Impaired glymphatic system in genetic frontotemporal dementia: a GENFI study.

The glymphatic system is an emerging target in neurodegenerative disorders. Here, we investigated the activity of the glymphatic system in genetic frontotemporal dementia with a diffusion-based technique called diffusion tensor image analysis along the perivascular space. We investigated 291 subjects with symptomatic or presymptomatic frontotemporal dementia (112 with chromosome 9 open reading frame 72 [C9orf72] expansion, 119 with granulin [GRN] mutations and 60 with microtubule-associated protein tau [MAPT] mutations) and 83 non-carriers (including 50 young and 33 old non-carriers). We computed the diffusion tensor image analysis along the perivascular space index by calculating diffusivities in the x-, y- and z-axes of the plane of the lateral ventricle body. Clinical stage and blood-based markers were considered. A subset of 180 participants underwent cognitive follow-ups for a total of 640 evaluations. The diffusion tensor image analysis along the perivascular space index was lower in symptomatic frontotemporal dementia (estimated marginal mean ± standard error, 1.21 ± 0.02) than in old non-carriers (1.29 ± 0.03, P = 0.009) and presymptomatic mutation carriers (1.30 ± 0.01, P < 0.001). In mutation carriers, lower diffusion tensor image analysis along the perivascular space was associated with worse disease severity (ß = -1.16, P < 0.001), and a trend towards a significant association between lower diffusion tensor image analysis along the perivascular space and higher plasma neurofilament light chain was reported (ß = -0.28, P = 0.063). Analysis of longitudinal data demonstrated that worsening of disease severity was faster in patients with low diffusion tensor image analysis along the perivascular space at baseline than in those with average (P = 0.009) or high (P = 0.006) diffusion tensor image analysis along the perivascular space index. Using a non-invasive imaging approach as a proxy for glymphatic system function, we demonstrated glymphatic system abnormalities in the symptomatic stages of genetic frontotemporal dementia. Such measures of the glymphatic system may elucidate pathophysiological processes in human frontotemporal dementia and facilitate early phase trials of genetic frontotemporal dementia.

Beyond CAG Repeats: The Multifaceted Role of Genetics in Huntington Disease.

Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG expansion on the huntingtin (HTT) gene and is characterized by progressive motor, cognitive, and neuropsychiatric decline. Recently, new genetic factors besides CAG repeats have been implicated in the disease pathogenesis. Most genetic modifiers are involved in DNA repair pathways and, as the cause of the loss of CAA interruption in the HTT gene, they exert their main influence through somatic expansion. However, this mechanism might not be the only driver of HD pathogenesis, and future studies are warranted in this field. The aim of the present review is to dissect the many faces of genetics in HD pathogenesis, from cis- and trans-acting genetic modifiers to RNA toxicity, mitochondrial DNA mutations, and epigenetics factors. Exploring genetic modifiers of HD onset and progression appears crucial to elucidate not only disease pathogenesis, but also to improve disease prediction and prevention, develop biomarkers of disease progression and response to therapies, and recognize new therapeutic opportunities. Since the same genetic mechanisms are also described in other repeat expansion diseases, their implications might encompass the whole spectrum of these disorders.

Incidence of young-onset dementia in Italy: The Brescia register study.

INTRODUCTION: The goal of the present work was to assess the incidence of dementia with onset before the age of 65 years (i.e., young-onset dementia [YOD]) and define the frequencies of young-onset Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD), and dementia with Lewy bodies (DLB) in the general population. METHODS: The study was conducted from January 1, 2019 to December 31, 2019 in Brescia province (population: 1,268,455). During the study period, all new YOD cases (incident YOD) were counted, and all patients' records reviewed. The incidence was standardized to the Italian general population in 2019. RESULTS: A total of 29 YOD patients were diagnosed. The age-sex standardized incidence rate was 4.58 (95% confidence interval, 3.07-6.58) per 100,000 person-years. No difference in incidence rate between YOD due to AD or FTLD (P = 0.83) and between sexes (P = 0.81) was observed. YOD incidence increased with age, reaching its peak after 60 years. DISCUSSION: Presenting neurodegenerative YOD phenotypes encompasses both AD and FTLD. Improved knowledge on YOD epidemiology is essential to adequately plan and organize health services.

Trans-synaptic degeneration in the optic pathway: Exploring the role of lateral geniculate nucleus in early stages of relapsing-remitting multiple sclerosis.

BACKGROUND: Optic pathway is considered an ideal model to study the interaction between inflammation and neurodegeneration in multiple sclerosis (MS). METHODS: Optical Coherence Tomography (OCT) and 3.0 T magnetic resonance imaging (MRI) were acquired in 92 relapsing remitting (RR) MS at clinical onset. Peripapillary RNFL (pRNFL) and macular layers were measured. White matter (WM) and gray matter (GM) lesion volumes (LV), lateral geniculate nucleus (LGN) volume, optic radiations (OR) WM LV, thickness of pericalcarine cortex were evaluated. OCT and MRI control groups (healthy controls [HC]-OCT and HC-MRI) were included. RESULTS: A significant thinning of temporal pRNFL and papillo-macular bundle (PMB) was observed (p<0.001) in 16 (17%) patients presented with monocular optic neuritis (MSON+), compared to 76 MSON- and 30 HC (-15 µm). In MSON-, PMB was reduced (-3 µm) compared to HC OCT (p<0.05). INL total volume was increased both in MSON+ (p<0.001) and MSON- (p = 0.033). Inner retinal layers volumes (macular RNFL, GCL and IPL) were significantly decreased in MSON+ compared to HC (p<0.001) and MSON- (p<0.001). Reduced GCL volume in the parafoveal ring was observed in MSON- compared to HCOCT (p < 0.05). LGN volume was significantly reduced only in MSON+ patients compared to HC-MRI (p<0.001) and MSON- (p<0.007). GCL, IPL and GCIP volumes associated with ipsilateral LGN volume in MSON+ and MSON-. Finally, LGN volume associated with visual cortex thickness with no significant difference between MSON+ and MSON-. CONCLUSIONS: Anterograde trans-synaptic degeneration is early detectable in RRMS presenting with optic neuritis but does not involve LGN.

Early neurotransmitters changes in prodromal frontotemporal dementia: A GENFI study.

BACKGROUND: Neurotransmitters deficits in Frontotemporal Dementia (FTD) are still poorly understood. Better knowledge of neurotransmitters impairment, especially in prodromal disease stages, might tailor symptomatic treatment approaches. METHODS: In the present study, we applied JuSpace toolbox, which allowed for cross-modal correlation of Magnetic Resonance Imaging (MRI)-based measures with nuclear imaging derived estimates covering various neurotransmitter systems including dopaminergic, serotonergic, noradrenergic, GABAergic and glutamatergic neurotransmission. We included 392 mutation carriers (157 GRN, 164 C9orf72, 71 MAPT), together with 276 non-carrier cognitively healthy controls (HC). We tested if the spatial patterns of grey matter volume (GMV) alterations in mutation carriers (relative to HC) are correlated with specific neurotransmitter systems in prodromal (CDR® plus NACC FTLD = 0.5) and in symptomatic (CDR® plus NACC FTLD≥1) FTD. RESULTS: In prodromal stages of C9orf72 disease, voxel-based brain changes were significantly associated with spatial distribution of dopamine and acetylcholine pathways; in prodromal MAPT disease with dopamine and serotonin pathways, while in prodromal GRN disease no significant findings were reported (p < 0.05, Family Wise Error corrected). In symptomatic FTD, a widespread involvement of dopamine, serotonin, glutamate and acetylcholine pathways across all genetic subtypes was found. Social cognition scores, loss of empathy and poor response to emotional cues were found to correlate with the strength of GMV colocalization of dopamine and serotonin pathways (all p < 0.01). CONCLUSIONS: This study, indirectly assessing neurotransmitter deficits in monogenic FTD, provides novel insight into disease mechanisms and might suggest potential therapeutic targets to counteract disease-related symptoms.

Unravelling neurotransmitters impairment in primary progressive aphasias.

Primary progressive aphasias (PPAs) are a group of neurodegenerative diseases mainly characterized by language impairment, and with variably presence of dysexecutive syndrome, behavioural disturbances and parkinsonism. Detailed knowledge of neurotransmitters impairment and its association with clinical features hold the potential to develop new tailored therapeutic approaches. In the present study, we applied JuSpace toolbox, which allowed for cross-modal correlation of magnetic resonance imaging (MRI)-based measures with nuclear imaging derived estimates covering various neurotransmitter systems including dopaminergic, serotonergic, noradrenergic, GABAergic and glutamatergic neurotransmission. We included 103 PPA patients and 80 age-matched healthy controls (HC). We tested if the spatial patterns of grey matter volume (GMV) alterations in PPA patients (relative to HC) are correlated with specific neurotransmitter systems. As compared to HC, voxel-based brain changes in PPA were significantly associated with spatial distribution of serotonin, dopamine, and glutamatergic pathways (p < .05, False Discovery Rate corrected-corrected). Disease severity was negatively correlated with the strength of GMV colocalization of D1 receptors (p = .035) and serotonin transporter (p = .020). Moreover, we observed a significant negative correlation between positive behavioural symptoms, as measured with Frontal Behavioural Inventory, and GMV colocalization of D1 receptors (p = .007) and serotonin transporter (p < .001). This pilot study suggests that JuSpace is a helpful tool to indirectly assess neurotransmitter deficits in neurodegenerative dementias and may provide novel insight into disease mechanisms and associated clinical features.

Dissecting the Many Faces of Frontotemporal Dementia: An Imaging Perspective.

Frontotemporal dementia (FTD) is a heterogeneous clinical and neuropathological disorder characterized by behavioral abnormalities, executive dysfunctions and language deficits. FTD encompasses a wide range of different pathological entities, associated with the accumulation of proteins, such as tau and TPD-43. A family history of dementia is found in one third of cases, and several genes causing autosomal dominant inherited disease have been identified. The clinical symptoms are preceded by a prodromal phase, which has been mainly studied in cases carrying pathogenetic mutations. New experimental strategies are emerging, in both prodromal and clinical settings, and outcome markers are needed to test their efficacy. In this complex context, in the last few years, advanced neuroimaging techniques have allowed a better characterization of FTD, supporting clinical diagnosis, improving the comprehension of genetic heterogeneity and the earliest stages of the disease, contributing to a more detailed classification of underlying proteinopathies, and developing new outcome markers on clinical grounds. In this review, we briefly discuss the contribution of brain imaging and the most recent techniques in deciphering the different aspects of FTD.

Neuroanatomical correlates of screening for aphasia in NeuroDegeneration (SAND) battery in non-fluent/agrammatic variant of primary progressive aphasia.

Background: Non-fluent/agrammatic variant of Primary Progressive Aphasia (avPPA) is primarily characterized by language impairment due to atrophy of the inferior frontal gyrus and the insula cortex in the dominant hemisphere. The Screening for Aphasia in NeuroDegeneration (SAND) battery has been recently proposed as a screening tool for PPA, with several tasks designed to be specific for different language features. Applying multivariate approaches to neuroimaging data and verbal fluency tasks, Aachener Aphasie Test (AAT) naming subtest and SAND data may help in elucidating the neuroanatomical correlates of language deficits in avPPA. Objective: To investigate the neuroanatomical correlates of language deficits in avPPA using verbal fluency tasks, AAT naming subtest and SAND scores as proxies of brain structural imaging abnormalities. Methods: Thirty-one avPPA patients were consecutively enrolled and underwent extensive neuropsychological assessment and MRI scan. Raw scores of verbal fluency tasks, AAT naming subtest, and SAND subtests, namely living and non-living picture naming, auditory sentence comprehension, single-word comprehension, words and non-words repetition and sentence repetition, were used as proxies to explore structural (gray matter volume) neuroanatomical correlates. We assessed univariate (voxel-based morphometry, VBM) as well as multivariate (source-based morphometry, SBM) approaches. Age, gender, educational level, and disease severity were considered nuisance variables. Results: SAND picture naming (total, living and non-living scores) and AAT naming scores showed a direct correlation with the left temporal network derived from SBM. At univariate analysis, the left middle temporal gyrus was directly correlated with SAND picture naming (total and non-living scores) and AAT naming score. When words and non-words repetition (total score) was considered, a direct correlation with the left temporal network (SBM) and with the left fusiform gyrus (VBM) was also evident. Conclusion: Naming impairments that characterize avPPA are related to specific network-based involvement of the left temporal network, potentially expanding our knowledge on the neuroanatomical basis of this neurodegenerative condition.

Differences and similarities between familial and sporadic frontotemporal dementia: An Italian single-center cohort study.

Introduction: The possibility to generalize our understandings on treatments and assessments to both familial frontotemporal dementia (f-FTD) and sporadic FTD (s-FTD) is a fundamental perspective for the near future, considering the constant advancement in potential disease-modifying therapies that target particular genetic forms of FTD. We aimed to investigate differences in clinical features, cerebrospinal fluid (CSF), and blood-based biomarkers between f-FTD and s-FTD. Methods: In this longitudinal cohort study, we evaluated a consecutive sample of symptomatic FTD patients, classified as f-FTD and s-FTD according to Goldman scores (GS). All patients underwent clinical, behavioral, and neuropsychiatric symptom assessment, CSF biomarkers and serum neurofilament light (NfL) analysis, and brain atrophy evaluation with magnetic resonance imaging. Results: Of 570 patients with FTD, 123 were classified as f-FTD, and 447 as s-FTD. In the f-FTD group, 95 had a pathogenic FTD mutation while 28 were classified as GS = 1 or 2; of the s-FTD group, 133 were classified as GS = 3 and 314 with GS = 4. f-FTD and s-FTD cases showed comparable demographic features, except for younger age at disease onset, age at diagnosis, and higher years of education in the f-FTD group (all P < .05). f-FTD showed worse behavioral disturbances as measured with Frontal Behavioral Inventory (FBI) negative behaviors (14.0 ± 7.6 vs. 11.6 ± 7.4, P = .002), and positive behaviors (20.0 ± 11.0 vs. 17.4 ± 11.8, P = .031). Serum NfL concentrations were higher in patients with f-FTD (70.9 ± 37.9 pg/mL) compared to s-FTD patients (37.3 ± 24.2 pg/mL, P < .001), and f-FTD showed greater brain atrophy in the frontal and temporal regions and basal ganglia. Patients with f-FTD had significantly shorter survival than those with s-FTD (P = .004). Discussion: f-FTD and s-FTD are very similar clinical entities, but with different biological mechanisms, and different rates of progression. The parallel characterization of both f-FTD and s-FTD will improve our understanding of the disease, and aid in designing future clinical trials for both genetic and sporadic forms of FTD. Highlights: Do clinical features and biomarkers differ between patients with familial frontotemporal dementia (f-FTD) and sporadic FTD (s-FTD)?In this cohort study of 570 patients with FTD, f-FTD and s-FTD share similar demographic features, but with younger age at disease onset and diagnosis in the f-FTD group.f-FTD showed higher serum neurofilament light concentrations, greater brain damage, and shorter survival, compared to s-FTD.f-FTD and s-FTD are very similar clinical entities, but with different cognitive reserve mechanisms and different rates of progression.

Sex influences clinical phenotype in frontotemporal dementia.

INTRODUCTION: Frontotemporal dementia (FTD) encompasses a wide spectrum of genetic, clinical, and histological findings. Sex is emerging as a potential biological variable influencing FTD heterogeneity; however, only a few studies explored this issue with nonconclusive results. OBJECTIVE: To estimate the role of sex in a single-center large cohort of FTD patients. METHODS: Five hundred thirty-one FTD patients were consecutively enrolled. Demographic, clinical, and neuropsychological features, survival rate, and serum neurofilament light (NfL) concentration were determined and compared between sex. RESULTS: The behavioral variant of FTD was more common in men, whereas primary progressive aphasia was overrepresented in women (p < 0.001). While global cognitive impairment was comparable, females had a more severe cognitive impairment, namely in Trail Making Test parts A and B (p = 0.003), semantic fluency (p = 0.03), Short Story Recall Test (p = 0.003), and the copy of Rey Complex Figure (p = 0.005). On the other hand, men exhibited more personality/behavioral symptoms (Frontal Behavior Inventory [FBI] AB, p = 0.003), displaying higher scores in positive FBI subscales (FBI B, p < 0.001). In particular, apathy (p = 0.02), irritability (p = 0.006), poor judgment (p = 0.033), aggressivity (p = 0.008), and hypersexuality (p = 0.006) were more common in men, after correction for disease severity. NfL concentration and survival were not statistically different between men and women (p = 0.167 and p = 0.645, respectively). DISCUSSION: The present study demonstrated that sex is a potential factor in determining FTD phenotype, while it does not influence survival. Although the pathophysiological contribution of sex in neurodegeneration is not well characterized yet, our findings highlight its role as deserving biological variable in FTD.

Retinal inner nuclear layer thinning is decreased and associates with the clinical outcome in ocrelizumab-treated primary progressive multiple sclerosis.

BACKGROUND: Ocrelizumab was found to decrease brain atrophy rate in primary progressive multiple sclerosis (PPMS), but no data are currently available on the effect of ocrelizumab on retinal layer thicknesses in the PPMS population. OBJECTIVE: To assess retinal layer changes in ocrelizumab-treated PPMS and test their possible application as biomarkers of therapy response. METHODS: 36 PPMS patients, treated with ocrelizumab for at least 6 months, and 39 sex- and age-matched healthy controls (HC) were included in a blind, longitudinal study. Spectrum-domain optical coherence tomography (SD-OCT) was performed at study entry (T0) and after 6 (T6) and 12 months (T12). At month 24 (T24), patients were divided into responders (no evidence of 1-year confirmed disability progression, 1y-CDP) and non-responders (evidence of 1y-CDP). RESULTS: At T24, 23/36 (64%) patients were considered responders and 13/36 (36%) non-responders. At T0, peripapillary retinal nerve fiber layer (pRNFL) thickness, macular ganglion cell-inner plexiform layer (GCIPL) and inner retinal layer (IRL) volume were significantly lower in PPMS compared to HC (p = 0.001 for all comparisons). At T6 and T12, non-responders significantly differed in the inner nuclear layer (INL) thinning rate compared to responders (p = 0.005 at both time-points). CONCLUSIONS: Ocrelizumab significantly slows down INL thinning rate in PPMS responders. The longitudinal analysis of retina layer changes by means of OCT may be a promising prognostic test, and merits further investigations.

Retinal Hyperreflecting Foci Associate With Cortical Pathology in Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Microglia, the resident immune cell of the brain and retina, is widespread activated in the white and gray matter (GM) in multiple sclerosis (MS). The objective of this study is to evaluate the presence and number of hyperreflecting foci (HRF), considered clusters of activated and proliferating retinal microglia, and their association with clinical and radiologic disease parameters in relapsing-remitting MS (RRMS). METHODS: At baseline, 80 patients with RRMS underwent optical coherence tomography (OCT) and 3T-MRI (including 3-dimensional T1, fluid-attenuated inversion recovery, and double inversion recovery sequences), closed to their disease onset (6.3 ± 5.1 months). These patients were then clinically and radiologically followed up for a mean of 43 months, evaluating the no evidence of disease activity (NEDA) condition, further divided into clinical (cNEDA) and radiologic (rNEDA). Patients with a clinical history or MRI/OCT findings suggestive of optic neuritis (ON) were excluded from the study. RESULTS: Compared with healthy controls, the HRF number was significantly higher in the inner nuclear layer (INL) of patients with RRMS (19.55 ± 5.65 vs 13.84 ± 2.57, p < 0.001) and associated with INL volume (ß: 1.21, p < 0.001). GM lesion volume significantly correlated with the INL HRF count (p = 0.008). Survival analysis revealed a significant association between INL HRF and both cNEDA (p = 0.017) and rNEDA (p = 0.002). DISCUSSION: We found a strong association between retinal microglial proliferation and cortical pathology in RRMS, a finding suggesting a possible underlying common immunopathologic mechanism. Furthermore, microglial activation at baseline was observed to predict subsequent inflammatory events, indicating that HRF might be a candidate prognostic biomarker worthy of further investigation. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with early RRMS but without ON, the number of HRF on OCT of the retinal inner nuclear layer is associated with cNEDA and rNEDA.

Increasing Brain Gamma Activity Improves Episodic Memory and Restores Cholinergic Dysfunction in Alzheimer's Disease.

OBJECTIVE: This study aimed to assess whether non-invasive brain stimulation with transcranial alternating current stimulation at gamma-frequency (γ-tACS) applied over the precuneus can improve episodic memory and modulate cholinergic transmission by modulating cerebral rhythms in early Alzheimer's disease (AD). METHODS: In this randomized, double-blind, sham controlled, crossover study, 60 AD patients underwent a clinical and neurophysiological evaluation including assessment of episodic memory and cholinergic transmission pre and post 60 minutes treatment with γ-tACS targeting the precuneus or sham tACS. In a subset of 10 patients, EEG analysis and individualized modelling of electric field distribution were carried out. Predictors to γ-tACS efficacy were evaluated. RESULTS: We observed a significant improvement in the Rey Auditory Verbal Learning (RAVL) test immediate recall (p < 0.001) and delayed recall scores (p < 0.001) after γ-tACS but not after sham tACS. Face-name associations scores improved with γ-tACS (p < 0.001) but not after sham tACS. Short latency afferent inhibition, an indirect measure of cholinergic transmission, increased only after γ-tACS (p < 0.001). ApoE genotype and baseline cognitive impairment were the best predictors of response to γ-tACS. Clinical improvement correlated with the increase in gamma frequencies in posterior regions and with the amount of predicted electric field distribution in the precuneus. INTERPRETATION: Precuneus γ-tACS, able to increase γ-power activity on the posterior brain regions, showed a significant improvement of episodic memory performances, along with restoration of intracortical excitability measures of cholinergic transmission. Response to γ-tACS was dependent on genetic factors and disease stage. ANN NEUROL 2022;92:322-334.

Impact of Visual Impairment on Vision-Related Quality of Life in Parkinson's Disease.

BACKGROUND: Visual impairment is frequent and highly disabling in Parkinson's disease (PD); however, few studies have comprehensively evaluated its impact on vision-related quality of life. OBJECTIVE: To evaluate the relationship between visual function tests and the visual impairment perceived by PD patients in daily living activities. METHODS: We cross-sectionally evaluated 62 PD patients and 33 healthy controls (HC). Visual disability was measured with a comprehensive battery of primary visual function and visual cognition tests (visual outcomes), and vision-related quality of life was evaluated with the National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ-25). The relationship between visual outcomes and NEI VFQ-25 sub-scores was analyzed with Pearson's correlations and stepwise linear regression. RESULTS: In PD patients, and not in HC, most NEI VFQ-25 sub-scores were significantly correlated with Cube Analysis and Dot Counting from Visual Object and Space Perception (VOSP) battery (visual perception), Clock Drawing Test (visuoconstructive capacity) and Trail Making Test part-A (visual attention and processing speed) and to a lesser extent with high- and low-contrast visual acuity. Dot Counting (VOSP) was the test primarily associated with most NEI VFQ-25 sub-scores (5 out of 12). Roth-28 color test was the one that best explained the variance of Peripheral Vision (R2: 0.21) and Role Difficulties (R2: 0.36) sub-scores of NEI VFQ-25, while photopic contrast sensitivity explained 41% of Driving sub-score variance. CONCLUSION: Vision-related quality of life in PD is mainly influenced by alterations in visual perception, visuoconstructive capacity and visual attention and processing speed. Future studies are warranted to confirm and further extend our findings.

Essential tremor and cognitive impairment: who, how, and why.

BACKGROUND AND AIMS: Recent years have witnessed the switch from considering essential tremor (ET) a monosymptomatic disorder to consider it as part of a spectrum, including other neurological signs, such as mild cognitive impairment and dementia, thus defining it as "ET plus." There are few data on cognitive impairment in ET patients. The aim of this review is to analyze the clinical characteristics of ET patients developing cognitive impairment, their neuropsychological profile, the underpinning mechanisms, and the possible biomarkers. METHODS: The authors performed a narrative review on cognitive decline in essential tremor, including articles written in English since the year 2000. DISCUSSION: The most recent pathogenetic theories of cognitive impairment in ET rely on the cerebellar dysfunction, being part of the Cerebellar Cognitive Affective Syndrome spectrum. Cognitive impairment in ET patients could be assessed through many tests that demonstrate the involvement of different domains, such as attention, executive functions, and language. There are some clinical characteristics of ET that may indicate a greater risk of developing cognitive impairment, namely, cerebellar symptoms, falls, age at onset, and family history. However, there are no established clinical, neurophysiological, neuropathological, and fluid biomarkers of cognitive impairment in ET. CONCLUSIONS: Increasing data are showing in ET the presence of cerebellar symptoms and cognitive impairment. Further studies are needed to better understand cognition in ET patients, and to define the boundary between ET and ET plus, since deeper phenotyping might have important clinical and therapeutic implications.

Foveal Remodeling of Retinal Microvasculature in Parkinson's Disease.

BACKGROUND: Retinal microvascular alterations have been previously described in Parkinson's disease (PD) patients using optical coherence tomography angiography (OCT-A). However, an extensive description of retinal vascular morphological features, their association with PD-related clinical variables and their potential use as diagnostic biomarkers has not been explored. METHODS: We performed a cross-sectional study including 49 PD patients (87 eyes) and 40 controls (73 eyes). Retinal microvasculature was evaluated with Spectralis OCT-A and cognitive status with Montreal Cognitive Assessment. Unified PD Rating Scale and disease duration were recorded in patients. We extracted microvascular parameters from superficial and deep vascular plexuses of the macula, including the area and circularity of foveal avascular zone (FAZ), skeleton density, perfusion density, vessel perimeter index, vessel mean diameter, fractal dimension (FD) and lacunarity using Python and MATLAB. We compared the microvascular parameters between groups and explored their association with thickness of macular layers and clinical outcomes. Data were analyzed with General Estimating Equations (GEE) and adjusted for age, sex, and hypertension. Logistic regression GEE models were fitted to predict diagnosis of PD versus controls from microvascular, demographic, and clinical data. The discrimination ability of models was tested with receiver operating characteristic curves. RESULTS: FAZ area was significantly smaller in patients compared to controls in superficial and deep plexuses, whereas perfusion density, skeleton density, FD and lacunarity of capillaries were increased in the foveal zone of PD. In the parafovea, microvascular parameters of superficial plexus were associated with ganglion cell-inner plexiform layer thickness, but this was mainly driven by PD with mild cognitive impairment. No such associations were observed in controls. FAZ area was negatively associated with cognition in PD (non-adjusted models). Foveal lacunarity, combined with demographic and clinical confounding factors, yielded an outstanding diagnostic accuracy for discriminating PD patients from controls. CONCLUSION: Parkinson's disease patients displayed foveal microvascular alterations causing an enlargement of the vascular bed surrounding FAZ. Parafoveal microvascular alterations were less pronounced but were related to inner retinal layer thinning. Retinal microvascular abnormalities helped discriminating PD from controls. All this supports OCT-A as a potential non-invasive biomarker to reveal vascular pathophysiology and improve diagnostic accuracy in PD.

Multiple Sclerosis Incidence and Prevalence Trends in the Province of Padua, Northeast Italy, 1965-2018.

BACKGROUND: Previous studies, dating back to the 1960s disclosed a progressive increase in multiple sclerosis (MS) incidence and prevalence in the Province of Padua. To further analyze whether this trend is the effect of the improved diagnostic procedures or is primarily related to a real increase risk of MS, we analyzed MS incidence and prevalence of the 5-year period 2011-2015. METHODS: Patients with a diagnosis of MS or clinically isolated syndrome highly suggestive of MS were included in the study. All available sources of clinical and administrative information were evaluated. Mean annual incidence in the 5-year period 2011-2015 and the prevalence on December 31, 2015 were calculated. RESULTS: The 2011-2015 mean incidence was 6.5/100,000/year, 7.9 for females, 4.1 for males. The overall prevalence was 182/100,000, 241 for females, 116 for males. Compared to the 2000-2009 period, mean age at onset, onset-diagnosis delay and F/M ratio did not significantly change. Since the 1960s, incidence and prevalence of MS linearly increased with no interposed plateau periods. CONCLUSIONS: MS incidence and prevalence further and significantly increased in the period 2011-2015. Our 1965-2015 data indicate a real increased risk of MS and stress a role of exogenous factors in MS susceptibility.