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Control of breathing was studied in a patient with a lesion in the ventral pons; no volitional behaviour, including voluntary breathing acts, was possible (locked-in syndrome, LIS). Spontaneous breathing via a tracheostomy maintained a normal PETCO2 of 39-40 mmHg. Variability of ventilatory parameters awake was similar to that seen in five tracheostomized(More)
We have studied post-hyperventilation breathing pattern in eight, awake, healthy, naive volunteers after 5 min voluntary or mechanical hyperventilation during normocapnia (PETCO2 = 38 mmHg) and 'hypocapnia (24 mmHg). Breathing was monitored for 10 min post-hyperventilation, 'non-invasively', using calibrated respiratory inductance plethysmography;(More)
OBJECTIVE Obstructive sleep apnea (OSA) causes hypoxemia and fragmented sleep, which lead to neurocognitive deficits. We hypothesised that focal loss of cortical gray matter generally within areas associated with memory processing and learning and specifically within the hippocampus would occur in OSA. METHODS Voxel-based morphometry, an automated(More)
BACKGROUND Obstructive sleep apnoea (OSA) is a common disease that leads to daytime sleepiness and cognitive impairment. Attempts to investigate changes in brain morphology that may underlie these impairments have led to conflicting conclusions. This study was undertaken to aim to resolve this confusion, and determine whether OSA is associated with changes(More)
Sleep disordered breathing is characterised by periodic breathing, episodes of hypoxia and repeated arousals from sleep; symptoms include excessive daytime sleepiness, impairment of memory, learning and attention. Recent evidence from animal studies suggests that both intermittent hypoxia and sleep fragmentation can independently lead to neuronal defects in(More)
The objective of this study was to determine the efficacy of gabapentin as adjunctive therapy in doses required to achieve the most effective seizure control. There were 2016 patients with partial seizures requiring adjunctive therapy who received gabapentin at doses up to 3600 mg/day in this open-label, multicenter, 16-week study. Of the 1055 patients(More)
We have compared the effects on breathing of inspiratory mechanical support during wakefulness and sleep in healthy subjects. Nine awake volunteers breathed through a nose mask connected to a machine supplying variable levels of inspiratory positive airway pressure (IPAP). Tidal volume (VT), breath duration (TTOT) and end-tidal PCO2 (PETCO2) were measured(More)
The present study was designed to determine the effect of sleep on reflex pharyngeal dilator muscle activation by stimuli of negative airway pressure in human subjects. Intra-oral bipolar surface electrodes were used to record genioglossus electromyogram (EMG) responses to 500 ms duration pressure stimuli of 0 and -25 cmH2O applied, via a face-mask, in four(More)
OBJECTIVES The rostrolateral medulla (RLM) has been identified in animals as an important site of chemosensitivity; in humans such site(s) have not been defined. The aim of this study was to investigate the physiological implications of unilateral lesions in the lower brainstem on the control of breathing. METHODS In 15 patients breathing was measured(More)
In patients with obstructive sleep apnoea (OSA), the very low frequency power spectral density index (VLFI) derived from analysis of heart rate correlates with the severity of obstructive apnoeas. VLFI is also associated with Cheyne-Stokes respiration/central sleep apnoea (CSR/CSA) in congestive heart failure (CHF). The present authors have tested the(More)