Localizing apraxia in corticobasal syndrome: a morphometric MRI study.

Apraxia localization has relied on voxel-based, lesion-symptom mapping studies in left hemisphere stroke patients. Studies on the neural substrates of different manifestations of apraxia in neurodegenerative disorders are scarce. The primary aim of this study was to look into the neural substrates of different manifestations of apraxia in a cohort of corticobasal syndrome patients (CBS) by use of cortical thickness. Twenty-six CBS patients were included in this cross-sectional study. The Goldenberg apraxia test (GAT) was applied. 3D-T1-weighted images were analyzed via the automated recon-all Freesurfer version 6.0 pipeline. Vertex-based multivariate General Linear Model analysis was applied to correlate GAT scores with cortical thickness. Deficits in imitation of meaningless gestures correlated with bilateral superior parietal atrophy, extending to the angular and supramarginal gyri, particularly on the left. Finger imitation relied predominantly on superior parietal lobes, whereas the left angular and supramarginal gyri, in addition to superior parietal lobes, were critical for hand imitation. The widespread bilateral clusters of atrophy in CBS related to apraxia indicate different pathophysiological mechanisms mediating praxis in neurodegenerative disorders compared to vascular lesions, with implications both for our understanding of praxis and for the rehabilitation approaches of patients with apraxia.

Waist Circumference and Body Mass Index as Predictors of Disability Progression in Multiple Sclerosis: A Systematic Review and Meta-Analysis.

Background: While obesity has been shown to elevate the risk of developing multiple sclerosis (MS), there is a lack of strong evidence regarding its role in the disability progression and status of MS patients. Methods: This systematic review and meta-analysis aimed to provide comparative estimates of WC and BMI in patients with MS (PwMS) and to investigate potential associations between the waist circumference (WC) and body mass index (BMI) and demographic and specific MS characteristics. Adhering to PRISMA guidelines, a detailed search of the MEDLINE PubMed, Cochrane Library, and Scopus databases was conducted. Results: A total of 16 studies were included. The pooled mean WC and BMI among PwMS was estimated to be 87.27 cm (95%CI [84.07; 90.47]) and 25.73 (95%CI [25.15; 26.31]), respectively. Meta-regression models established a significant bidirectional relationship between WC and the Expanded Disability Scale (EDSS) (p < 0.001) but not between BMI and EDSS (p = 0.45). Sensitivity analyses showed no association between WC and age (p = 0.48) and a tendency between WC and disease duration (p = 0.08). Conclusions: Although WC measurements classify PwMS as normal weight, BMI measurements classify them as overweight. Therefore, WC should complement BMI evaluations in clinical practice. Additionally, our findings highlight the significant association between abdominal fat, as indicated by WC, and disease progression. Considering the heightened risk of cardiovascular comorbidity and mortality among PwMS, we recommend integrating both WC and BMI as standard anthropometric measurements in routine clinical examinations and targeted prevention strategies for PwMS.

Paraneoplastic Neurological Syndromes as Initial Presentation of Tumors: An Eight-Year Single-Center Experience.

BACKGROUND: Paraneoplastic Neurological Syndromes (PNS) comprise a diverse group of disorders propagated by immune-mediated effects of malignant tumors on neural tissue. METHODS: A single-center longitudinal study was performed including consecutive adult patients treated at a tertiary academic hospital between 2015 and 2023 and diagnosed with PNS. PNS were ascertained using the 2004 and the revised 2021 PNS-Care diagnostic criteria. RESULTS: Thirteen patients who fulfilled the 2004 definite PNS criteria were included. PNS comprise diverse neurological syndromes, with neuromuscular junction disorders (54%) and limbic encephalitis (31%) being predominant. PNS-related antibodies were detected in 85% of cases, including anti-AChR (n = 4), anti-P/Q-VGCC (n = 3), anti-Hu (n = 3), anti-Yo (n = 1), anti-Ma (n = 1), anti-titin (n = 1), anti-IgLON5 (n = 1), and anti-GAD65 (n = 1). Thymoma (31%), small-cell lung cancer (23%), and papillary thyroid carcinoma (18%) were the most frequent tumors. Imaging abnormalities were evident in 33% of cases. Early immunotherapy within 4-weeks from symptom onset was associated with favorable outcomes. At a mean follow-up of 2 ± 1 years, two patients with anti-Hu and anti-Yo antibodies died (18%). Four and three patients fulfilled the 2021 PNS-Care diagnostic criteria for definite and probable PNS, respectively. CONCLUSIONS: This study highlights the clinical heterogeneity of PNS, emphasizing the need for early suspicion and prompt treatment initiation for optimal outcomes.

Neuropsychological profiles comparison between Multiple Sclerosis patients and Multiple Sclerosis patients with overlapping features of Systemic Lupus Erythematosus.

AIM: Multiple sclerosis (MS) and Systemic Lupus Erythematosus (SLE) are autoimmune disorders that may lead to cognitive impairment. This study aimed to compare the neuropsychological profiles of patients with MS, and MS and coexisting SLE features. METHODS: We included a total of 90 participants, divided into 3 groups: 30 patients with clinically definite relapsing remitting MS, 30 with coexisting MS and incomplete SLE (overlap group) and 30 healthy controls (HC). All participants underwent neuropsychological assessment with the Montreal Cognitive Assessment (MoCA), Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Selective Reminding Test (SRT). RESULTS: Both groups scored lower on the MoCA compared to the HC (p < .001). The overlap group showed the lowest performance on the SDMT and PASAT compared to the other two groups (p < .01), while the MS group scored similarly to the HC in the PASAT (p > .05). Regarding the learning rate and long-term recall, the overlap group had lower scores compared to both the MS and HC (p < .001), but it outperformed both groups in the retention efficacy score (p < .001). The MS group did not differ significantly from the HC in these memory domains (p > .05). CONCLUSION: The overlap group exhibited a broader range of impairments, including slower processing speed, decreased working memory, reduced learning rate, and long-term retrieval deficits. Their retention ability remained intact. The coexistence of MS with SLE pathology had additive impacts on cognitive function.

Alzheimer's Disease CSF Biomarkers as Possible Indicators of Tap-Test Response in Idiopathic Normal Pressure Hydrocephalus.

The aim of the present study is the evaluation of established Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers in patients with idiopathic normal-pressure hydrocephalus (iNPH), both individually and as a total profile, and the investigation of their use as potential predictors of Tap-test responsiveness. Fifty-three patients with iNPH participated in the study. Aß42, Aß40, total Tau and phospho-Tau proteins were measured in duplicate with double-sandwich ELISA assays. Clinical evaluation involved a 10 m timed walk test before an evacuative lumbar puncture (LP) and every 24 h for three consecutive days afterwards. Neuropsychological assessment involved a mini-mental state examination, frontal assessment battery, 5-word test and CLOX drawing test 1 and 2, which were also performed before and 48 h after LP. Response in the Tap-test was defined as a 20% improvement in gait and/or a 10% improvement in neuropsychological tests. The Aß42/Aß40 ratio was found to be significantly higher in Tap-test responders than non-responders. Total Tau and phospho-Tau CSF levels also differed significantly between these two groups, with Tap-test responders presenting with lower levels compared to non-responders. Regarding the AD CSF biomarker profile (decreased amyloid and increased Tau proteins levels), patients with a non-AD profile were more likely to have a positive response in the Tap-test than patients with an AD profile.

The Dynamic Relationship between the Glymphatic System, Aging, Memory, and Sleep.

The process of memory entails the activation of numerous neural networks and biochemical pathways throughout the brain. The phenomenon of memory decline in relation to aging has been the subject of extensive research for several decades. The correlation between the process of aging and memory is intricate and has various aspects to consider. Throughout the aging process, there are various alterations that take place within the brain and, as expected, affect other functions that have already been linked to memory and its function such as involving microcirculation and sleep. Recent studies provide an understanding of how these mechanisms may be interconnected through the relatively new concept of the glymphatic system. The glymphatic system is strongly correlated to sleep processes. Sleep helps the glymphatic system remove brain waste solutes. Astrocytes expand and contract to form channels for cerebrospinal fluid (CSF) to wash through the brain and eliminate waste. However, the details have not been totally elusive, but the discovery of what we call the glymphatic system enables us to connect many pieces of physiology to understand how such factors are interconnected and the interplay between them. Thus, the purpose of this review is to discuss how the glymphatic system, sleep, memory, and aging are interconnected through a network of complex mechanisms and dynamic interactions.

The Presence of a Zygomatic Nerve Plexus in a Cadaveric Specimen Without a Zygomatic Branch of the Facial Nerve.

The extratemporal course of the facial nerve distributes in facial mimic muscles in a complex pattern. The traditional depictions of five main branches without anastomoses are not common. Davis classification remains the gold standard in the classification of facial nerve branching patterns. During a routine dissection of an 74-year-old male cadaveric specimen, we detected a very rare anatomical variation. The zygomatic branch of the facial nerve was totally absent. The temporofacial division of the main trunk was bifurcated to a temporal and a buccal branch. The anterior temporal and posterior buccal branches formed a plexus to supply the orbicularis oculi muscle. This unique variability highlights the complexity of the extratemporal facial nerve course. Retrograde facial nerve dissection requires deep knowledge of every anatomical variation of the facial nerve course to avoid an iatrogenic injury. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-03601-y.

Rehabilitation on cerebellar ataxic patients with multiple sclerosis: A systematic review.

Multiple Sclerosis (MS) is a chronic inflammatory, autoimmune disease of the Central Nervous System with a vast spectrum of clinical phenotypes. A major aspect of its clinical presentation is cerebellar ataxia where physiotherapy and treatment modalities play a significant role on its management. This systematic review aims to investigate the physiotherapeutic rehabilitation techniques regarding the management of cerebellar ataxia due to MS and secondary to stratify each protocol as part of a multi structural personalized rehabilitation approach based on the gravity of the symptoms. A Pubmed Medline, Scopus and Web of Science research was performed using the corresponding databases. The results were screened by the authors in pairs. In our study, six (6) non-pharmacological interventional protocols, 3 Randomized Controlled Trials and 3 pilot studies, were included with a total of 145 MS patients. Physiotherapeutic techniques, such as NDT-Bobath, robotic and visual biofeedback re-education protocols and functional rehabilitation techniques were included. In most cases cerebellar ataxic symptoms were decreased post-treatment. The overall quality of the studies included was of moderate level (level B). Rehabilitation in cerebellar ataxia due to MS should be based on multicentric studies with the scope of adjusting different types of treatments and physiotherapeutic techniques based on the severity of the symptom.

The Prevalence of Diabetes Mellitus Type II (DMII) in the Multiple Sclerosis Population: A Systematic Review and Meta-Analysis.

Introduction: The interactions between Diabetes Mellitus type II (DMII) and Multiple Sclerosis (MS) lead to higher levels of fatigue, higher risk of physical disability, faster cognitive decline, and in general a lower quality of life and a higher frequency of depression compared to the general population. All of the above accelerate the disability progression of patients with MS, reduce the patients' functional capacity, and further increase their psychological and economic burden. Methods: This systematic review and meta-analysis aims to calculate the prevalence of DMII in the MS population. Following PRISMA guidelines, a thorough search of the Medline Pubmed, Cochrane Library, and Scopus databases was performed, focusing on the frequency of DMII in the MS population. Results: A total of 19 studies were included in the synthesis. The results of the main meta-analysis of random effects using R studio 3.3.0 for Windows and the Meta r package showed that the prevalence of DMII in the MS population is 5% (95% CI [0.03, 0.07], 19 studies, I2 = 95%, pQ < 0.001). Additional subgroup analysis based on region showed a difference of 4.4% (I2 = 95.2%, pQ < 0.001), psubgroupdifference = 0.003) between European and non-European participants, while demographic- and MS-specific characteristic (EDSS, Disease Duration) did not seem to affect the prevalence of DMII in the MS population (p = 0.30, p = 0.539, p = 0.19, p = 0.838). No publication bias was discovered (Egger's p test value: 0.896). Conclusions: Even though the prevalence of DMII in the MS population is lower than 10% (the reported prevalence of DMII in the general population) the interactions between the two conditions create significant challenges for MS patients, their caregivers, and physicians. DΜΙΙ should be systematically recorded in the case of MS patients to clearly delineate any potential relationship between the two conditions. Additionally, more structured studies investigating the interactions of MS and DMΙΙ as well as the direction of the causation between those two conditions are necessary in order to gain a deeper insight into the nature of the interaction between MS and DMII.

Assessment of Aggregated and Exosome-Associated α-Synuclein in Brain Tissue and Cerebrospinal Fluid Using Specific Immunoassays.

Even though it is currently well-established that α-synuclein aggregation is closely associated with the pathological events in Parkinson's disease (PD) and several other neurodegenerative disorders, collectively called synucleinopathies, the mechanistic link between α-synuclein aggregates and the onset and progression of neurodegeneration in these diseases remain unclear. The process of aggregation initiates from a structurally distorted monomer that gradually oligomerizes to generate a repertoire of fibrillar and oligomeric multimers that deposit within diseased cells in the brain. Total α-synuclein has been proposed as a potential biomarker in PD, but most of the studies do not discriminate between distinct α-synuclein conformers. To correlate protein measurements to disease pathology, we have developed a conformation-specific ELISA method that selectively detects fibrillar and oligomeric forms of α-synuclein without cross-reacting with monomers. We have used this assay to determine the levels of aggregated α-synuclein in human and mouse brain tissue as well as in CSF and CSF-derived exosomes from patients with synucleinopathy and control subjects. Our results verify the ability of the new assay to detect aggregated α-synuclein in complex matrices and support the idea that the levels of these conformers are related to the age of onset in PD patients, while CSF analysis showed that these species exist in low abundance in CSF and CSF-derived exosomes. Future studies will be required to fully assess the diagnostic usefulness of this ELISA in synucleinopathies.

Safety of COVID-19 vaccines in multiple sclerosis: A systematic review and meta-analysis.

BACKGROUND: Data are sparse regarding the safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with multiple sclerosis (MS). OBJECTIVE: To estimate (1) the pooled proportion of MS patients experiencing relapse among vaccine recipients; (2) the rate of transient neurological worsening, adverse events, and serious adverse events; (3) the previous outcomes of interest for different SARS-CoV-2 vaccine types. METHODS: Systematic review and meta-analysis of pharmacovigilance registries and observational studies. RESULTS: Nineteen observational studies comprising 14,755 MS patients who received 23,088 doses of COVID-19 vaccines were included. Mean age was 43.3 years (95% confidence interval (CI): 40-46.6); relapsing-remitting, secondary-progressive, primary-progressive MS and clinically isolated syndrome were diagnosed in 82.6% (95% CI: 73.9-89.8), 12.6% (95% CI: 6.3-20.8), 6.7% (95% CI: 4.2-9.9), and 2.9% (95% CI: 1-5.9) of cases, respectively. The pooled proportion of MS patients experiencing relapse at a mean time interval of 20 days (95% CI: 12-28.2) from vaccination was 1.9% (95% CI: 1.3%-2.6%; I2 = 78%), with the relapse risk being independent of the type of administered SARS-CoV-2-vaccine (p for subgroup differences = 0.7 for messenger RNA (mRNA), inactivated virus, and adenovector-based vaccines). After vaccination, transient neurological worsening was observed in 4.8% (95% CI: 2.3%-8.1%) of patients. Adverse events and serious adverse events were reported in 52.8% (95% CI: 46.7%-58.8%) and 0.1% (95% CI: 0%-0.2%) of vaccinations, respectively. CONCLUSION: COVID-19 vaccination does not appear to increase the risk of relapse and serious adverse events in MS. Weighted against the risks of SARS-CoV-2-related complications and MS exacerbations, these safety data provide compelling pro-vaccination arguments for MS patients.

CSF Aß42 and Aß42/Aß40 Ratio in Alzheimer's Disease and Frontotemporal Dementias.

BACKGROUND: Alzheimer's disease dementia (ADD) may manifest with atypical phenotypes, resembling behavioral variant frontotemporal dementia (bvFTD) and corticobasal syndrome (CBS), phenotypes which typically have an underlying frontotemporal lobar degeneration with tau proteinopathy (FTLD-tau), such as Pick's disease, corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), or FTLD with TDP-43 proteinopathy (FTLD-TDP). CSF biomarkers total and phosphorylated tau (τT and τP-181), and amyloid beta with 42 and 40 amino acids (Aß42 and Aß40) are biomarkers of AD pathology. The primary aim of this study was to compare the diagnostic accuracy of Aß42 to Aß42/Aß40 ratio in: (a) differentiating ADD vs. frontotemporal dementias; (b) patients with AD pathology vs. non-AD pathologies; (c) compare biomarker ratios and composite markers to single CSF biomarkers in the differentiation of AD from FTD; Methods: In total, 263 subjects were included (ADD: n = 98; bvFTD: n = 49; PSP: n = 50; CBD: n = 45; controls: n = 21). CSF biomarkers were measured by commercially available ELISAs (EUROIMMUN). Multiple biomarker ratios (Aß42/Aß40; τT/τP-181; τT/Aß42; τP-181/Aß42) and composite markers (t-tau: τT/(Aß42/Aß40); p-tau: τP-181/(Aß42/Aß40) were calculated. ROC curve analysis was performed to compare AUCs of Aß42 and Aß42/Aß40 ratio and relevant composite markers between ADD and FTD, as defined clinically. BIOMARKAPD/ABSI criteria (abnormal τT, τP-181 Aß42, and Aß42/Aß40 ratio) were used to re-classify all patients into AD pathology vs. non-AD pathologies, and ROC curve analysis was repeated to compare Aß42 and Aß42/Aß40; Results: Aß42 did not differ from Aß42/Aß40 ratio in the differentiation of ADD from FTD (AUCs 0.752 and 0.788 respectively; p = 0.212). The τT/Aß42 ratio provided maximal discrimination between ADD and FTD (AUC:0.893; sensitivity 88.8%, specificity 80%). BIOMARKAPD/ABSI criteria classified 60 patients as having AD pathology and 211 as non-AD. A total of 22 had discrepant results and were excluded. Aß42/Aß40 ratio was superior to Aß42 in the differentiation of AD pathology from non-AD pathology (AUCs: 0.939 and 0.831, respectively; p < 0.001). In general, biomarker ratios and composite markers were superior to single CSF biomarkers in both analyses. CONCLUSIONS: Aß42/Aß40 ratio is superior to Aß42 in identifying AD pathology, irrespective of the clinical phenotype. CSF biomarker ratios and composite markers provide higher diagnostic accuracy compared to single CSF biomarkers.

Application of the AT(N) and Other CSF Classification Systems in Behavioral Variant Frontotemporal Dementia.

BACKGROUND: Patients with a frontotemporal lobar degeneration (FTLD) usually manifest with behavioral variant frontotemporal dementia (bvFTD). Alzheimer's disease (AD) may also manifest with a predominant behavioral-dysexecutive syndrome, similar to bvFTD. Cerebrospinal fluid (CSF) biomarkers, such as total tau (τT), phosphorylated tau (τP-181) and amyloid beta with 42 amino-acids (Aß42), can predict AD pathology in vivo. The aim of this study was to compare the τT/Aß42 and τP-181/Aß42 ratios, the BIOMARKAPD/ABSI criteria and the AT(N) classification system in a cohort of bvFTD patients. METHODS: A total of 105 bvFTD patients (21 possible bvFTD; 20%) with CSF data, examined from 2008 to 2022, were included. Seventy-eight AD patients and 62 control subjects were included. The CSF biomarkers were measured with Innotest (2008-2017 subcohort) and EUROIMMUN (2017-2022 subcohort) ELISAs. RESULTS: Depending on the classification system, 7.6 to 28.6% of bvFTD had an AD biochemical profile. The τT/Aß42 and τP-181/Aß42 ratios classified more patients as AD compared to the BIOMARKAPD/ABSI and AT(N) systems. The patients with possible bvFTD had higher frequencies of AD compared to the probable bvFTD patients. CONCLUSIONS: The four classification criteria of CSF AD biomarkers resulted in differences in AD allocation in this bvFTD cohort. A consensus on the optimal classification criteria of CSF AD biomarkers is pivotal.

Dopamine transporter SPECT imaging in Parkinson's disease and atypical Parkinsonism: a study of 137 patients.

INTRODUCTION: Differential diagnosis between Parkinson's disease (PD) and multiple system atrophy-parkinsonian type (MSA-P), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), collectively termed atypical Parkinsonism (AP), is challenging. Dopamine transporter density imaging with Ioflupane I123 (DaTscan) is a marker of presynaptic nigrostriatal dysfunction. The primary aim of this study was to investigate the utility of DaTscan in the differential diagnosis of MSA-P, CBD, and PSP. METHODS: Patients examined at Eginition Hospital (2011-2021), with available DaTscan data and a diagnosis of probable AP, clinically established PD, as well as a neurological control (NC) group were included. Mean binding specific index (BSI), BSI of the most affected side, asymmetry index, laterality, and caudate/putamen ratio were recorded. Analyses were performed by Kruskal-Wallis and ANCOVA. RESULTS: 137 patients were included (CBD: [Formula: see text]; MSA-P: [Formula: see text]; PSP: [Formula: see text]; PD: [Formula: see text]; NC: [Formula: see text]). There were significant differences when comparing CBS, PSP, and NC vs. all other groups combined. Pairwise between-group comparisons revealed significant differences between PSP and CBD (mean striatum BSI>1.95; sensitivity 74.1%; specificity 85.0%), CBD and MSA-P (mean striatum BSI>2.04; sensitivity 70.4%; specificity 86.7%), and CBD and PD (mean striatum BSI>2.11; sensitivity 66.7%; specificity 100.0%). There were no differences between PSP, MSA-P, and PD. PSP, MSA-P, and PD differed from NC subjects, with 100% specificity and high sensitivity. Differentiation of NC from CBD was suboptimal. DISCUSSION: CBD patients exhibit relatively mild DaTscan abnormalities. DaTscan may assist in the differentiation of CBD from PSP. DaTscan does not differentiate among PD, MSA-P, and PSP.

Hippocampal subfield volumetry in corticobasal syndrome of diverse underlying pathologies.

INTRODUCTION: Multiple pathologies may underlie corticobasal syndrome (CBS), including Alzheimer's disease (AD). Typical amnestic AD is characterized by early selective hippocampal atrophy. The profile of hippocampal atrophy in AD patients presenting as CBS (CBS-AD), compared to CBS patients of non-AD pathologies (CBS-nAD) and amnestic AD patients, has not been studied. OBJECTIVES: To compare hippocampal subfield atrophy patterns between CBS-AD, CBS-nAD, typical amnestic AD patients, and control subjects. METHODS: Automated hippocampal subfield volumetry was performed via the hippocampal subfield segmentation pipeline of Freesurfer 6.0 on 3D T1-weighted images. CBS patients were classified as CBS-AD or CBS-nAD based on CSF AD biomarkers by applying the AT(N) classification system. Mean volumes of nine hippocampal subfields, head-body-tail segments, total hippocampus, and entorhinal and parahippocampal gyrus cortical thickness were measured. RESULTS: Eighty-three subjects were included (CBS-AD: n = 14; CBS-nAD: n = 17; amnestic AD: n = 29; controls: n = 23). CBS-AD patients had greater whole hippocampal and hippocampal subfield atrophy compared to CBS-nAD. CBS-AD and amnestic AD patients did not differ in subfield volumes. CBS-nAD did not exhibit hippocampal atrophy compared to controls, with the exception of fimbria. (Cohen's d = 1.27; p = 0.038). Presubiculum (Cohen's d = 1.00; p = 0.002) and hippocampal body (Cohen's d = 0.95; p = 0.001) volumes exhibited the greatest differences between CBS-AD and CBS-nAD. Hippocampal subfield volume provided combined sensitivity and specificity < 80% for the discrimination of CBS-AD from CBS-nAD. CONCLUSION: CBS-AD and amnestic AD patients exhibit comparable, and significantly greater hippocampal atrophy compared to CBS-nAD patients. Hippocampal subfield volumetry in CBS is indicative of an AD underlying pathology.

Clinical, Neuroimaging, and Genetic Markers in Cerebral Amyloid Angiopathy-Related Inflammation: A Systematic Review and Meta-Analysis.

BACKGROUND: There are limited data regarding the prevalence of distinct clinical, neuroimaging and genetic markers among patients diagnosed with cerebral amyloid angiopathy-related inflammation (CAA-ri). We sought to determine the prevalence of clinical, radiological, genetic and cerebrospinal fluid biomarker findings in patients with CAA-ri. METHODS: A systematic review and meta-analysis of published studies including patients with CAA-ri was conducted to determine the prevalence of clinical, neuroimaging, genetic and cerebrospinal fluid biomarker findings. Subgroup analyses were performed based on (1) prospective or retrospective study design and (2) CAA-ri diagnosis with or without available biopsy. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using Cochran-Q and I2-statistics. RESULTS: We identified 4 prospective and 17 retrospective cohort studies comprising 378 patients with CAA-ri (mean age, 71.5 years; women, 52%). The pooled prevalence rates were as follows: cognitive decline at presentation 70% ([95% CI, 54%-84%]; I2=82%), focal neurological deficits 55% ([95% CI, 40%-70%]; I2=82%), encephalopathy 54% ([95% CI, 39%-68%]; I2=43%), seizures 37% ([95% CI, 27%-49%]; I2=65%), headache 31% ([95% CI, 22%-42%]; I2=58%), T2/fluid-attenuated inversion recovery-hyperintense white matter lesions 98% ([95% CI, 93%-100%]; I2=44%), lobar cerebral microbleeds 96% ([95% CI, 92%-99%]; I2=25%), gadolinium enhancing lesions 54% ([95% CI, 42%-66%]; I2=62%), cortical superficial siderosis 51% ([95% CI, 34%-68%]; I2=77%) and lobar macrohemorrhage 40% ([95% CI, 11%-73%]; I2=88%). The prevalence rate of the ApoE (Apolipoprotein E) ε4/ε4 genotype was 34% ([95% CI, 17%-53%]; I2=76%). Subgroup analyses demonstrated no differences in these prevalence rates based on study design and diagnostic strategy. CONCLUSIONS: Cognitive decline was the most common clinical feature. Hyperintense T2/fluid-attenuated inversion recovery white matter lesions and lobar cerebral microbleeds were by far the most prevalent neuroimaging findings. Thirty-four percent of patients with CAA-ri have homozygous ApoE ε4/ε4 genotype and scarce data exist regarding the cerebrospinal fluid biomarkers and its significance in these patients.

Cerebrospinal Fluid Biomarkers in iNPH: A Narrative Review.

Idiopathic normal pressure hydrocephalus (iNPH) is a neurological syndrome characterized by the clinical triad of gait disorder, cognitive impairment and urinary incontinence. It has attracted interest because of the possible reversibility of symptoms, especially with timely treatment. The main pathophysiological theory is based on a vicious circle of disruption in circulation of cerebrospinal fluid (CSF) that leads to the deceleration of its absorption. Data regarding CSF biomarkers in iNPH are contradictory and no definite CSF biomarker profile has been recognized as in Alzheimer's disease (AD), which often co-exists with iNPH. In this narrative review, we investigated the literature regarding CSF biomarkers in iNPH, both the established biomarkers total tau protein (t-tau), phosphorylated tau protein (p-tau) and amyloid peptide with 42 amino acids (Aß42), and other molecules, which are being investigated as emerging biomarkers. The majority of studies demonstrate differences in CSF concentrations of Aß42 and tau-proteins (t-tau and p-tau) among iNPH patients, healthy individuals and patients with AD and vascular dementia. iNPH patients present with lower CSF Aß42 and p-tau concentrations than healthy individuals and lower t-tau and p-tau concentrations than AD patients. This could prove helpful for improving diagnosis, differential diagnosis and possibly prognosis of iNPH patients.

Recognizing Atypical Presentations of Alzheimer's Disease: The Importance of CSF Biomarkers in Clinical Practice.

Besides the typical amnestic presentation, neuropathological studies indicate that Alzheimer's disease (AD) may present with atypical clinical pictures. The relative frequencies of typical and atypical or mixed presentations within the entire spectrum of AD remain unclear, while some mixed or atypical presentations may have not received adequate attention for them to be included in diagnostic criteria. We investigated the spectrum of clinical presentations in patients with the AD CSF biomarker profile (high tau and phospho-tau, low Aß42 levels), hospitalized in a tertiary academic center. Among 98 patients with the CSF AD profile, 46% of patients had the typical presentation of "hippocampal" amnestic dementia. Additionally, 23.5% and 15.3% fulfilled the criteria of mixed or atypical presentations, respectively, as described in the IWG-2 criteria. The remaining 15.3% had unusual presentations, including non-logopenic (semantic and non-fluent agrammatic) primary progressive aphasia, corticobasal syndrome, and Richardson syndrome, or could be diagnosed with normal pressure hydrocephalus. Despite selection bias (academic center), atypical clinical presentations of AD may be more common than previously thought. CSF biomarkers seem to be a useful tool for antemortem identification of such patients, which is likely to affect therapeutic decisions. Some of the unusual presentations described above should be incorporated in diagnostic criteria.

Silent Pauses and Speech Indices as Biomarkers for Primary Progressive Aphasia.

Background and Objectives: Recent studies highlight the importance of investigating biomarkers for diagnosing and classifying patients with primary progressive aphasia (PPA). Even though there is ongoing research on pathophysiological indices in this field, the use of behavioral variables, and especially speech-derived factors, has drawn little attention in the relevant literature. The present study aims to investigate the possible utility of speech-derived indices, particularly silent pauses, as biomarkers for primary progressive aphasia (PPA). Materials and Methods: We recruited 22 PPA patients and 17 healthy controls, from whom we obtained speech samples based on two elicitation tasks, i.e., cookie theft picture description (CTP) and the patients' personal narration of the disease onset and course. Results: Four main indices were derived from these speech samples: speech rate, articulation rate, pause frequency, and pause duration. In order to investigate whether these indices could be used to discriminate between the four groups of participants (healthy individuals and the three patient subgroups corresponding to the three variants of PPA), we conducted three sets of analyses: a series of ANOVAs, two principal component analyses (PCAs), and two hierarchical cluster analyses (HCAs). The ANOVAs revealed significant differences between the four subgroups for all four variables, with the CTP results being more robust. The subsequent PCAs and HCAs were in accordance with the initial statistical comparisons, revealing that the speech-derived indices for CTP provided a clearer classification and were especially useful for distinguishing the non-fluent variant from healthy participants as well as from the two other PPA taxonomic categories. Conclusions: In sum, we argue that speech-derived indices, and especially silent pauses, could be used as complementary biomarkers to efficiently discriminate between PPA and healthy speakers, as well as between the three variants of the disease.

Cerebrospinal Fluid Biomarker Profile in TDP-43-Related Genetic Frontotemporal Dementia.

Cerebrospinal fluid (CSF) biomarkers, namely total tau, phospho-tau and amyloid beta peptides, have received much attention specifically regarding Alzheimer's disease (AD), since they can detect the biochemical fingerprint of AD and serve as a diagnostic tool for accurate and early diagnosis during life. In the same way, biomarkers for other neurodegenerative disease pathologies are also needed. We present a case series of six patients with genetic frontotemporal dementia (FTD), with TDP-43 underlying proteinopathy, in an attempt to assess TDP-43 as a novel biomarker alone and in combination with established AD biomarkers for this specific patient group, based on the principles of personalized and precision medicine. Our results indicate that genetic TDP-43-FTD is characterized by increased CSF TPD-43 and increased TDP-43 × τΤ/τP-181 combination. Hence, TDP-43 combined with tau proteins could be a useful tool for the diagnosis of genetic FTD with TDP-43 underling histopathology, supplementing clinical, neuropsychological and imaging data.