Does the supplementary motor area keep patients with Ondine's curse syndrome breathing while awake?

Background: Congenital central hypoventilation syndrome (CCHS) is a rare neuro-respiratory disorder associated with mutations of the PHOX2B gene. Patients with this disease experience severe hypoventilation during sleep and are consequently ventilator-dependent. However, they breathe almost normally while awake, indicating the existence of cortical mechanisms compensating for the deficient brainstem generation of automatic breathing.

Proceedings of the fourth international conference on central hypoventilation.

Central hypoventilation syndromes (CHS) are rare diseases of central autonomic respiratory control associated with autonomous nervous dysfunction. Severe central hypoventilation is the hallmark and the most life-threatening feature. CHS is a group of not-fully defined disorders.

Severely impaired health-related quality of life in chronic hyperventilation patients: exploratory data.

Patients with hyperventilation syndrome (HVS) report severe symptom-related suffering and often complain from insufficient medical attention. However, quality of life data in this context are scarce. We aimed at assessing the health-related quality of life (HRQoL) of HVS patients.

Non-invasive ventilation effectiveness and the effect of ventilatory mode on survival in ALS patients.

Non-invasive ventilation (NIV) prolongs survival in amyotrophic lateral sclerosis (ALS), but there are no data with which to compare the effectiveness of the different ventilator modes - volume (Vol-NIV) or pressure-cycled (Pres-NIV) ventilation - in ALS. We aimed to determine whether the ventilatory mode has an effect on ventilation effectiveness and survival of ALS patients using NIV. We used a retrospective study that included all ALS patients for whom NIV was indicated in two referral units: one using Vol-NIV and the other using Pres-NIV.

New insights in gill/buccal rhythm spiking activity and CO(2) sensitivity in pre- and postmetamorphic tadpoles (Pelophylax ridibundus).

Central CO(2) chemosensitivity is crucial for all air-breathing vertebrates and raises the question of its role in ventilatory rhythmogenesis. In this study, neurograms of ventilatory motor outputs recorded in facial nerve of premetamorphic and postmetamorphic tadpole isolated brainstems, under normo- and hypercapnia, are investigated using Continuous Wavelet Transform spectral analysis for buccal activity and computation of number and amplitude of spikes during buccal and lung activities. Buccal bursts exhibit fast oscillations (20-30Hz) that are prominent in premetamorphic tadpoles: they result from the presence in periodic time windows of high amplitude spikes.

Analgesic effects of dyspnoea: "Air hunger" does not inhibit the spinal nociception reflex in humans.

Dyspnoea has distinct sensory modalities, including air hunger and the sensation of excessive breathing "work/effort". Both have analgesic properties. In the case of work/effort, spinal mechanisms have been documented (inhibitory effect on the spinal nociceptive flexor reflex, RIII).

Unrecognized suffering in the ICU: addressing dyspnea in mechanically ventilated patients.

Background: Intensive care unit (ICU) patients are exposed to many sources of discomfort. Although increasing attention is being given to the detection and treatment of pain, very little is given to the detection and treatment of dyspnea (defined as "breathing discomfort").

Methods: Published information on the prevalence, mechanisms, and potential negative impacts of dyspnea in mechanically ventilated patients are reviewed.

Diaphragmatic function is preserved during severe hemorrhagic shock in the rat.

Background: Acute diaphragmatic dysfunction has been reported in septic and cardiogenic shock, but few data are available concerning the effect of hemorrhagic shock on diaphragmatic function. The authors examined the impact of a hemorrhagic shock on the diaphragm.

Methods: Four parallel groups of adult rats were submitted to hemorrhagic shock induced by controlled exsanguination targeting a mean arterial blood pressure of 30 mmHg for 1 h, followed by a 1-h fluid resuscitation with either saline or shed blood targeting a mean arterial blood pressure of 80 mmHg.

Functional magnetic resonance imaging suggests automatization of the cortical response to inspiratory threshold loading in humans.

Inspiratory threshold loading (ITL) induces cortical activation. It is sustained over time and is resistant to distraction, suggesting automaticity. We hypothesized that ITL-induced changes in cerebral activation may differ between single-breath ITL and continuous ITL, with differences resembling those observed after cortical automatization of motor tasks.

Factor analysis in predominantly severe COPD: identification of disease heterogeneity by easily measurable characteristics.

Background: The clinical and demographic variables defining the heterogeneity of chronic obstructive pulmonary disease (COPD) are unclear. A post-hoc analysis of five randomised studies in patients with a history of previous exacerbations examined the clinical and demographic characteristics describing moderate-to-very-severe COPD.

Methods: Factor analysis was performed on all continuous baseline demographic and clinical data, without variable selection.

Intravenous adenosine activates diffuse nociceptive inhibitory controls in humans.

Experimentally induced pain can be attenuated by concomitant heterotopic nociceptive stimuli (counterirritation). Animal data indicate that this stems from supraspinal "diffuse noxious inhibitory controls" (DNICs) triggered by C and Aδ fibers. In humans, only noxious stimuli induce counterirritation.

Reversal of pulmonary hypertension after diaphragm pacing in an adult patient with congenital central hypoventilation syndrome.

Introduction: Patients with the congenital central hypoventilation syndrome (CCHS) suffer from life-threatening hypoventilation when asleep, making them dependent on mechanical ventilation (MV) at night or during naps. State-of-art respiratory management consists of intermittent positive-pressure ventilation via a tracheotomy or mask. In some patients hypoventilation is permanent, in which case ventilatory support must be extended to the waking hours.

Diaphragm dysfunction on admission to the intensive care unit. Prevalence, risk factors, and prognostic impact-a prospective study.

Rationale: Diaphragmatic insults occurring during intensive care unit (ICU) stays have become the focus of intense research. However, diaphragmatic abnormalities at the initial phase of critical illness remain poorly documented in humans.

Objectives: To determine the incidence, risk factors, and prognostic impact of diaphragmatic impairment on ICU admission.

The supplementary motor area exerts a tonic excitatory influence on corticospinal projections to phrenic motoneurons in awake humans.

Introduction: In humans, cortical mechanisms can interfere with autonomic breathing. Respiratory-related activation of the supplementary motor area (SMA) has been documented during voluntary breathing and in response to inspiratory constraints. The SMA could therefore participate in the increased resting state of the respiratory motor system during wake (i.

Dyspnea and surface inspiratory electromyograms in mechanically ventilated patients.

Context: Pressure support ventilation (PSV) must be tailored to the load capacity balance of the respiratory system. While "over assistance" generated hyperinflation and ineffective efforts, "under assistance" increased respiratory drive and causes dyspnea. Surface electromyograms (sEMGs) of extradiaphragmatic inspiratory muscles were responsive to respiratory loading/unloading.

Prognostic value of efficiently correcting nocturnal desaturations after one month of non-invasive ventilation in amyotrophic lateral sclerosis: a retrospective monocentre observational cohort study.

Abstract NIV adherence ('quantity' of ventilation) has a prognostic impact in amyotrophic lateral sclerosis (ALS). We hypothesized that NIV effectiveness ('quality') could also have a similar impact. NIV effectiveness was evaluated in 82 patients within the first month (M1) and every three months (symptoms, arterial blood bases, and nocturnal pulsed oxygen saturation - SpO2).

Noninvasive mechanical ventilation in patients having declined tracheal intubation.

Purpose: Noninvasive ventilation (NIV) is a treatment option in patients with acute respiratory failure who are good candidates for intensive care but have declined tracheal intubation. The aim of our study was to report outcomes after NIV in patients with a do-not-intubate (DNI) order.

Methods: Prospective observational cohort study in all patients who received NIV for acute respiratory failure in 54 ICUs in France and Belgium, in 2010/2011.

Diaphragm electromyographic activity as a predictor of weaning failure.

Purpose: To compare breathing pattern descriptors and diaphragm electromyographic activity (EAdi)-derived indices obtained from a neurally adjusted ventilatory assist catheter during a spontaneous breathing trial (SBT) in patients successfully and unsuccessfully separated from the ventilator and to assess their performance as a potential marker to discriminate these two categories of patients.

Methods: Fifty-seven ready-to-wean patients were included in a prospective observational study. During a 30-min SBT (pressure support 7 cmH(2)O, zero end expiratory pressure), tidal volume (V (T)) and respiratory rate (RR) were obtained from the flow signal at baseline and at 3, 10, 20 and 30 min during the SBT.

Acute bronchodilation increases ventilatory complexity during resting breathing in stable COPD: toward mathematical biomarkers of ventilatory function?

Human tidal breathing features mathematical complexity and breath-by-breath variability. Fluctuations in these descriptors from one state to another are related to the load imposed on the respiratory system. We hypothetized that bronchodilators would increase ventilatory complexity and variability in patients suffering from chronic obstructive pulmonary disease (COPD).

Dynamic respiratory mechanics and exertional dyspnoea in pulmonary arterial hypertension.

Patients with pulmonary arterial hypertension (PAH) may exhibit reduced expiratory flows at low lung volumes, which could promote exercise-induced dynamic hyperinflation (DH). This study aimed to examine the impact of a potential exercise-related DH on the intensity of dyspnoea in patients with PAH undergoing symptom-limited incremental cardiopulmonary cycle exercise testing (CPET). 25 young (aged mean±sd 38±12 yrs) nonsmoking PAH patients with no evidence of spirometric obstruction and 10 age-matched nonsmoking healthy subjects performed CPET to the limit of tolerance.

Persistent lung oscillator response to CO2 after buccal oscillator inhibition in the adult frog.

The automatic ventilatory drive in amphibians depends on two oscillators interacting with each other, the gill/buccal and lung oscillators. The lung oscillator would be homologous to the mammalian pre-Bötzinger complex and the gill/buccal oscillator homologous to the mammalian parafacial respiratory group/retrotrapezoid nucleus (pFRG/RTN). Dysfunction of the pFRG/RTN has been involved in the development of respiratory diseases associated to the loss of CO(2) chemosensitivity such as the congenital central hypoventilation syndrome.