Alzheimer Disease: Tekin S

Feldman HH, Ferris S, Winblad B, Sfikas N, Mancione L, He Y, Tekin S, Burns A, Cummings J, del Ser T, Inzitari D, Orgogozo JM, Sauer H, Scheltens P, Scarpini E, Herrmann N, Farlow M, Potkin S, Charles HC, Fox NC, Lane R. · Division of Neurology, University of British Columbia Hospital, Vancouver, Canada. · Lancet Neurol. · Pubmed #17509485 No free full text.

Abstract: OBJECTIVE: To assess the effect of rivastigmine in patients with mild cognitive impairment (MCI) on the time to clinical diagnosis of Alzheimer's disease (AD) and the rate of cognitive decline. METHODS: The study was a double-blind, randomised, placebo-controlled trial of up to 48 months. All patients had MCI operationally defined by having cognitive symptoms, a global clinical dementia rating stage of 0.5, a score of less than 9 on the New York University delayed paragraph recall test, and by not meeting the diagnostic criteria for AD. Primary efficacy variables were time to clinical diagnosis of AD, and change in performance on a cognitive test battery. This study is registered with the US National Institutes of Health clinical trials database (ClinicalTrials.gov), number NCT00000174. FINDINGS: Of 1018 study patients enrolled, 508 were randomly assigned to rivastigmine and 510 to placebo; 17.3% of patients on rivastigmine and 21.4% on placebo progressed to AD (hazard ratio 0.85 [95% CI 0.64-1.12]; p=0.225). There was no significant difference between the rivastigmine and placebo groups on the standardised Z score for the cognitive test battery measured as mean change from baseline to endpoint (-0.10 [95% CI -0.63 to 0.44], p=0.726). Serious adverse events were reported by 141 (27.9%) rivastigmine-treated patients and 155 (30.5%) patients on placebo; adverse events of all types were reported by 483 (95.6%) rivastigmine-treated patients and 472 (92.7%) placebo-treated patients. The predominant adverse events were cholinergic: the frequencies of nausea, vomiting, diarrhoea, and dizziness were two to four times higher in the rivastigmine group than in the placebo group. INTERPRETATION: There was no significant benefit of rivastigmine on the progression rate to AD or on cognitive function over 4 years. The overall rate of progression from MCI to AD in this randomised clinical trial was much lower than predicted. Rivastigmine treatment was not associated with any significant safety concerns.

Feldman H, Scheltens P, Scarpini E, Hermann N, Mesenbrink P, Mancione L, Tekin S, Lane R, Ferris S. · Division of Neurology, University of British Columbia, Vancouver Hospital and Health Sciences Center, Vancouver, British Columbia, Canada. · Neurology. · Pubmed #15079026 No free full text.

Abstract: The authors investigated neuropsychiatric symptoms in mild cognitive impairment (MCI) from baseline data of the Investigation in the Delay to Diagnosis of AD with Exelon (InDDEx) study (n = 1,010). Neuropsychiatric symptoms were reported in 59% of subjects (Neuropsychiatric Inventory [NPI]). NPI+ subjects had significantly greater impairment on global, cognitive, and functional scores than NPI- subjects. The presence of neuropsychiatric symptoms appears to be a marker of MCI severity.

Grossberg G, Sadowsky C, Fröstl H, Frölich L, Nagel J, Tekin S, Zechner S, Ros J, Orgogozo JM. · Department of Neurology and Psychiatry, St Louis University School of Medicine, 1438 South Grand Boulevard, St. Louis, MO 63104, USA. · Alzheimer Dis Assoc Disord. · Pubmed #19484917 No free full text.

Abstract: The primary objective of the open-label extension was to evaluate the long-term safety and tolerability of a transdermal rivastigmine patch up to 1 year, as a novel approach to treatment in Alzheimer disease. This was a 28-week extension to a 24-week, double-blind, double-dummy, placebo-controlled, and active-controlled study evaluating rivastigmine patches [9.5 mg/24 h (10 cm2) and 17.4 mg/24 h (20 cm2)] and oral capsules (3 to 6 mg twice-daily). Patients entering the extension were switched directly to 9.5 mg/ 24 h rivastigmine patch and increased to 17.4 mg/24 h patch, irrespective of their double-blind study treatment. Primary measures included safety and tolerability assessments, including adverse events and serious adverse events. Of 1195 patients randomized to treatment, 870 (72.8%) completed the double-blind study and entered the open-label extension. During weeks 1 to 4 of the extension, 9.5 mg/24 h rivastigmine patch was well tolerated overall by patients formerly randomized to rivastigmine capsule or patch groups: < or =2.5% reported nausea and < or =1.9% reported vomiting. No unexpected safety issues arose, and skin tolerability was good; similar to the double-blind study. During the 28-week, open-label extension phase, the patch seemed to be well tolerated with a favorable safety profile.

Marshall GA, Fairbanks LA, Tekin S, Vinters HV, Cummings JL. · Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, USA. · J Geriatr Psychiatry Neurol. · Pubmed #17341768 No free full text.

Abstract: Two subtypes of Alzheimer's disease (AD) have been commonly identified: early- and late-onset forms. Previous studies suggest that early-onset AD patients have more neuritic plaques (NPs) and neurofibrillary tangles (NFTs). In the current study, NP and NFT counts were performed for 8 brain regions in 25 subjects with definite AD. A repeated-measures analysis of variance of mean regional NP and NFT counts for early- and late-onset groups was performed. A significant between-subject effect indicating greater overall NP and NFT burden in the early-onset group was observed (NP: F = 6.8, df = 1, P = .015; NFT: F = 7.5, df = 1, P = .012). This analysis supports the hypothesis that early-onset AD is associated with greater pathologic burden than late-onset AD. This suggests that late-onset AD patients have less cognitive reserve than early-onset patients and require fewer pathologic changes to exhibit cognitive deterioration.

Bronnick K, Emre M, Lane R, Tekin S, Aarsland D. · Norwegian Centre for Movement Disorders, Stavanger University Hospital, Helse Stavanger, Norway. · J Neurol Neurosurg Psychiatry. · Pubmed #17287236 No free full text.

Abstract: OBJECTIVE: To compare the profile of cognitive impairment in Alzheimer's disease (AD) with dementia associated with Parkinson's disease (PDD). METHODS: Neuropsychological assessment was performed in 488 patients with PDD and 488 patients with AD using the Mini-Mental State Examination (MMSE) and the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). Logistic regression analysis was used to investigate whether the diagnosis could be accurately predicted from the cognitive profile. Additionally, the cognitive profiles were compared with a normative group using standardised effect sizes (Cohen's d). RESULTS: Diagnosis was predicted from the cognitive profile, with an overall accuracy of 74.7%. Poor performance of the AD patients on the orientation test in ADAS-cog best discriminated between the groups, followed by poor performance of the PDD patients on the attentional task in MMSE. Both groups showed memory impairment, AD patients performing worse than PDD patients. CONCLUSION: The cognitive profile in PDD differs significantly from that in AD. Performance on tests of orientation and attention are best in differentiating the groups.

Marshall GA, Fairbanks LA, Tekin S, Vinters HV, Cummings JL. · Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1769, USA. · Alzheimer Dis Assoc Disord. · Pubmed #16493237 No free full text.

Abstract: Functional status, reflected by measures of activities of daily living (ADLs), deteriorates as Alzheimer disease (AD) progresses. Decline in activities of daily living may be mediated by executive and frontal lobe dysfunction. The objective of this study was to examine the relationship between activities of daily living and pathologic burden in Alzheimer disease. Twenty two subjects with definite Alzheimer disease were selected from the UCLA ADRC neuropathology database. A total activities of daily living score was derived from the Retrospective Collateral Dementia Interview-Revised (RCDI-R) questionnaire, which was administered to caregivers of autopsied subjects included in the study. Neuritic plaque (NP) and neurofibrillary tangle (NFT) counts were performed for 8 brain regions. There was a significant positive correlation between total activities of daily living score (higher scores indicate more disability) and mean neuritic plaques and neurofibrillary tangle counts (r = 0.671, P = 0.001, and r = 0.542, P = 0.009, resp), as well as CA1 and prosubiculum neuritic plaques and neurofibrillary tangle counts, right and left orbital frontal neuritic plaques counts, and occipital neuritic plaques count. Total activities of daily living score did not correlate with age at death, age at symptom onset, dementia duration, gender, or education. Deteriorating activities of daily living in Alzheimer Disease subjects correlate with greater overall pathologic burden and possibly selectively with involvement of the medial temporal, occipital, and orbital frontal regions.

Marshall GA, Fairbanks LA, Tekin S, Vinters HV, Cummings JL. · Department of Neurology, University of California at Los Angeles, Reed Neurological Research Center, 2-238, 710 Westwood Plaza, CA 90095-1769, USA. · Dement Geriatr Cogn Disord. · Pubmed #16391476 No free full text.

Abstract: Apathy is the most commonly observed behavioral disturbance in Alzheimer's disease (AD) and has been suggested to be frontally mediated. Neuritic plaque (NP) and neurofibrillary tangle (NFT) counts were performed for 8 brain regions in 29 subjects with definite AD. Neuropsychiatric Inventory (NPI) for autopsied subjects was obtained from questioning of caregivers of subjects included in the study. Chronic apathy and total NPI composite scores correlated with anterior cingulate NFT counts (r = 0.518, p = 0.01, and r = 0.438, p = 0.032). This analysis suggests that chronic apathy in AD correlates with a greater anterior cingulate NFT burden and that chronic behavioral changes are more reflective than acute changes of disease pathology.

Farlow MR, He Y, Tekin S, Xu J, Lane R, Charles HC. · Department of Neurology, Indiana University School of Medicine, Clinical Building, Room 299, 541 Clinical Drive, Indianapolis, IN 46202-5111, USA. · Neurology. · Pubmed #15557508 No free full text.

Abstract: OBJECTIVE: The authors aimed to use baseline data of an ongoing large, prospective study in subjects with mild cognitive impairment (MCI) to investigate the impact of APOE genotype on the symptom profile of the condition. METHODS: Cognitive assessments included the AD Assessment Scale cognitive subscale (ADAS-cog), the Mini-Mental State Examination (MMSE), and a cognitive battery for assessment of memory, attention, and executive function. Behavioral assessments included the Neuropsychiatric Inventory and Beck Depression Inventory. Activities of daily living were assessed by the AD Cooperative Study Activities of Daily Living (ADCS-ADL) scale. Hippocampal volumes were measured with MRI. RESULTS: A total of 494 of 1,018 study subjects provided APOE data. Approximately 40% of the subjects were APOE epsilon4 carriers. APOE epsilon4 carriers had lower MMSE (p = 0.01) and higher ADAS-cog (p < 0.0001) scores than noncarriers, indicating worse cognitive impairment. APOE epsilon4 carriers also had greater deficits on New York University delayed paragraph recall and Buschke free and cued selective reminding tests, and on the ADCS-ADL scale (p < 0.001). They also had smaller hippocampal volumes (p = 0.002). Behavioral scores were similar across the subgroups. CONCLUSION: MCI subjects carrying the APOE epsilon4 allele showed distinct cognitive and imaging profiles, which appeared to resemble those of early Alzheimer patients. APOE epsilon4 genotype was associated with greater impairments in memory and functional activities as well as hippocampal atrophy.

Tekin S, Mega MS, Masterman DM, Chow T, Garakian J, Vinters HV, Cummings JL. · Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095, USA. · Ann Neurol. · Pubmed #11261510 No free full text.

Abstract: Few studies evaluate neuropathological correlates of behavioral changes in Alzheimer disease (AD). We identified 31 autopsy patients with a diagnosis of definite AD. Behavioral changes were assessed with the Neuropsychiatric Inventory. Brain sections were collected from bilateral orbitofrontal and left anterior cingulate, superior temporal, inferior parietal, occipital, and hippocampal cortices for quantification of neurofibrillary tangles (NFTs) and diffuse and neuritic plaques. Sections from frontal, cingulate, and hippocampal cortices were reviewed for the presence of Lewy bodies (LBs). Hypothesis-driven correlational analyses were performed by the bootstrap method. Subgroup analyses contrasted a group with high scores of one specific behavior to a group with low scores after equating groups for other behaviors. NFT burden in the left orbitofrontal cortex across all 31 patients significantly correlated with agitation scores (r = 0.41, p < 0.015) and NFTs correlated significantly (r = 0.66, p = 0.004) with higher agitation scores in the subgroup analysis. Left anterior cingulate NFTs, although not within our hypotheses, also showed a significant relationship to agitation within the subgroups (r = 0.76, p = 0.0003; Bonferroni p = 0.02). Seven patients, including three in the agitation subgroup, had cortical LBs. Aberrant motor behavior and NFT density in the left orbitofrontal cortex showed a significant relationship for the entire group (r = 0.38, p < 0.03) and for subgroups (r = 0.49, p = 0.04), whereas apathy and left anterior cingulate NFTs showed a significant relationship only for the entire group (r = 0.25, p < or = 0.01). These observations suggest that agitation and aberrant motor behavior are correlates of greater NFT pathology in the orbitofrontal cortex in AD, whereas increasing apathy may relate to greater NFT burden in the anterior cingulate.

Tekin S, Fairbanks LA, O'Connor S, Rosenberg S, Cummings JL. · Department of Neurology, Alzheimer Disease Research Center, and Department of Psychiatry and Biobehavioral Sciences, UCLA School of Medicine, Los Angeles, CA, USA. · Am J Geriatr Psychiatry. · Pubmed #11156757 No free full text.

Abstract: Using a retrospective data analysis, the authors investigated the relationships between instrumental activities of daily living (IADLs) and neuropsychiatric symptoms, cognitive impairment, and medical illness burden in patients with Alzheimer's disease (AD). One hundred forty-three patients fulfilling the clinical criteria for probable or possible AD in an outpatient clinic were assessed for IADLs, neuropsychiatric symptoms, cognitive impairment, and medical illness burden with the Functional Activities Questionnaire (FAQ), Neuropsychiatric Inventory (NPI), Mini-Mental State Exam (MMSE), and Cumulative Illness Rating Scale-Geriatric (CIRS-G). Both MMSE and NPI scores related significantly to IADLs as measured by the FAQ. Several psychiatric symptoms were correlated significantly with IADLs. FAQ scores had no correlation with CIRS-G. Neuropsychiatric findings also were associated significantly with MMSE and had a weak correlation with CIRS-G scores. IADLs changed with cognition and neuropsychiatric disturbances in AD. Medical illness burden had little influence on functional status and a limited impact on neuropsychiatric symptoms.