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PubMed1994

Memory bias in panic disorder.

We investigated selective memory effects in patients with panic disorder. Thirty patients with panic disorder and 20 normal controls learned panic-related, strongly pleasant, and strongly unpleasant words. During the incidental learning task, Ss imagined scenes combining the referent of a presented word with themselves. After a distractor task, Ss took a free-recall test. Panic Ss showed enhanced memory for panic-related words but not for positive or negative words.

Adult↗

PubMed1982

Effect of desmopressin on normal and impaired memory.

In view of the reported influence of vasopressin on the memory process of animals, trials were carried out on normal subjects and patients with memory disorders using the vasopressin analogue desmopressin. No beneficial effects could be demonstrated.

Adult↗

PubMed2000

Relationship of behavioral and psychological symptoms to cognitive impairment and functional status in Alzheimer's disease.

OBJECTIVE: This cross-sectional study examined the relationship of behavioral and psychological symptoms to cognitive and functional impairment in Alzheimer's disease (AD). DESIGN: One hundred and fourteen patients were evaluated consecutively at a university-affiliated outpatient memory disorders clinic and diagnosed with possible or probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria. Subjects were assessed with the Behavioral Pathology in Alzheimer's Disease Scale (BEHAVE-AD), Revised Memory and Behavior Problem Checklist (RMBPC), Blessed Dementia Scale (BDS), and Mini-Mental State Examination (MMSE). RESULTS: Several symptoms of behavioral pathology showed associations with MMSE scores, including activity disturbances, delusions, and hallucinations. After controlling for the variance associated with the MMSE, activity disturbances, diurnal disturbances, delusions, and hallucinations were linked with BDS scores. CONCLUSIONS: The results suggest that some non-cognitive symptoms may be related to the neurobiologic mechanisms underlying the increased cognitive dysfunction in AD. Specific symptoms of behavioral pathology may also impact a patient's ability to perform important self-maintenance behaviors.

Aged↗

PubMed2000

Pregnenolone sulfate increases hippocampal acetylcholine release and spatial recognition.

The pregnenolone sulfate is a neurosteroid with promnesic properties. Recently, a correlation between endogenous levels of pregnenolone sulfate in the hippocampus and performance in a spatial memory task has been reported in aged rats. Cholinergic transmission is known to modulate memory processes and to be altered with age. In the present experiment we investigated the effect of increasing doses of pregnenolone sulfate on hippocampal acetylcholine release. Our results show that intracerebroventricular administrations of this neurosteroid induced a dose-dependent increase in acetylcholine release. Administration of 12 and 48 nmol of pregnenolone sulfate induced a short lasting (20 min) enhancement of acetylcholine output with a maximum around 120% over baseline and the administration of 96 and 192 nmol doses induced a long-lasting (80 min) increase that peaked around 300% over baseline. In a second experiment we have observed that the 12 nmol dose enhanced spatial memory performance, whereas the 192 nmol dose was inefficient. These results are consistent with previous work suggesting that, a modest increase in acetylcholine release facilitates memory processes, while elevation beyond an optimal level is ineffective. Nevertheless, neurosteroids may be of value for reinforcing depressed cholinergic transmission in certain age-related memory disorders.

Acetylcholine↗

PubMed1985

Alpha 2-adrenergic mechanisms in prefrontal cortex associated with cognitive decline in aged nonhuman primates.

This study provides evidence that the alpha 2-adrenergic receptor agonist clonidine ameliorates the cognitive deficits exhibited by aged nonhuman primates through drug actions at alpha 2 receptors. Furthermore, pharmacological profiles in animals with lesions restricted to the dorsolateral prefrontal cortex indicate that this area may be the site of action for some of clonidine's beneficial effects. These results demonstrate that alpha-adrenergic systems contribute to cognitive function and suggest a new strategy for treating memory disorders in aged humans.

Aging↗

PubMed2000

Influence of diet and occlusal support on learning memory in rats behavioral and biochemical studies.

In order to verify the relationship between tooth loss and the learning memory in rat, male Wistar rats (25 weeks old) were divided into three separate groups: a control group (fed with a solid diet); a soft diet group (fed with a powder diet containing the same components as the solid one) and a molarless group (all molars were removed at 25 weeks and then fed with a powder diet). To evaluate both learning ability and memory, rats were tested with a one-way step through type of passive avoidance apparatus divided into light and dark chambers at 40-weeks. After the passive avoidance test, determination of acetylcholine (ACh) concentration of the cerebral cortex and hippocampus was performed. There was no significant difference between the molarless group and the control group in the response latency before the acquisition trails (non-stimulated period). At day 4 and 7 after the acquisition trials, the response latency of the molarless group was significantly shorter than that in the control group (p<0.05). The ACh levels of the molarless group in the cerebral cortex and hippocampus were significantly lower than that of the control group (p<0.05). It was apparent that tooth loss had an association with a loss of discriminative learning ability. This study suggested that the decrease of masticatory function caused by tooth loss leads to a decrease of ACh synthesis resulting in a learning memory disorder.

Acetylcholine↗

PubMedDate not supplied

[Comparative study of the effects of melatonin and epitalon on the protracted memory under the shuttle labyrinth test conditions in rats in the course of aging].

The influence of the chronic administration of melatonin (epiphyseal hormone) and epitalon (a synthetic tetrapeptide increasing melatonin production) on the learning process and the protracted memory has been studied in LIO rats in the course of aging for 2 years under standard illumination regime (12L :12D). The daily administration of melatonin (Sigma, USA) with drinking water (in 10 mg/liter dose at night) in rats beginning with the age of 4 months did not influence the learning processes in young and adult animals but it was found to contribute to optimization of the brain cognitive function in rats in the course of aging, by improving the protracted memory process. Epitalon administered in a daily dose of 0.1 microg per animal beginning with the age of 4 months showed mnemotropic properties (decreasing the extent of memory disorders) in old rats under conditions of the shuttle labyrinth test.

Age Factors↗

PubMed2005

[Schizophrenic disorders: current etiologic and clinical knowledge].

Brain anomalies associated with schizophrenic disorders may be of a cognitive, neurophysiological or neurological nature [the latter being relatively minor and nonspecific]. Brain imaging has revealed early anomalies such as cortical-subcortical atrophy and abnormal gyration. These anomalies can also be present in relatives free of schizophrenic symptoms. This raises the question of what determines the transition from vulnerability to clinical onset. There is now evidence that schizophrenic disorders are true brain diseases. This is based on neuropathological studies, brain imaging and clinical findings such as "soft" neurological signs (pyramidal and extrapyramidal symptoms, coordination difficulties, etc.). Cognitive dysfunctions such as attention and memory disorders and abnormal verbal fluency have also been described. Oculomotor pursuit and auditive evoked potentials have identified specific neurophysiological disorders such as N300 and P50 wave modifications. Schizophrenic disorders can also be associated with neuronal abnormalities, notably affecting factors involved in synaptic transmission and plasticity. For example, BDNF protein deficit is linked to certain late-onset forms of schizophrenia. Genetic studies are no longer focusing on a possible disease genotype but rather on phenotypic characteristics determined by simpler genotypes (P50 wave modulation, COMT and BDNF genes). The ultimate objective is to identify high-risk subjects, in order to shorten the treatment delay and thereby improve long-term outcome. The benefit of primary prophylaxis remains to be determined, however.

Brain↗

PubMed1990

Effects of aging on the dynamics of information processing and synaptic weight changes in the mammalian hippocampus.

It is clear that the properties of LTE make it a plausible mechanism for associative information storage at some synapses in the central nervous system. While many of the factors that regulate LTE's induction and expression have been discovered and a strong case is being developed for its role in learning and memory processes, until we understand more clearly the mechanisms underlying both the expression and maintenance of LTE, an understanding of its change with age will be difficult. Judging by the progress that has been made over the past several years in uncovering some of the molecular events that are critical for LTE's expression, one may be optimistic that answers will be forthcoming reasonably soon. Of particular importance to aging mammals, such answers may provide insights into why older organisms show faster forgetting. This may have a profound impact on therapeutic strategies for memory disorders in both normal and pathological conditions of aging.

Aging↗

PubMed1999

Differential effects of chronic stress on memory processes in the tree shrew.

Unpredictable and uncontrollable stressful events have been shown to affect cognitive processes. Interestingly, only hippocampus-mediated memory processes are thought to be sensitive to the effects of chronic stress. In contrast, the hippocampus-independent memory processes have been shown to be resistant to chronic stressful experiences. A central feature of the stress response is the activation of the hypothalamus-pituitary-adrenocortical (HPA)-axis, resulting in increased plasma levels of glucocorticoids, and several studies suggested that the performance of hippocampus-mediated memory processes might be directly modulated by these adrenal steroids. We investigated the impact of chronic psychosocial stress on hippocampus-mediated and hippocampus-independent memory processes in male tree shrews. By using a modified holeboard we followed memory performance during 23 weeks of alternating stress-free and stressful conditions. This schedule was designed to mimic a more realistic situation with stress-free conditions being sequentially interrupted by challenging events. The results indicate that chronic stress differentially affects hippocampus-mediated and hippocampus-independent memory processes in tree shrews. While hippocampus-independent memory processes remained unimpaired throughout the study, hippocampus-mediated memory was persistently impaired, not only during stress periods but also during recovery periods. This persistent impairment seems not to be exclusively triggered by glucocorticoids because urinary free cortisol concentration returned to normal during recovery periods. The present study is the first to evaluate the consequences of sequential stress exposure on memory performance in animals. Apparently, the mechanisms modulating cognitive processes are far from being understood and need a very systematic analysis in animal models with a high face and predictive validity to human stress-related memory disorders.

Aggression↗

PubMed1989

Recognition memory span in mildly and moderately demented patients with Alzheimer's disease.

An abbreviated form of Moss et al.'s (1986) Recognition Span Test (RST) was administered to patients with mild or moderate dementia of the Alzheimer type (DAT) and to intact control (NC) subjects. Memory spans for verbal (i.e., words), spatial and configurational (i.e., faces) information were assessed. Delayed recall (15 s and 2 min) of the words used on the verbal recognition span was also determined. The results showed that both DAT patient groups were impaired on the three recognition tasks and that the spatial and verbal forms differentiated the mildly from the moderately demented patients. The mean overall recognition span scores (spatial + verbal + facial) differentiated between DAT patients and intact controls, with 37 of the 39 patients falling beyond the 95% confidence limits derived from the control subjects' scores. On verbal recall, both the mildly and moderately demented patients were severely impaired and evidenced a very rapid rate of forgetting between the 15-s and 2-min recall attempts. These findings suggest that the RST is not only highly sensitive to memory disorders in the early stages of DAT but also effective in discriminating among various stages of this disorder.

Aged↗

PubMedDate not supplied

[Post-traumatic amnesia syndrome].

INTRODUCTION: Mnesic deficits are frequent in subjects which have suffered from head injury and may persist during may years. OBJECTIVE: We will analyze posttraumatic amnesia characteristics (PTA) as well as learning and memory deficits which are normally observed once the PTA phase is over. DEVELOPMENT: The PTA is defined as the period that follows a brain injury in which the affected person is incapable of consistently remembering at least the last 24 hours. That is, the period after the head injury in which the incorporation of new information in long term memory is not possible. The study of PTA has generally been focussed on the analysis of the alterations of temporo-spatial orientation and mnesic deficits, however other cognitive and behavioral alterations do exist (linguistic, attentional, critical judgement, information processing, perception, etc.), and they are associated with the particular memory disorder that we are studying, given their influence on it. We will take on board the different theories that have been proposed to explain mnesic deficits which occur during the PTA phase: lack of consolidation of new information within longterm memory; recall deficit as a result of inefficient coding of information; failures of the mechanisms to carry out the process of consolidation-recall, and poor organization in the coding of new material. We will put forward a guide for the neuropsychological assessment of memory based on the analytic and concrete study of each mnesic cognitive component, sustained generally by specific neurophysiological functional systems which allow us to establish a diagnosis, prognosis, and adequate therapeutic focus for each concrete case.

Amnesia↗

PubMedDate not supplied

[Frequency of neuropsychiatric signs and symptoms in patients with viral encephalitis].

INTRODUCTION: Acute viral encephalitis (AVE) is a frequent condition that usually courses with psychiatric alterations but few systematic studies have been conducted to investigate it. AIMS: To determine the frequency and the progression of the neuropsychiatric symptoms in patients with AVE. PATIENTS AND METHODS: A retrospective study was carried out. AVE was defined as an acute and progressively coursing condition in previously healthy subjects, with clinical signs of diffuse alteration of the central nervous system, abnormal electroencephalogram and/or inflammatory cerebrospinal fluid (CSF). We excluded patients who previously had epilepsy, a positive serodiagnosis for human immunodeficiency virus (HIV), and cases compatible with herpes simplex encephalitis from electroencephalographic or imaging data with focalisation towards temporal, frontal, regions or a positive DNA test for herpes in CSF. Finally, 83 patients were included. The psychiatric signs and symptoms that were produced were recorded during the acute phase and one year after discharge from hospital (sequelae). RESULTS: The psychiatric disorders in the acute phase were psychomotor agitation (67%), drowsiness (55%), disorientation (47%), visual hallucinations (43%) and aggressiveness (34%). One year after hospitalisation, in a sample of 70 patients in a clinical control, we found memory disorders (16%), aggressiveness (9%), aphasia (8%), visual hallucinations (8%), and auditory hallucinations (7%). The mortality rate was 6%. CONCLUSIONS: Neuropsychiatric disorders are very frequent during the acute phase of viral encephalitis, which is relevant for the differential diagnosis in patients who visit emergency departments with behavioural disorders. One year after hospital discharge, the main sequelae are of a neuropsychiatric nature and cognitive impairment is predominant.

Adolescent↗

PubMed1996

APOE-related frequency of cognitive and noncognitive symptoms in dementia.

Although memory disorders and the aphaso-apraxo-agnosic syndrome are the most relevant clinical symptoms in dementia, behavioral changes, mood-related disturbances and sleep disorders are the major cause of institutionalization and caregiver concern. In the present study we have investigated the frequency and progression of cognitive and noncognitive symptoms in Alzheimer's disease (AD) as well as the APOE-related frequency of clinical symptoms in dementia. Memory decline (100%), aphasia (94%), apraxia (99%), agnosia (94%) and motor dysfunction (90%) appeared in practically all cases with mild (GDS-3), moderate (GDS 3-4) and severe (GDS 6-7) dementia. The most frequent noncognitive symptoms include anxiety (76%), depression (68%), behavioral changes (67%), psychotic symptoms (43%), sleep disorders (43%), incontinence (23%) and cerebrovascular symptoms (75%). Anxiety, depression, behavioral changes, psychotic symptoms, motor dysfunction and cognitive deterioration paralleled the severity of dementia, increasing their frequency from mild to severe dementia. The most important sleep disorders were irregular sleep-wake pattern (67%) and insomnia (47%). Disorientation (90%) and drug administration (88%) appeared to be the most important factors in causing sleep disorders in dementia. Disorientation, agitation and motor disorders were slightly more frequent in patients with APOE-4/4, while anxiety and sleep disorders appeared more frequently in APOE-3/4. Behavioral changes and psychotic symptoms did not show any clear association with specific APOE subtypes. In conclusion, our results suggest that noncognitive symptoms are very important clinical events in the disease progression and in decision making for therapeutic intervention and institutionalization. Furthermore, it is likely that some brain dysfunctions leading to particular clinical symptoms might be associated with specific AD genotypes.

Aged↗

PubMed1975

Memory for speech and speech for memory.

Thirty kindergarteners, 15 who substituted /w/ for /r/ and 15 with correct articulation, received two perception tests and a memory test that included /w/ and /r/ in minimally contrastive syllables. Although both groups had nearly perfect perception of the experimenter's productions of /w/ and /r/, misarticulating subjects perceived their own tape-recorded w/r productions as /w/. In the memory task these same misarticulating subjects committed significantly more /w/-/r/ confusions in unspoken recall. The discussion considers why people subvocally rehearse; a developmental period in which children do not rehearse; ways subvocalization may aid recall, including motor and acoustic encoding; an echoic store that provides additional recall support if subjects rehearse vocally, and perception of self- and other- produced phonemes by misarticulating children-including its relevance to a motor theory of perception. Evidence is presented that speech for memory can be sufficiently impaired to cause memory disorder. Conceptions that restrict speech disorder to an impairment of communication are challenged.

Analysis of Variance↗

PubMedDate not supplied

Mismatch negativity: different water in the same river.

The mismatch negativity (MMN) is a frontal negative deflection in the human event-related potential that typically occurs when a repeating auditory stimulus changes in some manner. The MMN can be elicited by many kinds of stimulus change, varying from simple changes in a single stimulus feature to abstract changes in the relationship between stimuli. The main intracerebral sources for the MMN are located in the auditory cortices of the temporal lobe. Since it occurs whether or not stimuli are being attended, the MMN represents an automatic cerebral process for detecting change. The MMN is clinically helpful in terms of demonstrating disordered sensory processing or disordered memory in groups of patients. Improvements in the techniques for measuring the MMN and in the paradigms for eliciting it will be needed before the MMN can become clinically useful as an objective measurement of such disorders in individual patients.

Animals↗

PubMedDate not supplied

[Neuropsychological disorders in amyotrophic lateral sclerosis. Don't they exist or do they just go undetected?].

AIMS: The aims of this paper is to demonstrate the existence of neuropsychological disorders in amyotrophic lateral sclerosis (ALS) and to perform an in depth study of the cognitive functioning of the prefrontal lobes. PATIENTS AND METHODS: A neuropsychological study of 14 patients with ALS was conducted using an extensive battery of tests and were compared with a group of 14 healthy controls. Both groups were homogeneous as regards age, sex, education and manual dominance. In this clinical and research study, as well as the neuropsychological variables (subtest of the Barcelona PIEN Test neuropsychological battery), we also took the evolution of the disease, the age and neurological clinical features of the patients suffering from ALS into account. RESULTS: We found neuropsychological disorders in the ALS patients that were centred, either directly or indirectly, on functions of the prefrontal lobe, and in particular of the dorsolateral and premotor cortices, which had already been observed in other research work. No memory disorders were found, something which is usually mentioned in studies about neuropsychological disorders in this type of patients. CONCLUSIONS: Apart from the primary motor zones affected in ALS, there appears to be a degenerative process in most of the frontal lobe, and there is a need for longitudinal studies of the possible progressive disorders of the frontal lobe in these patients. This is difficult, since these patients end up with serious neurological alterations which prevent a correct neuropsychological exploration from being carried out cognitively, and hence no conclusions can be drawn either

Amyotrophic Lateral Sclerosis↗

PubMed2002

Apolipoprotein E genotype and cognitive impairment in community-dwelling black older adults.

OBJECTIVE: The relationship between the epsilon 4 allele of the apolipoprotein E gene (APOE-epsilon4) located on chromosome 19 and Alzheimer's disease is well documented among Caucasian populations. However, the findings of research addressing the link between APOE polymorphism and neurocognitive functioning in populations of African origin from around the world have been equivocal. Therefore, the current study explored the relation of APOE-epsilon4 with cognitive impairment in a sample of community-dwelling English-speaking elderly blacks. METHODS: All participants (N = 57) were recruited consecutively from a community memory-screening program at a University affiliated Memory Disorders Clinic and evaluated using standardized assessment procedures. Cognitive impairment was classified according to an age and education adjusted Mini-Mental State Exam score of less than 24 as well as poorer functioning on a measure of delayed verbal memory. RESULTS: Increased risk for global cognitive dysfunction (OR = 9.5, 95 percent CI = 2.3-55.3, p = .004) and poorer verbal recall performance (beta = -.36, p = .006) were linked with the APOE epsilon4 allele after controlling for the potentially confounding effects of age, education, and gender. CONCLUSIONS: This investigation supports the role of APOE polymorphism in determining neurocognitive impairment among black elders residing in the community.

Aged↗