing prospective memory performance. It also proved more popular, on account of its active reminders which helped trigger the retrieval of intentions, whilst reducing the need for monitoring. While further research is required to substantiate these initial findings, it is recommended that clinicians familiarise themselves with using Google Calendar, as it appears to offer additional potential in the management of prospective memory deficits following ABI.     

The autobiographical memory interview: a new assessment of autobiographical and personal semantic memory in amnesic patients

This paper describes a new technique for assessing "autobiographical" and "personal semantic" memory in amnesic patients and healthy controls. It provides evidence of the reliability and validity of the procedure, and reports an age-related temporal gradient in amnesic patients. The results are considered in terms of the severity, the rate of onset, and the duration of the amnesia; and a preliminary analysis is given of the findings in different diagnostic groups. The findings indicate that autobiographical and personal semantic memory show a consistent pattern of impairment, when a comparison is made which controls for the age of the memories and the subject's own past experience.     

Event-related brain potentials in memory: correlates of episodic, semantic and implicit memory.

OBJECTIVE: To study cognitive evoked potentials, recorded from scalp EEG and foramen ovale electrodes, during activation of explicit and implicit memory. The subgroups of explicit memory, episodic and semantic memory, are looked at separately. METHODS: A word-learning task was used, which has been shown to activate hippocampus in H(2)(15)O positron emission tomography studies. Subjects had to study and remember word pairs using different learning strategies: (i) associative word learning (AWL), which activates the episodic memory, (ii) deep single word encoding (DSWE), which activates the semantic memory, and (iii) shallow single word encoding (SSWE), which activates the implicit memory and serves as a baseline. The test included the 'remember/know' paradigm as a behavioural learning control. During the task condition, a 10-20 scalp EEG with additional electrodes in both temporal lobes regions was recorded from 11 healthy volunteers. In one patient with mesiotemporal lobe epilepsy, the EEG was recorded from bilateral foramen ovale electrodes directly from mesial temporal lobe structures. Event-related potentials (ERPs) were calculated off-line and visual and statistical analyses were made. RESULTS: Associative learning strategy produced the best memory performance and the best noetic awareness experience, whereas shallow single word encoding produced the worst performance and the smallest noetic awareness. Deep single word encoding performance was in between. ERPs differed according to the test condition, during both encoding and retrieval, from both the scalp EEG and the foramen ovale electrode recordings. Encoding showed significant differences between the shallow single word encoding (SSWE), which is mainly a function of graphical characteristics, and the other two strategies, deep single word (DSWE) and associative learning (AWL), in which there is a semantic processing of the meaning. ERPs generated by these two categories, which are both functions of explicit memory, differed as well, indicating the presence or the absence of associative binding. Retrieval showed a significant test effect between the word pairs learned by association (AWL) and the ones learned by encoding the words in isolation of each other (DSWE and SSWE). The comparison of the ERPs generated by autonoetic awareness ('remember') and noetic awareness ('know') exhibited a significant test effect as well. CONCLUSIONS: The results of behavioural data, in particular that of the 'remember/know' procedure, are evidence that the task paradigm was efficient in activating different kinds of memory. Associative word learning generated a high degree of autonoetic awareness, which is a result of the episodic memory, whereas both kinds of single word learning generated less. AWL, DSWE and SSWE resulted in different electrophysiological correlates, both for encoding as well as retrieval, indicating that different brain structures were activated in different temporal sequence.     

颅脑损伤患者术后创伤后成长与创伤后应激障碍的相关性

目的 观察颅脑损伤患者术后创伤后成长水平及创伤后应激障碍(PTSD)情况,分析创伤后成长水平与PTSD的关系.方法 选取2017-02—2019-02郑州市第九人民医院手术治疗的63例颅脑损伤患者,所有患者术后1个月接受创伤后成长评定量表(PTGI)评估,依据评估结果分为高水平组与低水平组,调查2组一般资料并评估患者术...     

FROST: a distributed neurocomputational model of working memory maintenance

Many studies suggest that the sustained activation underlying working memory (WM) maintenance is mediated by a distributed network that includes the prefrontal cortex and other structures (e.g., posterior parietal cortex, thalamus, globus pallidus, and the caudate nucleus). A computational model of WM, called FROST (short for FROntal-Striatal-Thalamic), is proposed in which the representation of items and spatial positions is encoded in the lateral prefrontal cortex. During delay intervals, activation in these prefrontal cells is sustained via parallel, prefrontal cortical-thalamic loops. Activation reverberates in these loops because prefrontal cortical excitation of the head of the caudate nucleus leads to disinhibition of the thalamus (via the globus pallidus). FROST successfully accounts for a wide variety of WM data, including single-cell recording data and human behavioral data.     

创伤性脑损伤患者创伤后成长与创伤后应激障碍的调查研究

目的分析创伤性脑损伤（TBI）患者创伤后成长（PTG）与创伤后应激障碍（PTSD）的现况及其影响因素。 方法通过便利抽样的方法,选取首都医科大学附属北京天坛医院神经外科自2019年7月至2020年1月就诊的85例TBI患者为研究对象,使用创伤后成长评定量表（PTGI）、创伤后应激障碍量表平民版（PCL-C）调查TBI患者的PTG水平、PTSD情况,并进一步分析TBI患者PTG的影响因素。 结果TBI患者PTGI总分为（58.41±23.05）分,处于低水平。PCL-C得分为（36.18±16.52）分,PCL-C阳性症状检出率为41.2%。多元线性回归分析结果显示,文化程度、性格类型、社会支持、警觉性增高、创伤再体验是TBI患者PTG的影响因素。TBI患者文化水平低、外向型性格、社会支持水平越高其PTG水平越高。TBI事件后警觉性反应低者,PTG水平较高,创伤再体验症状促进PTG的发生。 结论TBI患者创伤后早期同时出现PTG及PTSD,通过调动患者个体内部因素及外在社会联系等方面积极因素,可能提高患者PTG水平。     

颅脑外伤去骨瓣减压术后并发脑积水的预测模型建立与验证

目的基于临床资料建立并验证创伤性颅脑损伤（TBI）去骨瓣减压（DC）术后并发脑积水（PTH）的预测模型。 方法选取解放军联勤保障部队第九〇四医院神经外科自2010年1月至2019年12月诊治的符合纳入条件的451例TBI患者,随访6个月后根据PTH诊断标准分为PTH组（127例）和无PTH组（324例）,分析与之可能相关的15项因素。采用最小绝对收缩和选择算子（LASSO）回归降低数据维度和筛选预测因子。纳入多因素Logistic回归分析后建立预测模型并制作列线图,受试者工作特征曲线（ROC）和校准曲线用于检测模型的区分度和拟合优度,决策曲线分析（DCA）评价模型的临床适用性。 结果LASSO回归筛选出5个预测因子并用于构成模型。经过验证,模型的ROC曲线下面积为0.762。校准曲线显示预测概率与实际概率有很好的一致性。DCA表明模型在一定范围内的临床适用性。 结论本研究建立一个PTH的预测模型,具有良好的区分度、拟合优度和临床适用性,有利于高危患者的识别和针对性随访干预。     

Integrative assessment of brain and cognitive function in post-traumatic stress disorder

The present study combined neuropsychological and electrophysiological measures to obtain a comprehensive profile of the everyday attentional and memory dysfunction reported in PTSD. The event-related potential (ERP) literature has consistently found abnormalities in late components (N2, P3) reflecting working memory (WM) function. However, the neuropsychological profile reported in the literature has considerable variation. The present study examined ERP activity in 33 PTSD participants and matched controls during a standard two-tone auditory oddball task. Neuropsychological assessment was carried out using a task battery assessing a wide range of cognitive functions. Consistent with previous work, the PTSD group showed delayed N2 latency and reduced P3 target amplitude, together with slower and less accurate target detection. Scalp topography provided evidence of widespread abnormality during WM function, but with strongest effects broadly over the left hemisphere. Neuropsychological testing found concomitant difficulties on factorial measures of verbal memory retention/access and sustained attention but enhanced performance on measures of immediate recall. This integrative pattern of effects reflects a specific impairment in the operation of working memory systems that guide ongoing, planned behavior and that facilitate the acquisition and retention of new memories.     

Extent and neural basis of semantic memory impairment in mild cognitive impairment

An increasing number of studies indicate that semantic memory is impaired in mild cognitive impairment (MCI). However, the extent and the neural basis of this impairment remain unknown. The aim of the present study was: 1) to evaluate whether all or only a subset of semantic domains are impaired in MCI patients; and 2) to assess the neural substrate of the semantic impairment in MCI patients using voxel-based analysis of MR grey matter density and SPECT perfusion. 29 predominantly amnestic MCI patients and 29 matched control subjects participated in this study. All subjects underwent a full neuropsychological assessment, along with a battery of five tests evaluating different domains of semantic memory. A semantic memory composite Z-score was established on the basis of this battery and was correlated with MRI grey matter density and SPECT perfusion measures. MCI patients were found to have significantly impaired performance across all semantic tasks, in addition to their anterograde memory deficit. Moreover, no temporal gradient was found for famous faces or famous public events and knowledge for the most remote decades was also impaired. Neuroimaging analyses revealed correlations between semantic knowledge and perirhinal/entorhinal areas as well as the anterior hippocampus. Therefore, the deficits in the realm of semantic memory in patients with MCI is more widespread than previously thought and related to dysfunction of brain areas beyond the limbic-diencephalic system involved in episodic memory. The severity of the semantic impairment may indicate a decline of semantic memory that began many years before the patients first consulted.     

多奈哌齐治疗颅脑创伤后记忆和智能障碍的临床观察

目的 观察多奈哌齐治疗96 例颅脑创伤后记忆和智能障碍的疗效.方法 颅脑创伤后记忆和智能障碍患者96例,治疗组给予多奈哌齐片5mg,1次/d, 晚上睡前口服;对照组给予尼莫地平片常规治疗.治疗期为1个月.结果 治疗组患者记忆功能、认知功能改善较为明显, 与对照组比较有明显差异(P ＜ 0.05).结论 多奈哌齐对颅脑创伤后记忆和智能障碍患者早期治疗效果好, 安全性高, 不良反应少, 服用方便.