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Background Copy number variants (CNVs) include deletions or multiplications spanning genomic regions. These regions vary in size and may span genes known to play a role in human diseases. As examples, duplications and triplications of SNCA have been shown to cause forms of Parkinson’s disease, while duplications of APP cause early onset Alzheimer’s disease (AD). Results Here, we performed a systematic analysis of CNVs in a Turkish dementia cohort in order to further characterize the genetic causes of dementia in this population. One hundred twenty-four Turkish individuals, either at risk of dementia due to family history, diagnosed with mild cognitive impairment, AD, or frontotemporal dementia, were whole-genome genotyped and CNVs were detected. We integrated family analysis with a comprehensive assessment of potentially disease-associated CNVs in this Turkish dementia cohort. We also utilized both dementia and non-dementia individuals from the UK Biobank in order to further elucidate the potential role of the identified CNVs in neurodegenerative diseases. We report CNVs overlapping the previously implicated genes ZNF804A, SNORA70B, USP34, XPO1, and a locus on chromosome 9 which includes a cluster of olfactory receptors and ABCA1. Additionally, we also describe novel CNVs potentially associated with dementia, overlapping the genes AFG1L, SNX3, VWDE, and BC039545. Conclusions Genotyping data from understudied populations can be utilized to identify copy number variation which may contribute to dementia.

[Objectives] Cholinergic dysfunction plays a prominent role in cognitive impairment in Parkinson's disease (PD). The aim of this study was to assess the relationship of baseline and longitudinal basal forebrain atrophy with cognitive decline and dementia in PD., [Methods] We included 106 non-demented PD patients, 19 PD dementia (PDD) patients and 42 controls with longitudinal structural MRI and cognitive testing. After 4.2 ± 1.8 years, 20 non-demented PD patients were diagnosed with dementia (PD-dementia converters), whereas the rest of PD patients remained non-demented (stable-PD). We compared MRI volumes of the medial septum/diagonal band (Ch1/Ch2) and nucleus basalis of Meynert (Ch4) between groups. Cox regression analyses were applied to test whether Ch1/Ch2 or Ch4 atrophy could predict future dementia and linear mixed models assessed their association with cognitive decline., [Results] Compared to controls, we found reduced Ch4 baseline volumes in PD-dementia converters (p = .003) and those who already had PDD (p < .001) but not in stable-PD. Over time, there was a greater loss in Ch1/Ch2 volumes in PD-dementia converters and PDD compared to the other groups (p = .004). Baseline and longitudinal Ch4 volumes were associated with cognition (p < .002) and longitudinal Ch4 atrophy predicted future dementia (p = .009)., [Conclusions] Atrophy of Ch4 precedes and predicts future dementia in PD and is followed by changes in Ch1/Ch2, reflecting a posterior-anterior pattern of basal forebrain atrophy. This pattern could be used to track the spread of cholinergic degeneration and identify patients at risk of developing dementia., Work at the authors' research center was supported by the European Research Council, the Swedish Research Council, the Knut and Alice Wallenberg foundation, the Marianne and Marcus Wallenberg foundation, the Strategic Research Area MultiPark (Multidisciplinary Research in Parkinson's disease) at Lund University, the Swedish Alzheimer Foundation, the Swedish Brain Foundation, The Parkinson foundation of Sweden, The Parkinson Research Foundation, the Skåne University Hospital Foundation, the Swedish federal government under the ALF agreement, the Swedish Foundation for Strategic Research (SSF), the Strategic Research Programme in Neuroscience at Karolinska Institutet (StratNeuro), Stiftelsen Olle Engkvist Byggmästare, Birgitta och Sten Westerberg, and the Åke Wiberg Foundation.

We investigated the brain atrophy distribution pattern and rate of regional atrophy change in Parkinson's disease (PD) in association with the cognitive status to identify the morphological characteristics of conversion to mild cognitive impairment (MCI) and dementia (PDD). T1-weighted longitudinal 3T MRI data (up to four follow-up assessments) from neuropsychologically well-characterized advanced PD patients (n = 172, 8.9 years disease duration) and healthy elderly controls (n = 85) enrolled in the LANDSCAPE study were longitudinally analyzed using a linear mixed effect model and atlas-based volumetry and cortical thickness measures. At baseline, PD patients presented with cerebral atrophy and cortical thinning including striatum, temporoparietal regions, and primary/premotor cortex. The atrophy was already observed in “cognitively normal” PD patients (PD-N) and was considerably more pronounced in cognitively impaired PD patients. Linear mixed effect modeling revealed almost similar rates of atrophy change in PD and controls. The group comparison at baseline between those PD-N whose cognitive performance remained stable (n = 42) and those PD-N patients who converted to MCI/PDD (“converter” cPD-N, n = 26) indicated suggested cortical thinning in the anterior cingulate cortex in cPD-N patients which was correlated with cognitive performance. Our results suggest that cortical brain atrophy has been already expanded in advanced PD patients without overt cognitive deficits while atrophy progression in late disease did not differ from “normal” aging regardless of the cognitive status. It appears that cortical atrophy begins early and progresses already in the initial disease stages emphasizing the need for therapeutic interventions already at disease onset. CA extern

Item does not contain fulltext IMPORTANCE: Cerebral amyloid-beta aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies. OBJECTIVE: To use individual participant data meta-analysis to estimate the prevalence of amyloid pathology as measured with biomarkers in participants with normal cognition, subjective cognitive impairment (SCI), or mild cognitive impairment (MCI). DATA SOURCES: Relevant biomarker studies identified by searching studies published before April 2015 using the MEDLINE and Web of Science databases and through personal communication with investigators. STUDY SELECTION: Studies were included if they provided individual participant data for participants without dementia and used an a priori defined cutoff for amyloid positivity. DATA EXTRACTION AND SYNTHESIS: Individual records were provided for 2914 participants with normal cognition, 697 with SCI, and 3972 with MCI aged 18 to 100 years from 55 studies. MAIN OUTCOMES AND MEASURES: Prevalence of amyloid pathology on positron emission tomography or in cerebrospinal fluid according to AD risk factors (age, apolipoprotein E [APOE] genotype, sex, and education) estimated by generalized estimating equations. RESULTS: The prevalence of amyloid pathology increased from age 50 to 90 years from 10% (95% CI, 8%-13%) to 44% (95% CI, 37%-51%) among participants with normal cognition; from 12% (95% CI, 8%-18%) to 43% (95% CI, 32%-55%) among patients with SCI; and from 27% (95% CI, 23%-32%) to 71% (95% CI, 66%-76%) among patients with MCI. APOE-epsilon4 carriers had 2 to 3 times higher prevalence estimates than noncarriers. The age at which 15% of the participants with normal cognition were amyloid positive was approximately 40 years for APOE epsilon4epsilon4 carriers, 50 years for epsilon2epsilon4 carriers, 55 years for epsilon3epsilon4 carriers, 65 years for epsilon3epsilon3 carriers, and 95 years for epsilon2epsilon3 carriers. Amyloid positivity was more common in highly educated participants but not associated with sex or biomarker modality. CONCLUSIONS AND RELEVANCE: Among persons without dementia, the prevalence of cerebral amyloid pathology as determined by positron emission tomography or cerebrospinal fluid findings was associated with age, APOE genotype, and presence of cognitive impairment. These findings suggest a 20- to 30-year interval between first development of amyloid positivity and onset of dementia.

An essential component of the brain extracellular space is the extracellular matrix contributing to the spatial assembly of cells by binding cell-surface adhesion molecules, supporting cell migration, differentiation, and tissue development. The most interesting and complex functions of the central nervous system are the abilities to encode new information (learning) and to store this information (memory). The creation of perineuronal nets, consisting mostly of chondroitin sulfate proteoglycans, stabilizes the synapses and memory trails and forms protective shields against neurodegenerative processes but terminates plasticity and the potential for recovery of the tissue. Age-related changes in the extracellular matrix composition and the extracellular space volume and permissivity are major determinants of the onset and development of the most common neurodegenerative disorder, Alzheimer's disease. In this regard, heparan sulfate proteoglycans, involved in amyloid clearance from the brain, play an important role in Alzheimer's disease and other types of neurodegeneration. Additional key players in the modification of the extracellular matrix are matrix metalloproteinases. Recent studies show that the extracellular matrix and matrix metalloproteinases are important regulators of plasticity, learning, and memory and might be involved in different neurological disorders like epilepsy, schizophrenia, addiction, and dementia. The identification of molecules and mechanisms that modulate these processes is crucial for the understanding of brain function and dysfunction and for the design of new therapeutic approaches targeting the molecular mechanism underlying these neurological disorders.

We discuss relevant aspects in two siblings with a neurodegenerative process of unclear aetiology who developed progressive dementia with global aphasia and hyperoral behaviour at the ages of 39 and 46 years and who died 6 and 5 years after disease onset. The cases were reported to the National Reference Center for TSE Surveillance in Gottingen, Germany. Detailed clinical examinations, CSF, blood samples, and copies of the important diagnostic tests (magnetic resonance imaging, electroencephalogram, laboratory tests) were obtained. Further neuropathological and genetic analyses were performed. Cerebral magnetic resonance imaging of both siblings showed prominent changes in signal intensity, especially in the left medial temporal cortex, but also the hippocampal formation. Neuropathological examination revealed spongiform changes, neuronal loss, and astrocytic gliosis, which are typical in Creutzfeldt-Jakob disease. However, no prion protein deposits were detectable by immunohistochemical analysis, Western blot, or PET blot, though abundant tau protein deposits were observed. A mutation in the coding region of the prion protein genes of both siblings was excluded. A detailed search of the literature revealed no other cases with a similar clinical and neuropathological appearance. While the disease aetiology remains unclear, the findings point to a neurodegenerative process and most likely a genetic disease.

Background Although diffusion tensor imaging has been a major research focus for Alzheimer’s disease in recent years, it remains unclear whether it has sufficient stability to have biomarker potential. To date, frequently inconsistent results have been reported, though lack of standardisation in acquisition and analysis make such discrepancies difficult to interpret. There is also, at present, little knowledge of how the biometric properties of diffusion tensor imaging might evolve in the course of Alzheimer’s disease. Methods The biomarker question was addressed in this study by adopting a standardised protocol both for the whole brain (tract-based spatial statistics), and for a region of interest: the midline corpus callosum. In order to study the evolution of tensor changes, cross-sectional data from very mild (N = 21) and mild (N = 22) Alzheimer’s disease patients were examined as well as a longitudinal cohort (N = 16) that had been rescanned at 12 months. Findings and Significance The results revealed that increased axial and mean diffusivity are the first abnormalities to occur and that the first region to develop such significant differences was mesial parietal/splenial white matter; these metrics, however, remained relatively static with advancing disease indicating they are suitable as ‘state-specific’ markers. In contrast, increased radial diffusivity, and therefore decreased fractional anisotropy–though less detectable early–became increasingly abnormal with disease progression, and, in the splenium of the corpus callosum, correlated significantly with dementia severity; these metrics therefore appear ‘stage-specific’ and would be ideal for monitoring disease progression. In addition, the cross-sectional and longitudinal analyses showed that the progressive abnormalities in radial diffusivity and fractional anisotropy always occurred in areas that had first shown an increase in axial and mean diffusivity. Given that the former two metrics correlate with dementia severity, but the latter two did not, it would appear that increased axial diffusivity represents an upstream event that precedes neuronal loss.

Boxing has received increased public attention and acceptance in recent years. However, this development has not been accompanied by a critical discussion of the early and late health complications.We selectively review recent studies on the acute, subacute, and chronic neuropsychiatric consequences of boxing.Cerebral concussions ('knock-outs') are the most relevant acute consequence of boxing. The number of reported cases of death in the ring seems to have mildly decreased. Subacute neuropsychological deficits appear to last longer than subjective symptoms. The associated molecular changes demonstrate neuronal and glial injury correlated with the number and severity of blows to the head (altered total tau, beta-amyloid, neurofilament light protein, glial fibrillary acidic protein, and neuron-specific enolase). The risk of a punch-drunk syndrome (boxer's dementia, dementia pugilistica) as a late effect of chronic traumatic brain injury is associated with the duration of a boxer's career and with his earlier stamina. There are similarities (e.g. increased risk with ApoE4-polymorphism, beta-amyloid pathology) and differences (more tau pathology in boxers) compared with Alzheimer's disease.Protective gear has led to a remarkable reduction of risks in amateur boxing. Similar measures can also be used in professional boxing, but may decrease the thrill, which does appeal to many supporters.

Background Spinocerebellar ataxia type 17 is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in the TATA box-binding protein gene. Ataxia is typically the first sign whereas behavioral symptoms occur later. Objective To characterize the unusual phenotypic expression of a large spinocerebellar ataxia type 17 kindred. Design Clinical, neuropathological, and molecular genetic characterization of a 4-generation family with 16 affected patients. Results Behavioral symptoms and frontal impairment dominated the early stages preceding ataxia, rigidity, and dystonic movements. Neuropathological examination showed cortical, subcortical, and cerebellar atrophy. Purkinje cell loss and gliosis, pseudohypertrophic degeneration of the inferior olive, marked neuronal loss and gliosis in the caudate nucleus, and in the medial thalamic nuclei were salient features together with neuronal intranuclear inclusions stained with anti–TATA box-binding protein and antipolyglutamine antibodies. The disease was caused by a stable 52 CAG repeat expansion of the TATA box-binding protein gene, although there was apparent variability in the age of onset. Conclusion The characteristics of this family broaden the clinical picture of spinocerebellar ataxia type 17: initial presenile dementia with behavioral symptoms should be added to ataxia, rigidity, and dystonic movements, which are more commonly encountered.