Resting-State Functional Connectivity Changes in Older Adults with Sleep Disturbance and the Role of Amyloid Burden

Sleep and related disorders could lead to changes in various brain networks, but little is known about the role of amyloid β (Aβ) burden-a key Alzheimer's disease (AD) biomarker-in the relationship between sleep disturbance and altered resting state functional connectivity (rsFC) in older adults. This cross-sectional study examined the association between sleep disturbance, Aβ burden, and rsFC using a large-scale dataset from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Sample included 489 individuals (53.6% cognitively normal, 32.5% mild cognitive impairment, and 13.9% AD) who had completed sleep measures (Neuropsychiatric Inventory), PET Aβ data, and resting-state fMRI scans at baseline. Within and between rsFC of the Salience (SN), the Default Mode (DMN) and the Frontal Parietal network (FPN) were compared between participants with sleep disturbance versus without sleep disturbance. The interaction between Aβ positivity and sleep disturbance was evaluated using linear regressions, controlling for age, diagnosis status, gender, sedatives and hypnotics use, and hypertension. Although no significant main effect of sleep disturbance was found on rsFC, a significant interaction term emerged between sleep disturbance and Aβ burden on rsFC of SN (β=0.11, P=0.006). Specifically, sleep disturbance was associated with SN hyperconnectivity, only with the presence of Aβ burden. Sleep disturbance may lead to altered connectivity in the SN when Aβ is accumulated in the brain. Individuals with AD pathology may be at increased risk for sleep-related aberrant rsFC; therefore, identifying and treating sleep problems in these individuals may help prevent further disease progression.

APPLICATION OF QUALITATIVE METHODS IN THE DEVELOPMENT OF AN INFORMANT-REPORTED MEASURE OF LUCIDITY

The aim was a qualitative evaluation of a lucidity measure for front-line staff or family informants. A sequential approach to item development and evaluation was followed: refinement of the operationalization of the construct; review of seminal items, modification, and purification; confirmation of the feasibility of reporting methodology. Modified focus groups were conducted with 20 staff and 10 family members who participated using a web-based survey. Sample themes included: reaction when hearing the term; words that come to mind; description of and first reaction to referenced or observed “lucidity” events. Data were extracted from Qualtrics for analysis using NVivo. Semi-structured cognitive interviews were conducted with10 health professionals working with older adults with cognitive impairment. An external advisory board reviewed the clarity, breadth, and scope of the conceptual definition and item content. Suggestions for item modification derived from the focus groups and cognitive interviews resulted in the final lucidity measure.

Results of in situ fixation of Andersson lesion by posterior approach in 35 cases

STUDY OBJECTIVE

Due to the rarity of the Andersson lesion (AL), the literature is ambiguous regarding the type of surgical fixation, need for debridement and deformity correction. The purpose of this retrospective study is to evaluate the efficacy, feasibility and functional outcome of posterior fixation in AL.

MATERIALS AND METHODS

This study included 35 patients having thoracolumbar AL operated for in situ fixation and fusion with minimum of 24-month follow-up. VAS (Visual Analogue Score) back pain, ODI (Oswestry Disability Index), Frankel's grade were compared and analyzed. Union status was noted with complications.

RESULTS

The mean age of 35 patients was 56.34(± 11.3) years with average follow-up of 51.49 months. Two patients had AL at two levels. 27/37 AL were at discal level. Average estimated blood loss (EBL) was 276.43 ml and duration of surgery was 130.43 min. On an average, operated segments needed 7.77 screws. There were ten minor complications without long-term sequel. Neurological improvement was noted in 30 patients. Average preoperative VAS score improved from 8.69 to 3.14, ODI score improved from 68.76 to 18.77 at final follow-up which were significant (p < 0.05). There was significant improvement in Frankel's grading (Z = - 4.354, P = 0.00).

CONCLUSIONS

Surgical management of AL by posterior approach and posterior stabilization can give satisfactory results without the need of extensive anterior reconstruction, bone grafting or deformity correction procedures without added morbidity and complications.

Development of a Staff Informant Measure of Lucidity

Lucidity Measure Development: An existing questionnaire measuring lucidity length, degree, content, coinciding circumstances, and time from lucid episode to death was expanded to include time of day, expressive and receptive communication and speech the month prior to and during the lucid event. Pilot Study: 33 interviews with staff were conducted; 73% reported ever witnessing paradoxical lucidity. Among 29 events reported, 31% lasted several days, 20.7%, 1 day, and 24.1% less. In 78.6% the patient engaged in unexpected activity. 20% died within 3 days and 17% within 3 months after the event. Qualitative Analyses: To refine the measure, 10 family caregivers and 20 LTSS staff caregivers completed a web-based focus-group type exercise using QualtricsXM. A content-thematic analysis with an inductive approach was applied to make qualitative inferences by analyzing the meaning and semantic relationship of words, phrases, and concepts. Using the reduction method of selection, conceptual content categories will be developed.

Modification of everyday activities and its association with self-awareness in cognitively diverse older adults

Cognitive impairment (CI) in older adults is frequently accompanied by difficulty performing complex everyday activities (e.g., managing finances). However, it is unclear if and how older adults with CI modify their activities (i.e., Do individuals continue, monitor, seek help with, change their approach to, or stop different activities?). In the current study, we examined if older adults with CI are concerned about their ability to carry out complex activities, if and how they modify activities based on their concern, and the factors associated with activity modification. We hypothesized that older adults with CI will more frequently be concerned about, and modify, everyday activities than cognitively healthy (HE) older adults, and that higher awareness of memory loss in the CI group would relate to more frequent modification. The sample included 81 older adults (51 HEs; mean age 70.02 (7.34) and 30 CI; mean age 75.97 (8.12)). Compared to HEs, the CI group reported having more concern about, F(3,77) = 5.50, p = 0.02, and modifying a greater number of activities, F(3,77) = 5.02, p = 0.03. Medication management (30%) and completing taxes (33.3%) were among the most frequently modified activities for the CI and HE groups, respectively. In the CI group, higher memory awareness was associated with more concern (r = .53, p = .005) and activity modification (r = 0.55, p = .003). Findings provide novel information about how cognitively diverse older adults navigate complex activities in daily life. We propose a preliminary theoretical model by which self-awareness may influence navigation of everyday activities in the context of CI.

Trans-foraminal endoscopic uniportal decompression in degenerative lumbar spondylolisthesis: a technical and case report

Background

Degenerative spondylolisthesis is a common spinal pathology. Traditionally, spinal fusion is an accepted standard surgical treatment for listhesis. But fusion is a major intervention with its known pitfalls. With technological progression, minimally invasive spinal fusion (MISF) procedures are becoming mainstream. Percutaneous trans-foraminal endoscopic lumbar discectomy/decompressions (PTELD) without stabilization has many advantages over even a MISF for select group of patients.

Case presentation

In this case report, we describe using a uniportal unilateral trans-foraminal approach (TFA) for stable listhesis with lumbar disc herniation (LDH) causing chronic bilateral radicular symptoms and back pain with acute exacerbation. Under local anesthesia, we used a flat entry for PTELD, which facilitates an approach to both disc sides ventrally and even dorsal aspect lateral recess decompression on the dominant ipsilateral side. No fixation was done. An excellent outcome is obtained immediately at 6 weeks and maintained at 39 months of follow-up.

Conclusion

PTELD is worth considering as an intermediate procedure before fusion is offered in lateral recess stenosis in stable listhesis patients who have consented and understand the progressive cascade of spinal degeneration.

Cognitive training and neuroplasticity in mild cognitive impairment (COG-IT): protocol for a two-site, blinded, randomised, controlled treatment trial

INTRODUCTION

Mild cognitive impairment (MCI) is common in older adults and represents a high-risk group for progression to Alzheimer's disease (AD). Medication trials in MCI have generally failed, but new discoveries with brain plasticity in ageing have led to the study of cognitive training as a potential treatment to improve cognitive abilities. Computerised cognitive training (CCT) involves computerised cognitive exercises that target specific cognitive abilities and neural networks to potentially improve cognitive functioning through neuroplasticity.

METHODS AND ANALYSIS

In a two-site study (New York State Psychiatric Institute/Columbia University Medical Center and Duke University Medical Center), we will randomise 100 patients with MCI (Wechsler Memory Scale-III Logical Memory II score 0-11; Folstein Mini Mental State Examination ≥23) to home-based CCT (suite of exercises: memory, matching, spatial recognition, processing speed) or a home-based active control condition (computerised crossword puzzle training (CPT)) with 12 weeks of intensive training followed by regular booster sessions up to 78 weeks. All patients will receive standard neuropsychological and functional assessments in clinic as well as structural/functional brain MRI scans at study entry and endpoint. We will test if CCT, versus CPT, leads to improved cognitive functioning, transfers to functional ability and tasks of everyday life and impacts hippocampal volume changes and changes in the default mode network of the brain measured by resting-state functional MRI.

ETHICS AND DISSEMINATION

The study will be conducted following ethics approval and written informed consent will be obtained from all subjects. Study results will be disseminated via publication, clinicaltrials.gov, media and conference presentations. This will be the first controlled long-term trial to evaluate the effects of home-based CCT versus computerised CPT on cognitive abilities and functional measures and neural outcomes as determined by MRI indices in patients with MCI. Positive results from trial may support further development of home-based CCT.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier (NCT03205709).

A Link between Subjective Perceptions of Memory and Physical Function: Implications for Subjective Cognitive Decline

Subjective impairment in memory is a frequently defining feature of subjective cognitive decline (SCD), a state hypothesized to precede objectively apparent cognitive symptoms of Alzheimer's disease (AD) and to hold promise as a non-invasive, inexpensive, preclinical indicator of AD. However, a full model of the factors that contribute to subjective memory (SM), and therefore to SCD, has yet to be articulated. While SM impairment is widely known to be associated with negative affect, the extent to which SM functioning may also reflect other factors, particularly subjective beliefs or perceptions about one's health, is not known. To examine the extent to which SM is associated with subjective perceptions of health more broadly, the current study investigated the link between SM and subjective physical functioning (independent of depressive affect, and objective cognitive and physical function) in an ethnically diverse sample of 471 older adults enrolled in the population-based Northern Manhattan Aging Project. 199 (42%) participants endorsed no difficulty on a 5-point SM index while 272 (58%) endorsed some degree of difficulty. As hypothesized, SM correlated with both depression and subjective physical function, but not with age, education, global cognition, or objective physical function. When objective and subjective physical function were entered in two separate, adjusted linear regressions predicting SM, only subjective physical function and depressive affect independently predicted SM. Subjective perceptions of memory appear to reflect individuals' broader health perceptions in part. Articulating the various correlates of SM will improve identification of SCD specific to preclinical AD.

Comparing three methods of computerised cognitive training for older adults with subclinical cognitive decline

Cognitive rehabilitation for mild cognitive impairment (MCI) and early Alzheimer's disease is readily available to the geriatric population. Initial evidence suggests that techniques incorporating motivational strategies to enhance treatment engagement may provide more benefit than computerised training alone. Seventy four adults with subclinical cognitive decline were randomly assigned to computerised cognitive training (CCT), Cognitive Vitality Training (CVT), or an Active Control Group (ACG), and underwent neuropsychological evaluations at baseline and four-month follow-up. Significant differences were found in changes in performance on the Modified Mini Mental State Examination (mMMSE) and measures of verbal learning and memory across treatment groups. Experimental groups showed greater preservation of functioning on the mMMSE than the ACG group, the CVT group performed better than the ACG group on one measure of verbal learning and both measures of verbal memory, and the CCT group performed better than the ACG group on one measure of verbal learning and one measure of verbal memory. There were no significant group differences between the CVT and CCT groups on measures of verbal learning or memory. It was concluded that computerised cognitive training may offer the most benefit when incorporated into a therapeutic milieu rather than administered alone, although both appear superior to more generic forms of cognitive stimulation.

A randomized, prospective pilot study of patient expectancy and antidepressant outcome

BACKGROUND

This study is a randomized, prospective, investigation of the relationships between clinical trial design, patient expectancy and the outcome of treatment with antidepressant medication. Method Adult out-patients with major depressive disorder (MDD) were randomized to either placebo-controlled (PC, 50% probability of receiving active medication) or comparator (COMP, 100% probability of receiving active medication) administration of antidepressant medication. Independent-samples t tests and analysis of covariance (ANCOVA) were used to determine whether the probability of receiving active medication influenced patient expectancy and to compare medication response in the PC v. COMP conditions. We also tested the correlations between baseline expectancy score and final improvement in depressive symptoms across study groups.

RESULTS

Subjects randomized to the COMP condition reported greater expectancy of improvement compared to subjects in the PC condition (t = 2.60, df = 27, p = 0.015). There were no statistically significant differences in the analyses comparing antidepressant outcomes between subjects receiving medication in the COMP condition and those receiving medication in the PC condition. Higher baseline expectancy of improvement was correlated with lower final depression severity scores (r = 0.53, p = 0.021) and greater improvement in depressive symptoms over the course of the study (r = 0.44, p = 0.058).

CONCLUSIONS

The methods described represent a promising way of subjecting patient expectancy to scientific study. Expectancy of improvement is affected by the probability of receiving active antidepressant medication and seems to influence antidepressant response.

Nonlinear indices of circadian changes in individuals with dementia and aggression

Nonlinear analyses of actigraphy data were utilized to investigate circadian rest-activity system motor control in nursing-home residents with dementia and with/without aggressive behavior (AB). Significant differences observed between groups in measures of approximate entropy (ApEn) and fractal dimension (FD). ApEn and FD are sensitive to detecting and characterizing discrete changes in central motoric control and temporality of behaviors in dementia. Findings may inform understanding of clinical heterogeneity and possible physiologic sub-classifications of Alzheimer's dementia.

Antidepressant study design affects patient expectancy: a pilot study

BACKGROUND

Response to antidepressant medication is higher in comparator versus placebo-controlled randomized controlled trials (RCTs). Patient expectancy is an important influence on clinical outcome in the treatment of depression and may explain this finding. The results are reported from a pilot RCT studying expectancy and depression outcome in placebo-controlled versus comparator treatment conditions.MethodOut-patients aged 18-65 years with major depressive disorder (MDD) were enrolled in this 8-week RCT. Subjects were randomized to placebo-controlled (escitalopram or placebo) or comparator (escitalopram or citalopram) administration of antidepressant medication. Subjects reported their expected likelihood and magnitude of depression improvement before and after randomization using questions from the Credibility and Expectancy Scale (CES). A regressed change model of post-randomization expectancy of improvement was fit to the data to determine whether subjects in the comparator group reported greater expectancies of improvement than subjects in the placebo-controlled group.

RESULTS

Twenty subjects with mean age 56.5+/-11.7 years, a baseline Hamilton Depression Rating Scale (HAMD) score of 24.2+/-5.3, baseline Beck Depression Inventory (BDI) score of 24.9+/-6.4 and baseline Clinical Global Impressions (CGI) - Severity score of 4.0+/-0.3 were enrolled in the study. Adjusting for other factors, the effect of group assignment on expected magnitude of improvement was significant and large (effect size 1.5). No group differences in expected likelihood of improvement were found.

CONCLUSIONS

Randomization to comparator versus placebo-controlled administration of antidepressant medication produced greater expectancies of how much patients would improve during the trial. This expectancy difference may explain the higher response and remission rates that are observed in comparator versus placebo-controlled trials.

Voxel-based analysis of 11C-PIB scans for diagnosing Alzheimer's disease

The positron emission tomography (PET) radioligand N-methyl-11C-2-(4-methylaminophenyl)-6-hydroxybenzothiazole (also known as 11C-6-OH-BTA-1 or 11C-PIB) binds to amyloid-beta (Abeta), which accumulates pathologically in Alzheimer's disease (AD). Although 11C-PIB accumulation is greater in patients with AD than in healthy controls at a group level, the optimal method for discriminating between these 2 groups has, to our knowledge, not been established. We assessed the use of data-determined standardized voxels of interest (VOIs) to improve the classification capability of 11C-PIB scans on patients with AD.

METHODS

A total of 16 controls and 14 AD age-matched patients were recruited. All subjects underwent a 11C-PIB scan and structural MRI. Binding potential (a measure of amyloid burden) was calculated for each voxel using the Logan graphical method with cerebellar gray matter as the reference region. Voxel maps were then partial-volume corrected and spatially normalized by MRI onto a standardized template. The subjects were divided into 2 cohorts. The first cohort (control, 12; AD, 9) was used for statistical parametric mapping analysis and delineation of data-based VOIs. These VOIs were tested in the second cohort (control, 4; AD, 5) of subjects.

RESULTS

Statistical parametric mapping analysis revealed significant differences between control and AD groups. The VOI map determined from the first cohort resulted in complete separation between the control and the AD subjects in the second cohort (P < 0.02). Binding potential values based on this VOI were in the same range as other reported individual and mean cortical VOI results.

CONCLUSION

A standardized VOI template that is optimized for control or AD group discrimination provides excellent separation of control and AD subjects on the basis of 11C-PIB uptake. This VOI template can serve as a potential replacement for manual VOI delineation and can eventually be fully automated, facilitating potential use in a clinical setting. To facilitate independent analysis and validation with more and a broader variety of subjects, this VOI template and the software for processing will be made available through the Internet.

Screening of school children for blood lead levels and attempts to reduce them by nonpharmacological means in a coastal city of India

CONTEXT

Lead is a major health hazard, especially in children. Impact of lead poisoning on our society is not known. Effectiveness of environmental interventions in reducing blood lead levels is not exactly known, though the Center for Disease Control and Prevention strongly advocates use of such means.

AIMS

We aimed at screening school children for blood lead levels (BLLs) and reducing the BLLs of children with preliminary BLL> 20 microg/dL by environmental intervention and intensive education.

MATERIALS AND METHODS

To assess the extent of lead poisoning, a screening of 106 children was done, which showed that children belonging to a particular government primary school had higher BLLs. A second screening program of 87 children conducted in that school showed that only 19% had BLL < 10 microg/dL; whereas 44% had BLL between 10 and 20 microg/dL, and 37% had BLL> 20 microg/dL. Thirty-eight children having BLL> 20 microg/dL were selected from the two screening programs. After removing all potential sources of lead from their environment and educating them about the ways to prevent exposure to lead, follow-up of their BLLs was carried out at an interval of 6 months for a period of 1 year.

STATISTICAL ANALYSIS

Values of the different follow-up studies were compared using repeated-measure ANOVA.

RESULTS

Our results showed that there was a significant (P < 0.0001) reduction in the BLLs in the first and second follow-up studies.

CONCLUSIONS

The study is a proof of the concept that a decline in the BLLs can be achieved by intense education and avoiding the potential environmental sources of lead.

Disruptive behavior as a predictor in Alzheimer disease

BACKGROUND

Disruptive behavior is common in Alzheimer disease (AD). There are conflicting reports regarding its ability to predict cognitive decline, functional decline, institutionalization, and mortality.

OBJECTIVE

To examine whether the presence of disruptive behavior has predictive value for important outcomes in AD.

DESIGN

Using the Columbia University Scale for Psychopathology in Alzheimer Disease (administered every 6 months, for a total of 3438 visit-assessments and an average of 6.9 per patient), the presence of disruptive behavior (wandering, verbal outbursts, physical threats/violence, agitation/restlessness, and sundowning) was extracted and examined as a time-dependent predictor in Cox models. The models controlled for the recruitment cohort, recruitment center, informant status, sex, age, education, a comorbidity index, baseline cognitive and functional performance, and neuroleptic use.

SETTING

Five university-based AD centers in the United States and Europe (Predictors Study).

PARTICIPANTS

Four hundred ninety-seven patients with early-stage AD (mean Folstein Mini-Mental State Examination score, 20 of 30 at entry) who were recruited and who underwent semiannual follow-up for as long as 14 (mean, 4.4) years.

MAIN OUTCOME MEASURES

Cognitive (Columbia Mini-Mental State Examination score, < or = 20 of 57 [approximate Folstein Mini-Mental State Examination score, < or = 10 of 30]) and functional (Blessed Dementia Rating Scale score, parts I and II, > or = 10) ratings, institutionalization equivalent index, and death.

RESULTS

At least 1 disruptive behavioral symptom was noted in 48% of patients at baseline and in 83% at any evaluation. Their presence was associated with increased risks of cognitive decline (hazard ratio 1.45 [95% confidence interval (CI), 1.03-2.03]), functional decline (1.66 [95% CI, 1.17-2.36]), and institutionalization (1.47 [95% CI, 1.10-1.97]). Sundowning was associated with faster cognitive decline, wandering with faster functional decline and institutionalization, and agitation/restlessness with faster cognitive and functional decline. There was no association between disruptive behavior and mortality (hazard ratio, 0.94 [95% CI, 0.71-1.25]).

CONCLUSION

Disruptive behavior is very common in AD and predicts cognitive decline, functional decline, and institutionalization but not mortality.

Delusions and hallucinations are associated with worse outcome in Alzheimer disease

BACKGROUND

Delusions and hallucinations are common in Alzheimer disease (AD) and there are conflicting reports regarding their ability to predict cognitive decline, functional decline, and institutionalization. According to all previous literature, they are not associated with mortality.

OBJECTIVE

To examine whether the presence of delusions or hallucinations has predictive value for important outcomes in AD.

DESIGN, SETTING, AND PARTICIPANTS

A total of 456 patients with AD at early stages (mean Folstein Mini-Mental State Examination [MMSE] score of 21 of 30 at entry) were recruited and followed up semiannually for up to 14 years (mean, 4.5 years) in 5 university-based AD centers in the United States and Europe. Using the Columbia University Scale for Psychopathology in AD (administered every 6 months, for a total of 3266 visit-assessments, average of 7.2 per patient), the presence of delusions and hallucinations was extracted and examined as time-dependent predictors in Cox models. The models controlled for cohort effect, recruitment center, informant status, sex, age, education, a comorbidity index, baseline cognitive and baseline functional performance, behavioral symptoms, and use of neuroleptics and cholinesterase inhibitors.

MAIN OUTCOME MEASURES

Cognitive (Columbia MMSE score of < or =20/57 [approximate Folstein MMSE score of < or =10/30]), functional (Blessed Dementia Rating Scale [parts I and II] score of > or =10), institutionalization equivalent index, and death.

RESULTS

During the full course of follow-up, 38% of patients reached the cognitive, 41% the functional, 54% the institutionalization, and 49% the mortality end point. Delusions were noted for 34% of patients at baseline and 70% at any evaluation. Their presence was associated with increased risk for cognitive (risk ratio [RR], 1.50; 95% confidence interval [CI], 1.07-2.08) and functional decline (RR, 1.41; 95% CI, 1.02-1.94). Hallucinations were present in 7% of patients at initial visit and in 33% at any visit. Their presence was associated with increased risk for cognitive decline (RR, 1.62; 95% CI, 1.06-2.47), functional decline (RR, 2.25; 95% CI, 1.54-2.27), institutionalization (RR, 1.60; 95% CI, 1.13-2.28), and death (RR, 1.49; 95% CI, 1.03-2.14).

CONCLUSIONS

Delusions and hallucinations are very common in AD and predict cognitive and functional decline. Presence of hallucinations is also associated with institutionalization and mortality.

Longitudinal study of quality of life in people with advanced Alzheimer's disease

The authors examined three indicators of health-related quality of life in people with advanced Alzheimer's disease ([AD]; N=150): confinement to home, null activity, and null positive affect, as reported by patient proxies. Dementia severity predicted time-to-onset for all three disease milestones in models that controlled for sociodemographic indicators, nursing home status, and death in the follow-up period. Patients whose dementia worsened over follow-up were more likely to reach each milestone. These outcomes represent key milestones in the care of patients; they are sensitive to disease progression, and they are likely to be useful for studying treatment in advanced AD.

Depression: treating the patient with comorbid cardiac disease

Depressed patients develop symptomatic and fatal ischemic heart disease at a higher rate than nondepressed patients, even after studies are controlled for known cardiovascular risk factors. Changes in sympathetic and parasympathetic tone appear to make depressed patients more vulnerable to ventricular fibrillation. Tricyclic antidepressants share the electrophysiologic profile of type 1A antiarrhythmic compounds and therefore may carry a risk of increased mortality when given to patients with ischemic heart disease. Serotonin reuptake inhibitors have shown no antiarrhythmic effect in depressed patients with serious cardiovascular disease, but studies to date have been small and short-term.

Predicting time to nursing home care and death in individuals with Alzheimer disease

OBJECTIVE

To develop and validate an approach that uses clinical features that can be determined in a standard patient visit to estimate the length of time before an individual patient with Alzheimer disease (AD) requires care equivalent to nursing home placement or dies.

DESIGN

Prospective cohort study of 236 patients, followed up semiannually for up to 7 years. A second validation cohort of 105 patients was also followed.

SETTING

Three AD research centers.

PATIENTS

All patients met National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for probable AD and had mild dementia at the initial visit.

INTERVENTION

Predictive features, ascertained at the initial visit, were sex, duration of illness, age at onset, modified Mini-Mental State Examination (mMMS) score, and the presence or absence of extrapyramidal signs or psychotic features.

MAIN OUTCOME MEASURES

(1) Requiring the equivalent of nursing home placement and (2) death.

RESULTS

Prediction algorithms were constructed for the 2 outcomes based on Cox proportional hazard models. For each algorithm, a predictor index is calculated based on the status of each predictive feature at the initial visit. A table that specifies the number of months in which 25%, 50%, and 75% of patients with any specific predictor index value are likely to reach the end point is then consulted. Survival curves for time to need for care equivalent to nursing home placement and for time to death derived from the algorithms for selected predictor indexes fell within the 95% confidence bands of actual survival curves for patients. When the predictor variables from the initial visit for the validation cohort patients were entered into the algorithm, the predicted survival curves for time to death fell within the 95% confidence bands of actual survival curves for the patients.

CONCLUSIONS

The prediction algorithms are a first but promising step toward providing specific prognoses to patients, families, and practitioners. This approach also has clear implications for the design and interpretation of clinical trials in patients with AD.

Multicenter study of predictors of disease course in Alzheimer disease (the "predictors study"). II. Neurological, psychiatric, and demographic influences on baseline measures of disease severity

The "Predictors Study" is a prospective cohort study of the natural history of Alzheimer disease (AD), the aim of which is to identify milestones in disease progression and to develop a model to predict disease course in individual patients. The empirical background to this study is based on previous reports that the presence of extrapyramidal signs (EPS), myoclonus, and psychosis in AD may signify greater disease severity at any given stage and a more rapid course of the disease over time. The present analyses were conducted to determine whether these independent "predictor" variables were associated with greater disease severity at baseline within a new cohort of 224 mild AD patients recruited from three different medical centers (in New York, Baltimore, and Boston). Measures of disease severity were provided by the modified Mini-Mental State Examination (mMMSE) and the Blessed Dementia Rating Scale (BDRS), which measures functional capacity. Independent variables were EPS, delusions, and slowing of the posterior dominant EEG rhythm. The frequency of myoclonus and hallucinations was too low to permit adequate statistical assessment of their effects at this time. EPS and EEG slowing were associated with low mMMSE scores, whereas delusions were primarily associated with impaired functional capacity. These effects were independent of the influence of age and disease duration. These results indicate that the effects of these independent variables can be detected at mild stages of AD and that these effects can be generalized across different geographical regions.