1/142. Amnestic state in a holocaust survivor patient: psychogenic versus neurological basis.Differentiation between psychogenic and organic amnesia is sometimes quite difficult. This paper focuses on the psychogenic and organic components of a complex case of amnesia rooted in remote and prolonged traumatic stress and manifested under circumstances evoking dissociated memories. The Transient Global amnesia (TGA) of a concentration camp survivor who developed sudden amnesia during a psychiatric intake interview was clearly triggered by the pressure of repressed holocaust memories. The importance of distinguishing between TGA and dissociative amnesia is emphasized, and the role of psychological upset as a precipitant in TGA is stressed.- - - - - - - - - - ranking = 1keywords = trauma (Clic here for more details about this article) |
2/142. Basal forebrain amnesia: does the nucleus accumbens contribute to human memory?OBJECTIVE: To analyse amnesia caused by basal forebrain lesions. methods: A single case study of a patient with amnesia after bleeding into the anterior portion of the left basal ganglia. Neuropsychological examination included tests of attention, executive function, working memory, recall, and recognition of verbal and non-verbal material, and recall from remote semantic and autobiographical memory. The patient's MRI and those of other published cases of basal forebrain amnesia were reviewed to specify which structures within the basal forebrain are crucial for amnesia. RESULTS: attention and executive function were largely intact. There was anterograde amnesia for verbal material which affected free recall and recognition. With both modes of testing the patient produced many false positive responses and intrusions when lists of unrelated words had been memorised. However, he confabulated neither on story recall nor in day to day memory, nor in recall from remote memory. The lesion affected mainly the nucleus accumbens, but encroached on the inferior limb of the capsula interna and the most ventral portion of the nucleus caudatus and globus pallidus, and there was evidence of some atrophy of the head of the caudate nucleus. The lesion spared the nucleus basalis Meynert, the diagnonal band, and the septum, which are the sites of cholinergic cell concentrations. CONCLUSIONS: It seems unlikely that false positive responses were caused by insufficient strategic control of memory retrieval. This speaks against a major role of the capsular lesion which might disconnect the prefrontal cortex from the thalamus. It is proposed that the lesion of the nucleus accumbens caused amnesia.- - - - - - - - - - ranking = 4093.0700485962keywords = brain (Clic here for more details about this article) |
3/142. Confabulation and delusional misidentification: a four year follow-up study.We describe a patient, AZ, who showed, in addition to an amnesic syndrome which eventually improved, longstanding confabulation and delusional misidentification following bilateral frontal and right temporal post-traumatic lesions. Confabulation appeared in personal recollections and on long-term verbal memory testing. Misidentification concerned mainly his wife and house. During the four year follow-up AZ's confabulation progressively shrinked so as to become restricted to verbal memory tasks. By contrast, misidentification persisted. General semantic memory was unimpaired throughout, while performance on frontal tests was initially poor and partly improved in time. We argue that confabulation and misidentification, though often intermingled and occurring after similar lesion pattern, should be considered as different neuropsychological entities.- - - - - - - - - - ranking = 1keywords = trauma (Clic here for more details about this article) |
4/142. Sensorimotor skill learning in amnesia: additional evidence for the neural basis of nondeclarative memory.We investigated sensorimotor skill learning, a form of nondeclarative (implicit) memory, in 28 subjects with declarative (explicit) memory defects caused by either mesial temporal (n = 15) or basal forebrain (n = 13) damage and in 66 normal control subjects. All 28 amnesics had normal learning of a rotor pursuit task. We also studied in detail the sensorimotor skill learning of patient Boswell. As a result of bilateral damage to both mesial and lateral aspects of the temporal lobes and to the basal forebrain, Boswell has one of the most severe impairments ever reported for learning of all types of declarative knowledge. Compared to matched controls, Boswell acquired and retained normally the skills associated with performing motor tasks. We conducted a long-term (2-year) followup study of Boswell's retention of the rotor pursuit task, and we found that he retained the skill as well as normal controls. Our study builds on previous work in the following respects: (1) It provides evidence, for the first time, that skill learning is normal in basal forebrain amnesics; (2) it shows that patient Boswell has normal learning and long-term retention of sensorimotor skills, in spite of his extensive damage; and (3) it offers additional evidence that mesial temporal lobe damage spares skill learning. These findings demonstrate unequivocally that sensorimotor skill learning does not require structures in mesial and lateral temporal regions nor in basal forebrain.- - - - - - - - - - ranking = 2338.8971706264keywords = brain (Clic here for more details about this article) |
5/142. neuroimaging and behavioral correlates of recovery from mnestic block syndrome and other cognitive deteriorations.OBJECTIVE: We conducted a follow-up study on a patient with enduring psychic shock-induced cognitive impairment to study by neuropsychological and functional imaging methods the degree of his recovery process on the brain and cognitive levels. BACKGROUND: Based on the assumption that trauma and stress conditions can alter the functions of the nervous systems, we report on a patient whom we studied 2 and 12 months after he suffered "mnestic block syndrome" and additional cognitive deterioration symptoms. methods: We report on a patient studied 2 and 12 months after he suffered "mnestic block syndrome" and additional cognitive deterioration symptoms. magnetic resonance imaging and fluorodeoxyglucose positron emission tomography were used for neural and detailed neuropsychological testing for cognitive deficits. RESULTS: The patient initially manifested severe intellectual decline, including severe anterograde and retrograde amnesia. His symptoms were correlated with major, although selective, reductions in his brain metabolism (2-3 SD below those of controls). Presently, he shows a normal brain metabolism and has regained parts of his memory and many of his other intellectual capabilities. Nevertheless, he still has long-term memory impairments. CONCLUSIONS: This case demonstrates a close relation between brain metabolism and cognitive performance, with major deficits of both at 2 months and major recovery of both at 12 months after a shocking event. It can serve as an example for possible stress-related deteriorations in certain brain regions, which can be partly corrected by psychotherapeutic interventions, passing time, and favorable environmental conditions.- - - - - - - - - - ranking = 2924.621463283keywords = brain, trauma (Clic here for more details about this article) |
6/142. Amnesic syndrome with bilateral mesial temporal lobe involvement in Hashimoto's encephalopathy.A 25-year-old woman presented with a subacute confusional state, headaches, unsteadiness, myoclonus, seizures, and an amnesic syndrome as a manifestation of Hashimoto's encephalopathy. Investigations showed biochemical hypothyroidism, raised thyroid microsomal antibodies, and weakly positive antineuronal antibodies. A T2-weighted MRI of the brain showed bilateral symmetric areas of increased signal in the mesial temporal lobes and hippocampi that had a low signal intensity on T1-weighted imaging. Despite clinical and radiologic improvement after steroid and thyroid hormone replacement therapy, a severe amnesic syndrome with associated localized MRI abnormalities persists.- - - - - - - - - - ranking = 584.7242926566keywords = brain (Clic here for more details about this article) |
7/142. Acquisition of novel semantic information in amnesia: effects of lesion location.Two patients with severe global amnesia are described who differ in the extent to which they have acquired new semantic information. Patient SS, who has extensive medial temporal lobe damage including the hippocampus as well as surrounding cortical areas, has failed to acquire virtually any new information regarding vocabulary or famous faces that entered the public domain since the onset of his amnesia. In contrast, patient PS, who has a selective lesion of the hippocampus proper, has gained a sense of familiarity of novel vocabulary and famous people, even though her effortful retrieval of this new semantic knowledge remains impaired. These findings extend to amnesia of adult onset, the proposal of Vargha-Khadem and colleagues that in patients with selective hippocampal injury, cortical areas surrounding the hippocampus may play an important role in new semantic learning [Vargha-Khadem, F., Gadian, D.G., Watkins, K. E., Connelly, A., Van Paesschen, W. and Mishkin, M., regarding the importance of the subhippocampal cortices in the mediation of new semantic learning in children with hippocampal lesions, science, 1997, 277, 376-380].- - - - - - - - - - ranking = 72.744883295835keywords = injury (Clic here for more details about this article) |
8/142. Amnesic confabulatory syndrome after focal basal forebrain damage.A 73-year-old woman developed amnesic confabulatory syndrome after a right focal basal forebrain hemorrhage. The confabulation, despite persistent antegrade amnesia, gradually subsided with improvement of the frontal executive function. The lesion appeared to disrupt connections of the medial and lateral limbic circuits important for memory. Simultaneous dysfunctioning of the two circuits involving the medial temporal and frontal lobes may be necessary for the development of this syndrome.- - - - - - - - - - ranking = 2923.621463283keywords = brain (Clic here for more details about this article) |
9/142. Electronic memory aids for outpatient brain injury: follow-up findings.The introduction of highly portable computers extends the range of tools potentially useful to persons with functional impairments of prospective memory resulting from brain injury. This study reviews the experience of 12 patients with brain injury undergoing outpatient treatment using palmtop computers to assist with memory dependent activities in their everyday lives. During the initial supervised trial period, each was provided a palmtop computer based memory aid capable of generating audible and visible reminder cues. Subsequently, patients were contacted for follow-up between 2 months and 4 years after initial trial usage, and surveyed as to the utility of the computer. Nine patients found palmtop computers were useful during supervised trials. Seven of nine patients actually continued to use such devices after the usage trials had ended. Experience with this technology has shown it to be useful in a high proportion of patients for assisting with memory dependent functions.- - - - - - - - - - ranking = 15378.974947861keywords = brain injury, brain, injury (Clic here for more details about this article) |
10/142. Functional anatomical study of psychogenic amnesia.Psychogenic amnesia is characterized by an inability to recall information already stored in the patient's memory. It is usually related to a stressful or traumatic event that cannot be explained by manifest brain damage. To examine the underlying functional disturbance of brain areas in this condition, we performed a positron emission tomography (PET) activation study on a psychogenic amnesic patient and on 12 normal control subjects. A task requiring explicit retrograde memory of faces was compared with a control task. To assess functional modifications associated with the processes of recovery, a second PET study was performed on the patient 12 months after onset. During the task, activation of the right anterior medial temporal region including the amygdala was increased in the psychogenic amnesic patient. Activation of the bilateral hippocampal regions increased only in the control subjects. During recovery, the right anterior medial temporal region became less active while the right hippocampal region became more active. Activation levels also differed in the anterior cingulate cortex, prefrontal cortex and some other cortical regions between control subjects and the patient. These findings suggest that the changes in these limbic and limbic-cortical functions are related to symptoms of the psychogenic amnesia.- - - - - - - - - - ranking = 1170.4485853132keywords = brain, trauma (Clic here for more details about this article) |
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