Evaluation Of Memory Impairment Research Articles

Prevalence of Alzheimer′s disease in rural and urban areas in Cuba and factors influencing on its occurrence: epidemiological cross-sectional protocol

IntroductionAccording to the World Alzheimer’s Report 2019, around 50 million people suffer from dementia, worldwide. Observational analysis revealed the existence of particular factors associated with the onset and progression of...

Evaluation of Memory Impairment Following Prenatal Exposure to Mosquito Coil Smoke

Background: Developmental Neurotoxicity can lead to the buildup of reactive oxygen species which is an indicator to oxidative stress in the prenatally exposed offspring. Neuronal oxidative stress induces neuroinflammation, precedes tangle formation, and disrupts synaptic plasticity. The result of such changes may be expressed into adulthood as behavioral deficits. All together, these mechanisms are implicated in memory disorders. Objectives: To investigate the histochemical changes in the hippocampus and entorhinal cortex of Wistar rats' offspring after prenatal exposure to mosquito coil smoke and its effect on memory. . Methods: 12 pregnant Wistar rats were grouped into four, 3 animals per group. Group I was exposed to fresh air. Groups II, III, and IV were exposed to mosquito coil smoke for 4, 6 and 8 hours daily respectively throughout gestation period. On Post-natal day (PND) 28 and 29, shortterm spatial and recognition memory of adolescent wistar rats were assessed using water licking task and novel object recognition test respectively. For each animal group (I-IV), a total of 8 animals were randomly selected from the litters for neurobehavioral studies. Experimental animals were humanely sacrificed and sections from the hippocampus and entorhinal cortex were processed for histochemical studies using Bielschowsky stain. Data were presented as mean ± SEM; analysed using One-way analysis of variance and Tukey's Multiple Comparison Test (p<0.05). Results and Conclusion: Our results showed significant impairment in short-term recognition and spatial memory of group III and IV adolescent wistar rats when compared with the control (p<0.05) and the formation of neurofibrillary tangle-like structures in neurons of the studied regions. .

An expanded role for neuroimaging in the evaluation of memory impairment.

Alzheimer disease affects millions of people worldwide. The neuropathologic process underlying this disease begins years, if not decades, before the onset of memory decline. Recent advances in neuroimaging suggest that it is now possible to detect Alzheimer-associated neuropathologic changes well before dementia onset. Here, we evaluate the role of recently developed in vivo biomarkers in the clinical evaluation of Alzheimer disease. We discuss how assessment strategies might incorporate neuroimaging markers to better inform patients, families, and clinicians when memory impairment prompts a search for diagnosis and management options.

Evaluation of memory impairment in aging adult survivors of childhood acute lymphoblastic leukemia treated with cranial radiotherapy.

Cranial radiotherapy (CRT) is a known risk factor for neurocognitive impairment in survivors of childhood cancer and may increase risk for mild cognitive impairment and dementia in adulthood. We performed a cross-sectional evaluation of survivors of childhood acute lymphoblastic leukemia (ALL) treated with 18 Gy (n = 127) or 24 Gy (n = 138) CRT. Impairment (age-adjusted score >1 standard deviation below expected mean, two-sided exact binomial test) on the Wechsler Memory Scale IV (WMS-IV) was measured. A subset of survivors (n = 85) completed structural and functional neuroimaging. Survivors who received 24 Gy, but not 18 Gy, CRT had impairment in immediate (impairment rate = 33.8%, 95% confidence interval [CI] = 25.9% to 42.4%; P < .001) and delayed memory (impairment rate = 30.2%, 95% CI = 22.6% to 38.6%; P < .001). The mean score for long-term narrative memory among survivors who received 24 Gy CRT was equivalent to that for individuals older than 69 years. Impaired immediate memory was associated with smaller right (P = .02) and left (P = .008) temporal lobe volumes, and impaired delayed memory was associated with thinner parietal and frontal cortices. Lower hippocampal volumes and increased functional magnetic resonance imaging activation were observed with memory impairment. Reduced cognitive status (Brief Cognitive Status Exam from the WMS-IV) was identified after 24 Gy (18.5%, 95% CI = 12.4% to 26.1%; P < .001), but not 18 Gy (8.7%, 95% CI = 4.4% to 15.0%; P = .11), CRT, suggesting a dose-response effect. Employment rates were equivalent (63.8% for 24 Gy CRT and 63.0% for 18 Gy CRT). Adult survivors who received 24 Gy CRT had reduced cognitive status and memory, with reduced integrity in neuroanatomical regions essential in memory formation, consistent with early onset mild cognitive impairment.

Diffusion Abnormality of Corpus Callosum in Alzheimer's Disease

This study investigated diffusion abnormalities in the parts of corpus callosum (CC) of patients with Alzheimer's disease (AD) using diffusion tensor magnetic resonance imaging (DT-MRI). Twenty-one patients with AD and 20 healthy volunteers participated in the study. MRI was performed with a 1.5 T system. Conventional MR images and diffusion tensor images were obtained for all participants. We divided the CC into three parts as rostrum, body and splenium. The apparent diffusion coefficiency (ADC) and fractional anisotropy (FA) were measured in all parts. FA values for the CC were lower in AD patients than the values of controls. In AD patients the lowest values were found in the rostrum of the CC and CC body FA values were also lower than the splenium, but the difference did not reach statistical significance. DT-MRI is a promising technique to investigate microstructural changes in white matter regions in AD. Early detection of the disease has been increasingly studied in AD. Further studies with larger populations are needed to confirm the role of diffusion tensor imaging in the evaluation of memory impairment.

Challenges to screening and evaluation of memory impairment among Hispanic elders in a primary care safety net facility

Implement a memory impairment screening procedure for elderly Hispanic primary care patients, and analyze its yield and challenges to further triage and diagnostic evaluation. Three hundred twenty nine Hispanic patients aged ≥60 years or proxy informants were enrolled from outpatient primary care clinics at an urban safety-net medical center. Patients were screened for memory impairment using the WHO-UCLA AVLT; for those without consent capacity, proxies were given the IQCODE. Bilingual research assistants conducted in-person or telephone screening. Age, gender, education, comorbidities, acculturation, overall health, access to care, and memory concerns were assessed as potential predictors of memory impairment. Based on identified implementation challenges, a multi-disciplinary stakeholder committee proposed revised approaches to increase diagnostic evaluation and sustainability. Of 677 eligible patients approached, 329 (49%) were screened, and 77 (23%) met criteria for memory impairment using the WHO-UCLA AVLT (N=60) or the IQCODE (N=17). Only male gender and higher comorbidity uniquely predicted memory impairment (ps<0.05). Few screen-positive patients declined further triage and evaluation, but a substantial proportion could not be subsequently contacted. Challenges to implementing a memory screening program included staff time and adequate clinic space for in-person screening; challenges to follow-up of positive screening results included inability to contact patients and lack of primary care continuity to facilitate further triage and referral. Nearly one-fourth of primary care Hispanic elders screened as memory-impaired, but few factors predicted positive screening. Stakeholder-guided adaptations are needed-particularly in resource-constrained settings-to overcome challenges to further diagnostic evaluation and referral.

Potential Role of Diffusion Tensor MRI in the Differential Diagnosis of Mild Cognitive Impairment and Alzheimer's Disease

The purpose of this study was to evaluate the fractional anisotropy values of several white matter tracts with the aim of differentiating a healthy population from persons with mild cognitive impairment or Alzheimer's disease. Seventy-nine patients with memory impairment and 16 volunteer controls participated in the study. MRI was performed with a 1.5-T system. Conventional MR images and diffusion tensor images were obtained for all participants. The diffusion tensor imaging data were postprocessed, and low b-value, fractional anisotropy, and fractional anisotropy color-coded maps were calculated. With the three maps as an anatomic reference, fractional anisotropy was measured for hippocampal formations, superior longitudinal fascicles, posterior cingulate gyri, and the splenium of the corpus callosum. Kruskal-Wallis and Steel-type multiple-comparison nonparametric tests were performed for the statistical analysis. The fractional anisotropy values for the splenium of the corpus callosum, bilateral posterior cingulate gyri, and bilateral superior longitudinal fascicles of patients with mild cognitive impairment and those with probable Alzheimer's disease were significantly lower than the values of controls. No differences were found in hippocampal formations in any group. No significant difference was found in fractional anisotropy values in comparisons of mild cognitive impairment versus possible Alzheimer's disease and probable Alzheimer's disease or comparisons of probable Alzheimer's disease and possible Alzheimer's disease. Diffusion tensor imaging is a promising technique for the evaluation of patients with probable mild cognitive impairment. Early detection of the disease expands the treatment options, increasing the likelihood of a good clinical response and enhancing the quality of life of patients and their relatives. Further studies with larger populations are needed to confirm the role of diffusion tensor imaging in the evaluation of memory impairment.