Postural control deficits due to bilateral pyramidal tract lesions exemplified by hereditary spastic paraplegia (HSP) originate from increased feedback time delay and reduced long-term error corrections.

Pyramidal tract lesions determine the clinical syndrome of Hereditary Spastic Paraplegia (HSP). The clinical impairments of HSP are typically exemplified by their deficits in mobility, leading to falls and injuries. The first aim of this study was to identify the cause for postural abnormalities caused by pyramidal tract lesions in HSP. The second aim was to specify the effect of treadmill training for postural abnormalities. We examined nine HSP patients before and after treadmill training, as well as nine healthy control subjects during perturbed and unperturbed stance. We found that HSP was associated with larger sway amplitudes and velocities. Body excursions following platform tilts were larger, and upper body excursions showed a phase lead. Model-based analysis detected a greater time delay and a reduced long-term error correction of postural reactions in the center of mass. HSP patients performed significantly better in clinical assessments after treadmill training. In addition, treadmill training reduced sway amplitudes and body excursions, most likely by increasing positional and velocity error correction gain as a compensatory mechanism, while the time delay and long-term error correction gain remained largely unaffected. Moreover, the upper body's phase lead was reduced. We conclude that HSP leads to very specific postural impairments. While postural control generally benefits from treadmill training, the effect seems to mainly rely on compensatory mechanisms, whereas the original deficits are not affected significantly.

The economic impact of a local, collaborative, stepped, and personalized care management for older people with chronic diseases: results from the randomized comparative effectiveness LoChro-trial.

BACKGROUND: Within the ageing population of Western societies, an increasing number of older people have multiple chronic conditions. Because multiple health problems require the involvement of several health professionals, multimorbid older people often face a fragmented health care system. To address these challenges, in a two-group parallel randomized controlled trial, a newly developed care management approach (LoChro-Care) was compared with usual care. METHODS: LoChro-Care consists of individualized care provided by chronic care managers with 7 to 16 contacts over 12 months. Patients aged 65 + with chronic conditions were recruited from inpatient and outpatient departments. Healthcare utilization costs are calculated by using an adapted version of the generic, self-reporting FIMA©-questionnaire with the application of standardized unit costs. Questionnaires were given at 3 time points (T0 baseline, T1 after 12 months, T2 after 18 months). The primary outcome was overall 3-month costs of healthcare utilization at T1 and T2. The data were analyzed using generalized linear models with log-link and gamma distribution and adjustment for age, sex, level of care as well as the 3-month costs of care at T0. RESULTS: Three hundred thirty patients were analyzed. The results showed no significant difference in the costs of healthcare utilization between participants who received LoChro-Care and those who received usual care, regardless of whether the costs were evaluated 12 (adjusted mean difference € 130.99, 95%CI €-1477.73 to €1739.71, p = 0.873) or 18 (adjusted mean difference €192.99, 95%CI €-1894.66 to €2280.65, p = 0.856) months after the start of the intervention. CONCLUSION: This study revealed no differences in costs between older people receiving LoChro-Care or usual care. Before implementing the intervention, further studies with larger sample sizes are needed to provide robust evidence on the cost effects of LoChro-Care. TRIAL REGISTRATION: German Clinical Trials Register (DRKS): DRKS00013904, https://drks.de/search/de/trial/DRKS00013904 ; date of first registration 02/02/2018.

Local, collaborative, stepped, and personalized care management for older people with chronic diseases - results from the randomized controlled LoChro-trial.

BACKGROUND: In the aging population of Western societies, an increasing number of older adults have multiple chronic diseases. As multifaceted health problems imply the involvement of several healthcare professionals, multimorbid older people frequently face a fragmentation of health care. Addressing these challenges, we developed a local, collaborative, stepped, and personalized care management approach (LoChro-Care) and evaluated its effectiveness. METHODS: A two-group, parallel randomized controlled trial was conducted comparing LoChro-Care recipients (IG) to participants with usual care (CG). Patients aged 65 + with chronic conditions were recruited at inpatient and outpatient departments of the Medical Center, University of Freiburg. Participants were allocated using block randomization (nIG = 261, nCG = 263). LoChro-Care comprised individualized care provided by chronic care managers with 7 to 13 contacts over 12 months. Questionnaires were given at 3 time points (T0: baseline, T1: after 12 months, T2: after 18 months). The primary outcome was the physical, psychological, and social health status represented by a composite score of functional health and depressive symptoms. Secondary outcomes were the participants' evaluation of their health care situation, health-related quality of life (HRQL), and life-satisfaction (LS). The data were analyzed using linear mixed modelling. RESULTS: We analyzed N = 491 participants (nIG = 244, nCG = 247), aged M = 76.78 years (SD = 6.35). For the composite endpoint, neither a significant difference between IG and CG (p = .88) nor a group-time interaction (p = .52; p = .88) could be observed. Participants in both groups showed a significant decline on the primary outcome between T0 and T2 (p < .001). Post hoc analyses revealed a decline in both functional health (p < .001) and depressive symptoms (p = .02). Both groups did not differ in their evaluation of their health care situation (p = .93), HRQL (p = .44) or LS (p = .32). Relevant confounding variables were female gender and multimorbidity. CONCLUSION: Supporting patients' self-management in coordinating their individual care network through LoChro-Care did not result in any significant effect on the primary and secondary outcomes. A decline of functional health and depressive symptoms was observed among all participants. Potential future intervention adaptations are discussed, such as a more active case management through direct referral to (in-)formal support, an earlier treatment initiation, and the consideration of specific sociodemographic factors in care management planning. TRIAL REGISTRATION: German Clinical Trials Register (DRKS): DRKS00013904 (02.02.2018), https://drks.de/search/de/trial/DRKS00013904.

[Interprofessional team building-An interuniversity qualification program]. / Interprofessionelle Teambildung ­ ein hochschulübergreifendes Qualifizierungsprogramm.

BACKGROUND: With the growing number of older and old patients as well as patients affected by multimorbidity, cognitive impairments and frailty in hospital and expansion of long-term care, the challenges in the various geriatric and gerontological care settings are also increasing. Social networks and resources become fragile due to the changing family structures. A strong interprofessional team building and networking of the main actors in the nursing and healthcare systems become necessary. OBJECTIVE: A qualification program for students of medicine, social work and relevant study courses for nursing was established. In this program participants should collectively learn to deal with the concerns and needs of geriatric patients in a case-related manner and to develop suitable plans for treatment and interventions. METHOD: The qualification program for interprofessional team building was evaluated during the development phase as a pilot project and scientifically evaluated (n = 78) using the Freiburg questionnaire on interprofessional learning evaluation (FILE). RESULTS: The program experienced a high level of approval by approximately 98% of the participants. The measurement of change showed an improvement in team skills and ability to work in a team. CONCLUSION: Opening up a learning field for interprofessional learning and working to students of different disciplines and professions during their studies creates a good basis for successful interprofessional team building in the subsequent professional practice. The interuniversity and interprofessional teaching project presented is now firmly anchored in the curriculum at the participating universities with the teaching module "The geriatric patient". It is therefore a possible model for similar projects.

Patient-centeredness in the multimorbid elderly: a focus group study.

BACKGROUND: Patient-centeredness (PC) aims to adapt health care to the individual needs and preferences of patients. An existing integrative model of PC comprises several dimensions of PC which have not yet been investigated from the patients' perspective. Older patients with multimorbidity represent a target group for patient-centered care, as their care needs are particularly complex and should be addressed individually. We aimed to assess the perspective that older patients with multimorbidity have of patient-centered care and to examine the transferability of the integrative model of PC to this specific population. METHOD: We performed 4 guided focus group interviews with a total of 20 older individuals with multimorbidity. The focus group interviews were audio-recorded and transcribed verbatim. Patients' statements were content-analyzed applying an a priori designed system of categories that included the dimensions of PC from the integrative model and the additional category 'prognosis and life expectancy', which had emerged from an initial literature search on aspects of PC specific to the multimorbid elderly. RESULTS: The new category 'prognosis and life expectancy' was confirmed and expanded to 'individual care needs related to aging and chronic disesase'. All dimensions of our integrative PC model were confirmed for older patients with multimorbidity. Among these, we found that eight dimensions (individual care needs related to aging and chronic disease, biopsychosocial perspective, clinician-patient communication, essential characteristics of the clinician, clinician-patient-relationship, involvement of family and friends, coordination and continuity of care, access to care) were complemented by aspects specific to this target population. CONCLUSIONS: The integrative PC model is applicable to the population of older patients with multimorbidity. For a population-specific adaptation, it might be complemented by the dimension 'individual care needs in aging and chronic disease', in conjunction with age-specific aspects within existing dimensions. Together with corresponding results from a Delphi survey, our adapted PC model will serve as the basis for a subsequent systematic review of instruments measuring PC in older patients with multimorbidity. TRIAL REGISTRATION: PROSPERO ( https://www.crd.york.ac.uk/prospero; CRD42018084057; 2018/02/01), German Clinical Trials Register ( www.drks.de ; DRKS00013309; 2018/01/23).

[Integrated care management for older people with chronic diseases in domesticity: evidence from Cochrane reviews]. / Integriertes Versorgungsmanagement für chronisch erkrankte ältere Menschen in der eigenen Häuslichkeit: Evidenz aus Cochrane-Reviews.

BACKGROUND: The number of multiple chronically ill older people is increasing and multimorbidity is associated with high utilization of health services. Integrated care management is increasingly used to address this problem; however, there is a substantial lack of reliable data on its effectiveness in this target group. OBJECTIVE: To assess the effectiveness of components of integrated care management in adults of all ages and to estimate the transferability to older, multimorbid people in Germany. METHODS: A systematic search was carried out in the Cochrane Library for Cochrane reviews (CR) on (a) the 13 most frequent health problems in old age, which (b) evaluated components of integrated care management in (c) adults of all ages. Experts assessed the transferability of the included CR to multiple chronically ill older people in Germany. RESULTS: Out of 1412 hits 126 CR were included. Regarding independence and functional health outcomes, 25 CR showed clinically relevant results with at least a moderate level of evidence. The following intervention components were estimated to be transferable and could be adapted to be part of an effective integrated care management for multimorbid chronically ill older people, specified by indications and taking identified barriers into account: (1) physical activation, (2) multidisciplinary interventions (3) interventions that enhance self-management, (4) cognitive therapy modalities, (5) telemedical interventions and (6) disease management programs. CONCLUSION: The effectiveness of the identified components in frail older patients should be assessed in care-related and patient-related randomized controlled studies.

Intrinsic Alertness Is Impaired in Patients with Nigrostriatal Degeneration: A Prospective Study with Reference to [123I]FP-CIT SPECT and [18F]FDG PET.

BACKGROUND: Variations in alertness and attention are common in Lewy body diseases (LBD) and among the core features of dementia with Lewy bodies (DLB). Dopamine transporter SPECT is an accurate biomarker of nigrostriatal degeneration (NSD) in LBD. OBJECTIVE: The present study investigated performance on a computerized alertness test as a potential measure of attention in patients with NSD compared to patients without NSD. METHODS: Thirty-six patients with cognitive impairment plus at least one core feature of DLB referred for [123I]FP-CIT SPECT imaging were prospectively recruited. Performance in a computerized test of intrinsic alertness was compared between patients with and those without NSD as assessed by [123I]FP-CIT SPECT. RESULTS: Reaction times to auditory stimuli (adjusted for age, sex, and education) were significantly longer in patients with NSD compared to those with a normal [123I]FP-CIT SPECT scan (p < 0.05). Statistical analyses revealed no significant differences comparing reaction times to visual stimuli or dispersion of reaction times between groups. Exploratory analysis in a subgroup of patients with available [18F]FDG PET revealed that longer reaction times were associated with decreased glucose metabolism in the prefrontal cortex (statistical parametric mapping, adjusted for age and sex; p < 0.005, cluster extent > 50 voxels). CONCLUSION: Computerized assessment of auditory reaction times is able to detect alertness deficits in patients with NSD and might help to measure alertness deficits in patients with LBD and NSD. Future studies in larger samples are needed to evaluate the diagnostic utility of computerized alertness assessment for the differential diagnosis of LBD.

Abnormal trunk control determines postural abnormalities in Amyotrophic Lateral Sclerosis.

BACKGROUND: Postural instability in Amyotrophic Lateral Sclerosis (ALS) occurs at an early stage of the disease and often results in falls. As ALS is considered a multisystem neurodegenerative disorder, postural instability may result from motor, sensory and central processing deficits. OBJECTIVE AND METHODS: We analysed postural control of 12 ALS patients and 12 healthy age-matched control subjects. Postural control was characterised by spontaneous sway measures and measures of postural reactions to pseudorandom anterior-posterior platform tilts, which were then correlated with clinical test scores. RESULTS: Spontaneous sway amplitudes and velocities were significantly larger and sway frequencies higher in ALS patients than in control subjects. ALS patients' body excursions following platform tilts were smaller, with relatively higher upper body excursions. We found high correlations between abnormal postural reactions and clinical tests representing motor or balance deficits. CONCLUSIONS: We conclude that ALS patients' postural abnormalities are mainly determined by an abnormal axial control and abnormally small body excursions as a function of support surface tilts, seemingly indicating better postural stabilization than control subjects. The latter contradicts the hypothesis that muscle weakness is the main source for this deficit. Instead, we suggest an altered central control strategy.

Local, collaborative, stepped and personalised care management for older people with chronic diseases (LoChro): study protocol of a randomised comparative effectiveness trial.

BACKGROUND: Multimorbid older adults suffering from a long-term health condition like depression, diabetes mellitus type 2, dementia or frailty are at high risk of losing their autonomy. Disability and multimorbidity in the older population are associated with social inequality and lead to soaring costs. Our local, collaborative, stepped and personalised care management for older people with chronic diseases (LoChro-Care) aims at improving outcomes for older multimorbid patients with chronic conditions whose social and medical care must be improved. METHODS: The study will evaluate the effects of LoChro-Care on functional health, depressive symptoms and satisfaction with care, resource utilisation as well as health costs in older persons with long-term conditions. The trial will compare the effectiveness of LoChro-Care and usual care in a cross-sectoral setting from hospital to community care. We will recruit 606 older adults (65+) admitted to local hospital inpatient or outpatient departments who are at risk of loss of independence. Half of them will be randomised to receive the LoChro-Care intervention, comprising seven to 16 contacts with chronic care managers (CCM) within 12 months. The hypothesis that LoChro-Care will result in better patient-centred outcomes will be tested through mixed-method process and outcome evaluation and valid measures completed at baseline and at 12 and 18 months. Cost-effectiveness analyses from the healthcare perspective will include incremental cost-effectiveness ratios. DISCUSSION: The trial will provide evidence about the effectiveness of local, collaborative, stepped and personalised care management for multimorbid patients with more than one functional impairment or chronic condition. Positive results will be a first step towards the implementation of a systematic cross-sectoral chronic care management to facilitate the appropriate use of available medical and nursing services and to enhance self-management of older people. TRIAL REGISTRATION: German Clinical Trials Register (DRKS): DRKS00013904 ; Trial registration date: 02. February 2018.

Voxel-wise deviations from healthy aging for the detection of region-specific atrophy.

The identification of pathological atrophy in MRI scans requires specialized training, which is scarce outside dedicated centers. We sought to investigate the clinical usefulness of computer-generated representations of local grey matter (GM) loss or increased volume of cerebral fluids (CSF) as normalized deviations (z-scores) from healthy aging to either aid human visual readings or directly detect pathological atrophy. Two experienced neuroradiologists rated atrophy in 30 patients with Alzheimer's disease (AD), 30 patients with frontotemporal dementia (FTD), 30 with dementia due to Lewy-body disease (LBD) and 30 healthy controls (HC) on a three-point scale in 10 anatomical regions as reference gold standard. Seven raters, varying in their experience with MRI diagnostics rated all cases on the same scale once with and once without computer-generated volume deviation maps that were overlaid on anatomical slices. In addition, we investigated the predictive value of the computer generated deviation maps on their own for the detection of atrophy as identified by the gold standard raters. Inter and intra-rater agreements of the two gold standard raters were substantial (Cohen's kappa κ > 0.62). The intra-rater agreement of the other raters ranged from fair (κ = 0.37) to substantial (κ = 0.72) and improved on average by 0.13 (0.57 < κ < 0.87) when volume deviation maps were displayed. The seven other raters showed good agreement with the gold standard in regions including the hippocampus but agreement was substantially lower in e.g. the parietal cortex and did not improve with the display of atrophy scores. Rating speed increased over the course of the study and irrespective of the presentation of voxel-wise deviations. Automatically detected large deviations of local volume were consistently associated with gold standard atrophy reading as shown by an area under the receiver operator characteristic of up to 0.95 for the hippocampus region. When applying these test characteristics to prevalences typically found in a memory clinic, we observed a positive or negative predictive value close to or above 0.9 in the hippocampus for almost all of the expected cases. The volume deviation maps derived from CSF volume increase were generally better in detecting atrophy. Our study demonstrates an agreement of visual ratings among non-experts not further increased by displaying, region-specific deviations of volume. The high predictive value of computer generated local deviations independent from human interaction and the consistent advantages of CSF-over GM-based estimations should be considered in the development of diagnostic tools and indicate clinical utility well beyond aiding visual assessments.

Separating Symptomatic Alzheimer's Disease from Depression based on Structural MRI.

Older patients with depression or Alzheimer's disease (AD) at the stage of early dementia or mild cognitive impairment may present with objective cognitive impairment, although the pathology and thus therapy and prognosis differ substantially. In this study, we assessed the potential of an automated algorithm to categorize a test set of 65 T1-weighted structural magnetic resonance images (MRI). A convenience sample of elderly individuals fulfilling clinical criteria of either AD (n = 28) or moderate and severe depression (n = 37) was recruited from different settings to assess the potential of the pattern recognition method to assist in the differential diagnosis of AD versus depression. We found that our algorithm learned discriminative patterns in the subject's grey matter distribution reflected by an area under the receiver operator characteristics curve of up to 0.83 (confidence interval ranged from 0.67 to 0.92) and a balanced accuracy of 0.79 for the separation of depression from AD, evaluated by leave-one-out cross validation. The algorithm also identified consistent structural differences in a clinically more relevant scenario where the data used during training were independent from the data used for evaluation and, critically, which included five possible diagnoses (specifically AD, frontotemporal dementia, Lewy body dementia, depression, and healthy aging). While the output was insufficiently accurate to use it directly as a means for classification when multiple classes are possible, the continuous output computed by the machine learning algorithm differed between the two groups that were investigated. The automated analysis thus could complement, but not replace clinical assessments.

Structured relearning of activities of daily living in dementia: the randomized controlled REDALI-DEM trial on errorless learning.

BACKGROUND: Errorless learning (EL) is a method for optimizing learning, which uses feed-forward instructions in order to prevent people from making mistakes during the learning process. The majority of previous studies on EL taught patients with dementia artificial tasks of little or no relevance for their daily lives. Furthermore, only a few controlled studies on EL have so far been performed and just a handful of studies have examined the long-term effects of EL. Tasks were not always trained in the patients' natural or home environment, limiting the external validity of these studies. This multicenter parallel randomized controlled trial examines the effects of EL compared with trial and error learning (TEL) on the performance of activities of daily living in persons with Alzheimer's or mixed-type dementia living at home. METHODS: Patients received nine 1-hour task training sessions over eight weeks using EL or TEL. Task performance was measured using video observations at week 16. Secondary outcome measures were task performance measured at week 26, satisfaction with treatment, need for assistance, challenging behavior, adverse events, resource utilization and treatment costs. RESULTS: A total of 161 participants were randomized, of whom 71 completed the EL and 74 the TEL arm at week 11. Sixty-nine EL patients and 71 TEL patients were assessed at the 16-week follow-up (the primary measurement endpoint). Intention-to-treat analysis showed a significantly improved task performance in both groups. No significant differences between the treatment groups were found for primary or secondary outcomes. CONCLUSIONS: Structured relearning improved the performance of activities of daily living. Improvements were maintained for 6 months. EL had no additional effect over TEL. TRIAL REGISTRATION: German Register of Clinical Trials DRKS00003117 . Registered 31 May 2011.

Category and design fluency in mild cognitive impairment: Performance, strategy use, and neural correlates.

The exploration and retrieval of words during category fluency involves different strategies to improve or maintain performance. Deficits in that task, which are common in patients with amnestic mild cognitive impairment (aMCI), mirror either impaired semantic memory or dysfunctional executive control mechanisms. Relating category fluency to tasks that place greater demands on either semantic knowledge or executive functions might help to determine the underlying cognitive process. The aims of this study were to compare performance and strategy use of 20 patients with aMCI to 30 healthy elderly controls (HC) and to identify the dominant component (either executive or semantic) for better task performance in category fluency. Thus, the relationship between category fluency, design fluency and naming was examined. As fluency tasks have been associated with the superior frontal gyrus (SFG), the inferior frontal gyrus (IFG), and the temporal pole, we further explored the relationship between gray matter volume in these areas and both performance and strategy use. Patients with aMCI showed significantly lower performance and significantly less strategy use during fluency tasks compared to HC. However, both groups equally improved their performance when repeatedly confronted with the same task. In aMCI, performance during category fluency was significantly predicted by design fluency performance, while in HC, it was significantly predicted by naming performance. In HC, volume of the SFG significantly predicted both category and design fluency performance, and strategy use during design fluency. In aMCI, the SFG and the IFG predicted performance during both category and design fluency. The IFG significantly predicted strategy use during category fluency in both groups. The reduced category fluency performance in aMCI seems to be primarily due to dysfunctional executive control mechanisms rather than impaired semantic knowledge. This finding is directly relevant to patients in the different stages of Alzheimer's disease as it links the known semantic fluency deficit in this population to executive functions. Although patients with aMCI are impaired in both performance and strategy use compared to HC, they are able to increase performance over time. However, only HC were able to significantly improve the utilization of fluency strategies in both category and design fluency over time. HC seem to rely more heavily on the SFG during fluency tasks, while in patients with aMCI additional frontal brain areas are involved, possibly reflecting compensational processes.

Contribution of the Cholinergic System to Verbal Memory Performance in Mild Cognitive Impairment.

Acetylcholine is critically involved in modulating learning and memory function, which both decline in neurodegeneration. It remains unclear to what extent structural and functional changes in the cholinergic system contribute to episodic memory dysfunction in mild cognitive impairment (MCI), in addition to hippocampal degeneration. A better understanding is critical, given that the cholinergic system is the main target of current symptomatic treatment in mild to moderate Alzheimer's disease. We simultaneously assessed the structural and functional integrity of the cholinergic system in 20 patients with MCI and 20 matched healthy controls and examined their effect on verbal episodic memory via multivariate regression analyses. Mediating effects of either cholinergic function or hippocampal volume on the relationship between cholinergic structure and episodic memory were computed. In MCI, a less intact structure and function of the cholinergic system was found. A smaller cholinergic structure was significantly correlated with a functionally more active cholinergic system in patients, but not in controls. This association was not modulated by age or disease severity, arguing against compensational processes. Further analyses indicated that neither functional nor structural changes in the cholinergic system influence verbal episodic memory at the MCI stage. In fact, those associations were fully mediated by hippocampal volume. Although the cholinergic system is structurally and functionally altered in MCI, episodic memory dysfunction results primarily from hippocampal neurodegeneration, which may explain the inefficiency of cholinergic treatment at this disease stage.

No difference in paired associative stimulation induced cortical neuroplasticity between patients with mild cognitive impairment and elderly controls.

OBJECTIVE: Paired associative stimulation (PAS) is a widely used transcranial magnetic stimulation (TMS) paradigm to induce synaptic long-term potentiation (LTP)-like plasticity in the intact human brain. The PAS effect is reduced in Alzheimer's dementia (AD) but has not yet been assessed in patients with mild cognitive impairment (MCI). METHODS: PAS was assessed in a group of 24 MCI patients and 24 elderly controls. MCI patients were further stratified by their cognitive profile as well as hippocampal atrophy and Apolipoprotein E (ApoE) genotype. RESULTS: There was no difference in PAS effects between MCI patients and healthy controls. MCI patients tended to show a higher response rate and an average PAS effect. PAS effects were not correlated with markers of disease severity or ApoE genotype but were more pronounced in individuals with shorter sleep duration and in MCI subjects with higher ratings of subjective alertness. CONCLUSIONS: Contrary to our initial hypothesis, there was no clear difference in PAS between MCI patients and healthy controls. SIGNIFICANCE: Our results argue against a continuous reduction of LTP-like plasticity along the spectrum of clinical MCI when stratified by MCI-subtype, APOE genotype or hippocampus atrophy.

Applying Automated MR-Based Diagnostic Methods to the Memory Clinic: A Prospective Study.

Several studies have demonstrated that fully automated pattern recognition methods applied to structural magnetic resonance imaging (MRI) aid in the diagnosis of dementia, but these conclusions are based on highly preselected samples that significantly differ from that seen in a dementia clinic. At a single dementia clinic, we evaluated the ability of a linear support vector machine trained with completely unrelated data to differentiate between Alzheimer's disease (AD), frontotemporal dementia (FTD), Lewy body dementia, and healthy aging based on 3D-T1 weighted MRI data sets. Furthermore, we predicted progression to AD in subjects with mild cognitive impairment (MCI) at baseline and automatically quantified white matter hyperintensities from FLAIR-images. Separating additionally recruited healthy elderly from those with dementia was accurate with an area under the curve (AUC) of 0.97 (according to Fig. 4). Multi-class separation of patients with either AD or FTD from other included groups was good on the training set (AUC >  0.9) but substantially less accurate (AUC = 0.76 for AD, AUC = 0.78 for FTD) on 134 cases from the local clinic. Longitudinal data from 28 cases with MCI at baseline and appropriate follow-up data were available. The computer tool discriminated progressive from stable MCI with AUC = 0.73, compared to AUC = 0.80 for the training set. A relatively low accuracy by clinicians (AUC = 0.81) illustrates the difficulties of predicting conversion in this heterogeneous cohort. This first application of a MRI-based pattern recognition method to a routine sample demonstrates feasibility, but also illustrates that automated multi-class differential diagnoses have to be the focus of future methodological developments and application studies.

Asymmetries of amyloid-ß burden and neuronal dysfunction are positively correlated in Alzheimer's disease.

Clinical Alzheimer's disease affects both cerebral hemispheres to a similar degree in clinically typical cases. However, in atypical variants like logopenic progressive aphasia, neurodegeneration often presents asymmetrically. Yet, no in vivo imaging study has investigated whether lateralized neurodegeneration corresponds to lateralized amyloid-ß burden. Therefore, using combined (11)C-Pittsburgh compound B and (18)F-fluorodeoxyglucose positron emission tomography, we explored whether asymmetric amyloid-ß deposition in Alzheimer's disease is associated with asymmetric hypometabolism and clinical symptoms. From our database of patients who underwent positron emission tomography with both (11)C-Pittsburgh compound B and (18)F-fluorodeoxyglucose (n = 132), we included all amyloid-positive patients with prodromal or mild-to-moderate Alzheimer's disease (n = 69). The relationship between (11)C-Pittsburgh compound B binding potential and (18)F-fluorodeoxyglucose uptake was assessed in atlas-based regions of interest covering the entire cerebral cortex. Lateralizations of amyloid-ß and hypometabolism were tested for associations with each other and with type and severity of cognitive symptoms. Positive correlations between asymmetries of Pittsburgh compound B binding potential and hypometabolism were detected in 6 of 25 regions (angular gyrus, middle frontal gyrus, middle occipital gyrus, superior parietal gyrus, inferior and middle temporal gyrus), i.e. hypometabolism was more pronounced on the side of greater amyloid-ß deposition (range: r = 0.41 to 0.53, all P < 0.001). Stronger leftward asymmetry of amyloid-ß deposition was associated with more severe language impairment (P < 0.05), and stronger rightward asymmetry with more severe visuospatial impairment (at trend level, P = 0.073). Similarly, patients with predominance of language deficits showed more left-lateralized amyloid-ß burden and hypometabolism than patients with predominant visuospatial impairment and vice versa in several cortical regions. Associations between amyloid-ß deposition and hypometabolism or cognitive impairment were predominantly observed in brain regions with high amyloid-ß load. The relationship between asymmetries of amyloid-ß deposition and hypometabolism in cortical regions with high amyloid-ß load is in line with the detrimental effect of amyloid-ß burden on neuronal function. Asymmetries were also concordant with lateralized cognitive symptoms, indicating their clinical relevance.