Medicine
Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/12
This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
Browse
4 results
Search Results
Item Olifactory impairment is more marked in patients with mild dementia with Lewy bodies than those with mild Alzheimer disease(BMJ Publishing Group, 2009) Williams, S.S.; Williams, J.; Combrinck, M.; Christie, S.; Smith, A.D.; McShane, R.BACKGROUND: Dementia patients with anosmia are more likely to have Lewy body pathology at postmortem, but clinicopathological studies have only assessed olfaction in moderate dementia or an average of 5 years before death. It is not known whether, in patients with mild dementia (MMSE score over 20), olfactory function is more impaired in Alzheimer disease (AD) than dementia with Lewy bodies (DLB). METHODS: Patients with mild DLB (n = 21), mild AD (n = 27), mild cognitive impairment (MCI) (n = 21) and controls (n = 47) were assessed using a 16-item olfactory identification test and an olfactory threshold test which used sticks impregnated with differing concentrations of butanol. RESULTS: Patients with mild DLB had impaired olfactory identification ability compared with those with mild AD or MCI, independent of age, cognitive function and sex. The sensitivity of a cutoff score of seven correct responses out of 16 was 0.81 for distinguishing mild DLB from mild AD (AUC 0.682). The specificity, positive predictive value and negative predictive value for the same cut-off score were 0.41, 0.48 and 0.73, respectively. The olfactory threshold was not different in the AD and DLB groups. CONCLUSIONS: Simple bedside tests of olfactory identification merit further examination for their potential to improve the identification of patients with DLB when used alongside existing criteria. They are insufficiently specific for use in screening.Item Medial temporal lobe atrophy, apolipoprotein genotype, and plasma homocysteine in Sri Lankan patients with Alzheimer's disease(Routledge, 2005) de Silva, H.A.; Gunatilake, S.B.; Johnston, C.; Warden, D.; Smith, A.D.The authors studied the association of Alzheimer's disease (AD) with total plasma homocysteine (tHcy) and apolipoprotein E (apoE)genotype, and the usefulness of measuring medial temporal lobe thickness (MTL) thickness for the diagnosis of AD in Sri Lankan patients. Using criteria of the NINCDS-ADRDA, 23 AD patients and 21 controls were recruited. All underwent MTL-oriented computed tomographic (CT) scans, measurement of plasma tHcy, and apoE genotyping. Mean plasma tHcy was significantly higher in AD patients than controls (p=.001). This association was independent of age, sex, body mass index (BMI), serum folate and vitamin B12, and serum creatinine. The frequency of apoE4 allele was significantly higher (p=.003) in AD patients, and the adjusted odds ratio of AD for the presence of one or more apoE4 alleles compared with none was 10.39 (95% CI 1.77-61.10; p=.010). The mean minimum MTL thickness was significantly higher in control subjects compared to that of AD patients (p<.001). This first report of apoE4, plasma tHcy, MTL thickness, and AD from Sri Lanka shows that high plasma tHcy, the presence of apoE4 allele, and MTL atrophy are associated with AD.Item The Prevalence of dementia in a semi-urban population in Sri Lanka : report from a regional survey(John Wiley, 2003) de Silva, H.A.; Gunatilake, S.B.; Smith, A.D.BACKGROUND: The prevalence of dementia in Sri Lanka, which has a rapidly ageing population, is unknown. OBJECTIVE: This study aimed to determine the prevalence of Alzheimer's disease (AD) and other dementias in a semi-urban elderly Sinhala-speaking population in Ragama, Sri Lanka. METHODS: The study was conducted in two phases. Phase I: After informed consent 703 subjects aged > or =65 years from the study area (population 15 828) were screened for cognitive impairment using the Sinhalese Mini Mental State Examination. Subjects scoring < or =17 were regarded as suspected dementia cases. Phase II: All subjects who screened positive in phase I were included in phase II for detailed evaluation fordementia according DSM IV and NINCDS-ADRDA criteria which included structured neuropsychiatric assessment, laboratory investigations, an axial CT scan of the brain and an informant interview. RESULTS: In the study sample, 61% were female and 86% were between 65-75 years. 42 subjects screened positive in phase I. Of these, 28 subjects were diagnosed as having dementia, giving an overall prevalence rate of 3.98% (95% Confidence Intervals (CI) =2.6-5.7%). Of these, 20 (71.4%) had probable AD, four had vascular dementia (14.3%), two had mixed (vascular and AD) dementia (7.1%), one had Lewy body dementia, and one had dementia due to syphilis. Greater age, illiteracy and female gender were associated with higher prevalence of dementia. CONCLUSION: Comparison with other community studies performed in North India suggests that dementia prevalence is higher in Sri Lanka. This may be due to regional differences in disease incidence.Item Abnormal functions of pottasium channels in the platelets of patients with Alzheimer's disease(Lancet Publishing Group, 1998) de Silva, H.A.; Aronson, J.K.; Grahame-Smith, D.G.; Jobst, K.A.; Smith, A.D.BACKGROUND:Reports of abnormalities of potassium-channel function in various cultured cells of Alzheimer's disease patients led us to attempt to characterise the pharmacological characteristics of the abnormal channel.METHODS: We studied platelets from 14 patients with Alzheimer-type dementia and 14 non-demented controls matched for age and sex. The effects of specific inhibitors of K+ channels on the efflux of rubidium-86 ions, a radioactive analogue of K+, from the platelets were measured.FINDINGS: Normal platelets contain three types of K+ channel, sensitive to the inhibitory actions of apamin (small-conductance calcium-dependent potassium channels), charybdotoxin (of less specificity, but probably intermediate-conductance calcium-dependent K+ channels), and alpha-dendrotoxin (voltage-sensitive K+ channels). However, 8Rb+ efflux from the platelets of patients with Alzheimer-type dementia was not inhibited by either apamin or charybdotoxin. By contrast, inhibition by alpha-dendrotoxin did occur. INTERPRETATION: Our results suggest that calcium-dependent K+ channels in platelets are selectively impaired in Alzheimer's disease. A similar abnormality in neurons could contribute to the pathophysiology of the disorder.