Rachelle S. Doody

Practice parameter: Diagnosis of dementia (an evidence-based review) Report of the Quality Standards Subcommittee of the American Academy of Neurology

Objective: To update the 1994 practice parameter for the diagnosis of dementia in the elderly. Background: The AAN previously published a practice parameter on dementia in 1994. New research and clinical developments warrant an update of some aspects of diagnosis. Methods: Studies published in English from 1985 through 1999 were identified that addressed four questions: 1) Are the current criteria for the diagnosis of dementia reliable? 2) Are the current diagnostic criteria able to establish a diagnosis for the prevalent dementias in the elderly? 3) Do laboratory tests improve the accuracy of the clinical diagnosis of dementing illness? 4) What comorbidities should be evaluated in elderly patients undergoing an initial assessment for dementia? Recommendations: Based on evidence in the literature, the following recommendations are made. 1) The DSM-III-R definition of dementia is reliable and should be used (Guideline). 2) The National Institute of Neurologic, Communicative Disorders and Stroke–AD and Related Disorders Association (NINCDS-ADRDA) or the Diagnostic and Statistical Manual, 3rd edition, revised (DSM-IIIR) diagnostic criteria for AD and clinical criteria for Creutzfeldt–Jakob disease (CJD) have sufficient reliability and validity and should be used (Guideline). Diagnostic criteria for vascular dementia, dementia with Lewy bodies, and frontotemporal dementia may be of use in clinical practice (Option) but have imperfect reliability and validity. 3) Structural neuroimaging with either a noncontrast CT or MR scan in the initial evaluation of patients with dementia is appropriate. Because of insufficient data on validity, no other imaging procedure is recommended (Guideline). There are currently no genetic markers recommended for routine diagnostic purposes (Guideline). The CSF 14-3-3 protein is useful for confirming or rejecting the diagnosis of CJD (Guideline). 4) Screening for depression, B12 deficiency, and hypothyroidism should be performed (Guideline). Screening for syphilis in patients with dementia is not justified unless clinical suspicion for neurosyphilis is present (Guideline). Conclusions: Diagnostic criteria for dementia have improved since the 1994 practice parameter. Further research is needed to improve clinical definitions of dementia and its subtypes, as well as to determine the utility of various instruments of neuroimaging, biomarkers, and genetic testing in increasing diagnostic accuracy.

A 24-week, double-blind, placebo-controlled trial of donepezil in patients with Alzheimer's disease

The efficacy and safety of donepezil as a treatment for patients with mild to moderate Alzheimers disease (AD) was investigated in a multicenter, double-blind study. Patients were randomly assigned to treatment with placebo(n = 162), 5 mg/d donepezil (n = 154), or 10 mg/d donepezil (n = 157) for 24 weeks followed by a 6-week, single-blind placebo washout. The primary efficacy measures were the cognitive portion of the Alzheimers Disease Assessment Scale (ADAS-cog) and the Clinicians Interview Based Assessment of Change-Plus (CIBIC plus), with the Mini-Mental State Examination (MMSE), Clinical Dementia Rating Scale-Sum of the Boxes (CDR-SB), and patient rated Quality of Life (QoL) used as secondary measures. Cognitive function, as measured by the ADAS-cog, was significantly improved in the 5- and 10-mg/d donepezil groups as compared with the placebo group at weeks 12, 18, and 24. Clinicians global ratings on the CIBIC plus also improved in both the 5- and 10-mg/d donepezil groups relative to placebo. At the end of the 6-week placebo washout phase, ADAS-cog scores and CIBIC plus ratings were not significantly different for the three groups. Significant treatment benefits were also observed consistently in both the 5- and 10-mg/d groups on the MMSE and the CDR-SB, but there was no consistent effect on the patient-rated QoL. Cholinergic side effects (primarily diarrhea, nausea, and vomiting) were reported more often in the 10-mg/d group than either the 5-mg/d or placebo groups. Side effects were transient and generally mild in severity. These data indicate that donepezil is a well-tolerated drug that improves cognition and global function in patients with mild to moderate AD.

Phase 3 Trials of Solanezumab for Mild-to-Moderate Alzheimer's Disease

BACKGROUND Alzheimers disease is characterized by amyloid-beta plaques, neurofibrillary tangles, gliosis, and neuronal loss. Solanezumab, a humanized monoclonal antibody, preferentially binds soluble forms of amyloid and in preclinical studies promoted its clearance from the brain. METHODS In two phase 3, double-blind trials (EXPEDITION 1 and EXPEDITION 2), we randomly assigned 1012 and 1040 patients, respectively, with mild-to-moderate Alzheimers disease to receive placebo or solanezumab (administered intravenously at a dose of 400 mg) every 4 weeks for 18 months. The primary outcomes were the changes from baseline to week 80 in scores on the 11-item cognitive subscale of the Alzheimers Disease Assessment Scale (ADAS-cog11; range, 0 to 70, with higher scores indicating greater cognitive impairment) and the Alzheimers Disease Cooperative Study-Activities of Daily Living scale (ADCS-ADL; range, 0 to 78, with lower scores indicating worse functioning). After analysis of data from EXPEDITION 1, the primary outcome for EXPEDITION 2 was revised to the change in scores on the 14-item cognitive subscale of the Alzheimers Disease Assessment Scale (ADAS-cog14; range, 0 to 90, with higher scores indicating greater impairment), in patients with mild Alzheimers disease. RESULTS Neither study showed significant improvement in the primary outcomes. The modeled difference between groups (solanezumab group minus placebo group) in the change from baseline was -0.8 points for the ADAS-cog11 score (95% confidence interval [CI], -2.1 to 0.5; P=0.24) and -0.4 points for the ADCS-ADL score (95% CI, -2.3 to 1.4; P=0.64) in EXPEDITION 1 and -1.3 points (95% CI, -2.5 to 0.3; P=0.06) and 1.6 points (95% CI, -0.2 to 3.3; P=0.08), respectively, in EXPEDITION 2. Between-group differences in the changes in the ADAS-cog14 score were -1.7 points in patients with mild Alzheimers disease (95% CI, -3.5 to 0.1; P=0.06) and -1.5 in patients with moderate Alzheimers disease (95% CI, -4.1 to 1.1; P=0.26). In the combined safety data set, the incidence of amyloid-related imaging abnormalities with edema or hemorrhage was 0.9% with solanezumab and 0.4% with placebo for edema (P=0.27) and 4.9% and 5.6%, respectively, for hemorrhage (P=0.49). CONCLUSIONS Solanezumab, a humanized monoclonal antibody that binds amyloid, failed to improve cognition or functional ability. (Funded by Eli Lilly; EXPEDITION 1 and 2 ClinicalTrials.gov numbers, NCT00905372 and NCT00904683.).

A PHASE 2 MULTIPLE ASCENDING DOSE TRIAL OF BAPINEUZUMAB IN MILD TO MODERATE ALZHEIMER DISEASE

Background: Bapineuzumab, a humanized anti-amyloid-beta (Aβ) monoclonal antibody for the potential treatment of Alzheimer disease (AD), was evaluated in a multiple ascending dose, safety, and efficacy study in mild to moderate AD. Methods: The study enrolled 234 patients, randomly assigned to IV bapineuzumab or placebo in 4 dose cohorts (0.15, 0.5, 1.0, or 2.0 mg/kg). Patients received 6 infusions, 13 weeks apart, with final assessments at week 78. The prespecified primary efficacy analysis in the modified intent-to-treat population assumed linear decline and compared treatment differences within dose cohorts on the Alzheimers Disease Assessment Scale–Cognitive and Disability Assessment for Dementia. Exploratory analyses combined dose cohorts and did not assume a specific pattern of decline. Results: No significant differences were found in the primary efficacy analysis. Exploratory analyses showed potential treatment differences (p < 0.05, unadjusted for multiple comparisons) on cognitive and functional endpoints in study “completers” and APOE ε4 noncarriers. Reversible vasogenic edema, detected on brain MRI in 12/124 (9.7%) bapineuzumab-treated patients, was more frequent in higher dose groups and APOE ε4 carriers. Six vasogenic edema patients were asymptomatic; 6 experienced transient symptoms. Conclusions: Primary efficacy outcomes in this phase 2 trial were not significant. Potential treatment differences in the exploratory analyses support further investigation of bapineuzumab in phase 3 with special attention to APOE ε4 carrier status. Classification of evidence: Due to varying doses and a lack of statistical precision, this Class II ascending dose trial provides insufficient evidence to support or refute a benefit of bapineuzumab.

A Phase 3 Trial of Semagacestat for Treatment of Alzheimer's Disease

BACKGROUND Alzheimers disease is characterized by the presence of cortical amyloid-beta (Aβ) protein plaques, which result from the sequential action of β-secretase and γ-secretase on amyloid precursor protein. Semagacestat is a small-molecule γ-secretase inhibitor that was developed as a potential treatment for Alzheimers disease. METHODS We conducted a double-blind, placebo-controlled trial in which 1537 patients with probable Alzheimers disease underwent randomization to receive 100 mg of semagacestat, 140 mg of semagacestat, or placebo daily. Changes in cognition from baseline to week 76 were assessed with the use of the cognitive subscale of the Alzheimers Disease Assessment Scale for cognition (ADAS-cog), on which scores range from 0 to 70 and higher scores indicate greater cognitive impairment, and changes in functioning were assessed with the Alzheimers Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, on which scores range from 0 to 78 and higher scores indicate better functioning. A mixed-model repeated-measures analysis was used. RESULTS The trial was terminated before completion on the basis of a recommendation by the data and safety monitoring board. At termination, there were 189 patients in the group receiving placebo, 153 patients in the group receiving 100 mg of semagacestat, and 121 patients in the group receiving 140 mg of semagacestat. The ADAS-cog scores worsened in all three groups (mean change, 6.4 points in the placebo group, 7.5 points in the group receiving 100 mg of the study drug, and 7.8 points in the group receiving 140 mg; P=0.15 and P=0.07, respectively, for the comparison with placebo). The ADCS-ADL scores also worsened in all groups (mean change at week 76, -9.0 points in the placebo group, -10.5 points in the 100-mg group, and -12.6 points in the 140-mg group; P=0.14 and P<0.001, respectively, for the comparison with placebo). Patients treated with semagacestat lost more weight and had more skin cancers and infections, treatment discontinuations due to adverse events, and serious adverse events (P<0.001 for all comparisons with placebo). Laboratory abnormalities included reduced levels of lymphocytes, T cells, immunoglobulins, albumin, total protein, and uric acid and elevated levels of eosinophils, monocytes, and cholesterol; the urine pH was also elevated. CONCLUSIONS As compared with placebo, semagacestat did not improve cognitive status, and patients receiving the higher dose had significant worsening of functional ability. Semagacestat was associated with more adverse events, including skin cancers and infections. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT00594568.)

A 1-year, placebo-controlled preservation of function survival study of donepezil in AD patients

Objective: To examine the effects of donepezil compared with placebo on the preservation of function in patients with AD over a 1-year period. Methods: This was a prospective, 54-week, double-blind, placebo-controlled, survival to endpoint study. Patients were required to have at entry: a diagnosis of probable AD (National Institute of Neurological and Communicative Disorders and Stroke criteria); Mini-Mental State Examination score of 12 to 20; Clinical Dementia Rating of 1 or 2; modified Hachinski ischemia score ≤4; and capability of performing 8 of 10 instrumental activities of daily living and 5 of 6 basic activities of daily living. Patients (n = 431) were randomized to placebo or donepezil (5 mg/day for 28 days, 10 mg/day thereafter). Outcome measures were the AD Functional Assessment and Change Scale, the Mini-Mental State Examination, and Clinical Dementia Rating scale. At each visit, investigators determined whether predefined criteria for clinically evident decline in functional status had been met. Patients who met the endpoint criteria were discontinued per protocol. Results: Donepezil extended the median time to clinically evident functional decline by 5 months versus placebo. The probability of patients treated with donepezil remaining in the study with no clinically evident functional loss was 51% at 48 weeks, compared with 35% for placebo. The Kaplan–Meier survival curves for the two treatment groups were different (p = 0.002, log-rank test). Conclusions: Patients with AD continue to show detectable disease progression over time, but treatment with donepezil for 1 year was associated with a 38% reduction in the risk of functional decline compared with placebo.

Validity and Reliability of the Alzheimer’s Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC)

Clinical global impressions of change (CGICs) are important measures of efficacy in clinical trials. CGIC scales have been used extensively as primary outcome criteria in psychopharmacological trials and in early clinical trials for antidementia drugs (e.g., Schneider and Olin, 1994). CGICs have been reported to be the most sensitive index of change in 14 of 17 dementia trials, when compared to other measures (Lehmann, 1984).

Effect of dimebon on cognition, activities of daily living, behaviour, and global function in patients with mild-to-moderate Alzheimer's disease: a randomised, double-blind, placebo-controlled study

BACKGROUND Although treatments for Alzheimers disease sometimes improve cognition, functional ability, or behaviour compared with baseline levels, such improvements are inconsistent across studies and measures, and effects diminish over time. More effective treatments are needed. We assessed the safety, tolerability, and efficacy of dimebon in the treatment of patients with mild-to-moderate Alzheimers disease. METHODS We enrolled 183 patients with mild-to-moderate Alzheimers disease (mini-mental state examination [MMSE] scores 10-24) at 11 sites in Russia. Patients were randomly assigned by a computer-generated randomisation scheme to receive oral dimebon, 20 mg three times a day (60 mg/day [n=89]), or matched placebo (n=94). Other antidementia drugs were not allowed. The primary outcome measure assessed cognition, the difference in mean change from baseline to week 26, or last completed observation on the cognitive subscale of the Alzheimers disease assessment scale (ADAS-cog). All patients and study personnel were blinded throughout the study. We compared dimebon with placebo with an intention-to-treat analysis, with last observation carried forward (ITT-LOCF) imputation. Analyses were repeated on the fully evaluable population, defined as all patients in the intention-to-treat population who had an ADAS-cog at week 26 and at least 80% compliance. 134 patients (68 in dimebon group, 66 in placebo group) enrolled in the 6-month blinded extension phase of the study. This trial is registered with Clinicaltrials.gov, number NCT00377715. FINDINGS 155 (85%) patients completed the trial (78 [88%] in dimebon group, 77 [82%] in placebo group). Treatment with dimebon resulted in significant benefits in ADAS-cog compared with placebo (ITT-LOCF) at week 26 (mean drug-placebo difference -4.0 [95% CI -5.73 to -2.28]; p<0.0001). Results of the ITT-LOCF and the evaluable population analyses were much the same for all measures. Patients given dimebon were significantly improved over baseline for ADAS-cog (mean difference -1.9 [-2.92 to -0.85]; p=0.0005). Dimebon was well tolerated: dry mouth and depressed mood or depression were the most common adverse events associated with dimebon (12 [14%] patients for each symptom by week 26). The percentage of patients who had adverse events in the two groups did not differ. INTERPRETATION Dimebon was safe, well tolerated, and significantly improved the clinical course of patients with mild-to-moderate Alzheimers disease.

Randomized controlled trial of atorvastatin in mild to moderate Alzheimer disease LEADe

Background: There is some evidence that statins may have a protective and symptomatic benefit in Alzheimer disease (AD). The LEADe study is a randomized controlled trial (RCT) evaluating the efficacy and safety of atorvastatin in patients with mild to moderate AD. Methods: This was an international, multicenter, double-blind, randomized, parallel-group study. Subjects had mild to moderate probable AD (Mini-Mental State Examination score 13–25), were aged 50–90 years, and were taking donepezil 10 mg daily for ≥3 months prior to screening. Entry low-density lipoprotein cholesterol levels (LDL-C) were >95 and <195 mg/dL. Patients were randomized to atorvastatin 80 mg/day or placebo for 72 weeks followed by a double-blind, 8-week atorvastatin withdrawal phase. Coprimary endpoints were changes in cognition (Alzheimers Disease Assessment Scale-Cognitive Subscale [ADAS-Cog]) and global function (Alzheimers Disease Cooperative Study Clinical Global Impression of Change [ADCS-CGIC]) at 72 weeks. Results: A total of 640 patients were randomized in the study. There were no significant differences in the coprimary endpoints of ADAS-cog or ADCS-CGIC or the secondary endpoints. Atorvastatin was generally well-tolerated. Conclusions: In this large-scale randomized controlled trial evaluating statin therapy as a treatment for mild to moderate Alzheimer disease, atorvastatin was not associated with significant clinical benefit over 72 weeks. This treatment was generally well-tolerated without unexpected adverse events. Classification of evidence: This study provides Class II evidence that intensive lipid lowering with atorvastatin 80 mg/day in patients with mild to moderate probable Alzheimer disease (aged 50–90), taking donepezil, with low-density lipoprotein cholesterol levels between 95 and 195 mg/dL over 72 weeks does not benefit cognition (as measured by Alzheimers Disease Assessment Scale-Cognitive Subscale) (p = 0.26) or global function (as measured by Alzheimers Disease Cooperative Study Clinical Global Impression of Change) (p = 0.73) compared with placebo.

Donepezil in vascular dementia A randomized, placebo-controlled study

Objective: To evaluate the efficacy and tolerability of donepezil in patients with vascular dementia (VaD). Methods: Patients (n = 616; mean age, 75.0 years) with probable or possible VaD, according to National Institute of Neurological Disorders and Stroke–Association Internationale pour la Recherche en l’Enseignement en Neurosciences criteria, were randomized to receive donepezil 5 mg/day (n = 208), donepezil 10 mg/day (after 5 mg/day for the first 28 days) (n = 215), or placebo (n = 193) for 24 weeks. Results: Seventy-six percent of the patients enrolled had probable VaD. A total of 75.3% of the 10 mg donepezil group and 80.8% of the 5 mg group completed the study compared with 83.4% of the placebo group. Both donepezil-treated groups showed improvements in cognitive function on the Alzheimer’s Disease Assessment Scale–cognitive subscale compared with placebo, with a mean endpoint treatment difference, as measured by the change from baseline score, of approximately 2 points (donepezil 5 mg, −1.65 [p = 0.003]; 10 mg, −2.09 [p = 0.0002]). Greater improvements on the Clinician’s Interview-Based Impression of Change–plus version were observed with both donepezil groups than with the placebo group (overall donepezil treatment vs placebo p = 0.008); 25% of the placebo group showed improvement compared with 39% (p = 0.004) of the 5 mg group and 32% (p = 0.047) of the 10 mg group. Withdrawal rates due to adverse events were low (placebo, 8.8%; donepezil 5 mg, 10.1%; 10 mg, 16.3%). Conclusions: Donepezil-treated patients demonstrated significant improvements in cognition and global function compared with placebo-treated patients, and donepezil was well tolerated.