Dopaminergic connectivity reconfiguration in the dementia with Lewy bodies continuum.

INTRODUCTION: The impairment of nigrostriatal dopaminergic network is a core feature of dementia with Lewy bodies (DLB). The involvement and reconfiguration of extranigrostriatal dopaminergic circuitries in the DLB continuum is still theme of debate. We aim to investigate in vivo the dynamic changes of local and long-distance dopaminergic networks across DLB continuum. METHODS: Forty-nine patients (including 29 with dementia and 20 prodromal cases) and fifty-two controls entered the study. Each subject underwent a standardized clinical and neurological examination and performed Brain SPECT to measuring brain dopamine transporter (DAT) density. Spatially normalized images underwent the occipital-adjusted specific binding to obtain parametric data. The ANCOVA was applied to assess 123I-FP-CIT differences between pDLB, overt-DLB and CG, considering age, gender, and motor impairment as variables of no interest. Between-nodes correlation analysis measured molecular connectivity within the ventral and dorsal dopaminergic networks. RESULTS: Prodromal DLB and DLB patients showed comparable nigrostriatal deficits in basal ganglia regions compared with CG. Molecular connectivity analyses revealed extensive connectivity losses, more in ventral than in dorsal dopaminergic network in DLB dementia. Conversely, the prodromal group showed increased connectivity compared to CG, mostly putamen-thalamus-cortical and striatal-cortical connectivity. CONCLUSIONS: This study indicates a comparable basal ganglia deficit in nigrostriatal projections in DLB continuum and supports a different reorganization of extra-striatal dopaminergic connectivity in the prodromal phases of DLB. The shift from an increased to a decreased bilateral putamen-thalamus-cortex connectivity might be a hallmark of transition from prodromal to dementia DLB stages.

What contributes most to the SPPB and its subscores in hospitalized geriatric patients: an ICF model-based approach.

BACKGROUND: Mobility deficits are highly prevalent among geriatric patients and have serious impact on quality of life, hospitalizations, and mortality. This study aims to capture predictors of mobility deficits in hospitalized geriatric patients using the International Classification of Functioning, Disability and Health (ICF) model as a framework. METHODS: Data were obtained from n = 397 patients (78 ± 7 years, 15 ± 7 ICD-11 diagnoses) on a geriatric ward at time of admission. Mobility was assessed using the Short Physical Performance Battery (SPPB) total score and gait, static balance and transfer subscores. Parameters from an extensive assessment including medical history, neuropsychological and motor examination, and questionnaires were assigned to the five components of the ICF model. Spearman's Correlation and multiple linear regression analyses were calculated to identify predictors for the SPPB total score and subscores. RESULTS: Use of walking aid, fear of falling (FOF, but not occurrence of previous falls), participation in society, ADL and grip strength were strongly associated with the SPPB total score and all subscores (p < .001). FOF and grip strength were significant predictors for the SPPB total score as well as for gait and transfer subscores. FOF also showed a strong association with the static balance subscore. The clinical parameters of the ICF model could only partially explain the variance in the SPPB total score (24%) and subscores (12-23%), with no parameter from the activities and participation component being significantly predictive. CONCLUSIONS: FOF and reduced grip strength are associated with mobility deficits in a hospitalized geriatric cohort. Further research should focus on interventions to reduce FOF and increase muscle strength in geriatric patients. Moreover, there is a need for ICF-based assessments instruments (especially in the activities and participation components) that allow a holistic view on mobility and further daily life-relevant health aspects in geriatric patients.

Phenylalanine Effects on Brain Function in Adult Phenylketonuria.

OBJECTIVE: To evaluate the relationship between circulating phenylalanine and brain function as well as neuropsychiatric symptoms in adults with phenylketonuria. METHODS: In this prospective cross-sectional study, early-treated patients with phenylketonuria older than 30 years and age- and sex-matched controls were included. Extensive neurologic evaluation, neuropsychological and behavioral testing, sensory and motor evoked potentials, and MRI were performed. CSF concentrations of neurodegenerative markers were evaluated in addition in a subset of 10 patients. RESULTS: Nineteen patients with phenylketonuria (median age 41 years) with different phenylalanine levels (median 873 µmol/L) entered the study. They showed higher prevalence of neurologic symptoms, cognitive and behavioral abnormalities, autonomic dysfunction, alterations in neurophysiologic measures, and atrophy in putamen and right thalamus compared to controls. In CSF, patients with phenylketonuria exhibited higher ß-amyloid 1-42 (p = 0.003), total tau (p < 0.001), and phosphorylated tau (p = 0.032) levels compared to controls. Plasma phenylalanine levels highly correlated with the number of failed neuropsychological tests (r = 0.64, p = 0.003), neuropsychiatric symptoms (r = 0.73, p < 001), motor evoked potential latency (r = 0.48, p = 0.030), and parietal lobe atrophy. CONCLUSIONS: Our study provides strong evidence for a correlation between phenylalanine levels and clinical, neuropsychological, neurophysiologic, biochemical, and imaging alterations in adult patients with phenylketonuria.

Extrastriatal dopaminergic and serotonergic pathways in Parkinson's disease and in dementia with Lewy bodies: a 123I-FP-CIT SPECT study.

PURPOSE: The aim of the study was to evaluate extrastriatal dopaminergic and serotonergic pathways in patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB) using 123I-FP-CIT SPECT imaging. METHODS: The study groups comprised 56 PD patients without dementia, 41 DLB patients and 54 controls. Each patient underwent a standardized neurological examination and 123I-FP-CIT SPECT. Binding in nigrostriatal and extrastriatal regions of interest was calculated in each patient from spatially normalized images. The occipital-adjusted specific to nondisplaceable binding ratio (SBR) in the different regions was compared among the PD patients, DLB patients and controls adjusting for the effects of age, sex, disease duration and serotonergic/dopaminergic treatment. Covariance analysis was used to determine the correlates of local and long-distance regions with extrastriatal 123I-FP-CIT deficits. RESULTS: Both PD and DLB patients showed lower 123I-FP-CIT SPECT SBR in several regions beyond the nigrostriatal system, especially the insula, cingulate and thalamus. DLB patients showed significantly lower 123I-FP-CIT SBR in the thalamus than controls and PD patients. Thalamic and cingulate 123I-FP-CIT SBR deficits were correlated, respectively, with limbic serotonergic and widespread cortical monoaminergic projections only in DLB patients but exhibited only local correlations in PD patients and controls. CONCLUSION: PD and DLB patients both showed insular dopamine deficits, whereas impairment of thalamic serotonergic pathways was specifically associated with DLB. Longitudinal studies are necessary to determine the clinical value of the assessment of extrastriatal 123I-FP-CIT SPECT.

Voluptuary Habits and Risk of Frontotemporal Dementia: A Case Control Retrospective Study.

Alcohol, coffee, and tobacco consumption was assessed on 151 FTD outpatients and 151 matched controls in a multicenter retrospective case-control design. No association was found for smoking and coffee intake. The risk of FTD was decreased by alcohol consumption (adj. OR 0.30, 95% CI 0.14-0.63); risk reduction was significant in current alcohol consumers (adj. OR 0.22, 95% CI 0.10-0.51). The risk of FTD inversely correlated with the duration of exposure (adj. OR 0.88, 95% CI 0.81-0.95, for every 5 years of exposure increase). Retrospective information and the unknown amount of consumed alcohol are limits of the present work.

Atypical presentation of a novel Presenilin 1 R377W mutation: sporadic, late-onset Alzheimer disease with epilepsy and frontotemporal atrophy.

Mutations within Presenilin 1 (PSEN1) represent the most common cause of monogenic Alzheimer Disease (AD). The clinical phenotype is highly variable, even if early onset disease with an autosomal dominant pattern of inheritance and presenting memory deficits usually occur. In the present work, we described the case of a late-onset AD patient, without any positive family history for dementia, and associated with seizures and behavioural symptoms. Structural and functional neuroimaging showed frontotemporal changes without posterior biparietal brain abnormalities. Cerebrospinal analysis was consistent with AD pattern, with decreased Aß42 and increased Tau and phospho-Tau. A novel pathogenetic mutation within PSEN1 gene was detected within exon 8, leading to a substitution from arginine to tryptophan (AGG > TGG: R377W), affecting a splice junction and protein function. The case herein reported further confirms the heterogeneity of PSEN1 mutations and the need to take into account genetic screening in those cases with atypical presentation.