Pulses of South Atlantic water into the tropical North Atlantic since 1825 from coral isotopes.

Decadal and multidecadal changes in the meridional overturning circulation may originate from either the subpolar North Atlantic or the Southern Hemisphere. New records of carbon and oxygen isotopes from an eastern Martinique Island (Lesser Antilles) coral reveal irregular, decadal, double-step events of low ∆14C and enhanced vertical mixing, high δ18O and high δ13C values starting in 1885. Comparison of the new and published ∆14C records indicates that the last event (1956-1969) coincides with a widespread, double-step ∆14C low of South Atlantic origin from 32°N to 18°S, associated with a major slowdown of the Caribbean Current transport between 1963 and 1969. This event and the past Martinique ∆14C lows are attributed to pulses of northward advection of low ∆14C Sub-Antarctic Mode Waters into the tropical Atlantic. They are coeval with changes of the tropical freshwater budget and likely driven by meridional overturning circulation changes since ~1880.

Practical Approaches and Knowledge Gaps in the Care for Children With Leukodystrophies.

Leukodystrophies are a group of neurodegenerative genetic disorders that affect approximately 1 in 7500 individuals. Despite therapeutic progress in individual leukodystrophies, guidelines in neurologic care are sparse and consensus among physicians and caregivers remains a challenge. At patient advocacy meetings hosted by Hunter's Hope from 2016-2018, multidisciplinary experts and caregivers met to conduct a literature review, identify knowledge gaps and summarize best practices regarding neurologic care. Stages of severity in leukodystrophies guided recommendations to address different levels of need based on a newly defined system of disease severity. Four core neurologic domains prioritized by families were identified and became the focus of this guideline: sleep, pain, seizures/epilepsy, and language/cognition. Based on clinical severity, the following categories were used: presymptomatic, early symptomatic, intermediate symptomatic, and advanced symptomatic. Across the leukodystrophies, neurologic care should be tailored to stages of severity while accounting for unique aspects of every disease and multiple knowledge gaps present. Standardized tools and surveys can help guide treatment but should not overburden families.

The role of polysomnography in decannulation of children with brain and spinal cord injuries.

OBJECTIVE: The objective of this retrospective review was to determine the utility of polysomnography (PSG) in influencing the decision to decannulate pediatric patients with brain and spinal cord injuries in an inpatient rehabilitation hospital setting. METHODS: Between 2010 and 2016, data were collected on pediatric patients with brain and/or spinal cord injuries who had PSG performed with the goal of decannulation. Patients underwent a decannulation protocol involving toleration of continuous tracheostomy capping and bedside tracheoscopy by otolaryngology. Decision to decannulate was determined with input from multiple disciplines. Associations were examined between decannulation success and findings on PSG as well as demographic factors, injury characteristics, otolaryngology findings, and timeline from initial injury to selected events. RESULTS: A total of 46 patients underwent PSG, after which 38 (83%) were deemed appropriate and eight (17%) were deemed inappropriate for decannulation. Individuals who were deemed ready for decannulation had significantly lower obstructive apnea hypopnea indexes (AHI) (1.7 vs 5.4 events/h, P = 0.03), respiratory disturbance indexes (RDI) (2.4 vs 7.6 events/h, P = 0.006), and peak end tidal carbon dioxide (CO2 ) levels (50.0 vs 58.7 torr, P = 0.009) on PSG compared to those who were not decannulated. There were no complications following decannulation prior to discharge. CONCLUSION: PSG provided important additional information as part of a multidisciplinary team assessment of clinical readiness for decannulation in pediatric patients with brain and spinal cord injuries who underwent a decannulation protocol. Obstructive AHI, RDI, and peak end tidal CO2 level were associated with successful decannulation prior to discharge from inpatient rehabilitation.

Prediction of cognitive worsening in de novo Parkinson's disease: Clinical use of biomarkers.

BACKGROUND: Cognitive impairment is a frequent and disabling feature of Parkinson's disease. Identifying the factors able to predict cognitive worsening since the early stage may improve disease management. The objective of this study was to define the best predictors of future cognitive worsening in a group of patients with newly diagnosed PD and to propose cutoff values potentially useful at the individual level. METHODS: Fifty-four consecutive drug-naive patients with de novo PD were prospectively evaluated by clinical and neuropsychological assessment, resting EEG, and 123 I-FP-CIT-SPECT and clinically classified into mainly motor, diffuse/malignant, and intermediate PD subtypes; they were then followed up for an average of 5 years. Cognitive outcome was defined by identifying cognitively stable or worsened patients. RESULTS: Step-wise logistic regression selected the posterior qEEG mean frequency and 123 I-FP-CIT-SPECT uptake at caudate level (P < 0.0001). The posterior qEEG mean frequency (cut point, 8.3 Hz) and the caudate 123 I-FP-CIT-SPECT uptake (cut point, 2.3, specific to nondisplaceable binding ratio) achieved 82% and 80% of accuracy, respectively, in predicting cognitive outcome. Survival analysis showed decreasing expected time to cognitive worsening associated with scores below the established thresholds for qEEG and 123 I-FP-CIT-SPECT and with the presence of a malignant clinical phenotype. CONCLUSIONS: Resting EEG and 123 I-FP-CIT-SPECT are good predictors of future cognitive worsening, in de novo drug-naive PD patients. Wherever available, these biomarkers could add valuable prognostic information to classification into different clinical phenotypes. © 2017 International Parkinson and Movement Disorder Society.

Progressive Disintegration of Brain Networking from Normal Aging to Alzheimer Disease: Analysis of Independent Components of 18F-FDG PET Data.

Brain connectivity has been assessed in several neurodegenerative disorders investigating the mutual correlations between predetermined regions or nodes. Selective breakdown of brain networks during progression from normal aging to Alzheimer disease dementia (AD) has also been observed. Methods: We implemented independent-component analysis of 18F-FDG PET data in 5 groups of subjects with cognitive states ranging from normal aging to AD-including mild cognitive impairment (MCI) not converting or converting to AD-to disclose the spatial distribution of the independent components in each cognitive state and their accuracy in discriminating the groups. Results: We could identify spatially distinct independent components in each group, with generation of local circuits increasing proportionally to the severity of the disease. AD-specific independent components first appeared in the late-MCI stage and could discriminate converting MCI and AD from nonconverting MCI with an accuracy of 83.5%. Progressive disintegration of the intrinsic networks from normal aging to MCI to AD was inversely proportional to the conversion time. Conclusion: Independent-component analysis of 18F-FDG PET data showed a gradual disruption of functional brain connectivity with progression of cognitive decline in AD. This information might be useful as a prognostic aid for individual patients and as a surrogate biomarker in intervention trials.

Functional neuroimaging and clinical features of drug naive patients with de novo Parkinson's disease and probable RBD.

INTRODUCTION: The association between Parkinson Disease (PD) and REM sleep behavior disorder (RBD) has been related to a specific, malignant clinical phenotype. Definite RBD diagnosis requires video-polysomnography that is often unfeasible. A malignant clinical PD-RBD phenotype could be expected also in PD patients with probable RBD. Aim of this cross-sectional study was to evaluate whether a more severe neuropsychological and functional neuroimaging phenotype can be identified in PD patients with probable RBD. METHODS: Thirty-eight de novo, drug naïve PD patients underwent a first-line clinical assessment and a second-line multimodal assessment, including neuropsychological evaluation, (123)I-FP-CIT-SPECT and (18)F-FDG-PET, which were compared between PD patients with (PD + RBD+) and without (PD + RBD-) probable RBD. RESULTS: On first-line assessment, PD + RBD + patients had significantly more constipation (p = 0.02) and showed worse olfaction (p = 0.01) compared with PD + RBD-while the two groups were similar as for age, presence of orthostatic hypotension, UPDRS-III and MMSE scores. On second-line assessment, PD + RBD + patients showed a worse neuropsychological test profile, more severe nigro-striatal dopaminergic impairment, mainly at caudate level in the less affected hemisphere (p = 0.004) and impaired brain glucose metabolism, with relative hypometabolism in posterior cortical regions and relative hypermetabolism mainly in anterior regions of the more affected hemisphere (p = 0.015). CONCLUSIONS: PD patients with probable RBD are likely to have a more severe neuropsychological and functional brain-imaging phenotype already at the time of diagnosis.

Mapping brain morphological and functional conversion patterns in predementia late-onset bvFTD.

PURPOSE: The diagnosis of behavioural variant frontotemporal dementia (bvFTD) is challenging during the predementia stage when symptoms are subtle and confounding. Morphological and functional neuroimaging can be particularly helpful during this stage but few data are available. METHODS: We retrospectively selected 25 patients with late-onset probable bvFTD. Brain structural MRI and FDG PET were performed during the predementia stage (mean MMSE score 27.1 ± 2.5) on average 2 years before. The findings with the two imaging modalities were compared (SPM8) with those in a group of 20 healthy subjects. The bvFTD patients were divided into two subgroups: those with predominant disinhibition (bvFTD+) and those with apathy (bvFTD-). RESULTS: Hypometabolism exceeded grey matter (GM) density reduction in terms of both extension and statistical significance in all comparisons. In the whole bvFTD group, hypometabolism involved the bilateral medial, inferior and superior lateral frontal cortex, anterior cingulate, left temporal and right parietal cortices and the caudate nuclei. GM density reduction was limited to the right frontal cortex and the left medial temporal lobe. In bvFTD+ patients hypometabolism was found in the bilateral medial and basal frontal cortex, while GM reduction involved the left anterior cingulate and left inferior frontal cortices, and the right insula. In bvFTD- patients, atrophy and mainly hypometabolism involved the lateral frontal cortex and the inferior parietal lobule. CONCLUSION: These findings suggest that hypometabolism is more extensive than, and thus probably precedes, atrophy in predementia late-onset bvFTD, underscoring different topographic involvement in disinhibited and apathetic presentations. If confirmed in a larger series, these results should prompt biomarker operationalization in bvFTD, especially for patient selection in therapeutic clinical trials.

Trauma exposure and sleep disturbance in a sample of youth from the National Child Traumatic Stress Network Core Data Set.

OBJECTIVE: Adverse childhood experiences are prevalent and have been associated with sleep disturbance. However, there are limited data examining factors that influence this relationship. The purpose of this study was to extend the current literature by characterizing the relationship between adverse childhood experiences and sleep disturbance in a sample of trauma-exposed youth and to identify factors that may influence this relationship. STUDY DESIGN: Data were collected from 56 mental health centers across the National Child Traumatic Stress Network. For the current study, secondary data analysis was conducted using de-identified data from the National Child Traumatic Stress Network Core Data Set. The present study included 4043 children and adolescents who met eligibility criteria. RESULTS: Sixteen percent of the sample (n=634) met criteria for a sleep disturbance as determined through clinician assessment and collateral report. Posttraumatic stress disorder (PTSD) symptom severity influenced the risk of disturbed sleep (ages 7-12: t=-4.33, ages 13-18: t=-7.12, P≤.001 for both analyses), with those meeting full criteria for PTSD at greatest risk (age 7-12: odds ratio [OR]=1.95; 95% confidence interval [CI], 1.17-3.24; age 13-18: OR=3.18; 95% CI, 1.87-5.43). Exposure to sexual assault and community violence also contributed independently to the risk of disturbed sleep (age 7-12, sexual assault: OR=1.76; 95% CI, 1.21-2.57; age 13-18, community violence: OR=1.61; 95% CI, 1.19-2.18). CONCLUSIONS: Comprehensive treatment strategies should include assessment of disturbed sleep in youth exposed to trauma, particularly those with elevated PTSD symptoms and exposure to sexual trauma or community violence.

Parkinson's Disease Sleep Scale 2: application in an Italian population.

Sleep disturbances and nocturnal disabilities are common in Parkinson's Disease (PD). The PD sleep scale, second version (PDSS-2), has been proposed as a helpful tool for measuring sleep disorders in PD. We aimed to validate the Italian version of the PDSS-2. One hundred and twenty-three consecutive PD outpatients (76 males) were evaluated by means of PDSS-2, Epworth Sleepiness Scale, Hamilton Depression Rating Scale, Parkinson's Disease Quality of Life Questionnaire (self-administered scales), Unified Parkinson's Disease Rating (motor section) and Hoehn and Yahr Scales, and Mini Mental State Examination. PDSS-2 internal consistency was satisfactory (Cronbach's α: 0.77) with significant item to total score correlation and high intra-class correlation coefficient for test-retest reliability (0.943). Total PDSS-2 score was correlated with the scores on all other clinical scales. The factor analysis identified five factors, related to five areas of nocturnal disturbances, similarly as the original PDSS-2. The five factors mainly reflected: (1) nocturnal movement-related problems, (2) quality of sleep, (3) dreaming distress, (4) fragmentation of sleep and (5) insomnia symptoms. The PDSS-2 scale has confirmed its usefulness in evaluating sleep problems in Italian PD patients.

Nigro-caudate dopaminergic deafferentation: a marker of REM sleep behavior disorder?

Forty-nine consecutive, drug naïve outpatients with de novo Parkinson's disease (PD) and 12 patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) underwent clinical examination and dopamine transporter single photon emission computed tomography with [(123)I]-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)nortropane as a biomarker of nigro-striatal function. PD patients were grouped into rapid eye movement sleep behavior disorder (RBD) negative (PD-RBD-) and RBD positive (PD-RBD+). Repeated measures and univariate analysis of variance were used to compare dopaminergic and clinical impairment among groups. The variations of dopamine transporter-single photon emission computed tomography specific binding ratios (SBR) as a function of group belonging were significantly different (p = 0.0013) at caudate with respect to putamen level. Indeed, putamen SBR progressively decreased from iRBD to PD-RBD- and PD-RBD+ groups while caudate SBR were higher in PD-RBD- group than in PD-RBD+ and even than in iRBD group. Motor impairment was more severe in PD patients with RBD than in those without RBD. Our data suggest that a more severe nigro-caudate dopaminergic deafferentation is related to RBD, both in its idiopathic form and in PD patients.