Vascular retinal biomarkers improves the detection of the likely cerebral amyloid status from hyperspectral retinal images

Introduction

This study investigates the relationship between retinal image features and β-amyloid (Aβ) burden in the brain with the aim of developing a noninvasive method to predict the deposition of Aβ in the brain of patients with Alzheimer's disease.

Methods

Retinal images from 20 cognitively impaired and 26 cognitively unimpaired cases were acquired (3 images per subject) using a hyperspectral retinal camera. The cerebral amyloid status was determined from binary reads by a panel of 3 expert raters on ¹⁸F-florbetaben positron-emission tomography (PET) studies. Image features from the hyperspectral retinal images were calculated, including vessels tortuosity and diameter and spatial-spectral texture measures in different retinal anatomical regions.

Results

Retinal venules of amyloid-positive subjects (Aβ+) showed a higher mean tortuosity compared with the amyloid-negative (Aβ−) subjects. Arteriolar diameter of Aβ+ subjects was found to be higher than the Aβ− subjects in a zone adjacent to the optical nerve head. Furthermore, a significant difference between texture measures built over retinal arterioles and their adjacent regions were observed in Aβ+ subjects when compared with the Aβ−. A classifier was trained to automatically discriminate subjects combining the extracted features. The classifier could discern Aβ+ subjects from Aβ− subjects with an accuracy of 85%.

Discussion

Significant differences in texture measures were observed in the spectral range 450 to 550 nm which is known as the spectral region known to be affected by scattering from amyloid aggregates in the retina. This study suggests that the inclusion of metrics related to the retinal vasculature and tissue-related textures extracted from vessels and surrounding regions could improve the discrimination performance of the cerebral amyloid status.

Winter irruptive Snowy Owls (Bubo scandiacus) in North America are not starving

Winter irruptions, defined as irregular massive movement of individuals over large distances, have been linked to food supply. Two hypotheses have been put forward: the “lack-of-food” suggests that a shortage of food forces individuals to leave their regular winter range and the “breeding output” suggests that unusually large food supplies during the preceding breeding season allows production of a large number of offspring dispersing in winter. According to the breeding output hypothesis, irruptive Snowy Owls (Bubo scandiacus (Linnaeus, 1758)) in eastern North America should not exhibit a lower body condition than individuals in regular wintering regions and individuals on the breeding grounds. Additionally, body condition of irruptive individuals should be unrelated to irruption intensity. Although body condition of juveniles was generally lower than that of adults and improved during the winter, we measured a fair body condition in both juvenile and adult irruptive Snowy Owls across North America. The results showed that Snowy Owls are not in a starving state during winter and that body condition of all age classes was not related to winter irruption intensity. Those results support the breeding output hypothesis suggesting that winter irruptions seem to be primarily the result of a large number of offspring produced when food availability on the breeding grounds is high.

Autonomous microfluidic capillaric circuits replicated from 3D-printed molds

We recently developed capillaric circuits (CCs) - advanced capillary microfluidic devices assembled from capillary fluidic elements in a modular manner similar to the design of electric circuits (Safavieh & Juncker, Lab Chip, 2013, 13, 4180-4189). CCs choreograph liquid delivery operations according to pre-programmed capillary pressure differences with minimal user intervention. CCs were thought to require high-precision micron-scale features manufactured by conventional photolithography, which is slow and expensive. Here we present CCs manufactured rapidly and inexpensively using 3D-printed molds. Molds for CCs were fabricated with a benchtop 3D-printer, poly(dimethylsiloxane) replicas were made, and fluidic functionality was verified with aqueous solutions. We established design rules for CCs by a combination of modelling and experimentation. The functionality and reliability of trigger valves - an essential fluidic element that stops one liquid until flow is triggered by a second liquid - was tested for different geometries and different solutions. Trigger valves with geometries up to 80-fold larger than cleanroom-fabricated ones were found to function reliably. We designed retention burst valves that encode sequential liquid delivery using capillary pressure differences encoded by systematically varied heights and widths. Using an electrical circuit analogue of the CC, we established design rules to ensure strictly sequential liquid delivery. CCs autonomously delivered eight liquids in a pre-determined sequence in <7 min. Taken together, our results demonstrate that 3D-printing lowers the bar for other researchers to access capillary microfluidic valves and CCs for autonomous liquid delivery with applications in diagnostics, research and education.

Real-life effectiveness and tolerability of the rivastigmine transdermal patch in patients with mild-to-moderate Alzheimer's disease: the EMBRACE study

OBJECTIVE

To assess the real-life effectiveness and tolerability of the rivastigmine transdermal patch in patients with mild-to-moderate Alzheimer's disease (AD) in Canada.

RESEARCH DESIGN AND METHODS

Eighteen-month observational, prospective, multi-center, open-label study conducted on AD patients with Standardized Mini-Mental State Examination (SMMSE) score of 10-26 and Global Deterioration Scale (GDS) score of 4-6. Patients were treated with the rivastigmine transdermal patch (Exelon patch*) 5 cm² (4.6 mg/24 hours) or 10 cm² (9.5 mg/24 hours), once daily.

MAIN OUTCOME MEASURES

Primary outcome was change in SMMSE from baseline to 18 months. Secondary outcomes included change in SMMSE at 6 and 12 months and change in GDS, Assessment of Patient Ability (APA-C), Overall Patient Assessment Rating (OPAR), caregiver-reported compliance and treatment satisfaction at 6, 12, and 18 months.

RESULTS

Among the 1204 patients enrolled, 969 were included in the ITT analysis. Mean (SD) age was 80.2 (8.00) years, disease duration was 0.6 (1.26) years, 62.0% of patients were women, 80.4% were living in the community, and 69.3% were treatment naïve. Mean (SD) baseline SMMSE and GDS scores were 21.8 (3.98) and 4.2 (0.61), respectively. Over 18 months of treatment there were no clinically significant changes in SMMSE and GDS. The majority of patients showed improvement or no change in GDS, APA-C and OPAR over 18 months. The proportion with reported improvement in GDS, APA-C and OPAR was higher than the proportion that deteriorated. Compliance improved from baseline to 18 months and for 88.2% of patients caregivers preferred the transdermal patch to oral medications.

CONCLUSIONS

The rivastigmine transdermal patch is effective in maintaining cognitive function over 18 months of treatment in patients with mild-to-moderate AD. The safety profile was comparable to the data in the Canadian product monograph. Lack of a comparator group is a potential limitation of the study.

100 years after Alzheimer: contemporary neurology practice assessment of referrals for dementia

BACKGROUND

The prevalence of dementia is placing an increased burden on specialists.

METHODS

Canadian neurologists responded to a structured questionnaire to assess reasons for referral and services provided as well as to compare the neurologists' perceptions of their practice characteristics against cases seen over a 3-month period.

RESULTS

The audit confirmed the participants' perception that family practitioners are the main referral source (358/453, 79%). Sixty-two percent of patients had undergone clinical investigation for dementia prior to being seen by the neurologist; 39% (177/453) were on pharmacotherapy at the time of referral, 68% were initiated on pharmacotherapy by the neurologist. A fifth of the referrals did not meet clinical criteria for dementia, which may be directly related to the prevalence of prior workup that did not include mental status testing.

CONCLUSIONS

Neurologists currently treat patients referred for dementia who may already have been adequately evaluated and treated by primary care providers.

Diagnosis and treatment of dementia: 2. Diagnosis

BACKGROUND

Dementia can now be accurately diagnosed through clinical evaluation, cognitive screening, basic laboratory evaluation and structural imaging. A large number of ancillary techniques are also available to aid in diagnosis, but their role in the armamentarium of family physicians remains controversial. In this article, we provide physicians with practical guidance on the diagnosis of dementia based on recommendations from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, held in March 2006.

METHODS

We developed evidence-based guidelines using systematic literature searches, with specific criteria for study selection and quality assessment, and a clear and transparent decision-making process. We selected studies published from January 1996 to December 2005 that pertained to key diagnostic issues in dementia. We graded the strength of evidence using the criteria of the Canadian Task Force on Preventive Health Care.

RESULTS

Of the 1591 articles we identified on all aspects of dementia diagnosis, 1095 met our inclusion criteria; 620 were deemed to be of good or fair quality. From a synthesis of the evidence in these studies, we made 32 recommendations related to the diagnosis of dementia. There are clinical criteria for diagnosing most forms of dementia. A standard diagnostic evaluation can be performed by family physicians over multiple visits. It involves a clinical history (from patient and caregiver), a physical examination and brief cognitive testing. A list of core laboratory tests is recommended. Structural imaging with computed tomography or magnetic resonance imaging is recommended in selected cases to rule out treatable causes of dementia or to rule in cerebrovascular disease. There is insufficient evidence to recommend routine functional imaging, measurement of biomarkers or neuropsychologic testing.

INTERPRETATION

The diagnosis of dementia remains clinically integrative based on history, physical examination and brief cognitive testing. A number of core laboratory tests are also recommended. Structural neuroimaging is advised in selected cases. Other diagnostic approaches, including functional neuroimaging, neuropsychological testing and measurement of biomarkers, have shown promise but are not yet recommended for routine use by family physicians.

Patterns of cortical thinning in Alzheimer's disease and frontotemporal dementia

In vivo measurement of cortical thickness is a sensitive representation of pathology in neurodegenerative disorders which primarily target the gray mantle. In this study we used magnetic resonance images to describe the patterns of cortical thinning in 11 frontotemporal dementia (FTD), 38 Alzheimer's disease (AD) and 34 healthy elderly (H(E)) subjects. AD and FTD displayed significant thinning of the cortical mantle compared to the H(E) group, but with distinctive distributions. AD subjects had significantly thinner cortex in all lobes whereas FTD compared to H(E) showed significant differences only in specific regions of frontal and temporal lobes. When compared to AD, the FTD subjects had a trend of thinner cortex in the anterior cingulate region and in selective regions of anterior frontal and temporal regions. In conclusion, the cortical thinning in dementia when compared to H(E), is disease specific whereby FTD subjects display a pattern distinct than that seen in Alzheimer's disease.

REM sleep behavior disorder and REM sleep without atonia in probable Alzheimer disease

STUDY OBJECTIVE

To determine the frequency of rapid eye movement (REM) sleep behavior disorder (RBD) and REM sleep without atonia among patients with Alzheimer disease and control subjects.

DESIGN

Overnight polysomnography.

SETTINGS

Sleep laboratory.

PATIENTS

Fifteen patients with probable Alzheimer disease (mean age +/-SD, 70.2+/-5.6) and 15 age-matched healthy control subjects (mean age +/- SD, 67.9 +/-5.4).

INTERVENTION

N/A.

RESULTS

Four patients with Alzheimer disease presented REM sleep with-out atonia. One of these patients had all the polysomnographic features of RBD, including behavioral manifestations during REM sleep.

CONCLUSION

RBD is rare, but REM sleep without atonia is relatively fre-quent in patients with probable Alzheimer disease, a tauopathy.

Predictors of driving cessation in mild-to-moderate dementia

BACKGROUND

Although physicians in most provinces are mandated to report patients whose driving ability is impaired by illness, little is known about dementia-related factors associated with driving cessation. The purpose of our study was to explore factors that may affect the likelihood of driving cessation in a sample of elderly, community-dwelling patients with dementia.

METHODS

A 3-year prospective study, the Canadian Outcomes Study in Dementia (COSID) has enrolled 883 patients with mild-to-moderate dementia at 32 centres across Canada. Assessment tools included the Mini-Mental State Examination (MMSE) for cognition, the Global Deterioration Scale (GDS) for staging (severity), the Functional Autonomy Measurement System (SMAF) for function, and the Neuropsychiatric Inventory (NPI) for behaviour. Factors associated with the decision to quit driving after the baseline assessment were tested with Cox survival analysis.

RESULTS

Of 719 subjects who were or had been drivers, 203 (28.2%) were still driving at baseline. Over an observation period that averaged 23 months, 97 (48.5%) of 200 patients quit driving. Factors predictive of driving cessation included GDS (hazard ratio [HR] 1.68, 95% confidence interval [CI] 1.15-2.45), MMSE score (HR 0.90, 95% CI 0.83-0.97) and NPI findings (HR 1.63 for presence of > or = 3 behaviours, 95% CI 1.01-2.62). Among the NPI behaviours, when they were analyzed separately, agitation led to a decreased likelihood of driving cessation (p = 0.019), whereas apathy (p = 0.031) and hallucinations (p = 0.050) led to an increased likelihood.

INTERPRETATION

Cognitive impairment and behaviours such as agitation, apathy and hallucinations were significant predictors of driving cessation in patients with a mild to moderate degree of dementia. These findings should be considered when one counsels patients and their families.

The contribution of neuropsychiatric symptoms to the cost of dementia care

OBJECTIVE

To estimate the contribution of behavioral and psychological symptoms of dementia (BPSD) to the costs of care.

METHOD

A one-year prospective study of resource utilization recorded monthly by 500 caregivers of community dwelling patients with dementia. The effect of behavior on total, direct and indirect costs of care was examined.

RESULTS

The total cost of care was $1,298 per month and there was a significant independent relationship between costs and BPSD. The incremental cost of a one point increase in Neuropsychiatric Inventory score was $30 per month (95% CI: $19-$41).

CONCLUSION

BPSD contribute significantly to the overall costs of dementia care. Interventions targeted at BPSD may help to reduce the staggering societal costs of this illness.

Rivastigmine for dementia associated with Parkinson's disease

BACKGROUND

Cholinergic deficits are prominent in patients who have dementia associated with Parkinson's disease. We investigated the effects of the dual cholinesterase inhibitor rivastigmine in such patients.

METHODS

Patients in whom mild-to-moderate dementia developed at least 2 years after they received a clinical diagnosis of Parkinson's disease were randomly assigned to receive placebo or 3 to 12 mg of rivastigmine per day for 24 weeks. Primary efficacy variables were the scores for the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog) and Alzheimer's Disease Cooperative Study-Clinician's Global Impression of Change (ADCS-CGIC). Secondary clinical outcomes were the scores for the Alzheimer's Disease Cooperative Study-Activities of Daily Living, the 10-item Neuropsychiatric Inventory, the Mini-Mental State Examination, Cognitive Drug Research power of attention tests, the Verbal Fluency test, and the Ten Point Clock-Drawing test.

RESULTS

A total of 541 patients were enrolled, and 410 completed the study. The outcomes were better among patients treated with rivastigmine than among those who received placebo; however, the differences between these two groups were moderate and similar to those reported in trials of rivastigmine for Alzheimer's disease. Rivastigmine-treated patients had a mean improvement of 2.1 points in the score for the 70-point ADAS-cog, from a baseline score of 23.8, as compared with a 0.7-point worsening in the placebo group, from a baseline score of 24.3 (P<0.001). Clinically meaningful improvements in the scores for the ADCS-CGIC were observed in 19.8 percent of patients in the rivastigmine group and 14.5 percent of those in the placebo group, and clinically meaningful worsening was observed in 13.0 percent and 23.1 percent, respectively (mean score at 24 weeks, 3.8 and 4.3, respectively; P=0.007). Significantly better outcomes were seen with rivastigmine with respect to all secondary efficacy variables. The most frequent adverse events were nausea (affecting 29.0 percent of patients in the rivastigmine group and 11.2 percent of those in the placebo group, P<0.001), vomiting (16.6 and 1.7 percent, P<0.001), and tremor (10.2 and 3.9 percent, P=0.01).

CONCLUSIONS

In this placebo-controlled study, rivastigmine was associated with moderate improvements in dementia associated with Parkinson's disease but also with higher rates of nausea, vomiting, and tremor.

Potential treatment effects of donepezil not detected in Alzheimer's disease clinical trials: a physician survey

OBJECTIVES

Clinical trials of the cholinesterase inhibitor donepezil have used standard psychometric tools to evaluate treatment efficacy. These trials, however, appear not to capture clinically demonstrable, but otherwise unmeasured, beneficial treatment effects. We sought to identify and categorize clinically recognizable effects of donepezil treatment in Alzheimer's disease.

METHODS

A list of potential effects was developed using clinical trials data and the experience of an expert panel. These were incorporated in a questionnaire, which was tested with a focus group, revised and then used in a postal survey of physicians. Data were classified by cognitive domain, and reviewed by a second panel.

RESULTS

Items that were most often rated as being improved were related to frontal systems function, including attentional capacity and initiative. Behavioral symptoms that were among the highest rated items were apathy, mood, and agitation. The top two other items were social interactions and involvement in domestic activities. Of the top ten symptomatic treatment effects, only four appeared to be readily identified by current standard measures.

CONCLUSIONS

Physicians recognize as important several treatment effects that are not well captured by current standard measures. New methods are needed to capture such effects, which also have the potential to offer insight into the neurobiology of the human cholinergic system.

Canadian Outcomes Study in Dementia: study methods and patient characteristics

OBJECTIVE

To describe the methods and patient characteristics of the Canadian Outcomes Study in Dementia (COSID).

METHODS

COSID is a 3-year prospective study of dementia patients living in the community at the time of study registration. We assessed patients' cognition, behaviour, and functioning every 6 months, using the Modified Mini-Mental State Examination (3MS), the Neuropsychiatric Inventory (NPI), and the Functional Autonomy Measurement System (SMAF), respectively. We assessed caregivers, using the Zarit Burden Interview (ZBI). Additional information included the Global Deterioration Scale (GDS), patients' driving status, and clinical information including family history, dementia type, concomitant medications, and comorbid conditions. From the patient or caregiver, we collected details of inpatient and outpatient resources used by the patient and (or) caregiver.

RESULTS

We enrolled 766 patients from 31 Canadian sites. Overall mean age was 76.8 years, and mean age of onset was 73.1 years. Of the total patients, 98% were white, 54% were women, and 84% were diagnosed with Alzheimer's disease. Mean baseline 3MS was 66.5, NPI was 9.5, and SMAF was 18.30. Of these patients, 48% reported a GDS score of 3 (that is, moderate), 16% reported a GDS score of 4 (that is, moderately severe), and the remaining 36% reported a GDS score of 1 or 2 (that is, mild or very mild). At baseline, 83% of patients received cholinesterase inhibitors, 46% received nonsteroidal antiinflammatory drugs, 39% received vitamin E, and 25% received antidepressants. Adult day care and home help were the largest cost factors in this population, with mean monthly costs of $65 and $64, respectively. We found interesting differences in the resources used among geographic regions and care settings.

CONCLUSIONS

COSID is already generating valuable information about treatment patterns, outcomes, and resource use in Canadian patients with dementia. As the data mature, it will be possible to build robust models on treatment effectiveness and costs of care.

Visual retinocortical function in dementia of the Alzheimer type

BACKGROUND

Some histological investigations have reported anomalies in the primary visual pathways of individuals with dementia of the Alzheimer type (DAT), while others have suggested that these visual structures are spared by the disease process.

OBJECTIVES

This study was conducted to address this issue of substantial controversy. We determined in vivo whether DAT alters the functioning of the primary visual pathways by evaluating pattern-reversal electroretinograms (ERGs) and cortical visual evoked potentials (VEPs).

METHODS

Twenty-seven individuals with mild to moderate DAT and 27 age- and sex-matched control subjects were included in the investigation. ERG and VEP recordings were obtained from all participants with the use of a clinical electrodiagnostic system. Stimulus conditions were biased towards a preferential response from the magnocellular and parvocellular subdivisions of the visual system.

RESULTS

Amplitude and latency of the ERG were not affected by DAT. The VEP amplitude was not attenuated in DAT individuals, but there was a delay in the latency of the VEPs arising from both magnocellular and parvocellular streams of visual processing.

CONCLUSION

Our results indicate that while the inner retina appears to be spared by the disease process, the visual function is altered upstream in the retinocortical visual pathways of individuals with DAT.

Tattooing and body piercing among adolescent detainees: relationship to alcohol and other drug use

PURPOSE

The purpose of this preliminary study was to document self-reported tattooing and body piercing behavior among a sample of 860 adolescent detainees. Additionally, the study examined the relationship of alcohol and drug use to tattooing and body piercing--an often overlooked HIV risk behavior.

METHODS

Adolescents (N = 860) participating in a substance use and HIV risk reduction intervention were surveyed upon entrance to a Youth Development Campus (YDC).

RESULTS

Twenty-nine percent of the sample (N = 245) had at least one tattoo, and more than half (69%) had at least one body piercing. Fifteen percent had two or more tattoos, while 28% had three or more piercings. Although a small percentage of the youth reported knowingly sharing needles for tattoos or piercings (2% and 1.5%, respectively), 21% had tattoos that had been administered unprofessionally and 20% had unprofessionally administered piercings. Marijuana and alcohol were the highest reported substances used in this sample, 62% and 54%, respectively. Alcohol, marijuana, antidepressants, and sedatives were significant correlates of having tattoos. Alcohol was found to be a marginally significant (P = .052) correlate of body piercing.

CONCLUSION

The popularity of tattooing and piercing and the risk involved with these activities make them an HIV risk behavior worthy of address. Risk reduction messages to youth should consistently address these behaviors and focus on them as they relate to substance use.

Normal optic nerve head topography in the early stages of dementia of the Alzheimer type

In view of the existing controversy as to whether or not the optic nerve head (ONH) is altered in Alzheimer disease, we used modern imaging technology to evaluate the ONH structure in individuals with dementia of the Alzheimer type (DAT). Real-time topographical images of the ONH were obtained with a Heidelberg retina tomograph from individuals in the early stages of DAT and age-matched controls. The various ONH parameters examined in this study did not differ significantly between DAT and age-matched subjects. These results suggest that the deficits in visual function that are known to occur in DAT are not related to ONH structural anomalies, at least in the earlier stages of the disease.

Effects of washout and dose-escalation periods on the efficacy, safety, and tolerability of galantamine in patients previously treated with donepezil: ongoing clinical trials

With the increasing number of acetylcholinesterase inhibitors (AChEIs) being marketed for the treatment of Alzheimer's disease (AD), physicians will need protocols for discontinuing one AChEI and initiating another ("switching"). Three clinical trials have been designed to provide data that will assist in the determination of the optimal conditions for switching patients from donepezil (the most widely prescribed AChEI) to galantamine (the most recently approved AChEI). The main objective of these studies is to investigate the effects of different washout periods (0 to 7 days) and dose-escalation schedules (fixed, fast vs slow) on the efficacy, safety, and tolerability of galantamine in patients with AD who were previously taking donepezil. The duration of the trials ranges from 12 to 52 weeks, and the last trial is expected to end in May 2002. No conclusions can yet be drawn from these ongoing trials, but the results should be helpful in establishing guidelines for physicians to use when switching patients with AD from donepezil to galantamine.

Neuroretinal function is normal in early dementia of the Alzheimer type

We recently demonstrated that retinal ganglion cell function, optic nerve head parameters and the retinal nerve fiber layer thickness are not altered in early dementia of the Alzheimer type (DAT). Our current objective was to assess whether the function of cells located more distally in the retina is also unaffected by the disease. We evaluated 23 individuals with early to moderate DAT and 23 healthy age-matched subjects, all displaying clinically normal visual function. Scotopic and photopic flash electroretinograms (fERGs) and oscillatory potentials (OPs) were recorded. The amplitude and latency of the retinal potentials did not differ between DAT and control subjects. Our current results showing normal fERGs and OPs in early DAT indicate that the underlying neurons giving rise to these signals are not impaired by the disease process. These data support and extend our recent findings suggesting that visual deficits in DAT do not stem from neuroretinal dysfunction.

An evaluation of the retinal nerve fiber layer thickness by scanning laser polarimetry in individuals with dementia of the Alzheimer type

PURPOSE

To determine, using scanning laser polarimetry, whether or not the retinal nerve fiber layer (RNFL) is altered in dementia of the Alzheimer type (DAT).

METHODS

Thirty individuals with mild to moderate DAT and 30 healthy age-matched controls participated in the study. Fundus images were acquired with a Nerve Fiber Analyzer. RNFL thickness measurements were obtained under an ellipse located 1.75 disc diameter from the optic nerve head (ONH) center.

RESULTS

No differences in RNFL thickness were observed between DAT and healthy subjects. The regional distribution of RNFL thickness was similar between the two test groups, with the RNFL being thickest in the superior and inferior retinal segments relative to the nasal and temporal regions.

CONCLUSIONS

Our data indicate that the RNFL is not altered in DAT, at least in the earlier stages of the disease.

Rivastigmine for Alzheimer's disease: Canadian interpretation of intermediate outcome measures and cost implications

BACKGROUND

Clinical studies have shown that patients with Alzheimer's disease (AD) who are treated with rivastigmine have statistically significantly better scores on 5 scales used to assess AD than control patients receiving placebo. However, the clinical meaning and cost implications of these differences are not clear.

OBJECTIVE

The purpose of this study was to assess the clinical meaning and cost implications of statistically significant results obtained in clinical trials of rivastigmine for the treatment of AD. Potential cost implications for the health care system, caregivers, and society are considered.

METHODS

Data on clinical effects of rivastigmine were obtained from published North American and European clinical studies of patients with mild to moderately severe AD receiving rivastigmine 6 to 12 mg/d (n = 828) or placebo (n = 647). Differences in scores on the Alzheimer's Disease Assessment Scale-Cognitive Function, Clinician's Interview-Based Impression of Change with both clinical and caregiver information considered, Progressive Deterioration Scale, Mini-Mental State Examination (MMSE), and Global Deterioration Scale were assessed. A convenience panel of 9 Canadian specialists experienced in the treatment of AD provided their opinions on the clinical importance of the trial results. Chart review was performed to identify specific behaviors that improved, and cost implications of improvements were assessed.

RESULTS

The panel determined that statistically significant differences in scores on all scales except the MMSE were likely associated with functional or cognitive differences that were clinically relevant for patients, reflecting stabilization that would have beneficial consequences for caregivers and health care resource use. Subsequent chart review showed that improvement on specific scale items confirmed the physician panel's opinion. Analysis of possible cost implications to society indicated that medication expenditures would be offset largely by delays in the need for paid home care and institutionalization, positive effects on caregiver health, and less time lost from work for the caregiver.

CONCLUSIONS

From the perspective of a Canadian specialist panel, rivastigmine treatment for AD produces clinically relevant effects for patients that are beneficial to caregivers. These effects suggest decreased use of caregiver resources and delays in the need for institutionalization, both of which reduce societal costs.

[Psychometric properties of the French version of the Modified Mini-Mental State (3MS) in elderly patients evaluated in geriatric psychiatry]

OBJECTIVE

This research evaluates the psychometric properties of the French version of the Modified Mini-Mental State (3MS), an instrument for the screening of dementia, in a sample of patients seen in geriatric psychiatry.

METHODS

Subjects (N = 94, 63 to 93 years of age) were outpatients of a service in geriatric psychiatry. In addition to the 3MS, a battery of tests evaluating the cognitive functioning and depressive symptomatology was administered.

RESULTS

Test-retest reliability coefficient was 0.87 for a subsample of 35 subjects. An exploratory factor analysis revealed 4 factors accounting for 63.2% of the variance. Cut-off scores of 79 to 80 (with years of education > or = 8) and 71 to 72 (with years of education < or = 7) presented the best combination sensitivity/specificity, respectively 0.80 and 0.96.

CONCLUSIONS

This study documents the psychometric properties of the French version of the 3MS for use in patients seen in geriatric psychiatry, in suggesting cut-off scores which take into account the level of education. This study underlines the influence of sociodemographic variables on test performance.

Translation of clinical and neuropsychological instruments into French: the CERAD experience

The increasing number of international and epidemiological studies of Alzheimer's disease points to the need for linguistically equivalent translations of measures for identifying the presence, types, and severity of dementia in cross-cultural populations. In translating the CERAD (Consortium to Establish a Registry for Alzheimer's Disease) neuropsychological instruments into French, several linguistic issues have emerged such as semantic, phonetic, and word-frequency equivalences. In verbal memory tests, these problems, though minor in appearance, can be major pitfalls in studies comparing cognitive function in populations differing in language. Description of the translation procedure and examples of problems encountered are presented, with measures taken to resolve them.

Deep left parietal lobe syndrome: conduction aphasia and other neurobehavioural disorders due to a small subcortical lesion

A patient with sudden onset of conduction aphasia in the context of an ischaemic stroke is reported. Other neurological and neuropsychological findings included bilateral ideomotor apraxia, right hemisensory defect and paradoxical left ear extinction on a dichotic listening test. Lesion location, as inferred from magnetic resonance imaging, involved a restricted subcortical area in the left parietal lobe, near the lateral wall of the cerebral ventricle. The anatomical correlate for each of the clinical findings is discussed in the light of classical anatomo-clinical correlations. It is concluded that this tetrad constitutes a specific syndrome which may be easily recognised and ascribed to a single lesion in the deep white matter of the left parietal lobe.

The lateralizing and localizing value of adversion in epileptic seizures

We studied 24 patients who had adversion as the first clinical manifestation of seizures. Seizures were recorded with depth electrodes as part of the evaluation for possible surgery for epilepsy. Head rotation did not help to lateralize the epileptic focus clinically, because deviations occurred ipsilaterally to the EEG focus in some patients, and because some patients had head rotation in either direction despite a unifocal epileptogenic abnormality. Furthermore, no cortical localization was consistently linked to either direction or degree of adversion. Adversion has no consistent lateralizing or localizing value.