Magnetic resonance imaging Locus Coeruleus abnormality in amnestic Mild Cognitive Impairment is associated with future progression to dementia.

BACKGROUND AND PURPOSE: Human neuropathological studies indicate that the pontine nucleus Locus Coeruleus (LC) undergoes significant and early degeneration in Alzheimer's disease. This line of evidence alongside experimental data suggests that the LC functional/structural decay may represent a critical factor for Alzheimer's disease pathophysiological and clinical progression. In the present prospective study, we used Magnetic Resonance Imaging (MRI) with LC-sensitive sequence (LC-MRI) to investigate in vivo the LC involvement in Alzheimer's disease progression, and whether specific LC-MRI features at baseline are associated with prognosis and cognitive performance in amnestic Mild Cognitive Impairment. METHODS: LC-MRI parameters were measured at baseline by a template-based method on 3.0-T magnetic resonance images in 34 patients with Alzheimer's disease dementia, 73 patients with amnestic Mild Cognitive Impairment, and 53 cognitively intact individuals. A thorough neurological and neuropsychological assessment was performed at baseline and 2.5-year follow-up. RESULTS: In subjects with Mild Cognitive Impairment who converted to dementia (n = 32), the LC intensity and number of LC-related voxels were significantly lower than in cognitively intact individuals, resembling those observed in demented patients. Such a reduction was not detected in Mild Cognitive Impairment individuals, who remained stable at follow-up. In Mild Cognitive Impairment subjects converting to dementia, LC-MRI parameter reduction was maximal in the rostral part of the left nucleus. Structural equation modeling analysis showed that LC-MRI parameters positively correlate with cognitive performance. CONCLUSIONS: Our findings highlight a potential role of LC-MRI for predicting clinical progression in Mild Cognitive Impairment and support the key role of LC degeneration in the Alzheimer clinical continuum.

Bipolar Spectrum disorders in Parkinson's disease: a systematic evaluation.

OBJECTIVE: Psychiatric disorders are very common in patients affected by Parkinson's disease (PD). However, comorbidity with Bipolar Spectrum disorders is understudied. The aim of this study is to explore the clinical correlates of PD associated with Bipolar Spectrum disorders. METHODS: One hundred PD patients were screened for psychiatric comorbidities, cognitive profile, motor, and non-motor symptoms. The sample was divided into three groups: PD-patients with Bipolar Spectrum disorders (bipolar disorder type I, type II, and spontaneous or induced hypomania; N = 32), PD-patients with others psychiatric comorbidities (N = 39), PD-patients without psychiatric comorbidities (N = 29). Clinical features were compared among the groups using analysis of variance and chi-square test. A logistic regression was performed to evaluate the association between Bipolar Spectrum disorders and early onset of PD (≤50 years) controlling for lifetime antipsychotic use. RESULTS: In comparison with PD patients with and without other psychiatric comorbidity, subjects affected by Bipolar Spectrum disorders were younger, showed more frequently an early onset PD, reported more involuntary movements and a higher rate of impulse control disorders and compulsive behaviors. No differences were observed in indexes of exposure to dopamine agonist treatments. The early onset of PD was predicted by Bipolar Spectrum comorbidity, independently from lifetime antipsychotic use. CONCLUSION: Bipolar Spectrum disorders are common in early onset PD. The presence of bipolar comorbidity could identify a particular subtype of PD, showing higher rates of neurological and psychiatric complications and deserving further investigation.

P2X7 receptor/NLRP3 inflammasome complex and α-synuclein in peripheral blood mononuclear cells: a prospective study in neo-diagnosed, treatment-naïve Parkinson's disease.

BACKGROUND AND PURPOSE: Neuroinflammation and probably systemic inflammation, with abnormal α-synuclein deposition, participate in the development of Parkinson's disease (PD). The P2X7 receptor/NLRP3 inflammasome complex is upregulated in the brain of PD patients. By a prospective approach, the degree of systemic activation of such complex, and its regulatory mechanisms, were explored in treatment-naïve PD individuals. METHODS: The expression and functional activity of the inflammasome were measured in peripheral blood mononuclear cells of 25 newly diagnosed PD patients and 25 controls at baseline and after 12 months of pharmacological treatment, exploring the intracellular signalling involved and its epigenetic regulation. RESULTS: De novo PD patients were characterized by a systemic hyper-expression of the P2X7R/NLRP3 inflammasome platform, probably able to modulate lymphomonocyte α-synuclein, whose brain deposits represent the main pathogenetic factor of PD. A reduced c-Jun N-terminal kinase (JNK) phosphorylation might be the intracellular signalling mediating this effect. miR-7 and miR-30, implied in the pathogenesis of PD and in the post-transcriptional control of α-synuclein and NLRP3 expression, were also increased in PD. After 1 year of usual anti-Parkinson treatments, such inflammatory platform was significantly reduced. CONCLUSIONS: Mononuclear cells of newly diagnosed PD subjects display a hyper-expression of the P2X7R/NLRP3 inflammasome platform that seems to modulate cellular α-synuclein content and is reduced after PD treatment; an impaired JNK phosphorylation might be the intracellular signalling mediating this effect, undergoing an epigenetic regulation by miR-7 and miR-30.

Connected speech in progressive supranuclear palsy: a possible role in differential diagnosis.

BACKGROUND: Progressive supranuclear palsy (PSP) is an atypical Parkinsonism characterized by motor and neuropsycological disorders. Language could be impaired in PSP patients, also in Richardson variant (PSP-RS). The analysis of connected speech is used in neurodegenerative disorder to investigate different levels of language organization, including phonetic, phonological, lexico-semantic, morpho-syntactic, and pragmatic processing. OBJECTIVE: In our study, we aimed to investigate the language profile, especially connected speech, in early-stage PSP-RS and Parkinson's disease (PD) patients without predominant speech or language disorders. METHODS: Language was assessed using the Screening for Aphasia in NeuroDegeneration (SAND); connected speech analysis was conducted from the picture description subtest. RESULTS: We enrolled 48 patients, 22 PD and 26 PSP (18 PSP-RS and 8 non-RS). PSP-RS patients presented an impairment in language domain, particularly regarding connected speech. PSP-RS patients presented worse performances than PD in different scores. The output of PSP-RS patients was characterized by a reduction in number of sentences and subordinates with respect to PD; PSP presented also more repaired sequences and phonological and lexico-semantic errors than PD. Number of sentences and number of subordinates of the picture description task were identified as predictors of PSP diagnosis. CONCLUSION: In summary, the SAND scale is able to identify language impairment in PSP patients. The analysis of connected speech could highlight some important aspects of language impairment in PSP-RS patients, and it could be helpful in the differential diagnosis with PD.

Is DAT imaging abnormality in normal pressure hydrocephalus always suggestive of degeneration?

Idiopathic normal pressure hydrocephalus (iNPH) is a debated entity with controversial pathogenesis, diagnostic criteria, and predictors of response after ventriculoperitoneal shunt (VPS). Parkinsonian signs are frequently reported in the clinical picture, sometimes due to the coexistence of an underlying neurodegenerative parkinsonism and sometimes in the absence thereof. To distinguish these two scenarios is crucial, since they may carry different long-term response to CSF drainage. 123I-FP-CIT-SPECT was believed to be helpful in this regard, however its role in predicting surgical outcome has been disputed. We illustrate a patient presented with gait disturbance, urinary incontinence, and asymmetrical parkinsonian signs, who underwent a 3T brain MRI and a 123I-FP-CIT-SPECT. VPS was performed. The patient repeated a 123I-FP-CIT-SPECT, 18 months after the operation, and was clinically followed up for 24 months. Our patient displayed clinical and radiological criteria for iNPH and an abnormal asymmetrical uptake in 123I-FP-CIT-SPECT, consistent with her asymmetrical parkinsonism. However, the organization of the substantia nigra studied with iron-sensitive sequences in 3T brain MRI scan appeared intact. The patient revealed an improvement both clinically and in 123I-FP-CIT-SPECT at postsurgical follow-up. Our report suggests that abnormal 123I-FP-CIT-SPECT may not necessarily reveal an overlap with neurodegenerative parkinsonism; its partial reversibility may suggest that the mechanical effect exerted on the striatum by ventriculomegaly ultimately leads to downregulation of dopaminergic transporters which may improve after VPS.

Effects of combined training on neuropsychiatric symptoms and quality of life in patients with cognitive decline.

BACKGROUND AND AIMS: Cognitive impairments associated with aging and dementia are major sources of neuropsychiatric symptoms (NPs) and deterioration in quality of life (QoL). Preventive measures to both reduce disease and improve QoL in those affected are increasingly targeting individuals with mild cognitive impairment (MCI) at early disease stage. However, NPs and QoL outcomes are too commonly overlooked in intervention trials. The purpose of this study was to test the effects of physical and cognitive training on NPs and QoL in MCI. METHODS: Baseline data from an MCI court (N = 93, mean age 74.9 ± 4.7) enrolled in the Train the Brain (TtB) study were collected. Subjects were randomized in two groups: a group participated to a cognitive and physical training program, while the other sticked to usual standard care. Both groups underwent a follow-up re-evaluation after 7 months from baseline. NPs were assessed using the Neuropsychiatric Inventory (NPI) and QoL was assessed using Quality of Life-Alzheimer's Disease (QOL-AD) scale. RESULTS: After 7 months of training, training group exhibited a significant reduction of NPs and a significant increase in QOL-AD with respect to no-training group (p = 0.0155, p = 0.0013, respectively). Our preliminary results suggest that a combined training can reduce NPs and improve QoL. CONCLUSIONS: Measuring QoL outcomes is a potentially important factor in ensuring that a person with cognitive deficits can 'live well' with pathology. Future data from non-pharmacological interventions, with a larger sample and a longer follow-up period, could confirm the results and the possible implications for such prevention strategies for early cognitive decline.

Dopamine Transporter, Age, and Motor Complications in Parkinson's Disease: A Clinical and Single-Photon Emission Computed Tomography Study.

BACKGROUND: Previous molecular imaging studies comparing dopamine function in vivo between early-onset PD and late-onset PD patients have shown contradictory results, presumably attributable to the aging-related decline in nigrostriatal function. OBJECTIVES: (1) To investigate baseline dopamine transporter availability in early-onset PD (<55 years) and late-onset PD (>70 years) patients, z-scores values of putamen and caudate [123 I]-ioflupane uptake were calculated using the respective age-matched controls in order to correct for early presynaptic compensatory mechanisms and age-related dopamine neuron loss; (2) to examine the associations of such baseline single-photon emission computed tomography measures with the emergence of late-disease motor complications. METHODS: In this retrospective study, 105 de novo PD patients who underwent [123 I]-ioflupane single-photon emission computed tomography at time of diagnosis were divided into three tertile groups according to age at disease onset (35 early-onset PD and 40 late-onset PD patients). Z-scores were compared between the two groups, and their predictive power for motor complications (during a mean follow-up of 7 years) was evaluated using Cox proportional hazard models. RESULTS: Despite a less-severe motor phenotype, early-onset PD patients exhibited more reduced [123 I]-ioflupane binding in the putamen and had a higher and earlier risk for developing motor complications than those with late-onset PD. Lower [123 I]-Ioflupane uptake in the putamen and caudate increased the risk of motor complications. CONCLUSIONS: Our findings indicate that a lower dopamine transporter binding in early-onset PD predicts the later development of motor complications, but it is not related to severity of motor symptoms, suggesting age-related differences in striatal compensatory mechanisms in PD. © 2020 International Parkinson and Movement Disorder Society.

Locus Coeruleus Magnetic Resonance Imaging in Neurological Diseases.

PURPOSE OF REVIEW: Locus coeruleus (LC) is the main noradrenergic nucleus of the brain, and its degeneration is considered to be key in the pathogenesis of neurodegenerative diseases. In the last 15 years,MRI has been used to assess LC in vivo, both in healthy subjects and in patients suffering from neurological disorders. In this review, we summarize the main findings of LC-MRI studies, interpreting them in light of preclinical and histopathological data, and discussing its potential role as diagnostic and experimental tool. RECENT FINDINGS: LC-MRI findings were largely in agreement with neuropathological evidences; LC signal showed to be not significantly affected during normal aging and to correlate with cognitive performances. On the contrary, a marked reduction of LC signal was observed in patients suffering from neurodegenerative disorders, with specific features. LC-MRI is a promising tool, which may be used in the future to explore LC pathophysiology as well as an early biomarker for degenerative diseases.

Theory of mind in Parkinson's disease: evidences in drug-naïve patients and longitudinal effects of dopaminergic therapy.

Theory of mind (ToM) is the ability to attribute mental states to one self and others and to understand that others have beliefs different from one's own. Different subcomponents of ToM have also been identified: cognitive and affective. Cognitive ToM refers to the capacity to infer others' beliefs and intentions, while affective ToM implies the ability to appreciate others' emotional states. The aim of this study was to explore ToM in drug-naïve Parkinson's disease (PD) patients and to investigate the effects of chronic dopaminergic therapy on different subcomponents of ToM during a 3 months and 1 year of follow-up. We examined 16 PD patients in three conditions: before (un-medicated) and after dopaminergic therapy (medicated 3 months: T1 and medicated 1 year: T2). We also compared our PD's ToM abilities with 11 healthy individuals. ToM was explored with 5 different tasks: Faux Pas Test, Picture Sequencing Task Capture Story, Emotion Attribution Task, Strange Stories Task, and Karolinska Directed Emotional Faces. Our study confirms that PD patients present deficits in cognitive components of ToM and preserved performances in the affective ones in early stages of disease. We also find a significant effect of dopaminergic therapy on ToM already after 3 months with a good persistency after 1 year of treatment.

Excessive daytime sleepiness and fatigue in neurological disorders.

Excessive daytime sleepiness (EDS) and fatigue are some of the most frequent symptoms in neurological diseases and could impact on quality of life by increasing the risk of accidents and generally affecting daily life activities. In this review, we will examine the variety of causes responsible for EDS in neurological diseases, including nocturnal sleep alterations, CNS pathological abnormalities with alterations in arousal and/or REM regulation systems, circadian rhythms disorders, drugs, and comorbid psychiatric or primary sleep disorders. Among neurological diseases, epilepsy, dementia, Parkinson disease, multiple sclerosis, and myotonic dystrophies represented a model for these interactions between EDS and neurological diseases. A complete diagnostic workup in neurological patients with EDS should be undertaken since EDS can worsen many different aspects such as psychiatric symptoms, cognitive deficit, and in some cases, the severity of the neurological disease per se. Moreover, quality of life and risk of accidents are dependent on EDS. An individualized approach to this symptom in neurological patients should be considered with a focus on modifiable causes such as SDB, psychiatric comorbidities, and drugs. When considering EDS and fatigue in neurological diseases, close attention to lifestyle and sleep hygiene is advisable. A critical review of ongoing pharmacological therapy should not be overlooked. Possible diagnosis and treatment of SDB should be always considered.

A longitudinal study of polysomnographic variables in patients with mild cognitive impairment converting to Alzheimer's disease.

The main condition at increased risk of dementia is considered to be mild cognitive impairment. Mild cognitive impairment has been defined as a transitional state between normal aging and dementia, of which it may represent a prodrome. The aim of our study was to evaluate whether sleep variables (both conventional and microstructural ones) in subjects with mild cognitive impairment correlate with conversion to dementia. Nineteen subjects with amnestic mild cognitive impairment (mean age 68.5 ±â€…7.0 years) and 11 cognitively intact healthy elderly individuals (mean age 69.2 ±â€…12.6 years) underwent ambulatory polysomnography for the evaluation of nocturnal sleep architecture and cyclic alternating pattern parameters. Amnestic mild cognitive impairment subjects were clinically and cognitively re-evaluated after 2 years, during routine follow-up, and further classified as amnestic mild cognitive impairment converters (that is, patients developing Alzheimer's disease, N = 11) and amnestic mild cognitive impairment non-converters. Compared with healthy elderly individuals, amnestic mild cognitive impairment showed disrupted sleep with decreased rapid eye movement sleep, cyclic alternating pattern rate and cyclic alternating pattern slow-wave-related phases (A1 index). Standard sleep architecture analysis did not show significant differences between the two subgroups of amnestic mild cognitive impairment, whereas cyclic alternating pattern analysis showed that cyclic alternating pattern rate, A1 index and A3 index are significantly reduced in converters compared with non-converters. Our data confirm that in amnestic mild cognitive impairment subjects there is a sleep impairment, particularly when considering more refined sleep parameters and that sleep variables at baseline are different among converters versus non-converters at the 2-year follow-up. Specific sleep alterations might represent potential further biomarkers for the diagnosis and prognosis of early-phase cognitive impairment.

Progression of tremor in early stages of Parkinson's disease: a clinical and neuroimaging study.

Rest tremor is one of the cardinal signs of Parkinson's disease. Kinetic and postural tremors may also occur. The coexistence of these three types of tremor at disease onset and their subsequent progression could have important clinical and therapeutic implications but remain to be fully elucidated. We aimed to: (i) evaluate prevalence and progression of these three types of tremor in early stages of the disease; and (ii) investigate longitudinally the relationship between dopaminergic and serotonergic terminal dysfunction, rest tremor severity and its response to dopaminergic therapy. The Parkinson's Progressive Markers Initiative database provided the baseline and 2-year follow-up clinical ratings and 123ioflupane-fluoropropyl-carbomethoxy-3-beta-4-iodophenyltropane (123I-FP-CIT) single photon emission computed tomography images for this study. 123I-FP-CIT measured putamen dopamine transporter and median raphe serotonin transporter availability. A raphe/putamen uptake ratio was calculated for each patient as an index of relative involvement of these structures. Clinical analysis of tremor was conducted on 378 patients: 87.8% presented with tremor at baseline; rest tremor occurred in 69.6% of patients at baseline; and 67.9% at follow-up. Postural and kinetic tremors occurred in about 50% of patients at both baseline and follow-up. Over 20% of patients presenting with tremor did not exhibit a rest component at baseline. The number of patients with isolated rest tremor was halved at follow-up. In tremor predominant patients, rest tremor severity was inversely correlated with raphe serotonin transporter availability both at baseline and follow-up (baseline: constancy P < 0.05, tremor index P < 0.05; follow-up: amplitude P < 0.05, constancy P < 0.05, tremor index P < 0.05). In the entire cohort, more severe tremor scores correlated with lower raphe/putamen uptake ratio values, indicative of more severe raphe dysfunction (baseline: constancy P < 0.01, tremor index P < 0.05; follow-up: amplitude P < 0.01, constancy P < 0.001, tremor index P < 0.001). The percentage of improvement in rest tremor amplitude after acute dopaminergic therapy was smaller in patients with lower raphe/putamen uptake ratio values (P < 0.01). Rest tremor is the most represented type of tremor in early Parkinson's disease. However, postural and kinetic tremor can affect approximately half of these patients and can occur in absence of resting tremor. As disease progresses, both raphe serotonergic dysfunction and putamen dopamine depletion could contribute to the occurrence of rest tremor. The former is linked to more severe tremor scores and poorer response to dopaminergic therapy. Non-dopaminergic treatments might be beneficial for patients whose tremor is associated with a raphe-predominant dysfunction.

Social cognition in idiopathic generalized epilepsies and potential neuroanatomical correlates.

Social cognition allows us to elaborate mental representations of social relationships and use them appropriately in a social environment. One of its main attributes is the so-called Theory of Mind (ToM), which consists of the ability to attribute beliefs, intentions, emotions, and feelings to self and others. Investigating social cognition may help understand the poor social outcome often experienced by persons with Idiopathic Generalized Epilepsies (IGE), who otherwise present with normal intelligence. In recent years, several studies have addressed social cognition in subjects with focal epilepsies, while literature on social cognition in IGE is scarce, and findings are often conflicting. Some studies on samples of patients with mixed IGE showed difficulties in emotion attribution tasks, which were not replicated in a homogeneous population of patients with Juvenile Myoclonic Epilepsy alone. Impairment of higher order social skills, such as those assessed by Strange Stories Test and Faux Pas Tasks, were consistently found by different studies on mixed IGE, suggesting that this may be a more distinctive IGE-associated trait, irrespective of the specific syndrome subtype. Though an interplay between social cognition and executive functions (EF) was suggested by several authors, and their simultaneous impairment was shown in several epilepsy syndromes including IGE, no formal correlations among the two domains were identified in most studies. People with IGE exhibit subtle brain structural alterations in areas potentially involved in sociocognitive functional networks, including mesial prefrontal and temporoparietal cortices, which may relate to impairment in social cognition. Heterogeneity in patient samples, mostly consisting of groups with mixed IGE, and lack of analyses in specific IGE subsyndromes, represent evident limitations of the current literature. Larger studies, focusing on specific subsyndromes and implementing standardized test batteries, will improve our understanding of sociocognitive processing in IGE. Concomitant high-resolution structural and functional neuroimaging may aid the identification of its neural correlates. This article is part of the Special Issue "Epilepsy and social cognition across the lifespan".

Present and Future of Ultra-High Field MRI in Neurodegenerative Disorders.

PURPOSE OF REVIEW: With a high signal-to-noise ratio, unparalleled spatial resolution, and improved contrasts, ultra-high field MR (≥ 7 T) has great potential in depicting the normal radiological anatomy of smaller structures in the brain and can also provide more information about morphological, quantitative, and metabolic changes associated with a wide range of brain disorders. By focusing attention on specific brain regions believed to be associated with early pathological change, or by more closely inspecting recognized foci of brain pathology, ultra-high field MR can improve the accuracy and sensitivity of neuroimaging. This article reviews recent studies at ultra-high field about Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). RECENT FINDINGS: The research on AD has mainly focused on detecting the thinning of hippocampal layers and the susceptibility effect supposed to be related to beta-amyloid deposition. In patients with PD, atypical parkinsonisms and subjects at risk of developing motor symptoms of Parkinson's disease, the main aim was to detect changes in the substantia nigra, probably related to increased iron deposition. In patients with ALS, both brain and spinal cord were investigated, with the aim of finding changes in the primary motor cortex and corticospinal tract which reflect neurodegeneration and neuroinflammation. Ultra-high field MR was shown to be useful for detecting subtle brain changes in patients with AD, and possible new diagnostic biomarkers in patients with PD and ALS were discovered. The ability of 7 T MR to provide prognostic biomarkers in subjects at risk for developing synucleinopathies is currently under evaluation.

The Precuneus - A Witness for Excessive Aß Gathering in Alzheimer's Disease Pathology.

Evidence of cortical beta-amyloid (Aß) load, assessed by Aß positron emission tomography (Aß-PET), is an established in vivo biomarker of Alzheimer's disease (AD)-related pathophysiology. Qualitative assessment of Aß-PET provides binary information; meanwhile semiquantitative approaches require a parcellation of PET image either manually or by placement of atlas-based volumes of interest. We supposed that a whole-brain approach with voxel-by-voxel standardized uptake value ratio (SUVr) parametric images may better elucidate the spatial trajectories of Aß burden along the continuum of AD. METHODS: We recruited 32 subjects with a diagnosis of probable AD dementia (ADD, n = 20) and mild cognitive impairment due to AD (MCI-AD, n = 12) according to the NIA-AA 2011 criteria. We also enrolled a control group of 6 cognitively healthy individuals (HCs) with preserved cognitive functions and negative Aß-PET scan. The PET images were spatially normalized using the AV45 PET template in the MNI brain space. Subsequently, parametric SUVr images were calculated using the whole cerebellum as a reference region. A voxel-wise analysis of covariance was used to compare (between groups) the Αß distribution pattern considering age as a nuisance covariate. RESULTS: Both ADD and MCI-AD subjects showed a widespread increase in radiotracer uptake when compared with HC participants (p < 0.001, uncorrected). After applying a multiple comparison correction (p < 0.05, corrected), a relative large cluster of increased [18F]-flor-betapir uptake was observed in the precuneus in the ADD and MCI-AD groups compared to HCs. Voxel-wise regression analysis showed a significant positive linear association between the voxel-wise SUVr values and the disease duration. CONCLUSIONS: The voxel-wise semiquantitative analysis shows that the precuneus is a region with higher vulnerability to Aß depositions when compared to other cortical regions in both MCI-AD and ADD subjects. We think that the precuneus is a promising PET-based outcome measure for clinical trials of drugs targeting brain Aß. We found a positive association between the overall Aß-PET SUVr and the disease duration suggesting that the region-specific slow saturation of Aß deposition continuously takes place as the disease progresses.

Olfactory evaluation in Mild Cognitive Impairment: correlation with neurocognitive performance and endothelial function.

Mild Cognitive Impairment (MCI) is an intermediate condition between normal aging and dementia, associated with an increased risk of progression into the latter within months or years. Olfactory impairment, a well-known biomarker for neurodegeneration, might be present in the condition early, possibly representing a signal for future pathological onset. Our study aimed at evaluating olfactory function in MCI and healthy controls in relation to neurocognitive performance and endothelial function. A total of 85 individuals with MCI and 41 healthy controls, matched for age and gender, were recruited. Olfactory function was assessed by Sniffin' Sticks Extended Test (Burghart, Medizintechnik, GmbH, Wedel, Germany). A comprehensive neurocognitive assessment was performed. Endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery by ultrasound. MCI individuals showed an impaired olfactory function compared to controls. The overall olfactory score is able to predict MCI with a good sensitivity and specificity (70.3 and 77.4% respectively). In MCI, olfactory identification score is correlated with a number of neurocognitive abilities, including overall cognitive status, dementia rating, immediate and delayed memory, visuospatial ability and verbal fluency. FMD was reduced in MCI (2.90 ± 2.15 vs. 3.66 ± 1.96%, P = 0.016) and was positively associated with olfactory identification score (ρs =0.219, P = 0.025). The association remained significant after controlling for age, gender, and smoking. In conclusion, olfactory evaluation is able to discriminate between MCI and healthy individuals. Systemic vascular dysfunction might be involved, at least indirectly, in olfactory dysfunction in MCI.

Diagnostic function of the neuroinflammatory biomarker YKL-40 in Alzheimer's disease and other neurodegenerative diseases.

INTRODUCTION: Neuroinflammation is a crucial mechanism in the pathophysiology of neurodegenerative diseases pathophysiology. Cerebrospinal fluid (CSF) YKL-40 - an indicator of microglial activation - has recently been identified by proteomic studies as a candidate biomarker for Alzheimer's disease (AD). Areas covered: We review the impact of CSF YKL-40 as a pathophysiological biomarker for AD and other neurodegenerative diseases. CSF YKL-40 concentrations have been shown to predict progression from prodromal mild cognitive impairment to AD dementia. Moreover, a positive association between CSF YKL-40 and other biomarkers of neurodegeneration - particularly total tau protein - has been reported during the asymptomatic preclinical stage of AD and other neurodegenerative diseases. Albeit preliminary, current data do not support an association between APOE-ε4 status and CSF YKL-40 concentrations. When interpreting the diagnostic/prognostic significance of CSF YKL-40 concentrations in neurodegenerative diseases, potential confounders - including age, metabolic and cardiovascular risk factors, diagnostic criteria for selecting cases/controls - need to be considered. Expert opinion/commentary: CSF YKL-40 represents a pathophysiological biomarker reflecting immune/inflammatory mechanisms in neurodegenerative diseases, associated with tau protein pathology. Besides being associated with tau pathology, CSF YKL-40 adds to the growing array of biomarkers reflecting distinct molecular brain mechanisms potentially useful for stratifying individuals for biomarker-guided, targeted anti-inflammatory therapies emerging from precision medicine.

ICARUS study: prevalence and clinical features of impulse control disorders in Parkinson's disease.

BACKGROUND: Impulse control disorders/other compulsive behaviours ('ICD behaviours') occur in Parkinson's disease (PD), but prospective studies are scarce, and prevalence and clinical characteristics of patients are insufficiently defined. OBJECTIVES: To assess the presence of ICD behaviours over a 2-year period, and evaluate patients' clinical characteristics. METHODS: A prospective, non-interventional, multicentre study (ICARUS (Impulse Control disorders And the association of neuRopsychiatric symptoms, cognition and qUality of life in ParkinSon disease); SP0990) in treated Italian PD outpatients. Study visits: baseline, year 1, year 2. Surrogate primary variable: presence of ICD behaviours and five ICD subtypes assessed by modified Minnesota Impulsive Disorder Interview (mMIDI). RESULTS: 1069/1095 (97.6%) patients comprised the Full Analysis Set. Point prevalence of ICD behaviours (mMIDI; primary analysis) was stable across visits: 28.6% (306/1069) at baseline, 29.3% (292/995) at year 1, 26.5% (245/925) at year 2. The most prevalent subtype was compulsive eating, followed by punding, compulsive sexual behaviour, gambling and buying disorder. Patients who were ICD positive at baseline were more likely to be male, younger, younger at PD onset, have longer disease duration, more severe non-motor symptoms (including mood and sexual function), depressive symptoms, sleep impairment and poorer PD-related quality of life. However, they did not differ from the ICD-negative patients in their severity of PD functional disability, motor performance and cognitive function. CONCLUSIONS: Prevalence of ICD behaviours was relatively stable across the 2-year observational period. ICD-positive patients had more severe depression, poorer sleep quality and reduced quality of life.

Cyclic alternating pattern and interictal epileptiform discharges during morning sleep after sleep deprivation in temporal lobe epilepsy.

PURPOSE: Sleep deprivation (SD) increases the occurrence of interictal epileptiform discharges (IED) compared to basal EEG in temporal lobe epilepsy (TLE). In adults, EEG after SD is usually performed in the morning after SD. We aimed to evaluate whether morning sleep after SD bears additional IED-inducing effects compared with nocturnal physiological sleep, and whether changes in sleep stability (described by the cyclic alternating pattern-CAP) play a significant role. METHODS: Adult patients with TLE underwent in-lab night polysomnography (n-PSG) and, within 7days from n-PSG, they underwent also a morning EEG after night SD (SD-EEG). We included only TLE patients in which both recordings showed IED. SD-EEG consisted of waking up patients at 2:00 AM and performing video EEG at 8:00 AM. For both recordings, we obtained the following markers for the first sleep cycle: IED/h (Spike Index, SI), sleep macrostructure, microstructure (NREM CAP rate; A1, A2 and A3 Indices), and SI association with CAP variables. RESULTS: The macrostructure of the first sleep cycle was similar in n-PSG and morning SD-EEG, whereas CAP rate and SI were significantly higher in SD-EEG. SI increase was selectively associated with CAP phases. CONCLUSIONS: SD increases the instability of morning recovery sleep compared with n-PSG, and particularly enhances CAP A1 phases, which are associated with the majority of IED. Thus, higher instability of morning recovery sleep may account at least in part for the increased IED yield in SD-EEG in TLE patients.

A single center study: Aß42/p-Tau181 CSF ratio to discriminate AD from FTD in clinical setting.

Abnormal levels of beta amyloid (Aß42) and tau protein concentrations in the cerebral spinal fluid (CSF) have been largely described in Alzheimer's disease (AD). Thus, CSF analysis of these biomarkers has been incorporated in recent AD diagnostic criteria, and it is increasingly performed for neurodegenerative dementia diagnostic workout in clinical setting. Nevertheless, the precise biomarkers CSF features in neurodegenerative dementia, either AD or Frontotemporal dementia (FTD), are still not fully clear today. This is mainly due to lack of CSF clear cutoff values due to a well-known intersite (but even intrasite) variability of CSF procedures, ranging from collection to analysis. Applying CSF biomarker ratios, rather than their single values could represent a useful tool, especially for the differential diagnosis of different forms of dementia. We explored clinical values of six CSF ratios (by combining Aß42 and tau) in order to better discriminate between AD and FTD; we identified Aß42/p-Tau181 ratio as a potential good candidate for helping differentiating AD from FTD in the clinical practice.