Non-invasive sound wave brain stimulation with Transcranial Pulse Stimulation (TPS) improves neuropsychiatric symptoms in Alzheimer's disease

BACKGROUND

This study explores Transcranial Pulse Stimulation (TPS) as a potential non-invasive treatment for Alzheimer's disease (AD), focusing on its impact on cognitive functions and behavioral symptoms.

METHODS

In a prospective, one-arm open-label trial, ten patients with mild to moderate dementia due to AD were assessed using the Alzheimer's Disease Assessment Scale (ADAS-Cog), Neuropsychiatric Inventory (NPI), Pfeffer Functional Activities Questionnaire, and Zarit Caregiver Burden Interview. Assessments occurred at 30- and 90-days post-treatment. The TPS protocol consisted of 10 sessions over five weeks, using the Neurolith® device to deliver 6000 focused shockwave pulses at 0.25 mJ/mm2 and a frequency of 4 Hz.

RESULTS

TPS significantly reduced neuropsychiatric symptoms, with NPI scores decreasing by 23.9 points (95% CI: -39.19 to -8.61, p = 0.0042) after 30 days, and by 18.9 points (95% CI: -33.49 to -2.91, p = 0.022) after 90 days. These changes had large effect sizes (Cohen's dz = 1.43 and dz = 0.94, respectively). A decreasing trend was observed in the ADAS-Cog score (-3.6, 95% CI: -7.18 to 0.00, p = 0.05) after 90 days, indicating a potential reduction in cognitive impairment, though not statistically significant.

CONCLUSION

The preliminary results indicate that TPS treatment leads to significant improvement in neuropsychiatric symptoms in AD patients, showing promise as a therapeutic approach for AD. Further research is needed to fully establish its effectiveness, especially concerning cognitive functions.

Diagnostic Performance of an Eye-Tracking Assisted Visual Inference Language Test in the Assessment of Cognitive Decline due to Alzheimer's Disease

BACKGROUND

The assessment of language changes associated with visual search impairment can be an important diagnostic tool in the Alzheimer's disease (AD) continuum.

OBJECTIVE

Investigate the performance of an eye-tracking assisted visual inference language task in differentiating subjects with mild cognitive impairment (MCI) or AD dementia from cognitively unimpaired older adults (controls).

METHODS

We assessed a group of 95 older adults (49 MCI, 18 mild dementia due to AD, and 28 controls). The subjects performed the same task under multiple experimental conditions which generate correlated responses that need to be taken into account. Thus, we performed a non-parametric repeated measures ANOVA model for verbal answers, and a linear mixed model (LMM) or its generalized version for the analysis of eye tracking variables.

RESULTS

Significant differences were found in verbal answers across all diagnostic groups independently of type of inference, i.e., logic or pragmatic. Also, eye-tracking parameters were able to discriminate AD from MCI and controls. AD patients did more visits to challenge stimulus (Control-AD, -0.622, SE = 0.190, p = 0.004; MCI-AD, -0.514, SE = 0.173, p = 0.011), more visits to the correct response stimulus (Control-AD, -1.363, SE = 0.383, p = 0.002; MCI-AD, -0.946, SE = 0.349, p = 0.022), more fixations on distractors (Control-AD, -4.580, SE = 1.172, p = 0.001; MCI-AD, -2.940, SE = 1.070, p = 0.020), and a longer time to first fixation on the correct response stimulus (Control-AD, -0.622, SE = 0.190, p = 0.004; MCI-AD, -0.514, SE = 0.173, p = 0.011).

CONCLUSION

The analysis of oculomotor behavior along with language assessment protocols may increase the sensitivity for detection of subtle deficits in the MCI-AD continuum, representing an important diagnostic tool.

Discourse abilities in euthymic elderly patients with bipolar disorder: a preliminary study

Cognitive impairment has been well described in euthymic patients with bipolar disorder (BD), as well as in elderly patients. Language disturbances are less studied, and several inconsistencies are reported in the literature. Most language studies focus on verbal fluency and semantic alterations, with a lack of studies addressing discursive abilities in BD.

Objective

The aim of this study was to evaluate discourse abilities in euthymic elderly individuals with BD.

Methods

We studied 19 euthymic elderly patients with BD and a control group of non-BD, which performed a cognitive assessment of attention, memory, executive functions, and visual abilities. All participants produced a description from the Cookie Theft Picture in oral and written modalities that was analyzed according to micro- and macrolinguistic aspects. Generalized linear models were performed to compare intergroup linguistic performance and to determine whether any cognitive domain was associated with linguistic outcomes.

Results

The BD group produced more cohesion errors in the oral and written modalities (p=0.016 and p=0.011, respectively) and fewer thematic units in the oral modality (p=0.027) than the control group.

Conclusions

BD patients presented minimal changes in the descriptive discourse task. The BD group produced more cohesion errors than the control group in the oral (p=0.016) and written discourse (p=0.011); also, the BD group produced fewer thematic units than controls in the oral discourse (p=0.027).

Impact of Cognitive Demand on Eye Movement Pattern in Patients with Alzheimer’s Disease

Background: Eye-movement behavior has been used as a reliable tool to identify cognitive and behavioral patterns in individuals with different neuropsychiatric disorders including Alzheimer’s disease (AD). Most studies in the field have been dedicated to evaluating eye-movement behavior during cognitive tasks in different protocols using multiple parameters. Objective: We aimed to evaluate the differences of eye-movement behavior in healthy subjects, subjects with mild cognitive impairment (MCI), and those with AD in a simple color task with and without cognitive demand. Methods: 91 subjects: 18 AD, 47 MCI, and 26 healthy controls had their oculomotor parameters assessed during baseline (no cognitive demand involved) and during a simple computational color memory task using an eye-tracker. Results: Baseline showed statistically different and heterogeneous results between normal cognition and MCI groups. Familiarization phase of the task could not discriminate between groups in any of the analyzed parameters. AD subjects made longer fixations and visits on distractors, and more frequent fixations and visits on the target areas than other groups during the response phase. Conclusion: Eye-tracking time-related parameters differentiate AD subjects from other groups under cognitive demand even in a simple color memory task.

Cognitive-communication disorder following right hemisphere damage: Narrative production

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Cognitive-communication disorder (CCD) is a common finding after RH damage.

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Alterations in discourse processing are highly prevalent in CCD.

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We analyzed 1,625 narratives to identify linguistic alterations related to RH lesions.

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The RH group produced narratives with more words, utterances, coherence errors, and lesser degree of information.

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CCD must be addressed through rehabilitation efforts to avoid restrictions on people's everyday life.

Background

Cognitive-communication disorder (CCD) results from the association of language and cognition impairment that may follow right hemisphere (RH) damage and impair the quality of life of affected persons.

Objective

We studied a set of 1,625 narratives produced by a cohort of 125 individuals (50 with a single right vascular lesion in the MCA territory and 75 cognitively healthy controls) using a task of picture-based discourse production. Discourse production was analyzed in its macro-and microlinguistic aspects to characterize better the linguistic mechanisms underlying RH patients' performance.

Results

The RH group produced more words and elocutions than controls, with a lower rate of informational content and a higher percentage of global coherence errors (all p-values <0.0001).

Conclusion

Individuals with RH lesions showed formal lexical and syntactic aspects of discourse mostly preserved. Alterations in the macrostructure of discourse prevailed over microstructural alterations in our sample, according to most literature studies. The group of individuals with RH lesions produced narratives containing more words and utterances, with a lesser degree of lexical information and more global coherence errors.

Neuropsychiatric symptoms and cerebrovascular risk in non-demented elders: cross-sectional study using the mild behavioural impairment checklist (MBI-C)

BACKGROUND

Neuropsychiatric symptoms (NPS) may represent early clinical manifestations of evolving brain diseases. Studies underpin the occurrence of NPS in the context of mild cognitive impairment (MCI) and prodromal Alzheimer's disease, where symptoms referred to as 'mild behavioural impairment' (MBI) have been shown to predict conversion to dementia and to hasten cognitive/functional decline. However, the association between NPS and cerebrovascular risk factors has been poorly investigated, despite the high prevalence of the latter among individuals with MCI. The aim of the present study was to investigate the association between MBI and cerebrovascular risk in a clinical sample of non-demented elders.

METHODS

Sixty-five MCI and 15 cognitively unimpaired older adults were cross-sectionally assessed with the Mild Behavioural Impairment Checklist (MBI-C), using the cut-off score > 6.5 to define positive screening. Participants were submitted to the Hachinski Ischaemic Score (HIS) to account for cerebrovascular symptoms, vascular risk, and related comorbidities. Neuroimaging scans (magnetic resonance imaging and/or 18F-fluorodeoxyglucose-positron emission tomography) and apolipoprotein E genotype were obtained.

RESULTS

Positive associations were found between total MBI-C scores and increasing number of comorbidities present (0-2 comorbidities), but not with three comorbidities. Two domains of the MBI-C-impulse dyscontrol and social inappropriateness-followed the same trend of the MBI-C total score, with higher scores with the increasing numbers of comorbidities. No significant associations were found between MBI symptoms and HIS or cerebrovascular burden in neuroimaging assessment.

CONCLUSION

We found weak associations between MBI-C total score and the presence of comorbidities with cerebrovascular risk, but not with structural or functional neuroimaging abnormalities or HIS. This finding may represent that the presence of comorbidities adds limited risk to the occurrence of MBI in this sample of non-demented elders.

AD-Related CSF Biomarkers Across Distinct Levels of Cognitive Impairment: Correlations With Global Cognitive State

AIM

Associations between cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) with the severity of cognitive impairment are unclear. We examined the correlations between CSF biomarkers and cognitive performance in the AD continuum.

METHODS

We studied 143 elderly patients: cognitively unimpaired (n = 51), mild cognitive impairment (MCI) amnestic (n = 55) and nonamnestic (n = 20), and mild AD (n = 17) assessed with the Cambridge Cognitive Test (CAMCOG). We correlated total CAMCOG and its subdomains with CSF Aβ42, T-tau, p-tau levels, and Aβ42/p-tau.

RESULTS

In the total sample, T-tau and Aβ42/p-tau correlated with the total CAMCOG (P < .01); all biomarkers correlated with memory (P < .001); T-tau correlated with language (P < .01).

CONCLUSION

Memory and T-tau levels may be the most suitable parameters to reflect cognitive/CSF biomarker correlations. At present, such correlations are of little use in routine clinical practice.

Textual Inference Comprehension in Mild Cognitive Impairment: The Influence of Semantic Processing and Verbal Episodic Memory

Language complaints, especially in complex tasks, may occur in mild cognitive impairment (MCI). Various language measures have been studied as cognitive predictors of MCI conversion to Alzheimer's type dementia. Understanding textual inferences is considered a high-demanding task that recruits multiple cognitive functions and, therefore, could be sensitive to detect decline in the early stages of MCI. Thus, we aimed to compare the performance of subjects with MCI to healthy elderly in a textual inference comprehension task and to determine the best predictors of performance in this ability considering one verbal episodic memory and two semantic tasks. We studied 99 individuals divided into three groups: (1) 23 individuals with amnestic mild cognitive impairment (aMCI), (2) 42 individuals with non-amnestic mild cognitive impairment (naMCI), (3), and (4) 34 cognitively healthy individuals for the control group (CG). A reduced version of The Implicit Management Test was used to assess different types of inferential reasoning in text reading. MCI patients performed poorer than healthy elderly, and there were no differences between MCI subgroups (amnestic and non-amnestic). The best predictors for inference-making were verbal memory in the aMCI and semantic tasks in the naMCI group. The results confirmed that the failure to understand textual inferences can be present in MCI and showed that different cognitive skills like semantic knowledge and verbal episodic memory are necessary for inference-making.

Semantic priming and neurobiology in schizophrenia: A theoretical review

In this theoretical review we bridge the cognitive and neurobiological sciences to shed light on the neurocognitive foundations of the semantic priming effect in schizophrenia. We review and theoretically evaluate the neurotransmitter systems (dopaminergic, GABAergic and glutamatergic) and neurobiological underpinnings of behavioural and electrophysiological (N400) semantic priming in the pathology, and the main hypotheses on their geneses: a disinhibition of the semantic spread of activation, a disorganised semantic storage or noisy lexical-semantic associations, a psychomotor artefact, an artefact of relatedness proportions, or an inability to mobilise contextual information. We further assess the literature on the endophenotype of Formal Thought Disorder from multiple standpoints, ranging from neurophysiology to cognition: considerations are weaved on neuronal (PV basket cell, SST, VIP) and receptor deficits (DRD1, NMDA), neurotransmitter imbalances (dopamine), cortical and dopaminergic lateralisation, inter alia. In conclusion, we put forth novel postulates on the underlying causes of controlled hypopriming, automatic hyperpriming, N400 reversals (larger amplitudes for close associations), indirect versus direct hyperpriming, and the endophenotype of lexical-semantic disturbances in schizophrenia.

Adjunctive Therapy to Manage Neuropsychiatric Symptoms in Moderate and Severe Dementia: Randomized Clinical Trial Using an Outpatient Version of Tailored Activity Program

BACKGROUND

Neuropsychiatric symptoms (NPS) such as aggression, apathy, agitation, and wandering may occur in up to 90%of dementia cases. International guidelines have suggested that non-pharmacological interventions are as effective as pharmacological treatments, however without the side effects and risks of medications. An occupational therapy method, called Tailored Activity Program (TAP), was developed with the objective to treat NPS in the elderly with dementia and has been shown to be effective.

OBJECTIVE

Evaluate the efficacy of the TAP method (outpatient version) in the treatment of NPS in individuals with dementia and in the burden reduction of their caregivers.

METHODS

This is a randomized, double-blind, controlled clinical trial for the treatment of NPS in dementia. Outcome measures consisted of assessing the NPS of individuals with dementia, through the Neuropsychiatric Inventory-Clinician rating scale (NPI-C), and assessing the burden on their caregivers, using the Zarit Scale. All the participants were evaluated pre-and post-intervention.

RESULTS

54 individuals with dementia and caregivers were allocated to the experimental (n = 28) and control (n = 26) groups. There was improvement of the following NPS in the experimental group: delusions, agitation, aggressiveness, depression, anxiety, euphoria, apathy, disinhibition, irritability, motor disturbance, and aberrant vocalization. No improvement was observed in hallucinations, sleep disturbances, and appetite disorders. The TAP method for outpatient settings was also clinically effective in reducing burden between caregivers of the experimental group.

CONCLUSION

The use of personalized prescribed activities, coupled with the caregiver training, may be a clinically effective approach to reduce NPS and caregiver burden of individuals with dementia.

Heterogeneity of Cerebrospinal Fluid Biomarkers Profiles in Individuals with Distinct Levels of Cognitive Decline: A Cross-Sectional Study

BACKGROUND

Decreased cerebrospinal fluid (CSF) concentrations of the amyloid-β (Aβ), along with increased total (T-tau) and phosphorylated tau protein (P-tau), are widely accepted as core biomarkers of Alzheimer's disease (AD) pathology. Nonetheless, there are a few remaining caveats that still preclude the full incorporation of AD biomarkers into clinical practice.

OBJECTIVE

To determine the frequency of clinical-biological mismatches in a clinical sample of older adults with varying degrees of cognitive impairment.

METHODS

204 participants were enrolled for a cross-sectional assessment and allocated into diagnostic groups: probable AD (n = 60, 29.4%); MCI (n = 84, 41.2%); or normal cognition (NC, n = 60, 29.4%). CSF concentrations of Aβ42, T-tau, and 181Thr-P-tau were determined, and Aβ42/P-tau ratio below 9.53 was used as a proxy of AD pathology. The AT(N) classification was further used as a framework to ascertain the biological evidence of AD.

RESULTS

The majority (73.7%) of patients in the AD group had the Aβ42/P-tau ratio below the cut-off score for AD, as opposed to a smaller proportion in the MCI (42.9%) and NC (23.3%) groups. In the latter, 21 subjects (35%) were classified as A+, 28 (46.7%) as T+, and 23 (38.3%) as N + . In the AD group, 66.7%of the cases were classified as A+, 78.3%as T+, and 80%as N+.

CONCLUSION

Analysis of CSF biomarkers was able to discriminate between AD, MCI, and NC. However, clinical-biological mismatches were observed in a non-negligible proportion of cases.

Early diagnosis and treatment of Alzheimer's disease: new definitions and challenges

The prevalence of Alzheimer's disease (AD), a progressive neurodegenerative disorder, is expected to more than double by 2050. Studies on the pathophysiology of AD have been changing our understanding of this disorder and setting a new scenario for drug development and other therapies. Concepts like the "amyloid cascade" and the "continuum of AD," discussed in this article, are now well established. From updated classifications and recommendations to advances in biomarkers of AD, we aim to critically assess the literature on AD, addressing new definitions and challenges that emerged from recent studies on the subject. Updates on the status of major clinical trials are also given, and future perspectives are discussed.

Cognitive impairment in remitted late-life depression is not associated with Alzheimer's disease-related CSF biomarkers

BACKGROUND

Cognitive impairment is a common feature of late-life depression (LLD). Early studies using Alzheimer's disease (AD) biomarkers inferred a biological link between AD pathology and LLD, but recent findings have challenged this association. The aim of this investigation was to determine a panel of AD-related cerebrospinal fluid (CSF) biomarkers in a cross-section of elders with mild cognitive impairment (MCI) with and without LLD.

METHODS

Subjects comprised 102 older adults: 27 with 'pure' amnestic MCI (aMCI), 53 with major depression and cognitive impairment - encompassing 22 late-onset (LOD) and 31 early-onset depression (EOD), and 22 euthymic elders without cognitive impairment (controls). Participants underwent lumbar puncture for determination of CSF concentrations of Aβ_1-42, T-tau, and P-tau. Cut-off scores for suspected AD were: Aβ_1-42 < 416p g/mL, P-tau > 36.1 pg/mL and Aβ/P-tau ratio < 9.53 (O. V. Forlenza et al. 2015). Statistical analyses consisted of analyses of variance (ANOVA), analyses of covariance (ANCOVA), Bonferroni post-hoc tests, and Pearson's chi-squared tests.

RESULTS

ANCOVA (age and schooling as covariates) displayed statistically significant results with respect to CSF biomarkers' profiles regardless of the socio-demographic divergencies previously identified by one-way ANOVA. Mean Aβ_1-42 values (pg/mL) were: aMCI, 360.3 (p < 0.001); LOD, 486.6 (p < 0.001); EOD, 494.2 (p < 0.001); controls, 528.3 (p < 0.001); p< 0.05. Mean Aβ_1-42/P-tau ratio: aMCI, 7.9 (p < 0.001); LOD 14.2 (p < 0.001); EOD, 15.3 (p < 0.001); controls, 17.1 (p < 0.001); p < 0.05. Post-hoc tests indicated that patients with aMCI showed significant differences in biomarker profile compatible with AD signature.

LIMITATION

The main limitation is the relatively small sample.

CONCLUSION

Our findings suggest that, distinctively from aMCI, cognitive impairment in LLD is not associated with AD's CSF pathological signature.

An intervention to reduce neuropsychiatric symptoms and caregiver burden in dementia: Preliminary results from a randomized trial of the tailored activity program-outpatient version

OBJECTIVE

To evaluate the efficacy of the tailored activity program-outpatient version (TAP-O) and to reduce neuropsychiatric symptoms (NPS) in patients with dementia and caregiver burden compared with a control group (psychoeducation intervention).

METHODS

Twenty-one persons with dementia and their caregivers were recruited and randomized. The intervention group received TAP-O, designed for outpatients with dementia and their caregivers. TAP-O consisted of eight sessions in which an occupational therapist assessed the patient's abilities and interests; prescribed tailored activities; and educated caregivers about dementia, NPS, and how to implement meaningful activities in the daily routine. The control group received eight sessions of a psychoeducation intervention about dementia and NPS.

RESULTS

Compared with controls, patients receiving TAP-O had a significant decrease in hallucination (P = 0.04), agitation (P = 0.03), anxiety (P = 0.02), aggression (P = 0.01), sleep disorder (P = 0.02), aberrant motor behavior (P = 0.02), and in caregiver burden (P = 0.003).

CONCLUSIONS

Findings suggest that TAP-O may be an effective nonpharmacological strategy to reduce NPS of outpatients with dementia and to minimize caregiver burden.

Linguistic abilities in major vascular cognitive impairment: a comparative study with Alzheimer's disease

We assessed the linguistic abilities of multi-infarct (cortical) dementia and subcortical ischemic vascular dementia (VaD) patients and compared the linguistic performance of VaD and Alzheimer's Disease (AD) patients. A total of 23 VaD patients, 20 mild AD patients, and 31 controls participated in the study. All were evaluated using the Arizona Battery for Communication Disorders of Dementia (ABCD). Neuropsychological testing was performed to ascertain that VaD and AD patients had comparable cognitive performance. Both dementia groups performed more poorly than controls in the ABCD measures, except for the comparative question subtest. Comparison between VaD and AD patients showed statistically significant differences only in the confrontation naming subtest (p < 0.05), where paraphasias and visual errors were the most prevalent. AD patients showed a trend towards more circumlocution errors than VaD patients (p = 0.0483). When compared to controls, linguistic abilities of VaD patients were impaired in all measures of linguistic expression and linguistic comprehension, except for the comparative question subtest. Linguistic differences between VaD and AD patients were observed only in the confrontation naming subtest.

Inference comprehension in text reading: Performance of individuals with right- versus left-hemisphere lesions and the influence of cognitive functions

Background

Right-hemisphere lesions (RHL) may impair inference comprehension. However, comparative studies between left-hemisphere lesions (LHL) and RHL are rare, especially regarding reading comprehension. Moreover, further knowledge of the influence of cognition on inferential processing in this task is needed.

Objectives

To compare the performance of patients with RHL and LHL on an inference reading comprehension task. We also aimed to analyze the effects of lesion site and to verify correlations between cognitive functions and performance on the task.

Methods

Seventy-five subjects were equally divided into the groups RHL, LHL, and control group (CG). The Implicit Management Test was used to evaluate inference comprehension. In this test, subjects read short written passages and subsequently answer five types of questions (explicit, logical, distractor, pragmatic, and other), which require different types of inferential reasoning. The cognitive functional domains of attention, memory, executive functions, language, and visuospatial abilities were assessed using the Cognitive Linguistic Quick Test (CLQT).

Results

The LHL and RHL groups presented difficulties in inferential comprehension in comparison with the CG. However, the RHL group presented lower scores than the LHL group on logical, pragmatic and other questions. A covariance analysis did not show any effect of lesion site within the hemispheres. Overall, all cognitive domains were correlated with all the types of questions from the inference test (especially logical, pragmatic, and other). Attention and visuospatial abilities affected the scores of both the RHL and LHL groups, and only memory influenced the performance of the RHL group.

Conclusions

Lesions in either hemisphere may cause difficulties in making inferences during reading. However, processing more complex inferences was more difficult for patients with RHL than for those with LHL, which suggests that the right hemisphere plays an important role in tasks with higher comprehension demands. Cognition influences inferential processing during reading in brain-injured subjects.

Sensitivity and specificity of a briefer version of the Cambridge Cognitive Examination (CAMCog-Short) in the detection of cognitive decline in the elderly: An exploratory study

OBJECTIVE

To create a reduced and briefer version of the widely used Cambridge Cognitive Examination (CAMCog) battery as a concise cognitive test to be used in primary and secondary levels of health care to detect cognitive decline. Our aim was to reduce the administration time of the original test while maintaining its diagnostic accuracy.

METHODS

On the basis of the analysis of 835 CAMCog tests performed by 429 subjects (107 controls, 192 mild cognitive impairment [MCI], and 130 dementia patients), we extracted items that most contributed to intergroup differentiation, according to 2 educational levels (≤8 and >8 y of formal schooling).

RESULTS

The final 33-item "low education" and 24-item"high education" CAMCog-Short correspond to 48.5% and 35% of the original version and yielded similar rates of accuracy: area under ROC curves (AUC) > 0.9 in the differentiation between controls × dementia and MCI × dementia (sensitivities > 75%; specificities > 90%); AUC > 0.7 for the differentiation between controls and MCI (sensitivities > 65%; specificities > 75%).

CONCLUSIONS

The CAMCog-Short emerges as a promising tool for a brief, yet sufficiently accurate, screening tool for use in clinical settings. Further prospective studies designed to validate its diagnostic accuracy are needed.

Aphasia in vascular lesions of the basal ganglia: A comprehensive review

Between 1970 and 1990, the study of aphasia secondary to subcortical lesions (including the basal ganglia - BG) was largely driven by the advent of modern neuroimaging techniques such as MRI and PET. However, attempts to characterize a pattern of language abnormalities in patients with basal ganglia lesions proved unfruitful. We conducted a comprehensive review of language disturbances after vascular lesions in the BG. Literature search in Medline and LILACS (1966-2016) and PsychINFO (last 25years) was conducted, and returned 145 articles, with 57 eligible for the review yielding data on 303 patients. We report the clinical and neuroimaging features of these cases. Results showed that aphasias caused by BG lesions are heterogeneous with weak clinicoanatomical correlations. Data derived from follow-up and flow/metabolism studies suggest that subcortical aphasia caused by BG lesions involves hypoperfusion in the cortical territories of the middle cerebral/internal carotid arteries (MCA/ICA) and their branches.

Cerebrospinal fluid biomarkers in Alzheimer's disease: Diagnostic accuracy and prediction of dementia

INTRODUCTION

Guidelines for the use of cerebrospinal fluid (CSF) biomarkers in the diagnosis of Alzheimer's disease (AD) establish that each laboratory must use internally qualified cutoff values. We determined the concentrations of biomarkers that discriminate cases from controls and combinations that predict the progression to dementia in a Brazilian cohort.

METHODS

Concentrations of amyloid-beta peptide (Aβ1-42), total tau (T-tau), and (181)Thr-phosphorylated-tau (P-tau) were determined in CSF samples from 184 older adults (68 mild cognitive impairment, 41 AD, 34 non-AD cognitive impairment, and 41 controls) by the INNO-BIA AlzBio3 assay.

RESULTS

Cutoff values discriminating AD from controls are as follows: Aβ1-42: 416.0 pg/mL (sensitivity [SE]: 83%, specificity (SP): 70%); T-tau: 76.7 pg/mL (SE: 82%, SP: 67%); P-tau: 36.1 pg/mL (SE: 83%, SP: 49%); Aβ1-42/P-tau <9.53 (SE: 88%, SP: 78%); and Aβ1-42/T-tau <4.13 (SE: 80%; SP: 80%). Combining values Aβ1-42 <416.5 pg/mL and Aβ1-42/P-tau <9.5 best predicted the conversion in 2 years (Cox regression: hazard ratio 7.24 [2.09-25.06], P = .002, SE: 74%, Sp: 73%).

DISCUSSION

Our findings are in line with most of the available evidence in this field; yet, our cutoff values are different from those derived from other laboratories.

Inference comprehension during reading: influence of age and education in normal adults

PURPOSE

To determine the effect of age and education on inferential comprehension from written texts in normal individuals.

METHODS

A total of 224 normal adults were stratified into nine groups according to age (young: 18-39 years, adults: 40-59 years, and elderly: 60-79 years) and educational level (low ≤4 years, medium: 5-8 years and high >8 years) and were evaluated through the battery La gestion de l'implicite (Implicit Information Management Test) to determine the ability to make inferences through different types of questions: explicit, logical, distractor, pragmatic and others.

RESULTS

The elderly showed worse performance for total score and distractor questions. Regarding educational level, all groups differed on explicit, logical, distractor questions, and on total test score. Subjects with high schooling performed better on pragmatic inferences and others.

CONCLUSION

Age influence on the comprehension of inferences may be due to difficulties in attention and executive functions. The strong effect of education can be explained by the interaction of inferential abilities with other cognitive functions such as working memory, vocabulary span, as well as world knowledge.

The use of the Clock Drawing Test in bipolar disorder with or without dementia of Alzheimer’s type

There is limited data regarding the cognitive profile from screening tests of older adults with bipolar disorder (BD) with dementia. Objective To investigate the Clock Drawing Test (CDT) among older adults with BD with and without Alzheimer’s disease (AD). Method 209 older adults (79 with BD without dementia and 70 controls; 60 with AD, being 27 with BD) were included to evaluate the performance of three CDT scoring scales, beyond the Mini-Mental State Examination (MMSE) and verbal fluency (VFT). Results Patients with BD without dementia presented with lower scores in MMSE, VF and one CDT scoring scale than controls. Patients with BD and AD presented with lower scores in VF and CDT scoring scales than patients with only AD. All CDT scales presented similar sensitivity and specificity for BD and non-BD groups. Conclusion Elderly subjects with BD showed greater impairment in CDT in both groups of normal cognition and AD.

Impairment of inferential abilities based on pictorial stimuli in patients with right-hemisphere damage

Inferences are mental representations derived from the interaction between explicit linguistic information and an individual's world knowledge. The right hemisphere (RH) is the main region responsible for this ability, particularly with regard to pictorial stimuli. The aims of this study were to evaluate the performance of RH-damaged patients on an inference comprehension task based on pictorial stimuli and to compare the effect of different lesion sites on this performance. We compared the inferential abilities of 75 healthy controls and 50 patients with RH damage of vascular origin using 13 pictorial stimuli from the instrument "300 Exercises of Comprehension of Logical and Pragmatic Inferences and Causal Chains." RH-damaged patients performed worse than controls in comprehending logical and pragmatic visual inferences independent of lesion site (p < .0001). The subgroup with posterior lesions performed worse than the other subgroups.

Reduced cerebrospinal fluid levels of brain-derived neurotrophic factor is associated with cognitive impairment in late-life major depression

OBJECTIVES

Late-life depression (LLD) is associated with reduced neurotrophic support and abnormalities in neurodegenerative cascades. The aim of the present study is to determine the concentrations of brain-derived neurotrophic factor (BDNF), amyloid-β42, total Tau, and phosphorylated Tau in the cerebrospinal fluid (CSF) of patients with LLD and cognitive impairment compared to healthy older adults.

METHOD

We included 25 antidepressant-free patients with LLD (10 with mild cognitive impairment [LLD + MCI] and 15 with no cognitive decline [LLD + NCD]) and 25 healthy older adults as a comparison group. Depressive symptoms were assessed by the 21-item Hamilton Depression Rating Scale (HDRS-21) and cognitive performance by a comprehensive cognitive battery.

RESULTS

Patients with LLD + MCI showed significantly lower CSF BDNF levels compared to LLD + NCD and healthy controls (p = .003). There were no significant differences in Alzheimer's disease-related CSF biomarkers between groups. CSF BDNF concentrations were positively correlated with Cambridge Cognitive Test (CAMCOG) scores (r = .36, p = .02).

DISCUSSION

The present study adds to the growing body of evidence that abnormalities in the BDNF system are involved in the pathophysiology of LLD. The reduction of the availability of BDNF in the central nervous system may indicate increased vulnerability to the development of several age-related neuropsychiatric disorders as well as to adverse cognitive outcomes.

Inferential abilities based on pictorial stimuli in patients with right hemisphere damage: influence of schooling

Inferences are mental representations, formed through the interaction between explicit linguistic information and an individual's world knowledge. It is well known that individuals with brain damage in the right hemisphere (RH) often fail on this task and that schooling may be a variable affecting this.

Performance of patients with frontotemporal lobar degeneration on artistic tasks: A pilot study

Several studies have addressed visuospatial and executive skills in artistic activities in Frontotemporal Lobar Degeneration (FTLD) and Alzheimer's disease (AD).

White matter abnormalities associated with Alzheimer's disease and mild cognitive impairment: a critical review of MRI studies

In this article, the authors aim to present a critical review of recent MRI studies addressing white matter (WM) abnormalities in Alzheimer's disease (AD) and mild cognitive impairment (MCI), by searching PubMed and reviewing MRI studies evaluating subjects with AD or MCI using WM volumetric methods, diffusion tensor imaging and assessment of WM hyperintensities. Studies have found that, compared with healthy controls, AD and MCI samples display WM volumetric reductions and diffusion tensor imaging findings suggestive of reduced WM integrity. These changes affect complex networks relevant to episodic memory and other cognitive processes, including fiber connections that directly link medial temporal structures and the corpus callosum. Abnormalities in cortico-cortical and cortico-subcortical WM interconnections are associated with an increased risk of progression from MCI to dementia. It can be concluded that WM abnormalities are detectable in early stages of AD and MCI. Degeneration of WM networks causes disconnection among neural cells and the degree of such changes is related to cognitive decline.

Cognitive-linguistic deficits in euthymic elderly patients with bipolar disorder

BACKGROUND

There is increasing evidence that bipolar disorder is also associated with neuropsychological impairments persisting during euthymia, thus representing a trait-like feature of the disease. Language and speech abnormalities are also present in bipolar disorder, especially in verbal fluency and verbal memory. However, there is a lack of studies in the literature investigating different levels of linguistic processing (phonological, syntactical, and semantic) in a single cohort of euthymic bipolar patients. Based on previous findings of pervasive language impairment in euthymic elderly bipolar patients, the aim of this study was to comprise a more thorough investigation on the subject.

METHODS

We studied 19 euthymic bipolar patients aged 60 and above, and 20 cognitively healthy subjects using the Arizona Battery for Communication Disorders of Dementia (ABCD) and the Test for Reception of Grammar Version 2 (TROG-2) in order to assess the phonological, syntactic, and semantic domains of language.

RESULTS

Bipolar patients performed poorer than controls in Linguistic Expression (p=0.011), in Linguistic Comprehension (Following Commands; p=0.025 and Reading Comprehension of Sentences; p=0.007), and in the TROG-2 (p=0.006).

LIMITATIONS

The small sample comprising only elderly patients; the lack of statistical power to analyze the potential effect of individual medications on the cognitive performance.

CONCLUSIONS

Our data demonstrate that linguistic impairment is present in euthymic bipolar patients, affecting mostly syntactic and lexical-semantic abilities, both in comprehension and production of language. These deficits are interrelated with other cognitive skills also known to be affected in bipolar disorder, such as executive functions and episodic memory.

Language impairment in Huntington's disease

Language alterations in Huntington's disease (HD) are reported, but their nature and correlation with other cognitive impairments are still under investigation. This study aimed to characterize the language disturbances in HD and to correlate them to motor and cognitive aspects of the disease. We studied 23 HD patients and 23 controls, matched for age and schooling, using the Boston Diagnostic Aphasia Examination, Boston Naming Test, the Token Test, Animal fluency, Action fluency, FAS-COWA, the Symbol Digit Modalities Test, the Stroop Test and the Hooper Visual Organization Test (HVOT). HD patients performed poorer in verbal fluency (p<0.0001), oral comprehension (p<0.0001), repetition (p<0.0001), oral agility (p<0.0001), reading comprehension (p=0.034) and narrative writing (p<0.0001). There was a moderate correlation between the Expressive Component and Language Competency Indexes and the HVOT (r=0.519, p=0.011 and r=0.450, p=0.031, respectively). Language alterations in HD seem to reflect a derangement in both frontostriatal and frontotemporal regions.

Formal Thought Disorder and language impairment in schizophrenia

Schizophrenia is a psychiatric illness in which disorders of thought content are a prominent feature. The disruption of normal flow of thought, or “Formal Thought Disorder” (FTD), has been traditionally assessed through the content and form of patients’ speech, and speech abnormalities in schizophrenia were considered as a by-product of the disruption in conceptual structures and associative processes related to psychosis. This view has been changed due to increasing evidence that language per se is impaired in schizophrenia, especially its semantic, discursive, and pragmatic aspects. Schizophrenia is currently considered by some authors as a “language related human specific disease” or “logopathy”, and the neuroanatomical and genetic correlates of the language impairment in these patients are under investigation. Such efforts may lead to a better understanding about the pathophysiology of this devastating mental disease. We present some current concepts related to FTD as opposed to primary neurolinguistic abnormalities in schizophrenia.

Screening for cognitive impairment in late onset depression in a Brazilian sample using the BBRC-Edu

Depression and dementia are the most prevalent neuropsychiatric disorders in the elderly population. Alzheimer's disease is the leading cause of dementia in most countries, being responsible for more than half of all dementia cases. Late-onset depression is a frequent cause of cognitive decline in the elderly. Differentiating between cognitive impairment secondary to depression and incipient dementia poses a challenge in the clinical setting.

Objective

To evaluate the performance of elderly depressed patients using the BBRC-Edu.

Methods

We studied 25 patients with late onset depression (mean age: 73.6 y (6.6); schooling: 9.1 y (5.7)) and 30 patients with mild AD (mean age 76.6 y (5.4); schooling: 7.5 y (7.1)), who were compared to a control group of 30 healthy elderly (mean age 73.8 y (5.8); schooling: 9.1 y (5.4)) using the CERAD and BBRC-Edu batteries.

Results

For the CERAD battery, depressed patients performed better than AD patients on all tasks (p<0.0001) except for Constructional Praxis (p>0.05), and performed poorer than controls on verbal fluency (animals) and Word List Recall tasks (p<0.0001). For the BBRC-Edu, depressed patients performed better than AD patients on all tasks (p<0.0001) except for Digit Span (direct order) (p=0.076) and Incidental Memory (p>0.05), and performed worse than controls on Learning (second presentation) and verbal fluency (fruits) tasks (p<0.0001).

Conclusion

Overall performance on the BBRC-Edu allowed differentiation of controls and depressed patients from AD patients.

Alzheimer's disease

Alzheimer's disease (AD) is a chronic neurodegenerative disease with well-defined pathophysiological mechanisms, mostly affecting medial temporal lobe and associative neocortical structures. Neuritic plaques and neurofibrillary tangles represent the pathological hallmarks of AD, and are respectively related to the accumulation of the amyloid-beta peptide (Aβ) in brain tissues, and to cytoskeletal changes that arise from the hyperphosphorylation of microtubule-associated Tau protein in neurons. According to the amyloid hypothesis of AD, the overproduction of Aβ is a consequence of the disruption of homeostatic processes that regulate the proteolytic cleavage of the amyloid precursor protein (APP). Genetic, age-related and environmental factors contribute to a metabolic shift favoring the amyloidogenic processing of APP in detriment of the physiological, secretory pathway. Aβ peptides are generated by the successive cleavage of APP by beta-secretase (BACE-1) and gamma-secretase, which has been recently characterized as part of the presenilin complex. Among several beta-amyloid isoforms that bear subtle differences depending on the number of C-terminal amino acids, Aβ (1-42) plays a pivotal role in the pathogenesis of AD. The neurotoxic potential of the Aβ peptide results from its biochemical properties that favor aggregation into insoluble oligomers and protofibrils. These further originate fibrillary Aβ species that accumulate into senile and neuritic plaques. These processes, along with a reduction of Aβ clearance from the brain, leads to the extracellular accumulation of Aβ, and the subsequent activation of neurotoxic cascades that ultimately lead to cytoskeletal changes, neuronal dysfunction and cellular death. Intracerebral amyloidosis develops in AD patients in an age-dependent manner, but recent evidence indicate that it may be observed in some subjects as early as in the third or fourth decades of life, with increasing magnitude in late middle age, and highest estimates in old age. According to recent propositions, three clinical phases of Alzheimer's disease may be defined: (i) pre-symptomatic (or pre-clinical) AD, which may last for several years or decades until the overproduction and accumulation of Aβ in the brain reaches a critical level that triggers the amyloid cascade; (ii) pre-dementia phase of AD (compatible with the definition of progressive, amnestic mild cognitive impairment), in which early-stage pathology is present, ranging from mild neuronal dystrophy to early-stage Braak pathology, and may last for several years according to individual resilience and brain reserve; (iii) clinically defined dementia phase of AD, in which cognitive and functional impairment is severe enough to surmount the dementia threshold; at this stage there is significant accumulation of neuritic plaques and neurofibrillary tangles in affected brain areas, bearing relationship with the magnitude of global impairment. New technologies based on structural and functional neuroimaging, and on the biochemical analysis of cerebrospinal fluid may depict correlates of intracerebral amyloidosis in individuals with mild, pre-dementia symptoms. These methods are commonly referred to as AD-related biomarkers, and the combination of clinical and biological information yields good diagnostic accuracy to identify individuals at high risk of AD. In other words, the characterization of pathogenic Aβ by means of biochemical analysis of biological fluids or by molecular neuroimaging are presented as diagnostic tools to help identify AD cases at the earliest stages of the disease process. The relevance of this early diagnosis of AD relies on the hypothesis that pharmacological interventions with disease-modifying compounds are more likely to produce clinically relevant benefits if started early enough in the continuum towards dementia. Therapies targeting the modification of amyloid-related cascades may be viewed as promising strategies to attenuate or even to prevent dementia. Therefore, the cumulative knowledge on the pathogenesis of AD derived from basic science models will hopefully be translated into clinical practice in the forthcoming years.

Comparison of language impairment in late-onset depression and Alzheimer's disease

OBJECTIVES

Depression and dementia are highly prevalent in the elderly. Language impairment is an inherent component of Alzheimer's disease (AD), which can also be encountered in depressed patients. The aim of this study wasto compare the profiles of language abilities in late-onset depression and mild AD groups.

METHODS

We studied 25 patients with late-onset depression (mean age 73.6 ± 6.6 years; schooling 9.1 ± 5.7 years) and 30 patients with mild AD (77.6 ± 5.4 years; 7.5 ± 7.1 years) using the Arizona Battery for Communication Disorders of Dementia (ABCD), compared to a group of 30 controls (73.8 ± 5.8 years; 9.1 ± 5.4 years). Cut-off scores to discriminate between Controls × Depression and Depression × AD were determined.

RESULTS

Depressed patients' scores were similar to AD in confrontation naming, concept definition, following commands, repetition and reading comprehension (sentence). Episodic memory and mental status subtests were useful in differentiating depressed patients from AD, a result that was reproduced when using analysis of covariance to control for the effect of age in the same subtests (p = 0.01 and 0.04, respectively).

CONCLUSION

Language impairment resembling AD was found in the aforementioned language subtests of the ABCD in elderly depressed patients; the mental status and episodic memory subtests were useful to discriminate between AD and depression. The ABCD has proven to be a suitable tool for language evaluation in this population and should aid in the differentiation of AD and pseudodementia (as that of depression).

Assessment of balance in mild and moderate stages of Alzheimer's disease: implications on falls and functional capacity

OBJECTIVE: To analyze the correlation between balance, falls and loss of functional capacity in mild and moderate Alzheimer's disease(AD). METHOD: 40 subjects without cognitive impairment (control group) and 48 AD patients (25 mild, 23 moderate) were evaluated with the Berg Balance Scale (BBS) and the Disability Assessment for Dementia (DAD). Subjects answered a questionnaire about falls occurrence in the last twelve months. RESULTS: Moderate AD patients showed poorer balance (p=0.001) and functional capacity (p <0.0001) and it was observed a correlation between falls and balance (r= -0.613; p=0.045). CONCLUSION: There is a decline of balance related to AD which is a factor associated to the occurrence of falls, albeit not the most relevant one. The loss of functional capacity is associated with the disease's progress but not to a higher occurrence of falls. The balance impairment did not correlate with functional decline in AD patients.

Clinical and biological predictors of Alzheimer's disease in patients with amnestic mild cognitive impairment

OBJECTIVE

To identify predictors of the progression from pre-dementia stages of cognitive impairment in Alzheimer's disease is relevant to clinical management and to substantiate the decision of prescribing antidementia drugs.

METHOD

Longitudinal study of a cohort of elderly adults with amnestic mild cognitive impairment and healthy controls, carried out to estimate the risk and characterize predictors of the progression to Alzheimer's disease.

RESULTS

Patients with amnestic mild cognitive impairment had a higher risk to develop Alzheimer's disease during follow-up (odds ratio = 4.5, CI₉₅(%) [1.3-13.6], p = 0.010). At baseline, older age, lower scores on memory tests and presence of the APOE*4 allele predicted the progression from amnestic mild cognitive impairment to Alzheimer's disease. In a sub sample of amnestic mild cognitive impairment patients, those who progressed to Alzheimer's disease had lower cerebrospinal fluid concentrations of amyloid-beta peptide (Aβ₄₂, p = 0.020) and higher concentrations of total TAU (p = 0.030) and phosphorylated TAU (p = 0.010), as compared to non-converters.

DISCUSSION

This is the first Brazilian study to report cerebrospinal fluid biomarkers in the prediction of the conversion from MCI to Alzheimer's disease. Our data are in accordance with those reported in other settings. The measurement of cerebrospinal fluid total-TAU, phospho-TAU and Aβ₄₂ may help identify patients with mild cognitive impairment at higher risk for developing Alzheimer's disease.

Characteristics of falls in mild and moderate Alzheimer's disease

The occurrence of falls in AD patients is frequent, and their consequences are cognitive decline, fractures and loss of independence. Many studies have addressed fall risk factors in order to establish effective prevention strategies.

Objectives

We describe the frequency and characteristics of falls in a sample of AD patients and their main risk factors.

Methods

We evaluated 40 subjects without cognitive impairment, and 45 AD patients, graded as CDR 1 and CDR 2.

Results

Environmental hazard risks were the most frequent cause associated with falls in CDR 1 (41.4%) and CDR 2 (46.7%). Instability (31%) and dizziness (17.2%) were frequent causes of falls in the CDR 1 group, and this group showed the highest rate of recurrence (28%). In both groups of AD patients, indoors falls predominated (70.3 and 80% respectively for CDR 1 and 2). In our sample, the remaining factors studied were not associated with increasing risk for falls.

Conclusions

These results reinforce the hypothesis that falls in AD are mutifactorial and that their risk factors are highly interconnected. Preventative strategies considering all aspects should be implemented most crucially eliminating environmental risks, maintaining constant presence of caregivers, and providing physical and functional stimulation, both in mild and moderate AD.

Performance of a Brazilian population on the test of functional health literacy in adults

OBJECTIVE

To analyze the scoring obtained by an instrument, which evaluates the ability to read and understand items in the health care setting, according to education and age.

METHODS

The short version of the Test of Functional Health Literacy in Adults was administered to 312 healthy participants of different ages and years of schooling. The study was conducted between 2006 and 2007, in the city of São Paulo, Southeastern Brazil. The test includes actual materials such as pill bottles and appointment slips and measures reading comprehension, assessing the ability to read and correctly pronounce a list of words and understand both prose passages and numerical information. Pearson partial correlations and a multiple regression model were used to verify the association between its scores and education and age.

RESULTS

The mean age of the sample was 47.3 years(sd=16.8) and the mean education was 9.7 years(sd=5; range: 1 - 17). A total of 32.4% of the sample showed literacy/numeracy deficits, scoring in the inadequate and marginal functional health literacy ranges. Among the elderly (65 years or older) this rate increased to 51.6%. There was a positive correlation between schooling and scores (r=0.74; p<0.01) and a negative correlation between age and the scores (r=-0.259; p<0.01). The correlation between the scores and age was not significant when the effects of education were held constant (rp=-0.031, p=0.584). A significant association (B=3.877, Beta =0.733; p<0.001) was found between schooling and scores. Age was not a significant predictor in this model (B=-0.035, Beta=-0.22; p=0.584).

CONCLUSIONS

The short version of the Test of Functional Health Literacy in Adults was a suitable tool to assess health literacy in the study population. The high number of individuals classified as functional illiterates in this test highlights the importance of special assistance to help them properly understand directions for healthcare.

Mild cognitive impairment: cognitive screening or neuropsychological assessment?

OBJECTIVE

To describe the neuropsychological profile of mild cognitive impairment subtypes (amnestic, non-amnestic and multiple-domain) of a clinical sample. We further address the diagnostic properties of the Mini-Mental State Examination and the Cambridge Cognitive Examination for the identification of the different mild cognitive impairment subtypes in clinical practice.

METHOD

Cross-sectional clinical and neuropsychological evaluation of 249 elderly patients attending a memory clinic at a university hospital in Sao Paulo, Brazil.

RESULTS

The performance of patients with mild cognitive impairment was heterogeneous across the different subtests of the neuropsychological battery, with a trend towards an overall worse performance for amnestic (particularly multiple domain) mild cognitive impairment as compared to non-amnestic subtypes. Screening tests for dementia (Mini-Mental State Examination and Cambridge Cognitive Examination) adequately discriminated cases of mild Alzheimer's disease from controls, but they were not accurate to discriminate patients with mild cognitive impairment (all subtypes) from control subjects.

CONCLUSIONS

The discrimination of mild cognitive impairment subtypes was possible only with the aid of a comprehensive neuropsychological assessment. It is necessary to develop new strategies for mild cognitive impairment screening in clinical practice.