Functional significance of mild cognitive impairment in elderly patients without a dementia diagnosis

The authors investigated differences in functional ability among three groups of subjects who were not diagnosed with dementia: normal control (NC) subjects (n=35); Clinical Dementia Rating Scale (CDRS) score of 0 (minimal impairment; n=26); and CDRS 0. 5 (questionable dementia; n=42). CDRS 0 and 0. 5 patients reported significantly poorer functioning than NCs in household and other activities, but CDRS 0 and CDRS 0. 5 groups did not differ in self-reported functioning. It is likely that CDRS 0. 5 patients overestimated their functional abilities. Correlations between self- and informant reports of functional status were significantly lower in the CDRS 0. 5 group than in the CDRS 0 group, an important finding for clinical management because patients with questionable dementia may actually be more impaired than they admit. Informants' reports or standardized performance-based assessment should be considered in the clinical evaluation of such patients.

Randomized trial of the platelet-activating factor antagonist lexipafant in HIV-associated cognitive impairment. Neurological AIDS Research Consortium

OBJECTIVE

To assess the safety and tolerability of lexipafant in HIV-associated cognitive impairment.

BACKGROUND

Cognitive impairment is the most common neurologic complication of advanced HIV-1 infection. There is evidence that a variety of inflammatory mediators, including platelet-activating factor (PAF), may contribute to neuronal injury. We hypothesized that lexipafant, a PAF antagonist, might improve cognitive dysfunction in HIV-infected people.

METHODS

We conducted a randomized, double-blind, placebo-controlled clinical trial to assess the safety and tolerability of lexipafant 500 mg/day. The primary outcome measure for tolerability was the ability to complete the study on the originally assigned dosage of medication. Thirty patients with cognitive impairment were enrolled.

RESULTS

Lexipafant was safe and well tolerated. Ninety-three percent in the placebo group and 88% in the lexipafant group completed the study at the originally assigned dosage. Trends toward improvement were seen in neuropsychological performance, especially verbal memory, in the lexipafant treatment group.

CONCLUSIONS

This study shows that lexipafant, the first PAF antagonist used in HIV-associated cognitive impairment, is a safe and well tolerated compound. The observed trends toward improvement in neuropsychological test scores warrant the pursuit of a larger and longer efficacy trial to assess the impact of lexipafant on cognitive performance.

Assessment of cognition in advanced AD: The test for severe impairment

Article abstract The Test for Severe Impairment (TSI) was compared with the Mini-Mental State Examination (MMSE) and a modified MMSE (mMMSE) in a multisite, longitudinal study of AD. The TSI correlated highly with the MMSE (r = 0.83) and the mMMSE (r = 0.82), but was not redundant. There was a wide range of scores on the TSI among those scoring in the severely impaired range on the MMSE and mMMSE. The slope of cognitive change over time detected by the TSI was greater than that revealed by the MMSE or the mMMSE. Performance on the TSI was a significant predictor of survival. The TSI is a valid measure that is sensitive to cognitive change over time in severely demented patients with AD.

Longitudinal changes in sexual risk behavior among HIV+ and HIV- male injecting drug users

Injecting drug users (IDUs) play a prominent role in the transmission of human immunodeficiency virus (HIV), particularly in urban areas such as New York City, where they comprise nearly half of all adult acquired immunodeficiency syndrome (AIDS) cases. Intervention studies have demonstrated that IDUs are responsive to safer sex messages, but sexual behavior appears to be more resistant to change than drug use behavior. This multidisciplinary study (without an intervention component) assesses changes in sexual risk behavior as a function of time, HIV status, and disease progression in a cohort of HIV+ and HIV- male IDUs (N = 144) for 4 years.

RESULTS

For HIV+ and HIV- men, there were increases in abstinence and monogamy, with decreases in the frequency of unprotected vaginal/anal sex and sexual risk index scores. With the exception of monogamy, HIV+ men reported lower levels of risk. Although there was also a decline in substance use, this accounted for only some of the decline in sexual risk behavior. Among the HIV+ men, a CD4 level below 200 was associated with more abstinence and monogamy. HIV-related medical symptoms were associated with increased abstinence, less unprotected sex, and lower sexual risk index scores. Lower neuropsychological memory test scores were associated with increased abstinence and lower sexual risk index scores. Neurological impairment and depression were not associated with sexual risk behavior.

CONCLUSION

IDU men in New York City have modified their sexual behavior toward safer practices. Lower levels of risk are found among HIV+ men, particularly those with more progressed HIV illness. Nevertheless, a substantial amount of sexual risk behavior remained in this cohort, indicating the continued need for education and intervention.

Risk of Alzheimer's disease in relatives of Parkinson's disease patients with and without dementia

OBJECTIVE

To determine whether first-degree relatives of PD patients with dementia were at increased risk for the development of AD compared with first-degree relatives of nondemented PD patients and nondemented normal subjects from the community.

METHODS

A structured family history interview was administered to 146 nondemented PD patients, 120 patients with PD and dementia, and 903 normal subjects from the community to ascertain the presence of AD among parents and siblings of these subjects. Cox proportional hazards models with double censoring techniques for missing information were used to model the risk of AD among relatives.

RESULTS

No increase in risk of AD was found among parents of patients with PD and dementia or parents of nondemented PD patients compared with parents of normal subjects. However, siblings of demented PD patients were three times as likely (relative risk [RR] = 3.2, 95% confidence interval [CI] = 1.1 to 9.4, p < 0.04) as siblings of normal subjects to develop AD. When only siblings >65 years of age were considered, there was a fivefold increase in risk of AD among siblings of demented PD patients compared with siblings of normal subjects (RR = 4.9, 95% CI = 1.1 to 21.4, p < 0.03). The risk of AD was also increased for female relatives, regardless of whether the woman was a relative of a demented PD patient, a nondemented PD patient, or a normal subject. Ethnicity and APOE genotype did not affect dementia status among relatives.

CONCLUSIONS

The increased risk of AD in siblings of demented PD patients compared with siblings of normal subjects supports the possibility of familial aggregation of AD and PD with dementia.

Progression of parkinsonian signs in Parkinson disease

BACKGROUND

Current knowledge about the rate of progression of extrapyramidal signs (EPSs) in Parkinson disease (PD) is derived largely from cross-sectional studies comparing subjects at various stages of illness rather than longitudinal studies in which the subjects were followed up over time.

OBJECTIVE

To longitudinally study the progression of EPSs in PD by quantifying the rate of change of EPSs and by examining each EPS (rigidity, bradykinesia, tremor, and postural instability) separately.

METHODS

A community-based cohort of 237 patients with PD living in Washington Heights-Inwood in Manhattan, NY, was evaluated at baseline and at yearly intervals. The EPSs were rated using the motor portion of the Unified Parkinson's Disease Rating Scale Motor Examination. Analyses of longitudinal data were performed by applying generalized estimating equations to regression analyses.

RESULTS

The total EPS score increased at an annual rate of 1.5 points (1.5%), but, among those who died, the total EPS score increased at an annual rate of 3.6 points (3.6%). Bradykinesia, rigidity, and gait and balance subscores worsened at similar annual rates of 2.0% to 3.1%, whereas the tremor subscore did not clearly worsen with time. Patients with a shorter disease duration (< or =3 years) may have progressed more rapidly than patients with longer disease duration (annual rate of change, 1.9% vs 1.4%, respectively), although this did not reach statistical significance. A high total EPS score was independently associated with dementia, low Activities of Daily Living score, and long disease duration at baseline.

CONCLUSIONS

In this cohort, the progression of EPSs in PD occurred at a rate of 1.5% per year and at twice that rate among those who died. Bradykinesia, rigidity, and gait and balance impairment worsened at similar rates, whereas tremor did not, suggesting that tremor may be relatively independent of these other cardinal manifestations of PD.

Dystonia in Huntington's disease: prevalence and clinical characteristics

BACKGROUND

The prevalence and clinical characteristics of dystonia in Huntington's disease (HD) have not been formally assessed.

OBJECTIVES

To study (1) the prevalence of dystonia in HD in a clinic population, (2) the clinical features of dystonia, and (3) clinical correlates of dystonia (for example, age, disease duration).

METHODS

Patients with HD attending the HD Center at the New York State Psychiatric Center were administered the Unified HD Rating Scale and underwent a standardized 5.5-minute videotaped examination. Two neurologists reviewed the videotaped examination and rated the severity and constancy of dystonia, calculating a total dystonia score for each patient.

RESULTS

Prevalence of dystonia of any severity was 95.2%. Twenty-four of 42 (57.1%) had dystonia in at least one body region that was moderate and present more than half of the time, and seven of 42 (16.7%) had dystonia that was severe and constant. The most prevalent types of dystonia were internal shoulder rotation (64.3%), sustained fist clenching (47.1%), excessive knee flexion (42.9%), and foot inversion (42.9%). In 37 of 42 (88.1%) patients, there were more than two types of dystonia, and in the average patient, three to four types of dystonia. The mean severity was between 1 (mild) and 2 (moderate), and the mean constancy was between 2 (present less than half of the time) and 3 (present more than half of the time). Multivariate linear regression revealed that disease duration (p = 0.0005) and taking an antidopaminergic agent (p = 0.03) were positively associated with the total dystonia score.

CONCLUSIONS

The majority of patients in this HD clinic exhibited some dystonia. The dystonia was present in several body regions and manifested by a variety of movements and postures not typical of idiopathic torsion dystonia. The dystonia was not bothersome to most patients, and its severity was a function of disease duration and use of an antidopaminergic agent.

A randomized, placebo-controlled dose-comparison trial of haloperidol for psychosis and disruptive behaviors in Alzheimer's disease

OBJECTIVE

The goal of this study was to compare the efficacy and side effects of two doses of haloperidol and placebo in the treatment of psychosis and disruptive behaviors in patients with Alzheimer's disease.

METHOD

In a 6-week random-assignment, double-blind, placebo-controlled trial (phase A), haloperidol, 2-3 mg/day (standard dose), and haloperidol, 0.50-0.75 mg/day (low dose), were compared in 71 outpatients with Alzheimer's disease. For the subsequent 6-week double-blind crossover phase (phase B), patients taking standard- or low-dose haloperidol were switched to placebo, and patients taking placebo were randomly assigned to standard- or low-dose haloperidol.

RESULTS

For the 60 patients who completed phase A, standard-dose haloperidol was efficacious and superior to both low-dose haloperidol and placebo for scores on the Brief Psychiatric Rating Scale psychosis factor and on psychomotor agitation. Response rates according to three sets of criteria were greater with the standard dose (55%-60%) than the low dose (25%-35%) and placebo (25%-30%). The advantage of standard dose over low dose was replicated in phase B. In phase A, extrapyramidal signs tended to be greater with the standard dose than in the other two conditions, primarily because of a subgroup (20%) who developed moderate to severe signs. Low-dose haloperidol did not differ from placebo on any measure of efficacy or side effects.

CONCLUSIONS

The results indicated a favorable therapeutic profile for haloperidol in doses of 2-3 mg/day, although a subgroup developed moderate to severe extrapyramidal signs. A starting dose of 1 mg/day with gradual, upward dose titration is recommended. The narrow therapeutic window observed with haloperidol may also apply to other neuroleptics used in Alzheimer's disease patients with psychosis and disruptive behaviors.

Sexual risk behavior changes among HIV+ and HIV-female injecting drug users over 4 years

This paper examines the sexual risk behavior of female injecting drug users who participated in a 4 year longitudinal study. Both HIV+ and HIV- women showed increases in monogamy, decreases in the frequency of unprotected vaginal/anal sex, and decreases in a risk index score throughout the study. HIV+ women had fewer occasions of unprotected sex than HIV-. However, a substantial proportion of the sample continued to engage in unprotected sex. Among the HIV+ women, depressed mood was significantly related to abstinence and to fewer occasions of unprotected sex, but CD4, medical symptoms, neurological impairment, and memory test performance were not associated with sexual risk behavior.

Characterization of the human mitochondrial aconitase gene (ACO2)

We have cloned and characterized the ACO2 gene on human chromosome 22q13, which encodes the essential iron-dependent metabolic enzyme mitochondrial aconitase. We determined that the ACO2 gene comprises 18 translated exons distributed over approximately 35 kilobasepairs (kbp) of DNA. We have shown that the ACO2 mRNA is 2.7kb in length and is expressed ubiquitously, and we can detect multiple isoforms of the ACO2 protein. As others had reported the existence of biochemically active electrophoretic variants of mitochondrial aconitase, we wished to find common ACO2 gene allozymes, functional polymorphisms that might be associated with susceptibility to human genetic diseases. We looked for ACO2 allozymes by DNA sequencing and genotyping in a population of 217 subjects, many of which had idiopathic Parkinson's disease (IPD). We studied patients with IPD because this movement disorder is thought to arise from defects in neuronal iron and energy metabolism, two properties with which aconitase is involved. Furthermore, reports of associations between alleles of the CYP2D6 locus (nearby on 22q13) and IPD, although inconsistent, indicated that an IPD susceptibility locus might be in strong linkage disequilibrium with CYP2D6. We found three functionally silent single nucleotide polymorphisms (SNPs) present in transcribed sequences that exist in similar frequencies in IPD patients and healthy controls. These ACO2 SNPs are in linkage disequilibrium with each other, providing evidence for distinct ACO2 haplotypes. We have, as yet, not detected polymorphisms that would lead to ACO2 allozymes, nor have we observed differences in ACO2 isoform prevalence or distribution in our population of IPD patients and controls. We conclude it is unlikely that polymorphism in the ACO2 gene or post-translational modification of the enzyme predispose to IPD.

Dietary iron, animal fats, and risk of Parkinson's disease

BACKGROUND

Recent studies have proposed a role for diet in Parkinson's disease (PD). PD is characterized by a high deposition of iron and a low concentration of ferritin in the substantia nigra. Few data in the literature are available on the possible role of dietary iron in the development of PD.

METHODS

In a population-based, case-control study, we addressed the hypothesis that high dietary iron intake was associated with PD. We assessed dietary iron intake with a semiquantitative food-frequency questionnaire in 104 PD patients and 352 control subjects, frequency matched for age and gender. We also studied the association of PD and dietary iron and animal fat intake in the presence of different iron stores measured by transferrin saturation.

RESULTS

No significant differences were observed between patients' and control subjects' dietary intake of iron from food or supplements (odds ratio [OR] for the highest quartile of intake, 0.9; 95% confidence interval [95% CI], 0.6, 1.3; p for trend = 0.60). Among those with low transferrin saturation levels (lower 50%), the odds ratio for PD associated with animal fat intake was ninefold higher than the risk of those with low intake (OR, 9.0; 95% CI, 2.7-29.9). Among those with high transferrin saturation, risk of PD was two times higher (relative risk, 1.9; 95% CI, 0.5-7.2) for those who reported high intake of animal fat compared with those who reported low intake.

CONCLUSION

Dietary iron intake after caloric adjustment was not associated with an increased risk of PD. However, the previously described association between animal fat intake and PD was modified by iron level stores as measured by transferrin saturation. These observations suggest that dietary fat and a systemic defect in iron metabolism may act synergistically in the process of lipid peroxidation in PD.

Prospective comparative study of the evolution of probable Alzheimer's disease and Parkinson's disease dementia

No previous comparison of test performance in probable Alzheimer's disease (pAD) and Parkinson's disease (PD) dementia has provided information about potential differences in the dementing process. This study compared the evolution of cognitive changes associated with these dementias. Generalized estimating equations (GEE) applied to regression analyses with repeated measures were used to evaluate cognitive changes over 1 to 3 years prior to the point when dementia was diagnosed in 40 matched pairs of patients with incident pAD and PD dementia. Both groups' performance declined on the Short Blessed, Selective Reminding Test (SRT; total recall, long-term retrieval, and delayed recall), Boston Naming Test, Category Fluency, and Similarities. The decline on naming and SRT delayed recall was more rapid in the PD dementia group, suggesting that these performance deficits emerge earlier in the development of pAD. The PD dementia group performed worse on Category Fluency throughout the follow-up period, suggesting either that dementia is overlaid on this preexisting performance deficit or that this type of executive deficit is an early manifestation of dementia in PD. The pAD group performed more poorly throughout the follow-up period on SRT delayed recognition, consistent with a pAD-specific encoding deficit. We conclude that while pAD and PD dementia are similar in many respects, differences in their evolution support previous observation of unique features in the 2 dementias and suggest different underlying pathologies.

Systemic iron metabolism and mortality from Parkinson's disease

Six measures of systemic iron metabolism were used to predict mortality among 103 patients with Parkinson's disease and 353 controls followed in a longitudinal study. Adjusting for gender, education, ethnicity, presence of dementia, and extrapyramidal signs, transferrin receptor concentration was strongly associated with mortality in patients with PD but not controls. This increase in serum transferrin receptor concentration before death suggests that the previously observed perturbation in iron metabolism continues throughout the disease course.

Postmenopausal estrogen use and Parkinson's disease with and without dementia

We investigated the effects of estrogen replacement therapy (ERT) on the risk of development of dementia in 87 women with Parkinson's disease without dementia (PDND), 80 women with Parkinson's disease with dementia (PDD), and 989 nondemented healthy women from the same community. ERT was protective for the development of dementia within the setting of PD (OR 0.22, 95% CI 0.05-1.0) and when PDD patients were compared with controls (OR 0.24, 95% CI 0.07-0.78), but did not affect the risk of PD. The results of the study suggest that a randomized clinical trial of ERT may be warranted.

The APOE-epsilon4 allele and the risk of Alzheimer disease among African Americans, whites, and Hispanics

CONTEXT

Although the association between Alzheimer disease (AD) and the apolipoprotein E epsilon4 (APOE-epsilon4) allele has been confirmed worldwide, it appears to be inconsistent among African Americans, Hispanics, and Nigerians.

OBJECTIVE

To investigate the association between the APOE-epsilon4 allele and AD in elderly African Americans, Hispanics, and whites.

DESIGN

Prospective, population-based, longitudinal study over a 5-year period (1991-1996).

SETTING

The Washington Heights-Inwood community of New York City.

PARTICIPANTS

A total of 1079 Medicare recipients without AD or a related disorder at baseline.

MAIN OUTCOME MEASURES

Risk of clinically diagnosed AD in the 3 ethnic groups and among individuals with and without an APOE-epsilon4 allele.

RESULTS

Compared with individuals with the APOE-epsilon3/epsilon3 genotype, the relative risk (RR) of AD associated with 1 or more copies of the APOE-epsilon4 allele was significantly increased among whites (RR, 2.5; 95% confidence interval [CI], 1.1-6.4), but not among African Americans (RR, 1.0; 95% CI, 0.6-1.6) or Hispanics (RR, 1.1; 95% CI, 0.7-1.6). In the absence of the APOE-epsilon4 allele, the cumulative risks of AD to age 90 years, adjusted for education and sex, were 4 times higher for African Americans (RR, 4.4; 95% CI, 2.3-8.6) and 2 times higher for Hispanics (RR, 2.3; 95% CI, 1.2-4.3) than for whites. In the presence of an APOE-epsilon4 allele, the cumulative risk of AD to age 90 years was similar for individuals in all 3 ethnic groups.

CONCLUSION

The presence of an APOE-epsilon4 allele is a determinant of AD risk in whites, but African Americans and Hispanics have an increased frequency of AD regardless of their APOE genotype. These results suggest that other genes or risk factors may contribute to the increased risk of AD in African Americans and Hispanics.

Cognitive function in nondemented older women who took estrogen after menopause

Investigations of the effects of estrogen replacement on cognitive function in healthy older women have yielded disparate results. We evaluated the relationship between a history of estrogen use and cognitive test performance in 727 women participating in a large community-based study. Participants were followed longitudinally for an average of 2.5 years. Estrogen use history was obtained at baseline. Standardized tests of memory, language, and abstract reasoning were administered at baseline and at follow-up. Results indicate that women who had used estrogen replacement scored significantly higher on cognitive testing at baseline than nonusers, and their performance on verbal memory improved slightly over time. The effect of estrogen on cognition was independent of age, education, ethnicity, and APOE genotype. Results suggest that estrogen replacement therapy may help to maintain cognitive function in nondemented postmenopausal women.

Environmental risk factors for Parkinson's disease in an urban multiethnic community

Environmental risk factors were examined using univariate and multivariate unconditional logistic regression models in 89 nondemented patients with Parkinson's disease (PD) and 188 control subjects in a multiethnic urban community. Rural living, area farming, and drinking well water were associated with PD only in African-Americans. In Hispanics, area farming was protective, whereas drinking unfiltered water was a risk factor for PD. Consideration of ethnic and cultural origin may add to the epidemiologic study of PD.

Altered systemic iron metabolism in Parkinson's disease

Iron deposition in the substantia nigra in Parkinson's disease has been associated with an increase in lactoferrin receptors and a reduction in ferritin concentration. This accumulation of iron in the brain may accelerate free radical formation, lipid peroxidation, and neuronal death. Remarkably, there are few data available concerning systemic iron metabolism in Parkinson's disease. We measured total iron binding capacity and circulating iron, ferritin, transferrin, and transferrin receptors; calculated transferrin saturation; and estimated dietary iron intake in patients with idiopathic Parkinson's disease and in controls. Concentrations of circulating iron, ferritin, and transferrin as well as total iron binding capacity and transferrin saturation were significantly lower in patients than controls. There were no differences in transferrin receptors or dietary intake of iron. The decrease in levels of systemic ferritin and transferrin and the total iron binding capacity parallels observations in a Parkinson's disease brain, but the reductions in serum iron concentrations and transferrin saturation do not, and were unexpected. These results suggest the existence of a defect in the systems that regulate the synthesis of the major proteins of iron metabolism in the liver as well as the brain in Parkinson's disease that may, over time, expedite entry of iron into the brain and decrease iron in the extracellular compartment.

Participation in clinical trials and long-term outcomes in Alzheimer's disease

The objective of this study was to determine whether participation in clinical trials affects long-term outcomes in Alzheimer's disease (AD). Participation in clinical trials for persons with dementia is often justified on the grounds that patients benefit from the medical oversight typical of trials, even when experimental agents do not demonstrate short-term benefits. This claim has not been rigorously assessed. Of 215 community-resident subjects enrolled in a prospective study of outcomes in AD, 101 participated in randomized clinical trials (RCTs) during the first 2 years of follow-up. These subjects were compared with subjects who met eligibility requirements for RCTs but did not participate (N = 57) and with subjects who were ineligible (N = 57), over a total of 3.5 years of follow-up. Survival analyses assessed risk of death, nursing home placement, and incident functional deficit end points, adjusting for baseline differences. Subjects who participated in RCTs were younger and more highly educated. Mortality, risk of hospitalization, number of medical examinations conducted by study physicians, and onset of severe functional deficit did not differ between the groups, but risk of nursing home admission was significantly lower among RCT participants compared with eligible nonparticipants and ineligible subjects (16.8% versus 36.8% and 31.6%, respectively [p = 0.01]). The difference in risk of nursing home placement may represent a long-term, drug-related benefit to patients, a selection effect (caregivers of patients who participate in RCTs differ from caregivers of patients who do not), or a positive effect on caregivers (greater contact with a medical service may be associated with better care-giving outcomes). Further research is required to assess these effects.

The validity of new memory complaints in the elderly

OBJECTIVE

To determine the validity of new subjective memory complaints (MCs) from individuals who previously, when without dementia, denied having MCs.

DESIGN

Prospective cohort.

SETTING

Longitudinal, community-based study of aging and dementia.

PATIENTS

One hundred thirty-three community-dwelling elderly individuals who were part of a registry for the study of conditions related to aging in North Manhattan, NY. Patients were selected if they were initially without dementia and had completed at least 2 successive annual clinical and neuropsychological evaluations and provided their own medical history.

MAIN OUTCOME MEASURES

Performance on memory tests--the Buschke Selective Reminding Test and a visual memory task--and global performance on a neuropsychological test battery and clinical evaluation, by which questionable dementia or dementia was diagnosed according to a well-defined paradigm.

RESULTS

Fifty-three subjects with MCs at the initial evaluation performed no worse on the memory test than the 80 subjects who denied MCs initially. There was a weak association between MCs and the diagnosis of questionable dementia at baseline (P = .04), but this was nonsignificant after adjusting for age and education. At 1-year follow-up, 21 of the 80 without baseline MCs now reported MCs. At the follow-up evaluation, these 21 subjects performed significantly worse on the memory tests, were 5 times more likely to have significant cognitive impairment, and had shown significantly greater decline over the preceding year on several of the cognitive measures than the 59 who continued to deny MCs.

CONCLUSION

New MCs from individuals, who when without dementia recently denied MCs, may suggest the presence of significant impairment of memory or cognition.

Is there a genetic susceptibility locus for Parkinson's disease on chromosome 22q13?

The cytochrome P450 mono-oxygenase gene, CYP2D6 on chromosome 22q13 (ch22q13), has been inconsistently associated with Parkinson's disease. Associations with CYP2D6 have either been absent altogether or have involved more than one polymorphism, many of which have the same metabolic effect on gene expression. We examined the association between CYP2D6 polymorphisms and Parkinson's disease in a case-control study and included 10 polymorphic dinucleotide repeat markers linked to CYP2D6 to determine whether the association was present or due to linkage disequilibrium. There was no association between any polymorphism of CYP2D6 and Parkinson's disease, but two of 10 dinucleotide repeat markers linked to CYP2D6 were associated with the disease. These results provide evidence to suggest that there may be an unidentified locus for susceptibility to Parkinson's disease that is in linkage disequilibrium with dinucleotide repeat markers mapping near CYP2D6 on ch22q13.

The absence of an apolipoprotein epsilon4 allele is associated with a more aggressive form of Alzheimer's disease

We investigated the relationship between APOE genotype and rate of disease progression and survival in 99 patients with probable Alzheimer's disease (AD) who were followed biannually for up to 6 years. Patients were stratified into two groups, those with and without at least one APOE epsilon4 allele. The rate of decline in modified Mini-Mental State Examination scores was slower, the presence of extrapyramidal signs was decreased, and the development of myoclonus occurred later among patients with APOE epsilon4 alleles compared with patients with other genotypes. Compared with patients without an APOE epsilon4 allele, the risk of mortality was also decreased in patients with at least one epsilon4 allele (RR = 0.38; CI = 0.17-0.84, p < 0.02). Because the decline in mental ability as well as the development of myoclonus and extrapyramidal signs are consistent manifestations of disease progression, our results imply that APOE epsilon4 is associated with a less aggressive form of AD.

Association of subjective memory complaints with subsequent cognitive decline in community-dwelling elderly individuals with baseline cognitive impairment

OBJECTIVE

The validity of subjective memory complaints has been questioned by clinical studies that have shown little relationship between memory complaints and objective memory performance. These studies often have been cross-sectional in design, have excluded individuals with cognitive impairment, or have lacked a comparison group. The authors conducted a study that attempted to avoid these limitations.

METHOD

Memory complaints of 364 nondemented, community-dwelling elderly individuals were recorded as present or absent at the baseline evaluation. After 1 year, 169 subjects were reevaluated. Standardized neurologic and neuropsychological evaluations were used at each assessment to classify subjects as normal or cognitively impaired.

RESULTS

At baseline, 31% of the normal subjects and 47% of those with cognitive impairment had memory complaints. Subjects with memory complaints had higher Hamilton depression scale scores than subjects without memory complaints but equivalent scores on a measure of total recall. At follow-up, multivariate analyses showed that subjects with baseline memory complaints had significantly greater decline in memory and cognition than subjects without memory complaints. Secondary analyses showed this effect to be confined to subjects with baseline cognitive impairment.

CONCLUSIONS

Memory complaints may lack validity in subjects with normal cognition, but in nondemented individuals with cognitive impairment, memory complaints may predict subsequent cognitive decline.

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.

The course of psychopathologic features in mild to moderate Alzheimer disease

BACKGROUND

The onset and course of the psychopathologic features of Alzheimer disease have not been established in prospective, longitudinal studies.

METHODS

Two hundred thirty-five patients with early, probable Alzheimer disease were recruited at 3 sites and observed naturalistically for up to 5 years. At 6-month intervals, the Columbia University Scale for Psychopathology in Alzheimer's Disease was administered. Markov analyses were used to predict the probability of a specific symptom developing or being maintained at the next visit. For each symptom category, the maximum frequency of occurrence at 4 consecutive points (duration, 2 years) was calculated.

RESULTS

Misidentification, wandering or agitation, and physical aggression increased during follow-up. At any visit, the likelihood of a new symptom developing was greatest for behavioral disturbance, intermediate for paranoid delusions and hallucinations, and least for depressed mood with vegetative features. Wandering or agitation occurred at 3 or more of 4 consecutive visits (duration, 2 years) in the majority of patients, paranoid delusions and hallucinations were intermediate in their degree of persistence, and depressed mood with vegetative signs rarely persisted.

CONCLUSIONS

Behavioral disturbance, particularly agitation, is common and persistent in patients with Alzheimer disease. Psychotic symptoms are less common and show moderate persistence over time. Depressed mood with vegetative signs is uncommon and rarely persists. These findings suggest leads about the optimal treatment duration for specific subtypes of psychopathologic features.