SEARCH · PubMed Health

Results for “Memory Disorders”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71Linked to original sources

PubMed2000

Working memory deficits in current and previous users of MDMA ('ecstasy').

Current and previous users of the drug MDMA ('ecstasy') were tested on measures of central executive functioning, information processing speed, and on self-report measures of arousal and anxiety. The results were compared with those for a control group who did not use MDMA. Relative to the control group, both user groups were found to be impaired in some aspects of central executive functioning. Also, there were significant group differences on the measures of anxiety (users were more anxious) and on arousal (previous users scoring higher on the arousal measure relative to current users). Users processed information as quickly as non-users but less accurately. Some possible mediators of the above group differences are discussed.

Adult↗

PubMed1998

Evidence of GABAergic modulation in melatonin-induced short-term memory deficits and food consumption.

Many of the pharmacological effects of melatonin have been found to be similar to those of benzodiazepines. In the present study, we analyzed the role of melatonin on short-term memory retrieval on transfer latency in elevated plus maze and food consumption behavior, and the effects were compared with those of diazepam. Melatonin dose-dependently (10-100 mg/kg) produced short-term memory deficit and it potentiated diazepam- (1 mg/kg) induced cognitive deficit in mice. Flumazenil (1 and 4 mg/kg) could reverse enhancement in diazepam-induced memory deficit by melatonin. Chronic treatment with melatonin (10 mg/kg/7d) produced a similar profile in transfer latency on elevated plus maze compared with that of diazepam. In a food consumption behavior study, melatonin (25 and 50 mg/kg) produced a significant hyperphagic effect compared to control. Flumazenil (4 mg/kg) could significantly reverse the hyperphagic effects induced by diazepam (2 mg/kg), but would be insignificant with regard to that due to melatonin. These findings provide further evidence that some of the pharmacological effects of melatonin are comparable with those of diazepam and may involve central GABAergic mechanism.

Animals↗

PubMed2005

Conditional inactivation of presenilin 1 prevents amyloid accumulation and temporarily rescues contextual and spatial working memory impairments in amyloid precursor protein transgenic mice.

Accumulation of beta-amyloid (Abeta) peptides in the cerebral cortex is considered a key event in the pathogenesis of Alzheimer's disease (AD). Presenilin 1 (PS1) plays an essential role in the gamma-secretase cleavage of the amyloid precursor protein (APP) and the generation of Abeta peptides. Reduction of Abeta generation via the inhibition of gamma-secretase activity, therefore, has been proposed as a therapeutic approach for AD. In this study, we examined whether genetic inactivation of PS1 in postnatal forebrain-restricted conditional knock-out (PS1 cKO) mice can prevent the accumulation of Abeta peptides and ameliorate cognitive deficits exhibited by an amyloid mouse model that overexpresses human mutant APP. We found that conditional inactivation of PS1 in APP transgenic mice (PS1 cKO;APP Tg) effectively prevented the accumulation of Abeta peptides and formation of amyloid plaques and inflammatory responses, although it also caused an age-related accumulation of C-terminal fragments of APP. Short-term PS1 inactivation in young PS1 cKO;APP Tg mice rescued deficits in contextual fear conditioning and serial spatial reversal learning in a water maze, which were associated with APP Tg mice. Longer-term PS1 inactivation in older PS1 cKO;APP Tg mice, however, failed to rescue the contextual memory and hippocampal synaptic deficits and had a decreasing ameliorative effect on the spatial memory impairment. These results reveal that in vivo reduction of Abeta via the inactivation of PS1 effectively prevents amyloid-associated neuropathological changes and can, but only temporarily, improve cognitive impairments in APP transgenic mice.

Aging↗

PubMed2004

Memory impairment in aged primates is associated with focal death of cortical neurons and atrophy of subcortical neurons.

Mechanisms of cognitive decline with aging remain primarily unknown. We determined whether localized cell loss occurred in brain regions associated with age-related cognitive decline in primates. On a task requiring the prefrontal cortex, aged monkeys were impaired in maintaining representations in working memory. Stereological quantification in area 8A, a prefrontal region associated with working memory, demonstrated a significant 32 +/- 11% reduction in the number of Nissl-stained neurons compared with young monkeys. Furthermore, the number of immunolabeled cholinergic neurons projecting to this region of cortex from the nucleus basalis was also reduced by 50 +/- 6%. In contrast, neuronal number was strikingly preserved in an adjoining prefrontal cortical region also associated with working memory, area 46, and in the component of the nucleus basalis projecting to this region. These findings demonstrate extensive but highly localized loss of neocortical neurons in aged, cognitively impaired monkeys that likely contributes to cognitive decline. Cell degeneration, when present, extends transneuronally.

Aging↗

PubMed2004

The basolateral amygdala interacts with the medial prefrontal cortex in regulating glucocorticoid effects on working memory impairment.

Previous findings indicate that the basolateral complex of the amygdala (BLA) interacts with other brain regions in regulating stress hormone effects on memory functions. Lesions of the BLA or infusions of a beta-adrenoceptor antagonist into the BLA block glucocorticoid effects on both memory consolidation and retrieval when administered either systemically or directly into the hippocampus. The present experiments examined BLA and beta-adrenoceptor involvement in regulating glucocorticoid effects on spatial working memory, a task that depends on the medial prefrontal cortex (mPFC). Male Sprague Dawley rats with bilateral sham- or NMDA-induced lesions of the BLA received either corticosterone (1.0 or 3.0 mg/kg, i.p.) systemically or the specific glucocorticoid receptor agonist 11beta,17beta-dihydroxy-6,21-dimethyl-17alpha-pregna-4,6-trien-20yn-3-one (RU 28362; 3.0 or 10.0 ng in 0.5 microl) into the mPFC shortly before testing on a delayed alternation task in a T-maze. Both glucocorticoid treatments induced comparable impairments in working memory performance in sham-lesioned controls. Although lesions of the BLA alone did not affect working memory, BLA lesions blocked the impairment induced by either corticosterone or RU 28362. Likewise, systemic injections of the centrally acting beta-adrenoceptor antagonist propranolol (2.0 mg/kg, i.p.) given before testing prevented corticosterone-induced working memory impairment. These findings indicate that BLA activity is essential for enabling glucocorticoid effects in the mPFC on working memory and suggest that stress hormone-induced modulation of working memory involves noradrenergic activation.

Adrenergic beta-Agonists↗

PubMed1978

Slowing of short-term memory scanning in alcoholics.

Hospitalized alcoholics taking disulfiram were found to process information in short-term memory at a slower rate than hospitalized controls, although short-term memory capacity was similar in the two groups.

Adult↗

PubMed2002

Marijuana: a decade and a half later, still a crude drug with underappreciated toxicity.

In 1984, I published in this journal a review entitled "Marijuana: A Crude Drug With a Spectrum of Underappreciated Toxicity." In the introduction to that article, I disclosed that our son Keith, who was 15 years old at the time, was in a long-term, modified outpatient adolescent drug and alcohol rehabilitation program because he had become dependent on marijuana with its associated behavioral, interpersonal, scholastic, and antisocial problems. Keith and most of his friends had experimented several times with LSD, beer, and several other drugs but never used injection drugs. Marijuana was clearly Keith's drug of choice and the only drug he used with regularity. Approximately 1 year later, Keith graduated from the treatment program. He completed the early aftercare component, relapsed several times, and completed a 4-month refresher drug rehabilitation program in another state. Nine years after admission to the first rehabilitation program, Keith finally attained some adult goals. Now 34 years old, he has been drug-free for 10 years. He is the president and owner of a successful discount cellular phone business that he started. More important, a decade ago, he reestablished an excellent and close relationship with his parents. As far as I can tell, Keith remains drug-free except for an occasional beer.

Adolescent↗

PubMed2005

[Semantic dementia: clinical and neuroimaging evaluation. Case report].

Semantic dementia is a clinical syndrome in the spectrum of frontotemporal lobar degeneration group. We report on a 63 years old man who presented with memory disorder of semantic nature for visual and mainly verbal material when he was 57 years old. Mild behavior impairment was present and related to exaggerated responses to algic stimuli and repetitive behavior. Structural and functional neuroimaging methods disclosed asymmetric bitemporal damage, mainly on the left. Differential diagnosis should be considered with Alzheimer's disease, another subtypes of the frontotemporal lobar degeneration group and any other syndrome that presents with a fluent aphasic progressive disorder.

Dementia↗

PubMed2006

Short-term memory loss associated with rosuvastatin.

Memory loss and cognitive impairment have been reported in the literature in association with several 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), but we found no published case reports associated with rosuvastatin. To our knowledge, this is the first reported case of rosuvastatin-related short-term memory loss. A 53-year-old Caucasian man with hypercholesterolemia experienced memory loss after being treated with rosuvastatin 10 mg/day. He had no other concomitant conditions or drug therapies. After discontinuation of rosuvastatin, the neuropsychiatric adverse reaction resolved gradually, suggesting a probable drug association. During the following year, the patient remained free from neuropsychiatric disturbances. Clinicians should be aware of possible adverse cognitive reactions during statin therapy, including rosuvastatin.

Fluorobenzenes↗

PubMed1993

Expenditures in caring for patients with dementia who live at home.

OBJECTIVES: Given the national interest in progressive dementia, we estimated expenditures incurred in caring for dementia patients who live at home. METHODS: Primary caregivers of 264 patients from a university-based memory disorders clinic were interviewed at baseline and asked to keep service use diaries for 6 months; 141 caregivers who returned the diaries are the focus of this report. We examined both formal and informal services (distinguished by whether money was exchanged) and associated expenditures. RESULTS: Neither caregivers returning diaries nor their patients differed at baseline from those not returning diaries and their patients. Expenditures incurred over 6 months were extensive for both formal ($6986) and informal ($786) services. Out-of-pocket expenditures were high (e.g., in-home companion or sitter, adult day care, visiting nurse). Multivariable analyses indicated that patients with more severe symptoms of dementia and families with higher incomes reported significantly higher expenditures. CONCLUSIONS: The expense of caring for patients with progressive dementia living at home may be higher than previously estimated and frequently involves expenses paid directly by patients and their families.

Aged↗

PubMed2004

Benefit-risk assessment of tolterodine in the treatment of overactive bladder in adults.

Overactive bladder is associated with symptoms of urgency, with or without urge incontinence, usually with daytime frequency and nocturia in the absence of local pathological factors. Muscarinic receptor antagonists (antimuscarinics) are the first-line pharmacotherapy. Tolterodine, a competitive, nonselective antimuscarinic specifically developed for the treatment of overactive bladder, demonstrated tissue selectivity for the bladder over the parotid gland in an animal model. As of March 5, 2003, the immediate-release (IR) formulation had been approved in 72 countries and the extended-release (ER) formulation had been approved in 28 countries, and tolterodine had been administered to 5 million patients. This review evaluates the benefit-risk profile of tolterodine in the treatment of adults with overactive bladder, summarising clinical trial and postmarketing surveillance data. Tolterodine has been found to significantly reduce micturition frequency, urgency perception and the number of episodes of urge incontinence and increase the volume voided per micturition. Dry mouth, an antimuscarinic class effect, is the most commonly reported adverse effect but is mostly mild to moderate in severity. Serious adverse effects are reported infrequently. Based on summary and review of postmarketing surveillance and clinical trial safety data received by the market authorization holder and contained in the Periodic Safety Update Reports for tolterodine, several monitored serious events of the gastrointestinal tract (e.g. ileus or haemorrhage), nervous system (e.g. syncope, convulsions and memory disorders) and cardiovascular system (e.g. ventricular arrhythmia, atrial fibrillation, palpitations, bradycardia, transient ischaemic attacks and hypertension) were not considered related to tolterodine. QT or corrected QT (QTc) prolongation was not observed in any of the five cases of verified ventricular arrhythmia in patients administered tolterodine; there is insufficient evidence to indicate that tolterodine causes ventricular arrhythmia or extrasystoles or any specific type of cardiac rhythm abnormality. The safety profile of tolterodine is similar in patients aged > or =65 years and in younger adults. Clinically relevant drug interactions are limited to cytochrome P450 3A4 inhibitors, such as ketoconazole, and co-administration with such agents warrants a tolterodine dosage decrease. In addition, tolterodine IR 2mg twice daily is similar in efficacy to oxybutynin IR 5mg three times daily, and tolterodine ER 4 mg once daily is similar in efficacy to oxybutynin ER 10mg once daily. Dry mouth occurred less frequently with tolterodine than oxybutynin, and moderate to severe dry mouth occurred more than three times less frequently. Based on the low frequency of adverse events, the absence of unexpected adverse events and the very low frequency of serious adverse events, we conclude that tolterodine is a well tolerated treatment for overactive bladder in adults, in whom it should be considered as first-line therapy.

Adult↗

PubMedDate not supplied

Neuropsychological functioning in treated phenylketonuria.

Comprehensive neuropsychological assessment was performed on a series of patients with treated classical phenylketonuria. All patients showed a similar cluster of performance deficits in motor and visual-motor functions, spatial operations, academic skill areas, and select areas of higher level reasoning. The results are consistent with other neuropsychological studies of patients with early and late diet termination that have used differing assessment methods, thus allowing for greater confidence in the findings. Examination of underlying factors indicates that poor motor coordination, limits in the complexity of spatial problem solving, and limits in the amount of information that can be "processed" simultaneously may account for most or all of the performance deficits observed among these patients. Suggestions for future research and both clinical and theoretical implications of the findings are discussed.

Adolescent↗

PubMed2003

Carbohydrate-induced memory impairment in adults with type 2 diabetes.

OBJECTIVE: Memory impairment is observed in adults with type 2 diabetes. The focus of this study was to determine whether acute carbohydrate consumption contributes to or exacerbates memory dysfunction. RESEARCH DESIGN AND METHODS: The impact of consuming 50 g of rapidly absorbed carbohydrate (one half bagel and white grape juice) at breakfast was examined in 19 adults with type 2 diabetes. Subjects (mean age 63 +/- 9 years, mean BMI 26.1 +/- 4.5 kg/m(2)) were tested, under fed and fasted conditions, on verbal declarative memory using both word list and paragraph recall tests (immediate and delayed [7-min] recall), Trails Test Part B as a measure of general brain function, and mood (subjectively monitoring global vigor and affect). RESULTS: Under baseline (fasting) conditions, elevated blood HbA(1c) was negatively associated with immediate and delayed paragraph recall performance (R(2) = 0.30; P = 0.024) and higher fasting blood glucose trended toward poorer word list recall (R(2) = 0.09; P = 0.102). Carbohydrate ingestion influenced measures of delayed, but not immediate, recall in a time-dependent fashion (time x food) (word list, P = 0.046; paragraph, P = 0.044) such that delayed recall was improved at 15 min postingestion but was impaired at 30 min. Neither Trails Test scores (P = 0.17) nor mood (affect, P = 0.68 and vigor, P = 0.45) were influenced by food ingestion. CONCLUSIONS: In adults with type 2 diabetes, poorer glycemic control is associated with lower performance on tests of declarative memory. Acute ingestion of high glycemic index carbohydrate foods further contributes to the underlying memory impairment.

Affect↗

PubMed1980

Psychological measurement of memory deficits in dialysis patients.

In light of recent research on "dialysis dementia," two questions were raised: (1) Is such dementia an all-or-none phenomenon or is it distributed in severity throughout the population of dialysis patients? (2) Is the dementia related to the uremia itself or to some aspect of dialysis? Memory decline was used as the operational definition of dementia. The Russell revision of the Wechsler Memory Scale was used to measure short- and long-term semantic and figural memory. Results suggested that both semantic and figural memory disturbances were distributed in varying degrees throughout the population of dialysis patients (n = 28). Further findings suggested that figural memory functioning was negatively correlated with the number of dialysis sessions and with the amount of time elapsed since the first dialysis session. Suggestions are made for further research and clinical considerations.

Adult↗

PubMed2001

Online data collection with special populations over the World Wide Web.

The quick ascendance of the World Wide Web as the dominant vehicle for internet communication has recently made experimentation in a multimedia environment feasible on the Internet. Although web sites containing online psychology demonstrations and experiments for non-handicapped individuals have appeared in recent years (especially in the areas of cognitive and social psychology), there appear to have been few attempts to conduct online experimentation with special populations. We recently completed two online pilot studies of families with Down syndrome or Williams syndrome members: a) A survey that asks (via Likert rating scales, adjective checklists, multiple-choice style questions, and text-entry boxes) about family background, computer use, and temperament of the special needs family member; and b) An experiment (completed by an individual with special needs) that includes auditory and visual digit span tasks and a memory-for-orientation task in which responses are entered via mouse clicks. Recruiting began with e-mail announcements to representative Down syndrome and Williams syndrome discussion groups, listserves, and bulletin boards, and submission of the project's URL (http://www.cofc.edu/~marcellm/testaw.htm) and key indexing terms to selected search engines. This paper reviews technical aspects of developing the online programmes as well as the strengths and weaknesses of online vs. traditional laboratory-based research in relation to issues such as experimental control, delivery of instructions, experimenter bias, participant recruitment, sample heterogeneity, generalization, attrition, privacy, financial costs, data integrity, and ethics. We conclude by offering our thoughts on two ways of implementing online experimentation with special populations: a) Using a remote parent 'helper' as a proxy to work with the target individual; and b) Collaborating with professional colleagues in Web-based projects conducted in traditional laboratory settings.

Child, Preschool↗

PubMed1999

The relevance of a nonword repetition task to assess phonological short-term memory in individuals with Down syndrome.

Phonological short-term memory capacity is generally measured with a word span task or a digit span task. Another way to measure it is to use a nonword repetition task. Gathercole and Adams (1993) claimed that this procedure can be used with children as young as two-years old. It seems that in normally developing children the quality of nonword repetition is influenced both by the length of nonwords and by the degree of wordlikeness. Can the phonological short-term memory of individuals with Down syndrome be assessed with a nonword repetition task? In order to answer this question, we decided to replicate Gathercole and collaborators' experiments (1991,1993) but with individuals with Down syndrome. The quality of nonword repetition in individuals with Down syndrome is, as in normally developing children, influenced both by the length of nonwords and by their degree of wordlikeness. Furthermore, our results seem to confirm the hypothesis which states that nonwords are temporarily stored in the phonological short-term memory system. As this system has a limited capacity, both normally developing children and people with Down syndrome recall more short nonwords than long nonwords. In conclusion, nonword repetition is a reliable task with which to assess phonological short-term memory in individuals with Down syndrome as well as in normally developing children.

Adolescent↗

PubMed2001

Short-term memory in Down syndrome: applying the working memory model.

This paper is divided into three sections. The first reviews the evidence for a verbal short-term memory deficit in Down syndrome. Existing research suggests that short-term memory for verbal information tends to be impaired in Down syndrome, in contrast to short-term memory for visual and spatial material. In addition, problems of hearing or speech do not appear to be a major cause of difficulties on tests of verbal short-term memory. This suggests that Down syndrome is associated with a specific memory problem, which we link to a potential deficit in the functioning of the 'phonological loop' of Baddeley's (1986) model of working memory. The second section considers the implications of a phonological loop problem. Because a reasonable amount is known about the normal functioning of the phonological loop, and of its role in language acquisition in typical development, we can make firm predictions as to the likely nature of the short-term memory problem in Down syndrome, and its consequences for language learning. However, we note that the existing evidence from studies with individuals with Down syndrome does not fit well with these predictions. This leads to the third section of the paper, in which we consider key questions to be addressed in future research. We suggest that there are two questions to be answered, which follow directly from the contradictory results outlined in the previous section. These are 'What is the precise nature of the verbal short-term memory deficit in Down syndrome', and 'What are the consequences of this deficit for learning'. We discuss ways in which these questions might be addressed in future work.

Down Syndrome↗

PubMed2001

Human verbal working memory impairments associated with thalamic damage.

Although animal studies, human neuroimaging studies, and numerous theoretical models suggest possible contributions of the thalamus to working memory, there are very few reported deficits in human working memory following thalamic lesions. The present study examined working memory performance in six individuals with isolated thalamic stroke and found evidence of impairment on a number of working memory span tasks, but not on a forward digit-span measure. Examination of additional aspects of working memory performance (e.g., spatial and object working memory), analysis of subjects with other sites of thalamic stroke, and functional neuroimaging suggest a role of the thalamus in working memory.

Aged↗