Diego Z. Carvalho

Mayo Clinic - Rochester

Sleep spindles have been suggested as surrogates of thalamo-cortical activity. Internal frequency modulation within a spindle's time frame has been demonstrated in healthy subjects, showing that spindles tend to decelerate their frequency before termination. We investigated internal frequency modulation of slow and fast spindles according to Obstru...

Excessive daytime sleepiness (EDS) and fatigue increases with age. The aim of this study was to investigate the association between EDS and fatigue with cortical thickness and hippocampal volume in cognitively normal, late middle-aged and older adults. We performed a cross-sectional observational study of 1374 cognitively-normal subjects aged 50 ye...

Importance Aging is associated with excessive daytime sleepiness (EDS), which has been linked to cognitive decline in the elderly. However, whether EDS is associated with the pathologic processes of Alzheimer disease remains unclear. Objective To investigate whether EDS at baseline is associated with a longitudinal increase in regional β-amyloid (...

Objective To assess whether informant-reported apneas during sleep (witnessed apneas) in cognitively unimpaired (CU) elderly persons are associated with higher levels of brain tau. Methods From the population-based Mayo Clinic Study of Aging, we identified 292 CU elderly ≥65 years of age with both AV-1451 tau-PET and Pittsburgh compound B (PiB)-PE...

Introduction Sleepiness has been associated with cognitive decline and dementia in the elderly. Older adults with excessive daytime sleepiness appear to be more vulnerable to longitudinal amyloid PET accumulation before the onset of the dementia. However, it remains unclear whether sleepiness is similarly associated with other biomarkers of Alzheim...

Introduction Meta-analytic studies support that insomnia is a risk factor for cognitive decline and dementia, but limited accounting of confounders reduces their validity. Further, it is unclear whether these associations are driven by specific insomnia phenotypes. In this study, we aimed to assess the relationship between insomnia and longitudinal...

Introduction The ICSD-3-TR defines idiopathic hypersomnia in terms of objective sleep times as sleeping at least 11 hours using 24-hour polysomnography or wrist actigraphy averaged over at least 7 days. Published studies on sleep duration are generally limited by lower sleep duration cut-offs (e.g., ≥ 9 hours), so prevalence data on longer sleep du...

Introduction Central sleep apnea (CSA) is associated with several medical conditions (e.g., heart failure, atrial fibrillation) and medications (e.g., opioids, ticagrelor, sodium oxybate and valproic acid). We report a case of a 31-year-old female with bipolar disorder treated with valproic acid diagnosed with central sleep apnea on polysomnography...

The aim of this study was to assess age- and sex-related differences in multiple sleep latency test (MSLT) results and in the performance of the Epworth Sleepiness Scale (ESS) at classifying objective hypersomnia (mean sleep latency (MSL) ≤ 8 min). We studied 480 consecutive adults (39.3 ± 15.3 years old [18–93], 67.7% female) who underwent hyperso...

Background Quantitative rapid eye movement (REM) sleep without atonia (RSWA) recorded during polysomnography (PSG) represents loss of normal REM sleep atonia. RSWA is the neurophysiologic signature of REM sleep behavior disorder (RBD). Visually scored RSWA is a candidate biomarker for synucleinopathies. However, visual RSWA scoring requires expert...

Background Restless legs syndrome (RLS) is a prevalent sensorimotor disorder that can dramatically impair sleep quality, daytime function, and quality of life. Although many patients benefit from standard pharmacological therapy, some patients suffer from insufficient treatment response or medication intolerance. Novel treatment approaches are ther...

Objective Advanced Parkinson's Disease (PD) is associated with Parkinson’s Disease gait impairment (PDg), which increases the risk for falls and is often treatment-refractory. Subthalamic nucleus (STN) and globus pallidus pars interna (GPi) deep brain stimulation (DBS) often fails to improve axial symptoms like PDg. Spinal cord stimulation (SCS) ha...

Study objectives: Accurate diagnosis of isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is crucial due to its injury potential and neurological prognosis. We aimed to analyze visual and automated REM sleep without atonia (RSWA) diagnostic thresholds applicable in varying clinical presentations in a contemporary cohort of iRBD pati...

Introduction Restless legs syndrome (RLS) can dramatically impair sleep quality and quality of life. Some patients have insufficient treatment response or intolerance to available pharmacological options. Exploration of novel therapeutic approaches is needed. Methods We report a case of spinal cord stimulation (SCS) providing benefit in RLS. We al...

Low frequency brain rhythms facilitate communication across large spatial regions in the brain and high frequency rhythms are thought to signify local processing among nearby assemblies. A heavily investigated mode by which these low frequency and high frequency phenomenon interact is phase-amplitude coupling (PAC). This phenomenon has recently sho...

Background and Objectives Our objective was to determine whether polysomnographic (PSG) sleep parameters are associated with neuroimaging biomarkers of cerebrovascular disease (CVD) related to white matter integrity in older adults with obstructive sleep apnea (OSA). Methods From the population-based Mayo Clinic Study of Aging, we identified parti...

Study objectives To evaluate whether or not the apnea–hypopnea index (AHI) from a peripheral arterial tonometry (PAT) home sleep apnea test (HSAT) is equivalent to the AHI provided by the mean of one, three, or seven nights from the Withings Sleep Analyzer (WSA) under-mattress device. Methods We prospectively enrolled patients with suspected OSA i...

Study Objectives Isolated REM sleep behavior disorder (iRBD) carries a high lifetime risk for phenoconversion to a defined neurodegenerative disease (NDD) including Parkinson disease, dementia with Lewy bodies, and multiple system atrophy. We aimed to examine iRBD patient values and preferences regarding prognostic counseling. Methods 113 iRBD pat...

Introduction We have previously shown that older adults with excessive daytime sleepiness (EDS) appear to be more vulnerable to longitudinal amyloid PET accumulation before the onset of the dementia. It remains unclear whether this vulnerability is specific to amyloid or extends to other biomarkers of Alzheimer’s disease pathology, or axonal integr...

Introduction Accurate, early diagnosis of isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is crucial given its injury potential and neurological prognosis. We aimed to analyze visual and automated REM sleep without atonia (RSWA) diagnostic thresholds in a current cohort of iRBD patients using submentalis (SM) and individual four li...

Introduction Orexin deficiency in cerebrospinal fluid (CSF) was first reported in human narcolepsy in 2001, included in diagnostic criteria for narcolepsy in 2014, and made clinically available at the Mayo Clinic in 2019. The purpose of this publication is to report orexin test utilization and results, and other clinically relevant findings from pa...

Arousal from sleep is a natural phenomenon and evolutionarily protective but may contribute to sleep disruption and daytime dysfunction. Arousals are classically defined as an abrupt change in EEG frequency but may occur in the absence of discernible EEG change. Arousals play an important role in the scoring of respiratory events and are typically...

Introduction REM sleep behavior disorder (RBD) is characterized by disruptive, violent dream enactment behaviors (DEB), necessitating symptomatic treatment to prevent injury and reduce DEB frequency and severity. Melatonin and clonazepam are regarded as RBD therapeutic mainstays, although outcomes data remains limited. We surveyed RBD patients to d...

A correction to this paper has been published: https://doi.org/10.1007/s13311-021-01060-3

A healthy brain requires balancing of waking and sleeping states. The normal changes in waking and sleeping states result in neurophysiological conditions that either increase or decrease the tendency of seizures and interictal discharges to occur. This article reviews the manifold and complex relationships between sleep and epilepsy and discusses...

This chapter provides an overview of the field of sleep and epilepsy and provides a guide to help clinicians navigate through the most common issues related to sleep, sleep disorders and epilepsy. It begins with a review of the epidemiology of sleep‐related seizures and epilepsies, essentials of sleep and circadian physiology for the epileptologist...

Introduction Sleepiness has been associated with functional and cognitive decline, and may present with excessive daytime sleepiness (EDS) and/or increased sleep duration. We investigated whether sleepiness and changes in sleep patterns are associated with FDG-PET levels in wake-promoting regions. Methods From the Mayo Clinic Study of Aging cohort...

The human electroencephalogram (EEG) of sleep undergoes profound changes with age. These changes can be conceptualized as "brain age (BA)," which can be compared to chronological age to reflect the degree of deviation from normal aging. Here, we develop an interpretable machine learning model to predict BA based on 2 large sleep EEG data sets: the...

The human electroencephalogram (EEG) of sleep undergoes profound changes with age. These changes can be conceptualized as "brain age", which can be compared to an age norm to reflect the deviation from normal aging process. Here, we develop an interpretable machine learning model to predict brain age based on two large sleep EEG datasets: the Massa...

Introduction Responsive Neurostimulation (RNS) provides an alternative treatment for medication-refractory epilepsy cases which are not a candidate for resective epilepsy surgery. It has been shown effective with complication rates comparable to similar procedures. This study reports the data on responsive neurostimulation patients from Massachuset...

Introduction The human electroencephalogram (EEG) of sleep undergoes profound changes with age, such as decreased sleep spindle amplitude and density in non-rapid eye movement stage 2 (NREM2). However, it is unknown how accurately a patient’s age can be predicted from EEG activity during sleep. A quantitative characterization of age-related EEG pro...

Postsedation neuroexcitation is sometimes attributed to intravenous injection of the sedative-hypnotic drug propofol. The movements associated with these events have strongly suggested convulsive activity, but they rarely have been comprehensively evaluated. We present video recordings of 3 healthy young patients who underwent elective surgery unde...

Introduction Excessive daytime sleepiness (EDS) increases with aging, and may be associated with cognitive decline in the elderly. As Alzheimer’s Disease dementia (AD) has been linked to metabolic changes particularly in areas involved with the default mode network (DMN), we investigated whether EDS is associated with metabolic changes in those reg...

As opposed to finger flexion response upon tapping the styloid process with absent brachioradialis reflex (inverted brachioradialis reflex), toe flexion response upon patellar percussion with absent quadriceps reflex is a quite underrecognized neurological sign, and has been reported only once in the literature. Similar to the inverted brachioradia...

Impaired inferior vena cava (IVC) outflow can lead to collateralization of blood to the valveless epidural venous plexus, causing epidural venous engorgement and venous congestion. Herein we describe a case of chronic IVC thrombosis presenting as venous congestive myelopathy treated with angioplasty and endovascular stenting. The pathophysiological...

Objectives Sleep EEG spectral patterns were investigated in eight newly diagnosed, non-depressed, non-demented, drug-naïve Parkinson’s disease patients compared to nine controls. Methods Mean relative spectral power density calculated for 0.25Hz frequency bins and for classical EEG frequency bands. Results Differences between patients and control...

In this study, Matching Pursuit (MP) procedure is applied to the detection and analysis of EEG sleep spindles in patients evaluated for suspected OSAS. Elements having the frequency of EEG sleep spindles are selected from different dictionary sizes, with and without a frequency modulation function (chirp) for signal description. This procedure was...

Introduction The 2005 International Classification of Sleep Disorders (ICDS 2) considers six primary diagnostic categories: Parassomnia, Respiratory, Insomnia, Movement, Sleepiness (Hypersomnia) and Circadian Sleep Disorders (not necessarily in that order). The PRIMSC acronym is being suggested as a mnemonic aid for primary care in Sleep Medicine,...

Background Sleep spindles, as detected on scalp electroencephalography (EEG), are considered to be markers of thalamo-cortical network integrity. Since obstructive sleep apnea (OSA) is a known cause of brain dysfunction, the aim of this study was to investigate sleep spindle frequency distribution in OSA. Seven non-OSA subjects and 21 patients with...

Supplementary figure showing the procedure employed for MP amplitude threshold selection. Matching Pursuit performance was tested on another sample (training dataset) pertaining to 9 healthy young subjects, where 513 sleep spindles had been visually identified during NREM sleep stage 2 (same database used in Schonwald et al; Benchmarking Matching P...

Sleep spindles are considered as a marker of integrity for thalamo-cortical circuits. Recently, attention has been given to internal frequency variation in sleep spindles. In this study, a procedure based on matching pursuit with a Gabor-chirplet dictionary was applied in order to measure chirp rate in atoms representing sleep spindles, also catego...

In this paper we introduce a procedure based on Matching Pursuit with Gabor-chirping dictionary and apply it to the spectral decomposition of a whole-night EEG sig-nal from a group of nine young normal subjects. It was thus possible to identify sleep spindles (SS) and quantify them not only in frequency but also in modulation of this fre-quency. We...