[Sleep-related breathing disorders - historical development, current status, future prospects]. / Schlafassoziierte Ventilationsstörungen - historische Entwicklung, Status quo und Ausblick.

Sleep-related breathing disorders are common adult illnesses in Western countries and classified as either dominant obstructive sleep apnoea or dominant central sleep apnoea. Cheyne-Stokes Respiration is part of the spectrum of CSA. The earliest descriptions of patients who presumably suffered from sleep apnoea were made in the 19th century. The term ''Pickwickian'' in connection with sleepy patients was introduced in 1889. The first electrophysiological sleep recordings of Pickwickian patients and the understanding of the syndrome as disordered breathing in sleep, were made during the late 1950s and 1960s at the universities of Heidelberg and Freiburg in Germany. The term sleep apnoea syndrome was introduced by Guilleminault from Stanford. The introduction of continuous positive airway pressure (CPAP) therapy by C. E. Sullivan and co-workers gave an enormous impetus to the field of sleep-disordered breathing. Its recognition as a public health problem was facilitated by the Wisconsin study, investigating the prevalence of sleep apnoea in the middle-aged general population. Nowadays obstructive sleep apnoea (OSA) is recognised as an independent risk factor for a wide range of clinical conditions, such as atherosclerosis, hypertension, heart failure, arrhythmias, stroke, diabetes, and depression. This article focuses on issues related to OSA and CSA/CSR, their pathogenesis, interaction with other comorbidities including cardiovascular diseases. Future research will focus on treatment effects on cardiovascular and metabolic outcomes in sleep apnoea and on the pathophysiological mechanisms responsible for the inflammatory state and cardiovascular morbidity in the syndrome. Other potential areas of research include biochemical markers, new diagnostic and therapeutic modalities.

Eponymous doctors associated with Edinburgh, Part 2--David Bruce, John Cheyne, William Stokes, Alexander Monro Secundus, Joseph Gamgee.

This, the second in a three-paper series with this title, looks at famous doctors who trained in Edinburgh and their eponyms. With one possible exception, none seems to have sought the eponym, nor awarded it to themselves, nor used it for self-promotion. Unlike those in the first paper, all eponyms in this paper are still in use and their brevity is in contrast to the lengthy description needed if the eponym is not used. Examples are Cheyne-Stokes respiration, Stokes-Adam attacks, Brucellosis and Gamgee dressing. Monro Secundus is included because of his vehement defence of his professional reputation and research findings when he suspected others of trying to detract credit from him, a characteristic seldom reported for the others.

Sleep of the great.

Both Lewis Carroll and William Shakespeare appear to have made clinical observations of sleep apnea syndromes long before they were discovered by medical science, and to have understood something about their physiological mechanisms. The somnolent dormouse in Alice in Wonderland indicates that his problem is one of sleep and breathing and is subject to modern treatment for obstructive apnea. Shakespeare in Henry IV presents a case of obstructive apnea along with a case of Cheyne-Stokes breathing and uses the plot of these history plays to explain by analogy the theoretical basis for periodic breathing.

Colles-Stokes contributions to the concept of heart failure.

"Colles fracture," "Colles law," "Stokes-Adams syndrome," "Cheyne-Stokes respiration," and "Corrigan pulse" are some of the contributions of the Irish school that are utilized for teaching purposes in medical schools and training programs, as well as in daily practice of medicine. We wish to add an important description by Drs. Colles and Stokes that personifies the considerable personal contributions of these 2 physicians in our understanding of the pathophysiologic expression of the syndrome of heart failure. The clinical-pathologic correlation of the disease that affected Dr. Colles is well described by Dr. Stokes in his treatise Diseases of the Heart and the Aorta. He recognized the cyclical nature of frequent decompensations in heart failure, the relation of clinical worsening in conjunction with reduced urine output, as well as the importance of reestablishing urinary flow to achieve a decrease in dyspnea. Dr. Colles also demonstrated a profound clinical insight when he noticed, first, that his affliction was "eventually a fatal disease and that remedies that work may lose effect over time," illustrating an observation that has stood the test of time and, secondly, when he told Dr. Smith "... I would direct particular attention to the heart and the lungs ... and the swelling in the right hypochondrium ... I suspect that there is some connexion between this swelling of the hypochondrium and the diseased state of the heart." We believe that the Colles-Stokes contributions, both in the clinical as well as the clinical-pathologic arenas, are one of the landmark descriptions that helped to evolve the concept of the syndrome of heart failure.

The definition of "Cheyne-Stokes rhythms".

The review of the literature on Cheyne-Stokes respiratory periods reveals enormous variation of the opinions expressed. The original description concerned periodicity characterized by rhythmic changes of respiratory phases and respiratory pauses in a relation of 60 : 15 seconds. In the respiratory phase there were 30 respirations of increasing depths and frequency at the beginning of the phase and decreasing depths and frequency at the end of the phase. Literature data about Cheyne-Stokes respiration comprise a multiplicity of all rhythymic forms. The duration of respiratory cycles varies between 12 and 130 seconds. The relation of the respiratory phase and respiratory pause between 6 : 4 or 75 : 70 seconds, and the number of breaths between 3 and 30 during one respiratory phase. Cheyne-Stokes periods were observed in health subjects as well as in patients with neurological, neurosurgical, cardiac, pulmonary and paediatric diseases. Cheyne-Stokes periods were explained as sequel of prolongation of circulation time between pulmonary alveoli and respiratory centre, through increased sensitivity of the respiratory centre to CO2, diminished sensitivity of the respiratory centre to CO2 and O2-deficit, local blood flow disturbances, section of pathways in the brain stem with disinhibition of basic rhythms, brain immaturity, alterations of consciousness, and respiratory obstructions. Rhythmic changes of the heart beat, of excitability of the heart muscle, of blood pressure, of EEG and of neurological and mental signs were observed. In spite of numerous observations detailed analysis of the respiratory cycle was performed in only a few cases. Major studies are lacking.