Stabilizing spin systems via symmetrically tailored RKKY interactions.

Spins of single atoms adsorbed on substrates are promising building blocks for spintronics and quantum computation schemes. To process spin information and for increased magnetic stability, these spins have to be coupled to arrays. For a single atom, a high symmetry of the environment increases its spin stability.

Predicting seizures in untreated temporal lobe epilepsy using point-process nonlinear models of heartbeat dynamics.

Symptoms of temporal lobe epilepsy (TLE) are frequently associated with autonomic dysregulation, whose underlying biological processes are thought to strongly contribute to sudden unexpected death in epilepsy (SUDEP). While abnormal cardiovascular patterns commonly occur during ictal events, putative patterns of autonomic cardiac effects during pre-ictal (PRE) periods (i.e.

Rotigotine may improve sleep architecture in Parkinson's disease: a double-blind, randomized, placebo-controlled polysomnographic study.

Background/objectives: Growing evidence demonstrates that in Parkinson's Disease (PD) sleep disturbances are frequent and difficult to treat. Since the efficacy of rotigotine on sleep is corroborated by studies lacking polysomnography (PSG), this study explores the possible rotigotine-mediated impact on PSG parameters in PD patients.

Methods: This is a randomized, double-blind, placebo-controlled, parallel-group study to determine the efficacy of rotigotine vs placebo on PSG parameters in moderately advanced PD patients.

Rapid eye movement sleep disruption and sleep fragmentation are associated with increased orexin-A cerebrospinal-fluid levels in mild cognitive impairment due to Alzheimer's disease.

The orexin system has been investigated in patients affected by mild cognitive impairment (MCI) due to Alzheimer's disease (AD) by measuring orexin-A concentrations in the cerebrospinal fluid (CSF), and correlated to subjective and objective sleep parameters, quantified by questionnaires and polysomnography, respectively. Twenty drug-naïve patients with MCI due to AD were studied and compared with a population of 26 age and/or sex matched controls, divided into subgroups on the basis of the Pittsburgh Sleep Quality Index (PSQI) score. Increased CSF-orexin levels were detected in patients with MCI due to AD in comparison with controls (p < 0.

Cerebrospinal fluid lactate is associated with multiple sclerosis disease progression.

Background: Altered cerebrospinal fluid (CSF) levels of lactate have been described in neurodegenerative diseases and related to mitochondrial dysfunction and neuronal degeneration. We investigated the relationship between CSF lactate levels, disease severity, and biomarkers associated with neuroaxonal damage in patients with multiple sclerosis (MS).

Methods: One-hundred eighteen subjects with relapsing-remitting multiple sclerosis (RRMS) were included, along with one-hundred fifty seven matched controls.

Heart rate variability in untreated newly diagnosed temporal lobe epilepsy: Evidence for ictal sympathetic dysregulation.

Objective: To compare heart rate variability (HRV) parameters in newly diagnosed and untreated temporal lobe epilepsy (TLE) between the interictal, preictal, ictal, and postictal states.

Methods: HRV parameters were extracted from single-lead electrocardiography data collected during video-electroencephalography (EEG) recordings from 14 patients with newly diagnosed TLE in a resting, awake, and supine state. HRV parameters in the time and frequency domains included low frequency (LF), high frequency (HF), standard deviation of all consecutive R wave intervals (SDNN), and square root of the mean of the sum of the squares of differences between adjacent R wave intervals (RMSSD).

Beta-amyloid and phosphorylated tau metabolism changes in narcolepsy over time.

Purpose: The aim od this study is to test whether metabolism of beta-amyloid and tau proteins changes in narcolepsy along with the disease course.

Methods: We analyzed a population of narcoleptic drug-naïve patients compared to a sample of healthy controls. Patients and controls underwent lumbar puncture for assessment of cerebrospinal fluid (CSF) beta-amyloid1-42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) levels.

Chronic dopaminergic treatment in restless legs syndrome: does it affect the autonomic nervous system?

Objective: The link between the autonomic nervous system and restless legs syndrome (RLS) has been recently postulated. Since dopaminergic agents are used as first-line treatment for RLS, the purpose of our study is to verify whether chronic pramipexole treatment could influence the autonomic control of cardiovascular reflexes and heart rate variability (HRV) in RLS during wakefulness.

Methods: Consecutive drug naive RLS patients underwent polysomnography (PSG), subjective scales, and cardiovascular function tests including head-up tilt test (HUTT), Valsalva maneuver, deep breathing, handgrip and cold face before and after 3-month pramipexole therapy.

Anterior Microsurgical Approach to Ventral Lower Cervical Spine Meningiomas: Indications, Surgical Technique and Long Term Outcome.

Ventral lower cervical spinal meningiomas with posterior displacement of the spinal cord are rare and anterior approach has been rarely reported in the literature. The authors present their experience about eight patients operated through anterior microsurgical approach. Exposure of meningiomas was achieved through one or two corpectomies, according to meningioma extension.

Heidenhain variant in two patients with inherited V210I Creutzfeldt-Jakob disease.

Objective: To report two members of the same family carrying the valine to isoleucine point mutation of the prion protein gene (PRNP) and presenting with visual symptoms as initial manifestation as in the "Heidenhain variant" of sporadic Creutzfeldt-Jakob disease (CJD).

Methods: Patients underwent neurological examination, electroencephalogram (EEG), brain magnetic resonance images (MRI) and cerebrospinal fluid (CSF) analysis including the Real Time Quaking Induced Conversion (RT-QuIC) test. Disease-specific mutations and polymorphism at codon 129 of the PRNP gene were also studied.

Optic Nerve Dysfunction in Obstructive Sleep Apnea: An Electrophysiological Study.

Study Objectives: The aim of this study was to evaluate the integrity of the visual system in patients affected by obstructive sleep apnea (OSA) by means of electroretinogram (ERG) and visual evoked potential (VEP).

Methods: We performed electrophysiological study of the visual system in a population of severe OSA (apnea-hypopnea events/time in bed ≥ 30/h) patients without medical comorbidities compared to a group of healthy controls similar for age, sex, and body mass index. Patients and controls did not have visual impairment or systemic disorders with known influence on the visual system.

Effect of chiral symmetry on chaotic scattering from Majorana zero modes.

In many of the experimental systems that may host Majorana zero modes, a so-called chiral symmetry exists that protects overlapping zero modes from splitting up. This symmetry is operative in a superconducting nanowire that is narrower than the spin-orbit scattering length, and at the Dirac point of a superconductor-topological insulator heterostructure. Here we show that chiral symmetry strongly modifies the dynamical and spectral properties of a chaotic scatterer, even if it binds only a single zero mode.

Continuous Positive Airway Pressure Treatment Increases Serum Vitamin D Levels in Male Patients with Obstructive Sleep Apnea.

Study Objective: Recent studies report a link between obstructive sleep apnea (OSA) syndrome, low vitamin D levels, and high parathyroid hormone (PTH) concentrations. The aim of the current study is to evaluate the effect of 7-night continuous positive airway pressure (CPAP) therapy on serum vitamin D, PTH, and calcium levels in patients with severe OSA syndrome.

Methods: Patients with severe OSA were enrolled into the study and compared to control subjects.

Orexinergic system dysregulation, sleep impairment, and cognitive decline in Alzheimer disease.

Importance: Nocturnal sleep disruption develops in Alzheimer disease (AD) owing to the derangement of the sleep-wake cycle regulation pathways. Orexin contributes to the regulation of the sleep-wake cycle by increasing arousal levels and maintaining wakefulness.

Objectives: To study cerebrospinal fluid levels of orexin in patients with AD, to evaluate the relationship of orexin cerebrospinal fluid levels with the degree of dementia and the cerebrospinal fluid AD biomarkers (tau proteins and β-amyloid 1-42), and to analyze potentially related sleep architecture changes measured by polysomnography.

Is autonomic nervous system involved in restless legs syndrome during wakefulness?

Objective: To investigate cardiovascular autonomic function in patients with restless leg syndrome (RLS) by means of cardiovascular reflexes and heart rate variability (HRV) during wakefulness.

Methods: Twelve RLS patients and 14 controls underwent cardiovascular function tests including head-up tilt test (HUTT), Valsalva maneuver, deep breathing, hand grip, and cold face. HRV analysis was performed in the frequency domain using both autoregressive (AR) and fast Fourier transform algorithms in rest supine condition and during HUTT.

CSF lactate levels, τ proteins, cognitive decline: a dynamic relationship in Alzheimer's disease.

Objectives: To investigate, in patients with Alzheimer's Disease (AD), the possible interplay linking alteration of neuronal energy metabolism, as measured via cerebrospinal fluid (CSF) lactate concentration, to severity of AD neurodegenerative processes and impairment of cognitive abilities.

Methods: In this study we measured and correlated CSF lactate concentrations, AD biomarker levels (τ-proteins and β-amyloid) and Mini-Mental State Examination (MMSE) score in a population of drug-naïve patients with AD ranging from mild (MMSE≥21/30) to moderate-severe (MMSE<21/30) cognitive decline. They were compared to healthy controls and patients with vascular dementia (VaD).