Blood biomarkers in mild cognitive impairment patients: Relationship between analytes and progression to Alzheimer disease dementia.

BACKGROUND AND PURPOSE: Blood-based biomarkers are promising tools for the diagnosis of Alzheimer disease (AD) at prodromal stages (mild cognitive impairment [MCI]) and are hoped to be implemented as screening tools for patients with cognitive complaints. In this work, we evaluated the potential of peripheral neurological biomarkers to predict progression to AD dementia and the relation between blood and cerebrospinal fluid (CSF) AD markers in MCI patients referred from a general neurological department. METHODS: A group of 106 MCI patients followed at the Neurology Department of Coimbra University Hospital was included. Data regarding baseline neuropsychological evaluation, CSF levels of amyloid ß 42 (Aß42), Aß40, total tau (t-Tau), and phosphorylated tau 181 (p-Tau181) were available for all the patients. Aß42, Aß40, t-Tau, p-Tau181, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) levels were determined in baseline stored serum and plasma samples by commercial SiMoA (Single Molecule Array) assays. Progression from MCI to AD dementia was assessed at follow-up (mean = 5.8 ± 3.4 years). RESULTS: At baseline, blood markers NfL, GFAP, and p-Tau181 were significantly increased in patients who progressed to AD at follow-up (p < 0.001). In contrast, plasma Aß42/40 ratio and t-Tau showed no significant differences between groups. NfL, GFAP, and p-Tau181 demonstrated good diagnostic accuracy to identify progression to AD dementia (area under the curve [AUC] = 0.81, 0.80, and 0.76, respectively), which improved when combined (AUC = 0.89). GFAP and p-Tau181 were correlated with CSF Aß42. Association of p-Tau181 with NfL was mediated by GFAP, with a significant indirect association of 88% of the total effect. CONCLUSIONS: Our findings highlight the potential of combining blood-based GFAP, NfL, and p-Tau181 to be applied as a prognostic tool in MCI.

Characterization of Progranulin Gene Mutations in Portuguese Patients with Frontotemporal Dementia.

In Portugal, heterozygous loss-of-function mutations in the progranulin (GRN) gene account for approximately half of the genetic mediated forms of frontotemporal dementia (FTD). GRN mutations reported thus far cause FTD through a haploinsufficiency disease mechanism. Herein, we aim to unveil the GRN mutation spectrum, investigated in 257 FTD patients and 19 family members from the central/north region of Portugal using sequencing methods. Seven different pathogenic variants were identified in 46 subjects including 40 patients (16%) and 6 relatives (32%). bvFTD was the most common clinical presentation among the GRN mutation patients, who showed a global pattern of moderate-to-severe frontotemporoparietal deficits in the neuropsychological evaluation. Interestingly, two mutations were novel (p.Thr238Profs*18, p.Leu354Profs*16), and five were previously described, although three of them only in the Portuguese population, suggesting a population-specific GRN mutational spectrum. The subjects harboring a GRN mutation showed a significant reduction in serum PGRN levels, supporting the pathogenic nature of these variants. This work broadens the mutation spectrum of GRN and the identification of the underlying GRN mutations provided an accurate genetic counselling and allowed the enrolment of subjects with GRN mutations (both asymptomatic and symptomatic) in ongoing clinical trials, which is essential to test new drugs for the disease.

Rare variants in TP73 in a frontotemporal dementia cohort link this gene with primary progressive aphasia phenotypes.

BACKGROUND AND PURPOSE: TP73 was recently reported to cause amyotrophic lateral sclerosis (ALS). ALS and frontotemporal dementia (FTD) are considered to form part of a continuum. We aimed to investigate whether TP73 variants may be associated with FTD. METHODS: We studied a thoroughly investigated cohort of 65 Portuguese patients with frontotemporal dementia using whole-exome sequencing. The patients had no other known genetic cause for their disease (C9orf72 expansion was also excluded). RESULTS: Of the 65 patients studied, two had rare variants in TP73 (p.Gly605Ser and p.Arg347Trp). Both variants had minor allele frequency <0.001 and were predicted to be pathogenic in silico. The two patients displayed a phenotype that included predominant language impairment, suggestive of non-fluent progressive aphasia. CONCLUSION: We show that two thoroughly studied patients without other known genetic changes harbored TP73 rare variants, which are pathogenic in silico. This adds evidence to support the role of TP73 in the ALS-FTD spectrum, especially in primary progressive aphasia cases.

Serum neurofilament light chain as a surrogate of cognitive decline in sporadic and familial frontotemporal dementia.

BACKGROUND AND PURPOSE: Neurofilament light chain (NfL) has recently been proposed as a promising biomarker in frontotemporal dementia (FTD). We investigated the correlation of both cerebrospinal fluid (CSF) and serum NfL with detailed neuropsychological data and cognitive decline in a cohort of sporadic and familial FTD. METHODS: CSF and serum NfL, as well as conventional CSF Alzheimer's disease (AD) biomarkers (Aß42, t-Tau, p-Tau181), were determined in 63 FTD patients (30 sporadic-FTD, 20 with progranulin (GRN) mutations [FTD-GRN], 13 with chromosome 9 open reading frame 72 [C9orf72] expansions [C9orf72-FTD]), 37 AD patients, and 31 neurologic controls. Serum NfL was also quantified in 37 healthy individuals. Correlations between baseline CSF and serum NfL levels, standardized neuropsychological tests, and the rate of cognitive decline in FTD patients were assessed. RESULTS: CSF and serum NfL presented with significantly higher levels in FTD than in AD patients and both control groups. Within FTD subtypes, genetic cases, and particularly FTD-GRN, had higher CSF and serum NfL levels. Significant correlations between NfL levels and overall cognitive function, abstract reasoning (CSF and serum), executive functions, memory, and language (serum) were found. A relationship between increased baseline CSF and serum NfL and a decay in cognitive performance over time was also observed. CONCLUSIONS: Our findings highlight the potential of serum NfL as a useful surrogate end point of disease severity in upcoming targeted treatments.

How Reliable Are Ultra-Short-Term HRV Measurements during Cognitively Demanding Tasks?

Ultra-short-term HRV features assess minor autonomous nervous system variations such as variations resulting from cognitive stress peaks during demanding tasks. Several studies compare ultra-short-term and short-term HRV measurements to investigate their reliability. However, existing experiments are conducted in low cognitively demanding environments. In this paper, we propose to evaluate these measurements' reliability under cognitively demanding tasks using a near real-life setting. For this purpose, we selected 31 HRV features, extracted from data collected from 21 programmers performing code comprehension, and compared them across 18 different time frames, ranging from 3 min to 10 s. Statistical significance and correlation tests were performed between the features extracted using the larger window (3 min) and the same features extracted with the other 17 time frames. We paired these analyses with Bland-Altman plots to inspect how the extraction window size affects the HRV features. The main results show 13 features that presented at least 50% correlation when using 60-second windows. The HF and mNN features achieved around 50% correlation using a 30-second window. The 30-second window was the smallest time frame considered to have reliable measurements. Furthermore, the mNN feature proved to be quite robust to the shortening of the time resolution.

Reading and Calculation Neural Systems and Their Weighted Adaptive Use for Programming Skills.

Software programming is a modern activity that poses strong challenges to the human brain. The neural mechanisms that support this novel cognitive faculty are still unknown. On the other hand, reading and calculation abilities represent slightly less recent human activities, in which neural correlates are relatively well understood. We hypothesize that calculus and reading brain networks provide joint underpinnings with distinctly weighted contributions which concern programming tasks, in particular concerning error identification. Based on a meta-analysis of the core regions involved in both reading and math and recent experimental evidence on the neural basis of programming tasks, we provide a theoretical account that integrates the role of these networks in program understanding. In this connectivity-based framework, error-monitoring processing regions in the frontal cortex influence the insula, which is a pivotal hub within the salience network, leading into efficient causal modulation of parietal networks involved in reading and mathematical operations. The core role of the anterior insula and anterior midcingulate cortex is illuminated by their relation to performance in error processing and novelty. The larger similarity that we observed between the networks underlying calculus and programming skills does not exclude a more limited but clear overlap with the reading network, albeit with differences in hemispheric lateralization when compared with prose reading. Future work should further elucidate whether other features of computer program understanding also use distinct weights of phylogenetically "older systems" for this recent human activity, based on the adjusting influence of fronto-insular networks. By unraveling the neural correlates of program understanding and bug detection, this work provides a framework to understand error monitoring in this novel complex faculty.

Can EEG Be Adopted as a Neuroscience Reference for Assessing Software Programmers' Cognitive Load?

An emergent research area in software engineering and software reliability is the use of wearable biosensors to monitor the cognitive state of software developers during software development tasks. The goal is to gather physiologic manifestations that can be linked to error-prone scenarios related to programmers' cognitive states. In this paper we investigate whether electroencephalography (EEG) can be applied to accurately identify programmers' cognitive load associated with the comprehension of code with different complexity levels. Therefore, a controlled experiment involving 26 programmers was carried. We found that features related to Theta, Alpha, and Beta brain waves have the highest discriminative power, allowing the identification of code lines and demanding higher mental effort. The EEG results reveal evidence of mental effort saturation as code complexity increases. Conversely, the classic software complexity metrics do not accurately represent the mental effort involved in code comprehension. Finally, EEG is proposed as a reference, in particular, the combination of EEG with eye tracking information allows for an accurate identification of code lines that correspond to peaks of cognitive load, providing a reference to help in the future evaluation of the space and time accuracy of programmers' cognitive state monitored using wearable devices compatible with software development activities.

Demyelinating disease of the central nervous system associated with Pembrolizumab treatment for metastatic melanoma.

Immune checkpoint inhibitors are used in metastatic melanoma with good efficacy and safety profile. We report the first case of an inflammatory demyelinating disease of the central nervous system during treatment with Pembrolizumab and discuss the evidence in the literature supporting its causative role. The patient had a good clinical recovery after intravenous steroids, plasma exchange and discontinuation of Pembrolizumab. Due to the expected increase in the importance of immune checkpoint inhibitors in cancer treatment, it is important to be aware of neurological adverse events, as early treatment usually leads to good clinical responses.

Woodhouse-Sakati Syndrome: First report of a Portuguese case.

Woodhouse-Sakati Syndrome is a very rare autosomal recessive disorder caused by pathogenic variants in the DCAF17 gene, which encodes DDB1- and CUL4-associated factor 17. It is a multisystemic disorder characterized by hypogonadism, adolescent- to young adult-onset diabetes mellitus, hypothyroidism, and alopecia. Neurologic involvement includes childhood-onset moderate bilateral sensorineural hearing loss, mild intellectual disability adolescent- to young adult-onset of extrapyramidal findings, dysarthria, and dysphagia. Brain imaging typically reveals iron deposition in the globus pallidus and periventricular leukodystrophy. We report the case of a 31-year-old Portuguese female, the only child of a consanguineous couple. She presented with cognitive impairment, spastic paraparesis, lower limb dystonia, dysarthria, and dysphagia. She also had hypergonadotrophic hypogonadism associated with primary amenorrhea, insulin-dependent diabetes mellitus with retinopathy, primary hypothyroidism, moderate bilateral sensorineural hearing loss, and alopecia. Serial brain magnetic resonance imaging showed a progressive periventricular leukodystrophy with pontine involvement and significant bilateral iron deposition in the globus pallidus, substantia nigra, and red nucleus. The diagnosis of Woodhouse-Sakati Syndrome was eventually proposed and DCAF17 gene sequencing identified a novel likely pathogenic homozygous variant NG_013038.1(NM_025000.3):c.1091+2T>C. Genetic testing allowed a more accurate prognosis and a precise genetic counseling for our patient's family.

Increased risk of melanoma in C9ORF72 repeat expansion carriers: A case-control study.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are considered part of the same pathological spectrum. There is an increased risk of ALS in patients who have had melanoma. The risk of FTLD in melanoma (or cancer) patients is unknown. We aimed to study if C9ORF72 expansion is linked to a higher prevalence of melanoma. METHODS: We selected patients with a diagnosis in the ALS-FTLD spectrum who were tested for pathogenic mutations. Medical history was reviewed, to identify those with pathologically documented melanomas. RESULTS: We included 189 patients. Sixty-two had identified pathogenic mutations (39 C9ORF72). C9ORF72 carriers had a significantly higher risk of melanoma (odds ratio = 24.709; P < 0.007). There was no association with phenotype. CONCLUSIONS: These findings suggest that patients with a history of melanoma may have an increased probability of carrying a C9ORF72 repeat expansion. ALS or FTLD carriers of C9ORF72 should undergo surveillance for skin changes. Muscle Nerve 59:362-365, 2019.

Increased CSF tau is associated with a higher risk of seizures in patients with Alzheimer's disease.

INTRODUCTION: Neurofibrillary tangles and tau protein, the neuropathological hallmarks of Alzheimer's disease (AD), have been identified in patients with epilepsy. Tau protein was also associated with the modulation of neuronal excitability in animal models of AD. MATERIALS AND METHODS: We evaluated in 292 patients with AD the association between the risk of seizure development and AD cerebrospinal fluid (CSF) biomarkers, demographic characteristics, baseline Mini-Mental State Examination (MMSE) score, comorbidities, and apolipoprotein E status. RESULTS: The development of seizures was associated with younger age at dementia's onset, lower baseline MMSE, and higher CSF total tau protein levels, but only MMSE (hazard ratio [HR] = 0.935; 95% confidence interval [CI] = [0.903, 0.968]; p < 0.001) and CSF tau (HR = 1.001; 95%CI = [1.001, 1.002]; p = 0.001) were independent predictors on multivariate analysis. DISCUSSION: While CSF tau and lower baseline MMSE association with seizure development could in part be explained by a greater degree of cortical damage, the role of tau in the modulation of neuronal excitability may also play a role and should be further investigated.

The Head Turning Sign in Dementia and Mild Cognitive Impairment: Its Relationship to Cognition, Behavior, and Cerebrospinal Fluid Biomarkers.

BACKGROUND/AIMS: The head turning sign (HTS) is frequently noticed in clinical practice, but few studies have investigated its etiological and neuropsychological correlates. METHODS: The presence and frequency of the HTS was operationalized and prospectively evaluated in patients with Alzheimer's disease (AD), amnestic mild cognitive impairment (MCI), and behavioral-variant frontotemporal dementia (bvFTD). Cerebrospinal fluid (CSF) samples for AD biomarkers were collected. Mini-Mental State Examination, Montreal Cognitive Assessment, Geriatric Depression Scale (GDS), and insight scale scores were ascertained. RESULTS: A total of 84 patients were included. The HTS was more prevalent in AD than in MCI or bvFTD. It correlated negatively with cognitive measures and depression. It also had a positive correlation with CSF total tau and hyperphosphorylated tau proteins. Total tau protein and GDS score were the only variables independently associated with the HTS. CONCLUSIONS: The presence of the HTS in a cognitively impaired individual suggests a diagnosis of AD. A higher HTS frequency correlates with higher CSF total tau levels, a smaller GDS score, and worse cognitive measures. In the MCI subgroup, the HTS may suggest a higher risk of progression.

Towards a neurocognitive profile in familial cerebral cavernous malformations.

BACKGROUND: Familial cerebral cavernous malformations (FCCM) is a rare autosomal dominant disease, characterized by vascular malformations that can lead to macro and microhemorrhages. The neurocognitive impact of FCCM is still underrecognized. METHODS: We report the clinical, neurocognitive, imaging and genetic data of a three generation family with FCCM. RESULTS: A 63-year-old man (proband) had progressive memory impairment since the last year. Neurologic exam was unremarkable. Brain MRI showed multiple large cavernomas (mainly in the pons, left temporal, and right temporo-parietal) and scattered microhemorrhages. Neuropsychological assessment mainly revealed left frontal and right temporo-parietal dysfunction. A 41-year-old daughter, presented with headache, vertigo and memory complaints in the last 2 years. Neurological examination revealed left central facial paralysis. Brain MRI showed two small right parietal and internal capsule cavernomas, as well as microhemorrhages. Neuropsychological assessment showed moderate temporal neocortical left dysfunction. A 34-year-old daughter had recurrent headache and memory complaints, with unremarkable neurological exam. Brain MRI revealed two large cavernomas (left fronto-orbitary and inferior temporal), with few microhemorrhages. Neuropsychological assessment was normal. A granddaughter had mild headaches and a small right cerebellar cavernoma, without microhemorrhages. Neuropsychological assessment showed mild temporal neocortical left dysfunction. A nonsense variant, c.55C > T; p.R19* generating a premature stop codon in CCM2 gene shared by all affected family members was identified. CONCLUSIONS: Neuropsychological evaluation showed that memory complaints and cognitive impairment could be an important unrecognized finding in FCCM. Its pathophysiological mechanisms are still unknown but the role of recurrent microhemorrhages could provide an interesting hypothesis.

SQSTM1 Pro392Leu presenting as a corticobasal syndrome with progressive nonfluent aphasia.

Corticobasal syndrome is generally considered to be a sporadic condition. There are familial and isolated genetic cases, associated with GRN, MAPT, c9orf72 or PNRP variants. Some reports implicate other genes: LRRK2, CHMP2B, GBA, CYP27A1, PSEN1, APP, TARDBP and TBK1. Here, we report a case of a patient carrying a SQSTM1 Pro392Leu variant. We report a 57-year-old right-handed-woman with a history of progressive speech impairment, marked right side rigidity and bradykinesia, with rest tremor and stimulus sensitive myoclonus. She had predominantly right-sided apraxia. She had right side agraphestesia and astereognosis. MRI showed asymmetrical left frontotemporoparietal atrophy. DaTSCAN showed predominantly left involvement, PiB-PET was negative. CSF NfL was of 9356.5pg/mL. She carried a heterozygous variant P392L in SQSTM1. This case report expands the spectrum of phenotypes associated with SQSTM1 pathogenic variants. It also expands the list of genes associated with corticobasal syndrome, supporting the involvement of the ubiquitin-proteasome system in this condition.

SERAC1 Deficiency- A New Phenotype.

Introduction - SERAC1 deficiency phenotype range from MEGD(H)EL syndrome, the most severe, to juvenile complicated spastic paraplegia, to adult-onset dystonic features (in only one patient). The MEGD(H)EL syndrome is characterized by (3-methylglutaconic aciduria with deafness-dystonia, [hepatopathy], encephalopathy, and Leigh-like syndrome). Biochemical abnormalities: elevated urinary 3 - metilglutaconic and 3-metilglutaric acids, high lactate and alanine in serum. Diagnosis is confirmed when biallelic pathogenic variants in SERAC1 gene are found. Brain MRI: basal ganglia lesions and generalized atrophy. Results/Case report - A 30-year-old patient with a moderate intellectual disability, developed, since the age of 25, a progressive loss of previous capacities (hand dexterity, oral language), and later subacute generalized dystonic features. Currently he has spastic tetraparesis, dystonia, scoliosis and autistic behavior, with bilateral basal ganglia lesions on brain MRI. Genetic study revealed biallelic pathogenic variants in SERAC1 gene, confirm MEGD(H)EL. A 73 years old patient with cognitive impairment and progressive spastic tetraparesis had multiple periventricular T2 hyperintense lesions. She has a homozygotic SERAC1 variant NM_032861: exon4:c.T139A: p.F471 (rs112780453), considered benign. Biochemical study revealed elevated plasmatic alanine and urinary3-metilglutaconic and 3-metilglutaric acid. This profile is concordant with mitochondrial dysfunction and SERAC1 Deficit. Conclusion - The first patient has the clinical symptoms associated to the MEGD(H)EL syndrome, and the biochemical and genetic confirmation of the diagnosis, without reservations. However, in the second patient, the progressive paraparesis and cognitive impairment did not appear to be caused by multiple sclerosis nor subcortical vascular leukoencephalopathy (without vascular risk factors). The abnormal biochemical profile is suggestive of SERAC1 Deficiency, even without genetic confirmation. In what should we believe?

It's Never Too Late for a Diagnosis.

BACKGROUND: Zellweger spectrum disorder (ZSD) (OMIM#214100) is a phenotypic continuum ranging from severe to mild presentations. ZSD is now used in all individuals with a defect in one of the 13 ZSD-PEX genes, regardless of phenotype. Diagnosis can be suggested by abnormal levels of very long-chain fatty acids, phytanic acid, pristanic acid, plasmalogens, pipecolic acid, or bile acids. However, false negatives are frequent, mostly in older patients. Definite diagnosis is established in a proband with suggestive clinical findings by identification of biallelic pathogenic variants in one of the 13 ZSD-PEX genes. CASE REPORT: A 39-year-old female patient had a global development delay since her first year of life. Never developed oral language but had sphincter control and was able to walk and laugh. At 8 years old, she had her first seizure and lost sphincter control when she was 20 years old. At 28 years old, she had an episode of status epilepticus, with severe prostration and became bedridden. She is currently mute, without capacity for communication or motor control. She has no consanguineous parents, has a 35 year old brother with global developmental delay and their mother had a history of an abortion, without other relevant family history. Brain MRI of the patient revealed severe leukodystrophy mainly periventricular, bilateral and symmetric, and less prominent in the cerebellar white matter, with severe cerebral and corpus callosum atrophy. Molecular study with a leukodystrophy gene panela identified a homozygotic pathogenic variant on PEX 1 gene (NM_000466.3) - c.2528G>A (p.(Gly843Asp)), confirming the diagnosis of ZSD. CONCLUSION: Homozygosity for PEX1 p.Gly843Asp seems to be associated with an intermediate/milder ZSD phenotype,with survival until adulthood. Some patients develop progressive degeneration of CNS myelin, a leukodystrophy pattern, like this patient, which may lead to regression. This girl with ZSD had a rapid and severe loss of previous skills after a seizure. Even though there is no specific treatment for this disease, a correct diagnosiswas very important for the parents and for family genetic counselling.

Neuropsychological Assessment in the Distinction Between Biomarker Defined Frontal-Variant of Alzheimer's Disease and Behavioral-Variant of Frontotemporal Dementia.

BACKGROUND: Frontal-variant of Alzheimer's disease (fvAD) was purposed for patients with AD pathology that, despite the typical amnestic presentation, show early and progressive deterioration of behavior and executive functions, closely resembling the behavioral-variant of frontotemporal dementia (bvFTD). This leads to a challenging differential diagnosis where neuropsychological evaluation and in vivo pathological evidence are essential. OBJECTIVE: To evaluate the contribution of a comprehensive neuropsychological assessment (NP) battery in distinguishing between fvAD-dementia and bvFTD supported by cerebrospinal fluid (CSF) biomarkers. METHODS: We included 40 patients with a baseline NP profile with prominent early executive and/or behavioral dysfunction, who meet both diagnosis of bvFTD and fvAD-dementia, according to international criteria. All patients underwent comprehensive NP assessment and CSF-AD biomarker evaluation. Neuropsychological domains as well as clinical and sociodemographic features, and APOE genotype were compared between groups. RESULTS: 21 patients (52.5%) met the biological criteria for AD (decreased Aß42 together with increased T-tau or P-tau in CSF) and were therefore classified as fvAD (mean age was 64.57, with 47.6% female). There were no differences between groups regarding age/age-at-onset, gender, or educational level. Regarding neuropsychological profile, performances in language and memory functions were equivalent in both groups. Significant differences were found in visuo-constructional abilities (p = 0.004), Trail Making Test A (p < 0.001), and Raven's Colored Progressive Matrices (p = 0.019), with fvAD patients showing worst performances. CONCLUSION: In patients with an early prominent frontal profile, a higher impairment in attention and visuo-spatial functions, signaling additional right hemisphere fronto-parietal dysfunction, point towards a diagnosis of fvAD-dementia and may be useful in clinical practice.

Montreal Cognitive Assessment in Mild Cognitive Impairment: Relationship with Cerebrospinal Fluid Biomarkers and Conversion to Dementia.

BACKGROUND: Mild cognitive impairment (MCI) is considered a prodromal state of dementia. Abnormal values of cerebrospinal fluid Alzheimer's disease biomarkers (CSF-AD-b) have been associated with a higher risk of conversion to dementia (due to Alzheimer's disease), but studies evaluating the ability of Montreal Cognitive Assessment (MoCA) in this task are lacking. OBJECTIVE: This study aims to investigate the relationship between MoCA and CSF-AD-b, as well as the ability of those tools to predict conversion to dementia. METHODS: Taking advantage of our MCI cohort with biological characterization on longitudinal follow-up (180 patients followed for 62.6 months during which 41.3% converted), we computed MoCA and MMSE z-scores, using Portuguese normative data. The performance in MoCA z-score was correlated with CSF-AD-b and the relative time to conversion and risk according to baseline characteristics were analyzed using Kaplan-Meier analysis and Cox regression models. RESULTS: MoCA z-scores were correlated with Aß42 (p = 0.026), t-tau (p = 0.033), and p-tau (p = 0.01). Impaired MMSE (p < 0.001) and MoCA z-scores (p = 0.019), decreased Aß42 (p < 0.001) and increased t-tau (p < 0.001) and p-tau (p < 0.001) were associated with shorter estimated time of conversion. Aß42 (p < 0.001) and MMSE z-scores (p = 0.029) were independent predictors of conversion. For those with at least 9 years of education, MoCA z-score (p = 0.004) (but not MMSE) was an independent predictor of conversion as well as Aß42. CONCLUSIONS: This study confirms the role of CSF-AD-b, namely Aß42, in predicting conversion from MCI to dementia and suggests the utility of MoCA in predicting conversion in highly educated subjects, supporting its use in the evaluation of MCI patients.

Serum Neurofilament Light Chain in the Diagnostic Evaluation of Patients with Cognitive Symptoms in the Neurological Consultation of a Tertiary Center.

Serum light-chain neurofilaments (sNfL) have been investigated as a potential minimally invasive biomarker that could help in the diagnosis of patients with cognitive symptoms. We assessed the correlation between sNfL and cerebrospinal fluid (CSF) biomarkers (sNfL versus CSF NfL, ρ= 0.70, p < 0.001), the performance of sNfL in distinguishing controls from patients (controls versus frontotemporal dementia, area under curve 0.86), and sNfL differences in mild cognitive impairment according to amyloid-ß (Aß) deposition (Aß versus non-Aß, p = 0.017). Our results support the role of this biomarker in the screening and risk stratification of patients followed in a neurological consultation of a tertiary center.