The Behavioural Neurology Assessment

About time: neurocognitive correlates of stimulus-bound and other time setting errors in the Clock Drawing Test

OBJECTIVE

Previous findings suggest that time setting errors (TSEs) in the Clock Drawing Test (CDT) may be related mainly to impairments in semantic and executive function. Recent attempts to dissociate the classic stimulus-bound error (setting the time to "10 to 11" instead of "10 past 11") from other TSEs, did not support hypotheses regarding this error being primarily executive in nature or different from other time setting errors in terms of neurocognitive correlates. This study aimed to further investigate the cognitive correlates of stimulus-bound errors and other TSEs, in order to trace possible underlying cognitive deficits.

METHODS

We examined cognitive test performance of participants with preliminary diagnoses associated with mild cognitive impairment. Among 490 participants, we identified clocks with stimulus-bound errors (n = 78), other TSEs (n = 41), other errors not related to time settings (n = 176), or errorless clocks (n = 195).

RESULTS

No differences were found on any dependent measure between the stimulus-bound and the other TSErs groups. Group comparisons suggested TSEs in general, to be associated with lower performance on various cognitive measures, especially on semantic and working memory measures. Regression analysis further highlighted semantic and verbal working memory difficulties as being the most prominent deficits associated with these errors.

CONCLUSION

TSEs in the CDT may indicate underlying deficits in semantic function and working memory. In addition, results support previous findings related to the diagnostic value of TSEs in detecting cognitive impairment.

Goal Setting Improves Cognitive Performance in a Randomized Trial of Chronic Stroke Survivors

BACKGROUND AND PURPOSE

Cognitive impairment after stroke, especially executive and attention dysfunction, is common, negatively affects daily functioning, and has limited treatment options. A single-blind, parallel-design, randomized controlled trial was used to examine the impact of goal setting on poststroke cognitive performance.

METHODS

Stroke survivors (n=72; mean age, 68.38 [SD=11.84] years; 69.4% men) in the chronic phase (≥3 months) after stroke from an academic stroke prevention clinic were randomly assigned to receive goal-setting instructions (n=36) or standard instructions (n=36) after completing baseline cognitive measures of executive function (primary outcome), attention/working memory, verbal learning, and verbal recall.

RESULTS

A one-way mixed multivariate analysis of covariance (MANCOVA) found a group by instructional manipulation interaction effect for executive function (Wilks λ=0.66; F[3,66]=11.30; P≤0.001; η²_p=0.34), after adjusting for age and years of education. After similar adjustment, attention/working memory (Wilks λ=0.86; F[5,63]=2.10; P=0.043; η²_p=0.16) and verbal learning (F[1,60]=5.81; P=0.019; η²_p=0.09) also showed improvement after instruction but not verbal recall (Wilks λ=0.95; F[1,56]=2.82; P=0.099; η²_p=0.05). There were no adverse events.

CONCLUSIONS

Goal setting improved executive function, attention/working memory, and learning in a heterogeneous sample in the chronic phase after stroke. This suggests that >3 months after stroke, vascular cognitive impairment is not a fixed deficit; there is a motivational contributor. Brief treatments targeting goal-oriented behavior and motivation may serve as a novel approach or adjunct treatment to improve cognitive outcomes after stroke. Future research should investigate the use of goal setting on functional outcomes (eg, instrumental activities of daily living and vocational function) in this population, highlighting new potential avenues for treatment for vascular cognitive impairment. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03511300.

Genetic and epigenetic study of an Alzheimer's disease family with monozygotic triplets

Age at onset of Alzheimer's disease is highly variable, and its modifiers (genetic or environmental) could act through epigenetic changes, such as DNA methylation at CpG sites. DNA methylation is also linked to ageing-the strongest Alzheimer's disease risk factor. DNA methylation age can be calculated using age-related CpGs and might reflect biological ageing. We conducted a clinical, genetic and epigenetic investigation of a unique Ashkenazi Jewish family with monozygotic triplets, two of whom developed Alzheimer's disease at ages 73 and 76, while the third at age 85 has no cognitive complaints or deficits in daily activities. One of their offspring developed Alzheimer's disease at age 50. Targeted sequencing of 80 genes associated with neurodegeneration revealed that the triplets and the affected offspring are heterozygous carriers of the risk APOE ε4 allele, as well as rare substitutions in APP (p.S198P), NOTCH3 (p.H1235L) and SORL1 (p.W1563C). In addition, we catalogued 52 possibly damaging rare variants detected by NeuroX array in affected individuals. Analysis of family members on a genome-wide DNA methylation chip revealed that the DNA methylation age of the triplets was 6-10 years younger than chronological age, while it was 9 years older in the offspring with early-onset Alzheimer's disease, suggesting accelerated ageing.

A Systematic Review on the Possible Relationship Between Bilingualism, Cognitive Decline, and the Onset of Dementia

A systematic review was conducted to investigate whether bilingualism has a protective effect against cognitive decline in aging and can protect against dementia. We searched the Medline, ScienceDirect, Scopus, and ERIC databases with a cut-off date of 31 March, 2019, thereby following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol. Our search resulted in 34 eligible studies. Mixed results were found with respect to the protective effect of bilingualism against cognitive decline. Several studies showed a protective effect whereas other studies failed to find it. Moreover, evidence for a delay of the onset of dementia of between 4 and 5.5 years in bilingual individuals compared to monolinguals was found in several studies, but not in all. Methodological differences in the set-up of the studies seem to explain these mixed results. Lifelong bilingualism is a complex individual process, and many factors seem to influence this and need to be further investigated. This can be best achieved through large longitudinal studies with objective behavioral and neuroimaging measurements. In conclusion, although some evidence was found for a cognitive reserve-enhancing effect of lifelong bilingualism and protection against dementia, to date, no firm conclusions can be drawn.

Usefulness of the Clock Drawing Test as a Cognitive Screening Instrument for Mild Cognitive Impairment and Mild Dementia: an Evaluation Using Three Scoring Systems

Background and Purpose

Although the clock drawing test (CDT) is a widely used cognitive screening instrument, there have been inconsistent findings regarding its utility with various scoring systems in patients with mild cognitive impairment (MCI) or dementia. The present study aimed to identify whether patients with MCI or dementia exhibited impairment on the CDT using three different scoring systems, and to determine which scoring system is more useful for detecting MCI and mild dementia.

Methods

Patients with amnestic mild cognitive impairment (aMCI), vascular mild cognitive impairment (VaMCI), mild Alzheimer's disease (AD), mild vascular dementia (VaD), and cognitively normal older adults (CN) were included. All participants were administered the CDT, the Korean-Mini Mental State Examination (K-MMSE), and the Clinical Dementia Rating scale. The CDT was scored using the 3-, 5-, and 15-point scoring systems.

Results

On all three scoring systems, all patient groups demonstrated significantly lower scores than the CN. However, while there were no significant differences among patients with aMCI, VaMCI, and AD, those with VaD exhibited the lowest scores. Area under the Receiver Operating Characteristic curves revealed that the three CDT scoring systems were comparable with the K-MMSE in differentiating aMCI, VaMCI, and VaD from CN. In differentiating AD from CN, however, the CDT using the 15-point scoring system demonstrated the most comparable discriminability with K-MMSE.

Conclusions

The results demonstrated that the CDT is a useful cognitive screening tool that is comparable with the Mini-Mental State Examination, and that simple CDT scoring systems are sufficient for differentiating patients with MCI and mild dementia from CN.

The Toronto Cognitive Assessment (TorCA): normative data and validation to detect amnestic mild cognitive impairment

Background

A need exists for easily administered assessment tools to detect mild cognitive changes that are more comprehensive than screening tests but shorter than a neuropsychological battery and that can be administered by physicians, as well as any health care professional or trained assistant in any medical setting. The Toronto Cognitive Assessment (TorCA) was developed to achieve these goals.

Methods

We obtained normative data on the TorCA (n = 303), determined test reliability, developed an iPad version, and validated the TorCA against neuropsychological assessment for detecting amnestic mild cognitive impairment (aMCI) (n = 50/57, aMCI/normal cognition). For the normative study, healthy volunteers were recruited from the Rotman Research Institute registry. For the validation study, the sample was comprised of participants with aMCI or normal cognition based on neuropsychological assessment. Cognitively normal participants were recruited from both healthy volunteers in the normative study sample and the community.

Results

The TorCA provides a stable assessment of multiple cognitive domains. The total score correctly classified 79% of participants (sensitivity 80%; specificity 79%). In an exploratory logistic regression analysis, indices of Immediate Verbal Recall, Delayed Verbal and Visual Recall, Visuospatial Function, and Working Memory/Attention/Executive Control, a subset of the domains assessed by the TorCA, correctly classified 92% of participants (sensitivity 92%; specificity 91%). Paper and iPad version scores were equivalent.

Conclusions

The TorCA can improve resource utilization by identifying patients with aMCI who may not require more resource-intensive neuropsychological assessment. Future studies will focus on cross-validating the TorCA for aMCI, and validation for disorders other than aMCI.

Bedside Approach to the Mental Status Assessment

PURPOSE OF REVIEW

This article presents a clinically useful approach to obtaining the history and performing the mental status examination of patients with cognitive, language, or behavioral problems.

RECENT FINDINGS

Laboratory and imaging biomarkers are being developed for accurate diagnosis of neurobehavioral disorders, yet few are currently available for clinical use. Moreover, not all centers have access to these potential tools. Practicing clinicians are therefore left primarily with their skills of history taking and examination. Although geared for research, diagnostic criteria have been refined over the past several years and can nevertheless aid the clinician with the diagnosis of disorders such as mild cognitive impairment, Alzheimer disease, frontotemporal dementia, dementia with Lewy bodies, the primary progressive aphasias, corticobasal syndrome, vascular cognitive impairment, and posterior cortical atrophy. Regularly revised criteria reflect ongoing knowledge gained from in-depth studies of these disorders.

SUMMARY

The focused history and mental status examination remain essential tools for the evaluation and diagnosis of neurologic disorders affecting cognition, language, and behavior.

Emotion Detection Deficits and Decreased Empathy in Patients with Alzheimer's Disease and Parkinson's Disease Affect Caregiver Mood and Burden

Background: Changes in social cognition occur in patients with Alzheimer’s disease (AD) and Parkinson’s disease (PD) and can be caused by several factors, including emotion recognition deficits and neuropsychiatric symptoms (NPS). The aims of this study were to investigate: (1) group differences on emotion detection between patients diagnosed with AD or PD and their respective caregivers; (2) the association of emotion detection with empathetic ability and NPS in individuals with AD or PD; (3) caregivers’ depression and perceived burden in relation to patients’ ability to detect emotions, empathize with others, presence of NPS; and (4) caregiver’s awareness of emotion detection deficits in patients with AD or Parkinson.

Methods: In this study, patients with probable AD (N = 25) or PD (N = 17), and their caregivers (N = 42), performed an emotion detection task (The Awareness of Social Inference Test—Emotion Evaluation Test, TASIT-EET). Patients underwent cognitive assessment, using the Behavioral Neurology Assessment (BNA). In addition, caregivers completed questionnaires to measure empathy (Interpersonal Reactivity Index, IRI) and NPS (Neuropsychiatric Inventory, NPI) in patients and self-reported on depression (Geriatric Depression Scale, GDS) and burden (Zarit Burden Interview, ZBI). Caregivers were also interviewed to measure dementia severity (Clinical Dementia Rating (CDR) Scale) in patients.

Results: The results suggest that individuals with AD and PD are significantly worse at recognizing emotions than their caregivers. Moreover, caregivers failed to recognize patients’ emotion recognition deficits and this was associated with increased caregiver burden and depression. Patients’ emotion recognition deficits, decreased empathy and NPS were also related to caregiver burden and depression.

Conclusions: Changes in emotion detection and empathy in individuals with AD and PD has implications for caregiver burden and depression and may be amenable to interventions with both patients and caregivers.

MicroRNA Expression Levels Are Altered in the Cerebrospinal Fluid of Patients with Young-Onset Alzheimer's Disease

Clinical diagnosis of Alzheimer’s disease (AD) prior to the age of 65 years is classified as young-onset (YOAD), whereas diagnosis after the age of 65 years is considered late-onset (LOAD). Although rare autosomal mutations more commonly associate with YOAD, most YOAD and LOAD cases are sporadic. YOAD and LOAD share amyloid and tau pathology, but many YOAD patients show increased disease severity and rate of progression. The current study examined the microRNA (miRNA) expression profile from exosomes isolated from the cerebrospinal fluid (CSF) of YOAD patients with biomarker-confirmed AD. Results uncovered miR-16-5p, miR-125b-5p, miR-451a, and miR-605-5p as differentially expressed in the CSF-derived exosomes of YOAD patients when compared with healthy controls (HC). In a cohort of LOAD patients, miR-125b-5p, miR-451a, and miR-605-5p were similarly altered in expression, but miR-16-5p showed similar expression to control. Analysis of the mRNA targets of these miRNAs revealed transcripts enriched in biological processes relevant to the post-mortem posterior cingulate cortex transcriptome in YOAD from a previously published microarray study, including those related to neuron projections, synaptic signaling, metabolism, apoptosis, and the immune system. Hence, these miRNAs represent novel targets for uncovering disease mechanisms and for biomarker development in both YOAD and LOAD.

Investigating Simulated Driving Errors in Amnestic Single- and Multiple-Domain Mild Cognitive Impairment

The areas of driving impairment characteristic of mild cognitive impairment (MCI) remain unclear. This study compared the simulated driving performance of 24 individuals with MCI, including amnestic single-domain (sd-MCI, n = 11) and amnestic multiple-domain MCI (md-MCI, n = 13), and 20 age-matched controls. Individuals with MCI committed over twice as many driving errors (20.0 versus 9.9), demonstrated difficulty with lane maintenance, and committed more errors during left turns with traffic compared to healthy controls. Specifically, individuals with md-MCI demonstrated greater driving difficulty compared to healthy controls, relative to those with sd-MCI. Differentiating between different subtypes of MCI may be important when evaluating driving safety.

The "DOC" screen: Feasible and valid screening for depression, Obstructive Sleep Apnea (OSA) and cognitive impairment in stroke prevention clinics

Background

Post-stroke Depression, Obstructive sleep apnea (OSA) and Cognitive impairment (“DOC”) are associated with greater mortality, worse recovery and poorer quality of life. Best practice recommendations endorse routine screening for each condition; yet, all are under-assessed, diagnosed and treated. We seek to determine the feasibility and validity of an integrated tool (“DOC” screen) to identify stroke clinic patients at high-risk of depression, OSA, and cognitive impairment.

Methods

All consecutive new referrals to a regional Stroke Prevention Clinic who were English-speaking and non-aphasic were eligible to be screened. Time for screen completion was logged. DOC screen results were compared to the neuropsychological battery and polysomnogram assessments using a modified receiver operator characteristic and area under the curve analysis. Data is reported to conform to STARD guidelines.

Findings

1503 people were screened over 2 years. 89% of eligible patients completed the screen in 5 minutes or less (mean 4.2 minutes), less than half the time it takes to complete the Montreal Cognitive Assessment (MoCA). 437 people consented to detailed testing. Of those, 421 completed the Structured Clinical Interview for Depression within 3 months of screening, 387 completed detailed neuropsychological testing within 3 months, and 88 had overnight polysomnograms. Screening scores combined with demographic variables (age, sex, education, body mass index), had excellent validity compared to gold standard diagnoses: DOC-Mood AUC 0.90; DOC-Apnea AUC 0.80; DOC-Cog AUC 0.81. DOC screen scores can reliably categorize patients in to low-, intermediate- or high-risk groups for further action and can do so with comparable accuracy to more time-consuming screens.

Conclusions

Systematic screening of depression, obstructive sleep apnea, and cognitive impairment in 5 minutes or less is feasible and valid in a high volume stroke clinic using the DOC screen. The DOC screen may facilitate improved identification and treatment of these comorbidities to improve function in patients after stroke and in those with other neurological diseases that share these comorbid conditions (e.g. Alzheimer’s disease/mild cognitive impairment, Parkinson’s disease, Traumatic Brain Injury, multiple sclerosis).

Clinical Report: Cognitive decline in a patient with Cardiofaciocutaneous syndrome

Cardiofaciocutaneous Syndrome (CFCS) is a rare genetic syndrome caused by mutations in one of four genes: BRAF, MAP2K1, MAP2K2, and KRAS. There is tremendous phenotypic heterogeneity in patients with CFCS and so confirmation of diagnosis requires genetic testing. Neurologic and/or cognitive symptoms are present in almost all CFCS individuals. Little is known about cognitive function in older patients with CFCS. In this report, we present the cognitive, neuropsychiatric, and imaging findings of a patient diagnosed with CFCS who after having remained stable developed progressive cognitive/behavioral and motor decline.

Can Clinical Data Predict Progression to Dementia in Amnestic Mild Cognitive Impairment?

Background:

To determine whether clinical data obtained by history and physical examination can predict eventual progression to dementia in a cohort of elderly people with mild cognitive impairment.

Methods:

A prospective, longitudinal study of a cohort of elderly subjects with amnestic Mild Cognitive Impairment (MCI). Ninety subjects meeting the criteria for amnestic MCI were recruited and followed annually for an average of 3.3 years. Main outcome measure was the development of dementia determined by clinical assessment with confirmatory neuropsychological evaluation.

Results:

Fifty patients (56%) developed dementia on follow-up. They were older, had lower Mini-mental status exam (MMSE) scores and a shorter duration of symptoms at the time of first assessment. Multivariate logistic regression analysis identified age at symptom onset as the only clinical parameter which distinguished the group that deteriorated to dementia from the group that did not. The odds ratio for age was 1.1 (confidence interval 1.04 - 1.18).

Conclusions:

Patients presenting with amnestic MCI insufficient for the diagnosis of dementia are at high risk of developing dementia on follow-up. In our cohort, 56% were diagnosed with dementia over an average period of 5.9 years from symptom onset. The only clinical predictor for the eventual development of dementia was older age at symptom onset. Clinical features alone were insufficient to predict development of dementia.

Prevalence of Primitive Reflexes and Parkinsonian Signs in Dementia

Objective:

Primitive reflexes and parkinsonian signs are used by clinicians to differentiate among dementias. We reviewed our clinical sample to determine whether primitive reflexes were more prevalent in frontally-based dementias and whether parkinsonian signs were more common in dementia with Lewy bodies (DLB) than in other types of dementia.

Design:

We retrospectively reviewed charts from 204 patients with dementia who presented for consultation at Baycrest's Ross Memory Clinic between April, 2003, to December, 2007.

Results:

A greater proportion of subjects with DLB and dementia of the Alzheimer type with cardiovascular disease had primitive reflexes than subjects with frontotemporal dementia (FTD). Primitive reflexes were not positively predictive of FTD or vascular dementia (VaD). Dementia with Lewy bodies subjects were more likely to have parkinsonian signs than the other dementias, and bradykinesia and rigidity were positively predictive of FTD. The palmomental reflex was the most common primitive reflex in the sample, and cogwheeling was the most common parkinsonian sign. There was no significant difference between early- and late-stage groups in presence of primitive reflexes or parkinsonian signs.

Conclusions:

Primitive reflexes appear not to be clinically discriminative of frontally-based dementias such as FTD and VaD.

Clomipramine in the treatment of compulsive behavior in frontotemporal dementia: a case series

Compulsive behaviors in patients with behavioral variant frontotemporal dementia (bvFTD) occur frequently and are challenging to manage. We report three cases of probable bvFTD associated with compulsive behaviors that responded well to treatment with clomipramine at daily dosages varying from 20 to 175 mg. The titration approach involved an initial 10-mg dose that was subsequently increased in 10 mg increments on a weekly basis until symptom relief without intolerable side effects. Our case series supports the consideration for a therapeutic trial with clomipramine in bvFTD when compulsive behavior occurs in these patients. It also highlights the need for further research on pharmacological treatments in bvFTD.

Impact of socioeconomic status on initial clinical presentation to a memory disorders clinic

BACKGROUND

Dementia affects 15% of Canadians 65 and older, and the prevalence is expected to double over the next two decades. Low socioeconomic status (SES) can increase the risk of Alzheimer's disease (AD) and the precursor mild cognitive impairment (MCI), but it is unknown what the relationship of SES is on initial clinical presentation to a memory disorders clinic.

METHODS

Data from 127 AD and 135 MCI patients who presented to our Memory Disorders Clinic from 2004 to 2013 were analyzed retrospectively. We examined the relationship between SES (measured using Hollingshead two-factor index) and (1) diagnosis of either AD or MCI; (2) age when first presented to clinic; (3) objective cognitive tests to indicate clinical severity; and (4) the use of cognitive enhancers, medication for treating mild-to-moderate AD patients.

RESULTS

AD patients had lower SES than MCI patients (p < 0.001, r = 0.232). Lower SES was associated with a greater age at initial time of diagnosis (χ2 = 11.5, p = 0.001). In MCI patients, higher SES individuals outperformed lower SES individuals on the BNA after correcting for the effect of age (p = 0.004). Lower SES was also associated with decreased use of cognitive enhancers in AD patients (p < 0.001, r = 0.842).

CONCLUSION

Individuals with lower SES come into memory clinic later when the disease has progressed to dementia, while higher SES individuals present earlier when the disease is still in its MCI stage. There were more higher SES individuals who presented to our memory clinic. Higher SES is associated with better cognitive functioning and increased use of cognitive enhancers. The health policy implication is that we need to better engage economically disadvantaged individuals, perhaps at the primary care level.

Kynurenines and other novel therapeutic strategies in the treatment of dementia

Dementia is a common neuropsychological disorder with an increasing incidence. The most prevalent type of dementia is Alzheimer's disease. The underlying pathophysiological features of the cognitive decline are neurodegenerative processes, a cerebrovascular dysfunction and immunological alterations. The therapeutic approaches are still limited, although intensive research is being conducted with the aim of finding neuroprotective strategies. The widely accepted cholinesterase inhibitors and glutamate antagonists did not meet expectations of preventing disease progression, and research is therefore currently focusing on novel targets. Nonsteroidal anti-inflammatory drugs, secretase inhibitors and statins are promising drug candidates for the prevention and management of different forms of dementia. The kynurenine pathway has been associated with various neurodegenerative disorders and cerebrovascular diseases. This pathway is also closely related to neuroinflammatory processes and it has been implicated in the pathomechanisms of certain kinds of dementia. Targeting the kynurenine system may be of therapeutic value in the future.

Profile of cognitive complaints in vascular mild cognitive impairment and mild cognitive impairment

Objective. Vascular mild cognitive impairment (VaMCI) is differentiated from mild cognitive impairment (MCI) by the presence of vascular events such as stroke or small vessel disease. Typically, MCI and VaMCI patients present with subjective complaints regarding cognition; however, little is known about the specific nature of these complaints. We aimed to create a profile of subjective cognitive complaints in MCI and VaMCI patients with similar levels of objective cognitive performance. Methods. Twenty MCI and twenty VaMCI patients were recruited from a Memory Disorders Clinic in Toronto. Subjective cognitive complaints were assessed and categorized using the Neuropsychological Impairment Scale. Results. MCI and VaMCI patients achieved similar scores on measures of objective cognitive function (P > 0.100). However, the VaMCI group had more subjective complaints than the MCI group (P = 0.050), particularly in the critical items, cognitive efficiency, memory, and verbal learning domains of the Neuropsychological Impairment Scale. Conclusions. Our findings support the idea that VaMCI and MCI differ in their clinical profiles, independent of neuroimaging. VaMCI patients have significantly more subjective cognitive complaints and may be exhibiting particular deficits in memory, verbal learning, and cognitive efficiency. Our findings promote the need for further research into VaMCI-specific cognitive deficits.

"Blue is music to my ears": multimodal synesthesias after a thalamic stroke

Acquired synesthesias have been reported in association with deafferentation of the visual system, temporal lobe seizures, and the use of psychedelics. Based on our review of the literature, the appearance of synesthesias after a thalamic stroke has been reported only once. We present the case of a 45-year-old hypertensive male who, 9 months after a hemorrhagic stroke involving the left lateral posterior nucleus of the thalamus developed persistent sound-tactile, sound-color, and grapheme-gustatory synesthesias. Moreover, the patient noted that even thinking about a sensory stimulus could trigger the experience of another sensory modality, a conceptual type of synesthesia.

Test-retest reliability of a new executive function battery for use in early childhood

This study reported test-retest reliability for a newly developed executive function battery designed for use in early childhood. A total of 140 predominantly low-income children (M = 48.1 months; 51% male; 43% African American) completed up to six tasks on two occasions an average of 18 (Mdn = 16) days apart. Pearson correlations between individual task scores indicated moderate retest reliability (mean r = .60; range = .52-.66) similar to that observed in other retest studies of executive function in preschool, school-aged, and adult samples. In contrast, confirmatory factor analyses of performance on the task battery across time indicated high retest reliability (ϕ = .95) that was identical to that observed in a recent study that used an identical method involving a sample of older adults. The short-term test-retest reliability of executive function in early childhood is comparable to that observed in childhood and adult samples. The retest reliability of children's performance on batteries of executive function tasks is appreciably stronger than the retest reliability of their performance on individual tasks. Studies that focus on inter- and intraindividual differences in executive function would be better served by using scores that are derived from task batteries than those derived from individual tasks.

Normal-pressure hydrocephalus: is there a genetic predisposition?

BACKGROUND

Normal-pressure hydrocephalus (NPH) is characterized by gait disturbance, cognitive impairment, with or without urinary incontinence, enlarged ventricles with or without cerebral atrophy and normal cerebrospinal fluid pressure.

METHODS

We report two sisters with NPH who lived together their entire lives and whose natural history might provide insights into genetic and environmental mechanisms underlying this disorder. Both patients were in their early seventies, single, had similar daily habits and hypertension. No other family members had NPH.

RESULTS

They both underwent shunt placement and showed improvement documented by history and neuropsychological assessment. Both showed a delayed deterioration due to vasculopathy. Both patients were homozygous for the apolipoprotein E (ApoE) e3 allele on chromosome 19. No environmental factors that might have influenced the development of NPH were identified.

CONCLUSION

Our report of two sisters with NPH may indicate the presence of genetic predisposition and further studies involving genetics and environmental factors are necessary to elucidate their role in the pathogenesis of NPH.

Bilingualism as a contributor to cognitive reserve: evidence from brain atrophy in Alzheimer's disease

Much of the research on delaying the onset of symptoms of Alzheimer's disease (AD) has focused on pharmacotherapy, but environmental factors have also been acknowledged to play a significant role. Bilingualism may be one factor contributing to 'cognitive reserve' (CR) and therefore to a delay in symptom onset. If bilingualism is protective, then the brains of bilinguals should show greater atrophy in relevant areas, since their enhanced CR enables them to function at a higher level than would be predicted from their level of disease. We analyzed a number of linear measurements of brain atrophy from the computed tomography (CT) scans of monolingual and bilingual patients diagnosed with probable AD who were matched on level of cognitive performance and years of education. Bilingual patients with AD exhibited substantially greater amounts of brain atrophy than monolingual patients in areas traditionally used to distinguish AD patients from healthy controls, specifically, the radial width of the temporal horn and the temporal horn ratio. Other measures of brain atrophy were comparable for the two groups. Bilingualism appears to contribute to increased CR, thereby delaying the onset of AD and requiring the presence of greater amounts of neuropathology before the disease is manifest.

Determining the association of medical co-morbidity with subjective and objective cognitive performance in an inner city memory disorders clinic: a retrospective chart review

BACKGROUND

Medical co-morbidity may be associated with impaired cognitive function based on prior studies. However, no studies to date have determined to what extent this association is linked to medical illness or other factors that may be linked to medical illness (such as education, income levels, depression or subjective memory loss). The present study examined how medical co-morbidity, socioeconomic status (defined as residential SES), education and depression are associated with subjective and objective memory function in a sample of patients recruited from a university affiliated Memory Disorders Clinic located in a large Canadian inner city teaching hospital.

METHODS

Data was collected from 85 consecutive referrals to an Inner City Memory Disorders Clinic including socio-demographic characteristics, cognitive status and medical co-morbidity. Descriptive and correlational analyses were conducted.

RESULTS

Impaired objective cognitive function correlated significantly with increased medical co-morbidity and partially with education but not with residential SES or depression. Elevated memory complaints correlated significantly with depression, inversely with residential SES and not at all with medical co-morbidity or education.

CONCLUSIONS

Increased medical co-morbidity is significantly associated with impaired cognitive performance but not with subjective memory complaints in an Inner City Memory Clinic sample.

Impact of socioeconomic status on the prevalence of dementia in an inner city memory disorders clinic

BACKGROUND

Socioeconomic status (SES) has been identified as a possible risk factor for the development of dementia, with low SES shown to be associated with a higher prevalence of dementia, increased psychiatric comorbidity and worse baseline cognitive functioning. Few studies have actually looked at the impact of SES within a clinical population using multiple measures of SES and cognition.

METHODS

Data on 217 patients seen in an Inner City Memory Disorders Clinic were analyzed with respect to demographic status, clinical status and SES. Correlations were then examined looking at the relationship of SES to clinical variables and neurocognitive status. Regression analysis was undertaken to examine the relative contribution of individual sociodemographic factors to a diagnosis of dementia.

RESULTS

In general, there was wide variation in the sample examined with respect to most measures of SES. Approximately one third (36%) of the sample had a diagnosis of dementia, the mean age was 66.1 years and the mean Mini-mental State Examination score was relatively high (25.4). There was a strong association between age, individual annual income range, education, medical comorbidity and a diagnosis of dementia, with increased age and medical comorbidity being the strongest predictors.

CONCLUSION

Increased age, low education, high medical comorbidity and low annual income are all associated with a diagnosis of dementia in an inner city setting. Age and medical comorbidity appear to be more strongly associated with a diagnosis of dementia than SES in an inner city setting.

Early onset dementia

Dementia is characterized by a decline in cognitive faculties and occurrence of behavioral abnormalities which interfere with an individual's activities of daily living. Dementing disorders usually affect elderly individuals but may occur in individuals younger than 65 years (early-onset dementia or EOD). EOD is often misdiagnosed or its diagnosis is delayed due to the fact that it has a more varied differential diagnosis than late-onset dementia. EOD affects individuals at the height of their career and productivity and produces devastating consequences and financial loss for the patient's family as well as society. EOD is not uncommon and is diagnosed in up to a third of patients presenting with dementia. Most importantly, some of the causes of EOD are curable which makes the need for a specific and timely diagnosis crucial. The present chapter presents a systematic approach to the differential diagnosis of EOD and provides readers with the clinical and neuroimaging features of these disorders as well as important considerations for their diagnostic evaluation. Specifically, the nuances of assessing the history and examination are discussed with careful attention to the various methods of cognitive and behavioral evaluation. A step-wise approach to diagnostic testing is followed by a discussion of anatomical localization, which often aids in identifying specific etiologies. Finally, in order to organize the subject for the reader, the various etiologies are grouped under the general categories of vascular, infectious, toxic-metabolic, immune-mediated, neoplastic/metastatic, and neurodegenerative.

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.

Panorama nacional da pesquisa sobre avaliação neuropsicológica de linguagem

Apesar da grande difusão de instrumentos internacionais de avaliação da linguagem no contexto neuropsicológico, no Brasil, verifica-se uma importante demanda de técnicas adequadas à realidade sócio-lingüístico-cultural nas áreas clínica e de pesquisa. O objetivo deste estudo é apresentar um panorama nacional das pesquisas que envolvem a avaliação de linguagem no contexto da neuropsicologia. Para tanto, foram realizadas buscas relativas a estudos brasileiros nos bancos de Teses e Dissertações da CAPES, IBICT Teses e Index Psi Teses, e nos bancos de periódicos LILACS, SciELO e Index Psi Periódicos Técnico-Científicos. Ccomo resultado, verificou-se um número reduzido de pesquisas sobre avaliação neuropsicológica da linguagem, sendo que a maior parte das publicações foi encontrada em periódicos de áreas médicas. Poucos estudos faziam referência a algum tipo de instrumento, e raros foram os que visaram a fins psicométricos. Entretanto, observou-se um aumento do número de artigos científicos sobre avaliação de linguagem no contexto neuropsicológico, predominantemente nos últimos seis anos.

Progressive anomia without semantic or phonological impairment

We describe a 59-year-old woman, M.T., with a progressive language impairment and neuroimaging findings of decreased perfusion (SPECT) and focal atrophy (MRI) in the left temporal region. The most prominent feature of her cognitive profile was a profound and progressive impairment in naming. In spite of this, she performed normally on tests of semantic processing and phonological output. Her spontaneous speech was fluent with preserved syntax and articulation but with notable word-finding problems. All other cognitive abilities were relatively stable and intact. These features are not typical of either fluent or non-fluent forms of neurodegenerative language disturbance. The cognitive mechanisms that may underlie this case are discussed.

Therapeutic issues in vascular dementia: studies, designs and approaches

Vascular dementia (VaD) is a heterogeneous disorder resulting from various cerebrovascular diseases (CVD) causing cognitive impairment that reflects severity and location of damage. Epidemiological studies suggest VaD is the second commonest cause of dementia, but autopsy series report that pure VaD is infrequent, while combined CVD and Alzheimer's Disease(AD) is likely the commonest pathological-dementia correlate. Both diseases share vascular risk factors and benefit from their treatment. The most widely used diagnostic criteria for VaD are highly specific but not sensitive. Vascular Cognitive Impairment (VCI) is a dynamic, evolving concept that embraces VaD, Vascular Cognitive Impairment No Dementia (VCIND) and mixed AD and CVD. Clinical trials to date have focused on probable and possible VaD with beneficial effects evident for different drug classes, including cholinergic agents and NMDA agonists. Limitations have included use of cognitive tools suitable for AD that are insensitive to executive dysfunction. Disease heterogeneity has not been adequately controlled and subtypes require further study. Diagnostic VaD criteria now 13 years old need updating. More homogeneous subgroups need to be defined and therapeutically targeted to improve cognitive-behavioural outcomes including optimal control of vascular risk factors. More sensitive testing of executive function outlined in recent VCI Harmonization criteria and longer trial duration are needed to discern meaningful effects. Imaging criteria must be well-defined, with centralized review and standardized protocols. Serial scanning with quantification of tissue atrophy and lesion burden is becoming feasible, and cognitive interventions, including rehabilitation pharmacotherapy, with drugs strategically coupled to cognitive -behavioural treatments, hold promise and need further development.

The influence of beta-blockers on delayed memory function in people with cognitive impairment

Adrenergic signaling is important for the retrieval of intermediate-term contextual and spatial memories. The role of norepinephrine in retrieval requires signaling through beta1-adrenergic receptors in the hippocampus. Environmental cues activate the locus ceruleus, the main adrenergic nucleus of the brain, when an environmental stimulus is memorable. This leads to norepinephrine activation in the hippocampus, which is important for retrieving memories. Although beta-blockers do not impair cognition in normal subjects, this article explores the possibility that central nervous system (CNS)-active beta-blockers could affect delayed memory in patients with cognitive impairment. The authors investigated the influence of beta-blockers on delayed memory function in cognitively impaired patients. There was a trend for worse delayed memory retrieval in patients who were on CNS-active beta-blockers. These data support the notion that common medications used in cognitively impaired elderly patients can worsen cognition and that careful selection of medications may help to maximize retrieval of newly formed memories.