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Neuropsychological testing following head injuries: prosopagnosia without visual field defect.

Assessment of residual cerebral dysfunction in the post-traumatic patient poses considerable problems particularly when the neurological examination yields minimal or equivocal findings. The clinical picture is frequently complicated by emotional disturbance not easily differentiated from "post-traumatic neurosis." This report describes such a patient whose disorder was elicidated by neuropsychological testing. Numerous studies have established the validity of neuropsychological tests particularly when they are interpreted by psychologists specifically trained in their use. These procedures are also useful in differentiating patients with neurologic complaints of a nonorganic etiology from patients with similar complaints secondary to confirmed brain lesions. Although the findings reported here pertain to a patient exhibiting a rare neurologic consequence of closed head injury, the methods employed are applicable to subtle behavioral manifestations of diverse etiologies. Neurophyshological findings in a patient unable to recognize faces of familiar persons (prosopagnosia) disclosed a severe impairment of visual perception despite intact visual acuity and fields. The prosopagnosia was also associated with a pervasive memory deficit without dementia. Our results challenge current concepts of prosopagnosia and support the need for neuropsychological evaluation of post-traumatic patients.

Black or African American↗

Neuropsychological functioning associated with high-altitude exposure.

This article focuses on neuropsychological functioning at moderate, high, and extreme altitude. This article summarizes the available literature on respiratory, circulatory, and brain determinants on adaptation to hypoxia that are hypothesized to be responsible for neuropsychological impairment due to altitude. Effects on sleep are also described. At central level, periventricular focal damages (leuko-araiosis) and cortical atrophy have been observed. Frontal lobe and middle temporal lobe alterations are also presumed. A review is provided regarding the effects on psychomotor performance, perception, learning, memory, language, cognitive flexibility, and metamemory. Increase of reaction time and latency of P300 are observed. Reduced thresholds of tact, smell, pain, and taste, together with somesthetic illusions and visual hallucinations have been reported. Impairment in codification and short-term memory are especially noticeable above 6,000 m. Alterations in accuracy and motor speed are identified at lower altitudes. Deficits in verbal fluency, language production, cognitive fluency, and metamemory are also detected. The moderating effects of personality variables over the above-mentioned processes are discussed. Finally, methodological flaws found in the literature are detailed and some applied proposals are suggested.

Adaptation, Physiological↗

[Clinico-neuropsychological syndromes involving the human gyrus cinguli].

There was performed clinical and neurophysiological observation of 41 patients with arteriovenous malformations (AVM) of gyrus cinguli. Disorders of memory appeared to be the main manifestations before the operation in 38 patients, moreover they had the features of Korsakov's syndrome in 5 patients. Autonomic and epileptic-like fits weren't quite characteristic. Memory impairment was observed in 23 from 38 patients after operation, however there weren't found any qualitatively new disorders. The first appearance of Korsakov's syndrome after operation was found in 3 patients. The degree of the increase of memory impairment correlated with the degree of the destruction of the gyrus cinguli as well as with the massivity of AVM passing into corpus callosum. Qualitative analysis of amnestic syndromes revealed that practically all the patients had the alteration of the selectivity of the memory traces, inability to keep in mind the meaning of the tale. It was accompanied by an absence of criticism toward patients' own defects. Similar signs of disorders had close resemblance with amnestic defects of the patients with frontal damages. That testified the significance of both damages of frontal lobes and their connections in formation of clinical pattern in human.

Adolescent↗

Neural plasticity and emotional memory.

Posttraumatic stress disorder is the pathological replay of emotional memory formed in response to painful, life-threatening, or horrifying events. In contrast, depression is often precipitated by more social context-related stressors. New data suggest that different types of life experiences can differentially impact biochemistry, physiology, anatomy, and behavior at the level of changes in gene expression. Repeated separation of neonatal rat pups from their mother results in many long-lasting alterations in biology and behavior paralleling that in depression, including hypercortisolism. The role of the amygdala in modulating emotional memory is highlighted, as well as some of its unique properties such as metaplasticity (i.e., the differential direction of long-term adaptation, either potentiation or depression) in response to the same input as a function of the prior history of stimulation. The implications of these emerging data on the physiological and molecular mechanisms underlying emotional memory emphasize the particular importance of prevention and early intervention.

Amygdala↗

Neurocognitive deficit in schizophrenia: a quantitative review of the evidence.

The neurocognitive literature on test performance in schizophrenia is reviewed quantitatively. The authors report 22 mean effect sizes from 204 studies to index schizophrenia versus control differences in global and selective verbal memory, nonverbal memory, bilateral and unilateral motor performance, visual and auditory attention, general intelligence, spatial ability, executive function, language, and interhemispheric tactile-transfer test performance. Moderate to large raw effect sizes (d > .60) were obtained for all 22 neurocognitive test variables, and none of the associated confidence intervals included zero. The results indicate that schizophrenia is characterized by a broadly based cognitive impairment, with varying degrees of deficit in all ability domains measured by standard clinical tests.

Attention↗

Gist recall in multiple sclerosis.

This study examined gist recall (memory for important story ideas) in patients with multiple sclerosis. Twelve patients with clinically probable or definite multiple sclerosis and 10 neurologically intact control subjects were read prose passages from the Wechsler Memory Scale-Revised Logical Memory subtest. The idea units from these passages contained low, medium, and high information content to the stories. In comparison with the control subjects, the patients recalled fewer total elements over immediate and delayed conditions. However, similar to controls, they recalled more ideas that were of high rather than low or medium importance. These results suggest that semantic sensitivity to important ideas of narratives is a relatively preserved feature in multiple sclerosis.

Adult↗

Adult clinical neuropsychology: lessons from studies of the frontal lobes.

Clinical neuropsychologists have adopted numerous (and sometimes conflicting) approaches to the assessment of brain-behavior relationships. We review the historical development of these approaches and we advocate an approach to clinical neuropsychology that is informed by recent findings from cognitive neuroscience. Clinical assessment of executive and emotional processes associated with the frontal lobes of the human brain has yet to incorporate the numerous experimental neuroscience findings on this topic. We review both standard and newer techniques for assessment of frontal lobe functions, including control operations involved in language, memory, attention, emotions, self-regulation, and social functioning. Clinical and experimental research has converged to indicate the fractionation of frontal subprocesses and the initial mapping of these subprocesses to discrete frontal regions. One anatomical distinction consistent in the literature is that between dorsal and ventral functions, which can be considered cognitive and affective, respectively. The frontal lobes, in particular the frontal poles, are involved in uniquely human capacities, including self-awareness and mental time travel.

Adult↗

Associative recognition in a patient with selective hippocampal lesions and relatively normal item recognition.

Previous work (Mayes et al., Hippocampus 12:325-340, 2002) found that patient YR, who suffered a selective bilateral lesion to the hippocampus in 1986, showed relatively preserved verbal and visual item recognition memory in the face of clearly impaired verbal and visual recall. In this study, we found that YR's Yes/No as well as forced-choice recognition of both intra-item associations and associations between items of the same kind was as well preserved as her item recognition memory. In contrast, YR was clearly impaired, and more so than she was on the above kinds of recognition, at recognition of associations between different kinds of information. Thus, her recognition memory for associations between objects and their locations, words and their temporal positions, abstract visual items or words and their temporal order, animal pictures and names of professions, faces and voices, faces and spoken names, words and definitions, and pictures and sounds, was clearly impaired. Several of the different information associative recognition tests at which YR was impaired could be compared with related item or inter-item association recognition tests of similar difficulty that she performed relatively normally around the same time. It is suggested that YR's familiarity memory for items, intra-item associations, and associations between items of the same kind was mediated by her intact medial temporal lobe cortices and was preserved, whereas her hippocampally mediated recall/recollection of these kinds of information was impaired. It is also suggested that the components of associations between different kinds of information are represented in distinct neocortical regions and that initially they only converge for memory processing within the hippocampus. No familiarity memory may exist in normal subjects for such associations, and, if so, YR's often chance recognition occurred because of her severe recall/recollection deficit. Conflicting data and views are discussed, and the way in which recall as well as item and associative recognition need to be systematically explored in patients with apparently selective hippocampal lesions, in order to resolve existing conflicts, is outlined.

Aged↗

Cognitive problems related to epilepsy syndromes, especially malignant epilepsies.

Neurocognitive impairment is frequent in epilepsy patients. Causes are multiple, and may be influenced by several factors including the epilepsy syndrome. Most cognitive complaints in adult patients are mental slowness, memory difficulties and attention deficits. In children, cognitive problems are more diffuse, responsible for language troubles, learning difficulties, poor academic outcome, behavior problems and finally unfortunate socio-professional prognosis. The most devastating epilepsy syndromes such as epileptic encephalopathies are nearly exclusively described in infancy and childhood. This paper will review the major cognitive complaints in relation to the epilepsy syndrome, with a more detailed interest for the malignant epilepsies in infancy and childhood such as Ohtahara and West syndrome, Lennox-Gastaut syndrome and epileptic encephalopathis with continuous spike-and-wase during slow wave sleep. The impact of surgery on cognition will be briefly discussed in adults and youger patients.

Cognition Disorders↗

Age vs Alzheimer's: a computational model of changes in representation.

Previous research has demonstrated that the language of older adults leads to denser representations in a high dimensional model of memory than does the language of younger adults (Conley & Burgess, in press), and thus that density in the model (HAL or the hyperspace analogue to language) may constitute a useful metric in comparing memory for younger and older adults. This paper extends the previous research by examining the role of density in semantic representations that emerged from the language generated by adults with Alzheimer' s and comparing the results with age-matched normal controls. We found that, just as older adults have denser representations in semantic space than do younger adults, adults with Alzheimer's have still denser representations than normal older adults. These results support the hypothesis that greater density, normally associated in the model with good semantic depth, may in fact reach a "saturation point" and affect retrieval in older adults and especially adults with Alzheimer's.

Age Factors↗

Lesions in nucleus basalis magnocellularis and medial septal area of rats produce qualitatively similar memory impairments.

The functional contribution of nucleus basalis magnocellularis (NBM) and the medial septal area (MSA) to memory was evaluated in two different spatial discriminations. Preoperatively, rats were trained to a criterion level of performance in a simultaneous left/right discrimination on the stem of a T-maze (a trial-independent memory) and a discrete-trial, rewarded alternation discrimination on the arms of the T-maze (a trial-dependent memory). Bilateral lesions were made by injecting ibotenic acid (IBO) into the NBM, MSA, both NBM and MSA, or dorsal globus pallidus (DGP), and by radiofrequency current (RF) in the NBM and MSA. Control rats received operations in which either no current was passed or no neurotoxin was injected. Lesions in the NBM, MSA, or both the NBM and MSA produced a similar pattern of behavioral changes relative to the performance of controls; postoperative reacquisition of the arm discrimination was initially impaired but showed recovery to normal levels, whereas postoperative reacquisition and reversal of the stem discrimination was not impaired (except following the combined NBM and MSA lesion). Lesions of the DGP had no effect on choice accuracy in any discrimination. When the discrimination on the arms was made more difficult by increasing the delay interval during which the information had to be remembered, rats with combined NBM and MSA lesions were again impaired relative to controls and showed no signs of recovery of function. These results provide information about the behavioral functions of the basal forebrain cholinergic system and suggest that pathological changes in certain components of this system can cause disorders of memory.

Animals↗

Non-degenerative mild cognitive impairment in elderly people and use of anticholinergic drugs: longitudinal cohort study.

OBJECTIVE: To assess the potential of anticholinergic drugs as a cause of non-degenerative mild cognitive impairment in elderly people. DESIGN: Longitudinal cohort study. SETTING: 63 randomly selected general practices in the Montpellier region of southern France. PARTICIPANTS: 372 people aged > 60 years without dementia at recruitment. MAIN OUTCOME MEASURES: Anticholinergic burden from drug use, cognitive examination, and neurological assessment. RESULTS: 9.2% of subjects continuously used anticholinergic drugs during the year before cognitive assessment. Compared with non-users, they had poorer performance on reaction time, attention, delayed non-verbal memory, narrative recall, visuospatial construction, and language tasks but not on tasks of reasoning, immediate and delayed recall of wordlists, and implicit memory. Eighty per cent of the continuous users were classified as having mild cognitive impairment compared with 35% of non-users, and anticholinergic drug use was a strong predictor of mild cognitive impairment (odds ratio 5.12, P = 0.001). No difference was found between users and non-users in risk of developing dementia at follow-up after eight years. CONCLUSIONS: Elderly people taking anticholinergic drugs had significant deficits in cognitive functioning and were highly likely to be classified as mildly cognitively impaired, although not at increased risk for dementia. Doctors should assess current use of anticholinergic drugs in elderly people with mild cognitive impairment before considering administration of acetylcholinesterase inhibitors.

Aged↗

Cognitive functioning following epilepsy surgery.

Temporal lobe resection is the most common surgery for intractable epilepsy because of its proven efficacy in seizure control. However, patients who may benefit from the procedure might be deterred from surgical evaluation due to concerns of postoperative cognitive decline. Recent reports on long-term follow-up indicate that, similar to findings within the year after surgery, cognition remains relatively stable in the years following right temporal resection. The verbal memory decline often observed 1 year after left temporal resection persists over time, yet is mitigated to some extent by good seizure outcome. Although memory decline observed on testing is not typically accompanied by functional decline, a small proportion of patients do experience reductions in occupational or academic status. Recent advances in functional imaging and refinements in preoperative mapping promise better prediction and protection of cognitive functioning. Additionally, results from studies comparing cognitive outcome among different surgical techniques suggest that more restricted resections benefit some patients, whereas more extended resections might be appropriate in a select group of well-defined patients. Preliminary reports on alternate treatments such as vagal nerve stimulation suggest no direct influence on cognition, although improvement in quality of life has been reported. The decision to pursue surgical treatment must balance the potential benefit of seizure control with the potential impact and probability of cognitive decline.

Anterior Temporal Lobectomy↗

Effects of a sustained release formulation of thyrotropin-releasing hormone on behavioral abnormalities in senescence-accelerated mice.

Effects of a sustained release formulation of thyrotropin-releasing hormone (TRH-SR) on reduced anxiety-like behavior and learning impairment in senescence-accelerated mice (SAM) were examined. SAMP8/Ta (SAMP8) mice showing age-related emotional changes as well as learning and memory impairments, and SAMR1TA (SAMR1) mice exhibiting normal aging were used at 8 months of age. Subcutaneous injection of TRH-SR (2.8 mg/kg as free TRH) produced a sustained increase in immunoreactive plasma TRH levels up to about 4 weeks after dosing in SAMP8. TRH-SR antagonized the reduced neophobia to novel food in SAMP8 in a dose-dependent manner when tested 10 days but not 3 days after the injection. In the elevated plus-maze test, the SAMP8 control group treated with vehicle had significant increases in the number of entries into open arms and the time spent in open arms in comparison to SAMR1 mice. TRH-SR showed dose-dependent decreases in the number of entries into open arms, and reduced the time spent in open arms in SAMP8 mice. Furthermore, TRH-SR significantly improved the impairment of water maze learning in SAMP8 mice. In contrast, bolus administration of TRH had no significant effects on behavioral abnormalities in SAMP8 even at high doses, implying that long-term and continuous infusion of TRH may be important for amelioration of the behavioral abnormalities. These results suggest that TRH-SR may be useful for treatment of age-related emotional disorders and memory disturbance in dementia.

Aging↗

Autobiographical memory specificity and the course of major depressive disorder.

This study examined the stability of autobiographical memory dysfunction (i.e., difficulties in retrieving specific memories) during the course of major depressive disorder, its relation to early adverse experiences, and its influence on the course of depressive disorder. Using the Autobiographical Memory Test (AMT), specificity of autobiographical memory was assessed in 25 subjects with a current depressive disorder at baseline, and at 3 and 7 months follow-up. Also, information about self-reported childhood traumatization, and demographic and clinical variables was obtained. Autobiographical memory performance was relatively stable over time despite clinical improvement in the sample. It was not related to depression severity at baseline, while higher levels of childhood traumatization were correlated with more specific memory performance to negative cue words at baseline, but not during follow-up. Specific autobiographical responses to negative cue words predicted a better prognosis, whereas specific responses to positive cue words were not related to prognosis. Autobiographical memory dysfunction in depression appears to be stable over time, is related to short-term prognosis in depression, and may act as a vulnerability factor that influences the long-term course of depressive disorders.

Adult↗

Impairment of memory organization in patients with schizophrenia or schizotypal disorder.

Verbal learning and the organization of memory in patients with schizophrenia or schizotypal disorder were compared with normal subjects. Three indices of memory organization (semantic clustering, serial clustering, and subjective clustering) were calculated from participants' responses on the Japanese Verbal Learning Test. Schizophrenic and schizotypal patients showed similar decrements in semantic organization compared with normal subjects. Neither patient group showed any effect of learning on their use of semantic organization, although both groups recalled more items as the number of trials increased. These results suggest that impairment of memory organization is a common characteristic of schizophrenia spectrum disorders.

Adolescent↗

[Neuropsychiatric performance of HIV-infected patients].

AIM: Can neuropsychic impairment which is clinically observed in the case of HIV-infected patients be objectivized, and what is the relationship to somatic features caused by the disease? PATIENTS AND METHOD: 65 HIV-infected men with no history of drug-addiction were examined by means of a test battery which monitored the functions memory/concentration and speed of response. The probands were then compared to a healthy control group which was parallelized with respect to age, sex and education. Immune status, HIV and AIDS associated symptoms as well as educational diseases were checked for their connection with neuropsychic impairment. RESULTS: Compared to healthy persons HIV patients presented significant deficits with respect to memory and concentration but showed no reduction of speed of response. Significant correlation could be determined with only one somatic feature: Half of the patients who had lost more than 10% of their body weight during the preceding three months suffered from clinically relevant memory and concentration disorders. CONCLUSIONS: 1. The massive memory and concentration disorders impair and isolate the patients and can have considerable job-related consequences. 2. Measures preventing loss of weight should be initiated as early as possible. 3. Training sessions, e.g. nutritional consultation, must take the patients' deficits with respect to concentration and memory into consideration. 4. Possible connections between loss of weight and changes in brain metabolism should be examined. 5. Future studies should determine whether measures weight increase coincide with an improvement of memory and concentration.

AIDS Dementia Complex↗

Treating the traumatic memories of patients with dissociative identity disorder.

OBJECTIVE: The author uses clinical experience informed by research findings to suggest approaches to the treatment of the traumatic memories of patients with dissociative identity disorder. METHOD: Recent findings in the treatment of patients with this disorder and current considerations with regard to memories of childhood trauma are used to develop recommended approaches. RESULTS: Treatment of traumatic memories appears crucial in the recovery of patients with dissociative identity disorder, even though the reported memories may not be historically accurate. Criteria are available for determining whether a patient with the disorder is able to undertake such efforts, and methods such as fractionated abreaction have been developed to make the process less unsettling. CONCLUSIONS: Despite the difficulties posed by the vulnerability of patients with dissociative identity disorder to decompensation when working with traumatic material and the vicissitudes of autobiographical memory, modern therapeutic approaches allow the processing of such patients' traumatic material in a manner that reduces the likelihood of disruptive events and the misuse of recovered material.

Abreaction↗