Computer-based Eye-tracking Analysis of King-Devick Test Differentiates Persons With Idiopathic Normal Pressure Hydrocephalus From Cognitively Unimpaired.

BACKGROUND: Functional defects in eye movements and reduced reading speed in neurodegenerative diseases represent a potential new biomarker to support clinical diagnosis. We investigated whether computer-based eye-tracking (ET) analysis of the King-Devick (KD) test differentiates persons with idiopathic normal pressure hydrocephalus (iNPH) from cognitively unimpaired [control (CO)] and persons with Alzheimer's disease (AD). METHODS: We recruited 68 participants (37 CO, 10 iNPH, and 21 AD) who underwent neurological examination, the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological test battery (CERAD-NB), and a Clinical Dementia Rating interview. The KD reading test was performed using computer-based ET. We analyzed the total time used for the reading test, number of errors, durations of fixation and saccade, and saccade amplitudes. RESULTS: The iNPH group significantly differed from the CO group in the KD test mean total time (CO 69.3 s, iNPH 87.3 s; P ≤0.009) and eye-tracking recording of the mean saccade amplitude (CO 3.6 degree, iNPH 3.2 degree; P ≤0.001). The AD group significantly differed from the CO group in each tested parameter. No significant differences were detected between the iNPH and AD groups. CONCLUSION: For the first time, we demonstrated altered reading ability and saccade amplitudes in patients with iNPH.

Third follow-up of the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) cohort investigating determinants of cognitive, physical, and psychosocial wellbeing among the oldest old: the CAIDE85+ study protocol.

BACKGROUND: The oldest old is the fastest growing age group worldwide and the most prone to severe disability, especially in relation to loss of cognitive function. Improving our understanding of the predictors of cognitive, physical and psychosocial wellbeing among the oldest old can result in substantial benefits for the individuals and for the society as a whole. The Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study investigated risk factors and determinants of cognitive impairment in a population-based longitudinal cohort, which was first examined between 1972 and 1992, when individuals were in their midlife, and re-assessed in 1998 and 2005-2009. Most of the study participants are currently aged 85 years or older. We aim to re-examine the cohort's survivors and gain further insights on the mechanisms underlying both cognitive and overall healthy ageing at old age. METHODS: CAIDE85+ is the third follow-up of the CAIDE study participants. All individuals still alive and living in the Kuopio and Joensuu areas of Eastern Finland, from the original CAIDE cohort (two random samples, N = 2000 + ~ 900), will be invited to a re-examination. The assessment includes self-reported data related to basic demographics and lifestyle, as well as psychosocial and physical health status. Cognitive and physical evaluations are also conducted. Blood biomarkers relevant for dementia and ageing are assessed. Primary outcomes are the measurements related to cognition and daily life functioning (CERAD, Trail Making Test-A, Letter-Digit Substitution Test, Clinical Dementia Rating and Activities of Daily Living). Secondary endpoints of the study are outcomes related to physical health status, psychosocial wellbeing, as well as age-related health indicators. DISCUSSION: Through a follow-up of more than 40 years, CAIDE85+ will provide invaluable information on the risk and protective factors that contribute to cognitive and physical health, as well as ageing and longevity. STUDY REGISTRATION: The present study protocol has been registered at https://clinicaltrials.gov/ (registration nr NCT03938727 , date 03.05.2019).

Cardiorespiratory fitness and brain volumes in men and women in the FINGER study.

Background: high cardiorespiratory fitness (CRF) is associated with larger brain volumes but data on sex differences in the association of CRF with brain volumes are scarce. We investigated whether the association of CRF with total grey matter (GM) and white matter volumes as well as medial temporal lobe and striatum volumes is different between men and women at increased risk for Alzheimer's disease (AD). Methods: we used baseline data from The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) in which the inclusion criteria were set to select individuals with cognitive performance at the mean level or slightly lower than expected for age according to Finnish population norms. Our sub-study included 39 randomly selected men and 29 women aged 61-75 years. CRF was assessed as peak oxygen consumption (VO2peak) measured in a maximal exercise test on cycle ergometer. Brain structural imaging was performed using a 1.5-T scanner. Results: in men, VO2peak was associated with cortical GM volume (ß = 0.56, P = 0.001) and total GM volume (ß = 0.54, P = 0.001). In women, no associations were found between VO2peak and brain volumes. VO2peak accounted for 23% and 1% of total variance of cortical GM volume as well as 25% and 4% of total variance of total GM volume in men and women, respectively. Conclusion: CRF is associated with cortical GM and total GM volumes in elderly men at increased risk for AD, but not in women.

The use of biomarkers for the etiologic diagnosis of MCI in Europe: an EADC survey.

We investigated the use of Alzheimer's disease (AD) biomarkers in European Alzheimer's Disease Consortium centers and assessed their perceived usefulness for the etiologic diagnosis of mild cognitive impairment (MCI). We surveyed availability, frequency of use, and confidence in diagnostic usefulness of markers of brain amyloidosis (amyloid positron emission tomography [PET], cerebrospinal fluid [CSF] Aß42) and neurodegeneration (medial temporal atrophy [MTA] on MR, fluorodeoxyglucose positron emission tomography [FDG-PET], CSF tau). The most frequently used biomarker is visually rated MTA (75% of the 37 responders reported using it "always/frequently") followed by CSF markers (22%), FDG-PET (16%), and amyloid-PET (3%). Only 45% of responders perceive MTA as contributing to diagnostic confidence, where the contribution was rated as "moderate". Seventy-nine percent of responders felt "very/extremely" comfortable delivering a diagnosis of MCI due to AD when both amyloid and neuronal injury biomarkers were abnormal (P < .02 versus any individual biomarker). Responders largely agreed that a combination of amyloidosis and neuronal injury biomarkers was a strongly indicative AD signature.

[Will memory be lost with menopause--can an ageing woman be protected from memory disorder?]. / Meneekö muisti menopaussin myötä--voiko ikääntyvä nainen suojautua muistisairaudelta?

Approximately two out of three persons affected with Alzheimer's disease are women. Estrogen is known to have positive effects on the levels of brain-derived mediators and circulation. Along with menopause, decreasing female sex hormone levels have been assumed to promote the development of memory disorders. It is possible that timing of the start of hormone replacement therapy exactly to the menopause could provide the best benefit in respect of memory and information processing. Prevention and treatment of risk factors of cardiovascular diseases along with regular exercise and a healthy diet are more important than hormone therapy in the prevention of memory disorders.

Integrating a multimodal lifestyle intervention with medical food in prodromal Alzheimer's disease: the MIND-ADmini randomized controlled trial.

BACKGROUND: The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) showed cognitive benefits from a multidomain lifestyle intervention in at-risk older people. The LipiDiDiet trial highlighted benefits of medical food in prodromal Alzheimer's disease (AD). However, the feasibility and impact of multimodal interventions combining lifestyle with medical food in prodromal AD is unclear. METHODS: MIND-ADmini was a 6-month multinational (Sweden, Finland, Germany, France) proof-of-concept randomized controlled trial (RCT). Participants were 60-85 years old, had prodromal AD (International Working Group-1 criteria), and vascular/lifestyle risk factors. The parallel-group RCT had three arms: multimodal lifestyle intervention (nutritional guidance, exercise, cognitive training, vascular/metabolic risk management and social stimulation); multimodal lifestyle intervention + medical food (Fortasyn Connect); and regular health advice/care (control). Participants were randomized 1:1:1 (computer-generated allocation at each site). Outcome evaluators were blinded to randomization. Primary outcome was feasibility of the multimodal intervention, evaluated by recruitment rate during a 6-month recruitment phase, overall adherence in each intervention arm, and 6-month retention rate. Successful adherence was pre-specified as attending ≥ 40% of sessions/domain in ≥ 2/4 domains (lifestyle intervention), and consuming ≥ 60% of the medical food (lifestyle intervention + medical food). The secondary outcomes included adherence/participation to each intervention component and overall adherence to healthy lifestyle changes, measured using a composite score for healthy lifestyle. Cognitive assessments were included as exploratory outcomes, e.g. Clinical Dementia Rating scale. RESULTS: During September 2017-May 2019, 93 individuals were randomized (32 lifestyle intervention, 31 lifestyle + medical food, and 30 control group). Overall recruitment rate was 76.2% (64.8% during the first 6 months). Overall 6-month retention rate was 91.4% (lifestyle intervention 87.5%; lifestyle + medical food 90.3%; control 96.7%). Domain-specific adherence in the lifestyle intervention group was 71.9% to cognitive training, 78.1% exercise, 68.8% nutritional guidance, and 81.3% vascular risk management; and in the lifestyle + medical food group, 90.3% to cognitive training, 87.1% exercise, 80.7% nutritional guidance, 87.1% vascular risk management, and 87.1% medical food. Compared with control, both intervention arms showed healthy diet improvements (ßLifestyle×Time = 1.11, P = 0.038; ßLifestyle+medical food×Time = 1.43, P = 0.007); the lifestyle + medical food group also showed vascular risk reduction (P = 0.043) and less cognitive-functional decline (P < 0.05, exploratory analysis). There were 5 serious adverse events (control group: 1; lifestyle intervention: 3; lifestyle + medical food: 1) unrelated to interventions. CONCLUSIONS: The multidomain lifestyle intervention, alone or combined with medical food, had good feasibility and adherence in prodromal AD. Longer-term cognitive and other health benefits should be further investigated in a larger-scale trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT03249688.

[Posterior variant of Alzheimer's disease and other atypical symptom pictures]. / Posteriorinen kortikaalinen atrofia ja muut Alzheimerin taudin epätyypilliset muodot.

Neuropathologically confirmed Alzheimer's disease may begin with symptoms other than memory problems, for instance visual perceptual disorders, difficulties in linguistic functions and expression in spoken language or executive functioning, occasionally even with behavioral symptoms. Among the forms of Alzheimer's disease appearing with atypical symptoms, the best know is the so-called posterior variant. The diagnosis is based on neuropsychological examination and findings in imaging. Additional diagnostic help is provided by the determination of markers for Alzheimer's disease in cerebrospinal fluid, as changes in markers correspond to the findings in traditional Alzheimer's disease.

A FinnGen pilot clinical recall study for Alzheimer's disease.

Successful development of novel therapies requires that clinical trials are conducted in patient cohorts with the highest benefit-to-risk ratio. Population-based biobanks with comprehensive health and genetic data from large numbers of individuals hold promise to facilitate identification of trial participants, particularly when interventions need to start while symptoms are still mild, such as for Alzheimer's disease (AD). This study describes a process for clinical recall studies from FinnGen. We demonstrate the feasibility to systematically ascertain customized clinical data from FinnGen participants with ICD10 diagnosis of AD or mild cognitive disorder (MCD) in a single-center cross-sectional study testing blood-based biomarkers and cognitive functioning in-person, computer-based and remote. As a result, 19% (27/140) of a pre-specified FinnGen subcohort were successfully recalled and completed the study. Hospital records largely validated registry entries. For 8/12 MCD patients, other reasons than AD were identified as underlying diagnosis. Cognitive measures correlated across platforms, with highest consistencies for dementia screening (r = 0.818) and semantic fluency (r = 0.764), respectively, for in-person versus telephone-administered tests. Glial fibrillary acidic protein (GFAP) (p < 0.002) and phosphorylated-tau 181 (pTau-181) (p < 0.020) most reliably differentiated AD from MCD participants. We conclude that informative, customized clinical recall studies from FinnGen are feasible.

Application of the PredictAD software tool to predict progression in patients with mild cognitive impairment.

BACKGROUND: The PredictAD tool integrates heterogeneous data such as imaging, cerebrospinal fluid biomarkers and results from neuropsychological tests for compact visualization in an interactive user interface. This study investigated whether the software tool could assist physicians in the early diagnosis of Alzheimer's disease. METHODS: Baseline data from 140 patients with mild cognitive impairment were selected from the Alzheimer's Disease Neuroimaging Study. Three clinical raters classified patients into 6 categories of confidence in the prediction of early Alzheimer's disease, in 4 phases of incremental data presentation using the software tool. A 5th phase was done with all available patient data presented on paper charts. Classifications by the clinical raters were compared to the clinical diagnoses made by the Alzheimer's Disease Neuroimaging Initiative investigators. RESULTS: A statistical significant trend (p < 0.05) towards better classification accuracy (from 62.6 to 70.0%) was found when using the PredictAD tool during the stepwise procedure. When the same data were presented on paper, classification accuracy of the raters dropped significantly from 70.0 to 63.2%. CONCLUSION: Best classification accuracy was achieved by the clinical raters when using the tool for decision support, suggesting that the tool can add value in diagnostic classification when large amounts of heterogeneous data are presented.

Shortening of Saccades as a Possible Easy-to-Use Biomarker to Detect Risk of Alzheimer's Disease.

BACKGROUND: Wide-ranging functional defects in eye movements have been reported in Alzheimer's disease (AD) dementia. The detection of abnormal eye movements and reading problems may identify persons at risk of AD when clear clinical symptoms are lacking. OBJECTIVE: To examine whether computer-based eye-tracking (ET) analysis of King-Devick (KD) test results differentiates cognitively healthy persons from persons with minor problems in cognitive testing or diagnosed mild AD. METHODS: We recruited 78 participants (57 non-demented, 21 with mild AD) who underwent neurological examination, the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological test battery (CERAD-NB), and a Clinical Dementia Rating (CDR) interview. The non-demented participants were further divided into control (normal CERAD subtests, mean MMSE = 28) and objective mild cognitive impairment (MCI; decline in at least one CERAD memory score, mean MMSE = 27) groups. The KD reading test was performed using computer-based ET. The total time used for the reading test, errors made, fixation and saccade durations, and saccade amplitudes were analyzed. RESULTS: We found significant differences between the control, objective MCI, and AD groups in regard to the mean saccade amplitude (3.58, 3.33, and 3.21 ms, respectively, p < 0.03) and duration (27.1, 25.3, and 24.8 ms, respectively, p < 0.05). The KD error scores in the AD group differed significantly (p < 0.01) from the other groups. CONCLUSION: Computed ET analysis of the KD test may help detect persons with objective MCI early when clear clinical symptoms are lacking. The portable device for ET is easy to use in primary health care memory clinics.

Effects of age, amyloid, sex, and APOE ε4 on the CSF proteome in normal cognition.

Introduction: It is important to understand which biological processes change with aging, and how such changes are associated with increased Alzheimer's disease (AD) risk. We studied how cerebrospinal fluid (CSF) proteomics changed with age and tested if associations depended on amyloid status, sex, and apolipoprotein E Ɛ4 genotype. Methods: We included 277 cognitively intact individuals aged 46 to 89 years from Alzheimer's Disease Neuroimaging Initiative, European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery, and Metabolic Syndrome in Men. In total, 1149 proteins were measured with liquid chromatography mass spectrometry with multiple reaction monitoring/Rules-Based Medicine, tandem mass tag mass spectrometry, and SOMAscan. We tested associations between age and protein levels in linear models and tested enrichment for Reactome pathways. Results: Levels of 252 proteins increased with age independently of amyloid status. These proteins were associated with immune and signaling processes. Levels of 21 proteins decreased with older age exclusively in amyloid abnormal participants and these were enriched for extracellular matrix organization. Discussion: We found amyloid-independent and -dependent CSF proteome changes with older age, perhaps representing physiological aging and early AD pathology.

Regional Strength of Large-Scale Functional Brain Networks is Associated with Regional Volumes in Older Adults and in Alzheimer's Disease.

Background: The association between regional volumes and resting-state functional networks was tested within the default-mode network (DMN), influenced by Alzheimer pathology, salience network (SalN), not under similar pathological influence, and sensorimotor network (SMN), usually spared by pathology. Methods: A total of 148 participants, with Alzheimer's disease (AD) dementia, mild cognitive impairment (MCI), and healthy controls underwent multimodal brain magnetic resonance imaging (MRI). Functional network identification was achieved with group-level independent-component analysis of functional MRI (fMRI) scans. T1 weighted images were also analyzed. Ten regions of interest (ROI) were defined in core hubs of the three networks. Gray-matter volume/functional network strength association was tested within-ROI and cross-ROI in each group by using partial-correlation models and ROI-to-ROI, ROI-to-voxel, and voxel-to-voxel correlations. Results: In controls, a negative association was found between right inferior-parietal volumes and SMN expression in the left precentral gyrus, as revealed by ROI-to-ROI models. In AD, DMN expression was positively associated with the volume of the left insula and the right inferior parietal lobule, and SalN expression was positively associated with volume of the left inferior parietal lobule. ROI-to-voxel models revealed significant associations between the volume of the posterior cingulate cortex and SMN expression in sensorimotor and premotor regions. No significant findings emerged in the MCI nor from voxel-to-voxel analyses. Discussion: Regional volumes of main network hubs are significantly associated with hemodynamic network expression, although patterns are intricate and dependent on diagnostic status. Since distinct networks are differentially influenced by Alzheimer pathology, it appears that pathology plays a significant role in influencing the association between regional volumes and regional functional network strength.

Obesity and Brain Vulnerability in Normal and Abnormal Aging: A Multimodal MRI Study.

BACKGROUND: How the relationship between obesity and MRI-defined neural properties varies across distinct stages of cognitive impairment due to Alzheimer's disease is unclear. OBJECTIVE: We used multimodal neuroimaging to clarify this relationship. METHODS: Scans were acquired from 47 patients clinically diagnosed with mild Alzheimer's disease dementia, 68 patients with mild cognitive impairment, and 57 cognitively healthy individuals. Voxel-wise associations were run between maps of gray matter volume, white matter integrity, and cerebral blood flow, and global/visceral obesity. RESULTS: Negative associations were found in cognitively healthy individuals between obesity and white matter integrity and cerebral blood flow of temporo-parietal regions. In mild cognitive impairment, negative associations emerged in frontal, temporal, and brainstem regions. In mild dementia, a positive association was found between obesity and gray matter volume around the right temporoparietal junction. CONCLUSION: Obesity might contribute toward neural tissue vulnerability in cognitively healthy individuals and mild cognitive impairment, while a healthy weight in mild Alzheimer's disease dementia could help preserve brain structure in the presence of age and disease-related weight loss.

Severe Obstructive Sleep Apnea and Increased Cortical Amyloid-ß Deposition.

BACKGROUND: The suggested association between severe obstructive sleep apnea (OSA) and risk of Alzheimer's disease (AD) needs further study. Only few recent reports exist on associations between brain amyloid-ß (Aß) burden and severe OSA in middle-aged patients. OBJECTIVE: Examine the possible presence of cortical Aß accumulation in middle-aged patients with severe OSA. METHODS: We performed detailed multimodal neuroimaging in 19 cognitive intact patients (mean 44.2 years) with severe OSA (Apnea-Hypopnea Index >30 h-1). Known etiological factors for possible Aß accumulation were used as exclusion criteria. Aß uptake was studied with [11C]-PiB-PET, glucose metabolism with [18F]-FDG-PET, and structural imaging with 3.0T MRI. RESULTS: When analyzed individually, in [11C]-PiB-PET a substantial number (∼32%) of the patients exhibited statistically significant evidence of increased cortical Aß uptake based on elevated regional Z-score values, mostly seen bilaterally in the precuneus and posterior cingulum regions. Cortical glucose hypometabolism in [18F]-FDG-PET was seen in two patients. MRI did not show structural changes suggestive of AD-related pathology. CONCLUSION: Increased [11C]-PiB uptake was seen in middle-aged cognitively intact patients with severe OSA. These findings are similar to those described in cognitive unimpaired older OSA patients. The changes in cortical Aß uptake suggest that severe OSA itself may predispose to alterations related to AD already in middle-age. Aß clearance may be compromised without simultaneous evidence of metabolic or structural alterations. The results emphasize the importance of early diagnostics and proper treatment of severe OSA in cognitively intact middle-aged subjects, possibly diminishing the individual risk for later cognitive dysfunction.

Production of Inflected Novel Words in Older Adults With and Without Dementia.

While cognitive changes in aging and neurodegenerative disease have been widely studied, language changes in these populations are less well understood. Inflecting novel words in a language with complex inflectional paradigms provides a good opportunity to observe how language processes change in normal and abnormal aging. Studies of language acquisition suggest that children inflect novel words based on their phonological similarity to real words they already know. It is unclear whether speakers continue to use the same strategy when encountering novel words throughout the lifespan or whether adult speakers apply symbolic rules. We administered a simple speech elicitation task involving Finnish-conforming pseudo-words and real Finnish words to healthy older adults, individuals with mild cognitive impairment, and individuals with Alzheimer's disease (AD) to investigate inflectional choices in these groups and how linguistic variables and disease severity predict inflection patterns. Phonological resemblance of novel words to both a regular and an irregular inflectional type, as well as bigram frequency of the novel words, significantly influenced participants' inflectional choices for novel words among the healthy elderly group and people with AD. The results support theories of inflection by phonological analogy (single-route models) and contradict theories advocating for formal symbolic rules (dual-route models).

Metabolic Profiles Help Discriminate Mild Cognitive Impairment from Dementia Stage in Alzheimer's Disease.

Accurate differentiation between neurodegenerative diseases is developing quickly and has reached an effective level in disease recognition. However, there has been less focus on effectively distinguishing the prodromal state from later dementia stages due to a lack of suitable biomarkers. We utilized the Disease State Index (DSI) machine learning classifier to see how well quantified metabolomics data compares to clinically used cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD). The metabolic profiles were quantified for 498 serum and CSF samples using proton nuclear magnetic resonance spectroscopy. The patient cohorts in this study were dementia (with a clinical AD diagnosis) (N = 359), mild cognitive impairment (MCI) (N = 96), and control patients with subjective memory complaints (N = 43). DSI classification was conducted for MCI (N = 51) and dementia (N = 214) patients with low CSF amyloid-ß levels indicating AD pathology and controls without such amyloid pathology (N = 36). We saw that the conventional CSF markers of AD were better at classifying controls from both dementia and MCI patients. However, quantified metabolic subclasses were more effective in classifying MCI from dementia. Our results show the consistent effectiveness of traditional CSF biomarkers in AD diagnostics. However, these markers are relatively ineffective in differentiating between MCI and the dementia stage, where the quantified metabolomics data provided significant benefit.

Gait Disturbances are Associated with Increased Cognitive Impairment and Cerebrospinal Fluid Tau Levels in a Memory Clinic Cohort.

BACKGROUND: Gait analysis with accelerometers is a relatively inexpensive and easy to use method to potentially support clinical diagnoses of Alzheimer's disease and other dementias. It is not clear, however, which gait features are most informative and how these measures relate to Alzheimer's disease pathology. OBJECTIVE: In this study, we tested if calculated features of gait 1) differ between cognitively normal subjects (CN), mild cognitive impairment (MCI) patients, and dementia patients, 2) are correlated with cerebrospinal fluid (CSF) biomarkers related to Alzheimer's disease, and 3) predict cognitive decline. METHODS: Gait was measured using tri-axial accelerometers attached to the fifth lumbar vertebra (L5) in 58 CN, 58 MCI, and 26 dementia participants, while performing a walk and dual task. Ten gait features were calculated from the vertical L5 accelerations, following principal component analysis clustered in four domains, namely pace, rhythm, time variability, and length variability. Cognitive decline over time was measured using MMSE, and CSF biomarkers were available in a sub-group. RESULTS: Linear mixed models showed that dementia patients had lower pace scores than MCI patients and CN subjects (p < 0.05). In addition, we found associations between the rhythm domain and CSF-tau, especially in the dual task. Gait was not associated with CSF Aß42 levels and cognitive decline over time as measured with the MMSE. CONCLUSION: These findings suggest that gait - particularly measures related to pace and rhythm - are altered in dementia and have a direct link with measures of neurodegeneration.

Olfactory identification in non-demented elderly population and in mild cognitive impairment: a comparison of performance in clinical odor identification versus Boston Naming Test.

Performance in olfactory identification was studied in mild cognitive impairment (MCI), using slightly expanded standard clinical approach to study the olfactory nerve. Four hundred and eighty-six cognitively normal individuals and 72 individuals with MCI underwent spontaneous and cued odor identification and delayed odor recall. Performance in these was compared with the performance in the CERAD version of the Boston Naming Test (BNT). The individuals with MCI scores significantly worse in all tests compared with controls, but the performance in tests assessing odor were less impaired than performance in the BNT. Standard assessment of olfactory nerve function is not sufficient to study cognitive impairment in MCI.

Cortical thickness analysis to detect progressive mild cognitive impairment: a reference to Alzheimer's disease.

BACKGROUND/AIMS: Mild cognitive impairment (MCI) is associated with an increased risk of Alzheimer's disease (AD). It would be advantageous to be able to distinguish the characteristics of those MCI patients with a high probability to progress to AD if one wishes to monitor the disease development and treatment. METHODS: We assessed the baseline MRI and maximum of 7 years clinical follow-up data of 60 MCI subjects in order to examine differences in cortical thickness (CTH) between the progressive MCI (P-MCI) and stable MCI (S-MCI) subjects. CTH was measured using an automatic computational surface-based method. During the follow-up, 15 MCI subjects converted to AD on average 1.9 +/- 1.3 years after the baseline examination, while 45 MCI subjects remained stable. RESULTS: The P-MCI group displayed significantly reduced CTH bilaterally in the superior and middle frontal, superior, middle and inferior temporal, fusiform and parahippocampal regions as well as the cingulate and retrosplenial cortices and also in the right precuneal and paracentral regions compared to S-MCI subjects. CONCLUSIONS: Analysis of CTH could be used in conjunction with neuropsychological testing to identify those subjects with imminent conversion from MCI to AD several years before dementia diagnosis.

Effects of morphological family on word recognition in normal aging, mild cognitive impairment, and Alzheimer's disease.

Reading a word activates morphologically related words in the mental lexicon. People with Alzheimer's disease (AD) or Mild Cognitive Impairment (MCI) often have difficulty retrieving words, though the source of this problem is not well understood. To better understand the word recognition process in aging and in neurodegenerative disorders such as MCI and AD, we investigated the nature of the activation of morphologically related family members in 22 Finnish speakers with AD, 24 with MCI, and 17 cognitively healthy elderly. We presented Finnish monomorphemic (base form) nouns in a single-word lexical decision experiment to measure the speed of word recognition and its relation to morphological and lexical variables. Morphological variables included morphological family size (separate for compounds and derived words) and pseudo-morphological family size (including the set of words that have a partially overlapping form but that do not share an actual morpheme, e.g., pet and carpet, or corn and corner). Pseudo-morphological family size was included to examine the influence of words with orthographic (or phonological) overlap that are not semantically related to the target words. Our analyses revealed that younger and elderly controls and individuals with MCI or AD were influenced by true morphological overlap (overlapping forms that also share meaning), as well as by the word's pseudo-morphological family. However, elderly controls and individuals with MCI or AD seemed to rely more on form overlap than young adults. This demonstrates that an increased reliance on form-based aspects of language processing in Alzheimer's disease is not necessarily due to a partial loss of access to semantics, but might be explained in part by a common age-related change of processes in written word recognition.