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Amnesia after unilateral temporal lobectomy: a case report.

We report a mixed handed (L > R) patient with exclusive right cerebral language representation who developed a permanent anterograde amnestic syndrome after right anterotemporal lobectomy. Preoperative neuropsychological performance consisted of impaired verbal memory and normal nonverbal memory. Wada memory performance was asymmetrical for objects presented soon after amobarbital injection in conjunction with no memory asymmetry for items presented later in the Wada evaluation. Pre- and postoperative magnetic resonance imaging (MRI) scans showed no structural lesions; however, postoperative MRI hippocampal volume measurements suggested decreased hippocampal volume for the nonresected temporal lobe. These results confirm the risk of anterograde amnesia after unilateral temporal lobectomy and demonstrate that baseline neuropsychological testing may falsely literalize material-specific memory functions in patients with atypical cerebral language dominance.

Adult↗

Mammillary body and cerebellar shrinkage in chronic alcoholics with and without amnesia.

Mammillary body and cerebellar atrophy have been described as postmorten neuropathologic markers of Korsakoff's syndrome. This study examined whether shrinkage in the mammillary bodies and cerebellum is present consistently in amnesic chronic alcoholics during life and whether the degree of abnormality in these patients differs from that in nonamnesic alcoholic and healthy controls. The severity of shrinkage in the mammillary bodies, cerebellar hemispheres, and cerebellar vermis visualizable on MRI scans was rated on a three-point scale in 33 chronic nonamnesic alcoholics, 9 amnesic alcoholics, and 20 healthy controls. Although both alcoholic groups showed significant mammillary body and cerebellar shrinkage relative to controls, the two patient groups did not differ from each other. Furthermore, four of eight amnesic patients in our sample did not demonstrate clinically significant mammillary body atrophy. These results suggest that alcoholism is associated with mammillary body and cerebellar tissue volume loss but do not provide evidence that these markers distinguish accurately between amnesic and nonamnesic patients. In addition, they suggest that visualizable mammillary body atrophy is not necessary for the development of amnesia in alcoholic patients.

Adult↗

Lymphopoiesis, apoptosis, and immune amnesia.

Bone marrow transplant recipients have a functional T-cell deficit long after T-cell counts have returned to normal levels. Early after BMT, T-cell phenotype is predominantly CD45RO+/CD29high/HLA-DR+/CD38high. This profile is associated with activated memory cells in healthy subjects, but also appears on the earliest mature naive T-cells in times of lymphopoietic stress. Most of these cells apoptose in short-term unstimulated culture, suggesting that they would have had a similar fate in vivo. Twelve to 24 months after BMT, CD45RA+/CD29low/HLA-DR-/CD38low T cells increase, apoptosis decreases, and T-cell function normalizes. We hypothesize that in the adult, mature memory T cells regulate their own replacement by rescuing a proportion of newly generated naive cells from apoptosis. Ablation of memory cells consequent to high dose therapy disrupts this process, resulting in a protracted period of high lymphocyte turnover with few cells surviving to make the antigen-driven transition to memory cells. Infection with HIV-1 also eventuates in immune deficiency associated with a loss in CD4+ T cells and dominance of the phenotypic/apoptotic profile which we have associated with lymphopoietic stress. Recent data independently confirm that T-cell turnover is greatly elevated in HIV infection. Catastrophic or chronic depletion of memory T cells due to marrow ablative therapy or HIV-1 infection interferes with memory replacement, substituting short-lived hypofunctional naive T cells which characterize the state of immune amnesia.

Acquired Immunodeficiency Syndrome↗

Inattentional blindness versus inattentional amnesia for fixated but ignored words.

People often are unable to report the content of ignored information, but it is unknown whether this reflects a complete failure to perceive it (inattentional blindness) or merely that it is rapidly forgotten (inattentional amnesia). Here functional imaging is used to address this issue by measuring brain activity for unattended words. When attention is fully engaged with other material, the brain no longer differentiates between meaningful words and random letters, even when they are looked at directly. These results demonstrate true inattentional blindness for words and show that visual recognition wholly depends on attention even for highly familiar and meaningful stimuli at the center of gaze.

Adult↗

Attenuation of amnesia in rats by systemically administered enkephalins.

The pentapeptides methionine-enkephalin and leucine-enkephalin are both able to reduce experimentally induced amnesia in rats. In contrast to the possible analgesic activity of these peptides, the anti-amnesic effect is seen after systemic administration of dosages of 30 micrograms or lower. The nature of the anti-amnesic effect is different for the two peptides.

Animals↗

Group and case study of the dysexecutive syndrome in alcoholism without amnesia.

OBJECTIVES: To test the dysexecutive syndrome (DES) hypothesis of chronic alcoholism by the neuropsychological group and case study approaches. METHODS: A comprehensive neuropsychological assessment, including the "behavioural assessment of dysexecutive syndrome", a battery of tests recently designed to be "ecologically valid", was administered to 17 patients with chronic alcoholism without amnesia to examine executive functions, intelligence, and memory. In terms of each neuropsychological measure, reciprocal analyses of group means and individual case profiles were conducted: for the first contrasting the alcoholic patients with 17 age matched healthy subjects; and for the second making intersubject and intrasubject comparison of the patients, according to percentile basis impairment indices obtained from the control subjects. RESULTS: Despite relatively unimpaired memory and intelligence, the patients as a whole had the impairment of a wide range of executive domains, extending to "everyday" problem solving as well as more elementary aspects of executive functions, such as visuospatial performance, mental set shifting, and the inhibition of habitual behaviour. The profile analysis divided individual patients into four groups: the representative DES characterised by a clear dissociation between impaired executive functions and preserved intelligence and memory; the group of a modified dysexecutive pattern in which memory as well as executive functions were impaired with intelligence preserved; the group of general cognitive deterioration; and the group of unimpaired cognitive functioning. About two thirds of the patients were categorised into either the first or the second type of DES. CONCLUSION: DES characterised by the even more pronounced impairment of executive functions than of intelligence and memory afflicts a considerable proportion of patients with chronic alcoholism. Due to its subtlety, this would be potentially left out, unless appropriate behavioural measures were administered. This condition may prevent patients with alcoholism from achieving full recovery and benefiting from rehabilitation.

Activities of Daily Living↗

Early Diagnosis and Treatment of Dementia Presenting as Transient Global Amnesia in a 76-Year-Old Man.

This article reports the case of a high-functioning patient who had an "event" diagnosed as probable transient global amnesia (TGA) 1 year before being diagnosed with evolving cognitive impairment. Formal psychometric testing was necessary to make this diagnosis owing to the insensitivity of simple tests in this high-functioning individual. Neuropsychological evaluation showed impairment of short-term verbal memory, compounded by observed fluctuations in attention. In light of its reported benefits for cognitive function and attention, galantamine was administered starting at 4 mg b.i.d., then increasing to 8 mg b.i.d. and finally to 12 mg b.i.d. During galantamine dose escalation, the patient experienced transient vomiting on the first day of taking 12 mg b.i.d. With reassurance, he returned to the same dose and tolerated it during long-term treatment without problems. His cognitive function has remained at an improved level for 18 months on galantamine administration.

Journal Article↗

The effect of vasopressin analogue [d(CH2)5(1),Tyr(Me)2]AVP on memory process in rats with experimental amnesia.

We investigated the effect of a single 2 micrograms dose of vasopressin (AVP) analogue [(CH2)5(1),Tyr(Me)2]AVP on the processes of retrieval of conditioned reflexes in rats with experimentally induced amnesia. The models used were: electroconvulsive shock (ECS) and hypoxia. It severely impaired the memory processes. The AVP analogue [d(CH2)5(1),Tyr(Me)2]AVP facilitated retrieval of passive avoidance in all animals.

Animals↗

American ginseng extract reduces scopolamine-induced amnesia in a spatial learning task.

OBJECTIVE: To determine if HT-1001, an extract of American ginseng, affects scopolamine-induced memory and performance deficits in a spatial learning task, alters brain concentrations of aminergic neurotransmitters, and alters choline uptake in synaptosome preparations. DESIGN: Animal study. ANIMALS: 48 Sprague Dawley rats. INTERVENTIONS: Long-term oral administration of a test material or control solution. Intraperitoneal administration of scopolamine (2 mg/kg) 30 minutes before testing. OUTCOME MEASURES: Performance on Morris water maze task, choline uptake, aminergic neurotransmitter analysis, in vitro monoamine oxidase analysis (of compounds). RESULTS: HT-1001 protected against scopolamine-induced amnesia and increased choline uptake in synaptosomal preparations. HT-1001 did not alter brain concentrations of norepinephrine, dopamine, 5-HT (serotonin), 3,4-dihydroxyphenylacetic acid or 5-hydroxyindoleactic acid. HT-1001 had a very weak ability to inhibit monoamine oxidase activity in vitro. CONCLUSIONS: HT-1001 demonstrates a capacity to protect against scopolamine-induced memory deficits.

Animals↗

[The founding of group analysis by Trigant Burrow - a peculiar amnesia within the tradition of group analysis].

The concept of group analysis as formulated by Trigant Burrow (1875-1950), the founder of group analysis, will be explicated on the basis of three of his most important essays. Emphasis will be placed 1. on Burrow's dialogue with psychoanalysis--he regarded group analysis as a methodological development of psychoanalysis--as well as 2. on the particular meaning of certain contents which are defended against on the social level and which can be made conscious and worked through in group analysis. Burrow's work has been largely forgotten by group analysts. This amnesia is understood as a social defense elicited by Burrow's thoughts and analyses of pathological social relationships, which exist throughout society and to which psychoanalysts and group analysts are also subject.

History, 20th Century↗

Comparison of multiple scoring methods for Rey's malingered amnesia measures.

The predictive accuracy of Andre Rey's malingered amnesia measures (Memory for Fifteen Items and Word Recognition List) was examined. Discriminant function and crosstabulation analytic strategies were applied to predict membership in either a traumatically brain injured group (n = 60) or in a litigated minor head injury group claiming permanent severe disability (n = 90). Satisfactory hit rates were achieved with Rey's original scoring methods, but improved hit rates were obtained with scoring modifications. Removal of dense amnesiacs from the sample resulted in even better hit rates. Rey's measures appear to be valid for the assessment of cognitive malingering in settings where litigated disability claims are out of proportion to injury characteristics. Rey's measures are not appropriate for globally and severely impaired patients in clinical settings.

Journal Article↗

Retrograde amnesia in praying mantis after two successive learning processes.

Learning and memory consolidation was investigated in the mantis Stagmatoptera biocellata, by two successive trainings: a) the attack (A) avoidance training in which animals were not allowed to catch a mobile star, followed by the deimatic reaction (DR) avoidance training of not displaying this defensive response, or b) DR-avoidance training followed by A-avoidance training. The results showed that the presence and the 1 of A-avoidance learning and DR-avoidance learning did not affect the learning of the other training. Total retention of A-avoidance memory was demonstrated when A-avoidance training was given first, whereas DR-avoidance memory was significantly lost (716%) when the DR-avoidance training was given first. The retroactive forgetting of DR-avoidance memory is considered as retrograde amnesia rather than retroactive memory inhibition because it depends on the activity during A-avoidance training (number of attacks) and not the quantity of A-avoidance learning. The magnitude of the amnesic effect due to this distracting activity in the A-avoidance training appears to be remarkably similar to that reported in a previous work using nitrogen-induced anoxia as the amnesic factor.

Animals↗

Effect of a spirocyclic cyclodipeptide derivate of MIF on passive avoidance behavior and amnesia in rats.

Cyclo (1-amino-1-cyclopentane-carbonyl-L-alanyl)-c(Acp-Ala), a derivative of MIF (prolyl-leucyl-glycinamide) affected passive avoidance behavior of rats when administered at different phases of the step-through type of experimental paradigm. c(Acp-Ala) given s.c. or orally in a 1 mg/kg dose increased avoidance latencies not only when administered before, or immediately after the shock trial but also when given before the pretraining trial, i.e. at the first exposure of animals to the experimental situation without shock treatment. The notion is discussed, that it is the influence of c(Acp-Ala) on processing of information received during the pretraining trial that manifests itself in the facilitation of avoidance response. The drug appears to have a long-term action since it was active when given 20 h before the pretraining trial or the shock trial or the test of retention. c(Acp-Ala) when administered immediately after the shock trial, attenuated amnesia in rats induced by electroconvulsive shock (ECS).

Animals↗

Comparison of psychomotor skills and amnesia after induction of anesthesia with midazolam or thiopental.

In two groups of 31 healthy patients undergoing minor elective surgery, anesthesia was induced intravenously with either midazolam maleate, 0.2 mg/kg, or thiopental, 3.5 mg/kg. All subjects received 2 micrograms/kg fentanyl 5 min before the induction agents. Induction time with midazolam was significantly longer than with thiopental (97.1 +/- 10.9 sec vs 59.4 +/- 5.0 sec) and time to orientation postoperatively was significantly longer after midazolam (31.7 +/- 4.2 min vs 11.0 +/- 1.1 min). Continued recovery after orientation, measured by a series of psychomotor tests, was also significantly longer with midazolam than with thiopental. Anterograde amnesia was evident in 84.8% of the midazolam treated patients and in only 31.4% of the thiopental group. This degree of absence of recall was acknowledged positively by the affected patients. The protracted recovery period may limit the use of midazolam in short surgical procedures.

Adult↗

[Recovery of memory impaired during learning in chickens: reversal of amnesia induced by blockers of protein synthesis].

Administration of protein synthesis inhibitors (PSI) produced an obvious amnesia in chicks (20-25% of avoidance responses). A "reminder" treatment: giving of environmental clues presented during learning, recovered of the learned avoidance response up to level of the control animals (75-80%). The data obtained suggest a possibility of memory recovery following the "reminder" treatment.

Animals↗

New learning and remote memory in the same and different domains of experience: implications for normal memory and amnesia.

This study investigated the correlation between new and remote memory ability in normal young subjects and evaluated whether using tests that tapped different domains of experience had any effect on the relationship between new and remote memory. Remote memory was assessed using a famous face test and new memory was evaluated using both novel faces and words. The main finding was a significant correlation between New and Remote face familiarity scores. A correlation was obtained when both tests tapped the same domain of memory, whereas when tests tapped different domains, there was no Remote-New correlation. Remote-New correlations may only exist between tests tapping the same domain of memory. This has implications for the interpretation of previous amnesic literature and for future investigations.

Adolescent↗