1.
Sudden unexpected death in Dravet syndrome: respiratory and other physiological dysfunctions.
Kalume, F
Respiratory physiology & neurobiology. 2013;(2):324-8
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Abstract
Sudden unexpected deaths in epilepsy (SUDEP) occur at an alarming higher rate in patients with Dravet syndrome (DS) than in patients with most other forms of epilepsy. DS is a severe infantile-onset epilepsy caused by a heterozygote loss-of-function mutation in SCN1A, which encodes the voltage-gated-sodium channel NaV 1.1. The mechanisms leading to SUDEP in DS or other epilepsies are not completely understood. Understanding the pathophysiological mechanisms of SUDEP, common to most epilepsies and those specific to DS, may pave the way toward the discovery of effective preventive strategies for these epilepsy-related tragic events.
2.
COPD recent findings: impact on clinical practice.
Couillard, A, Muir, JF, Veale, D
COPD. 2010;(3):204-13
Abstract
Chronic obstructive pulmonary disease is now considered as a systemic disease originating in the lungs. The natural history of this disease reveals numerous extrapulmonary manifestations and co-morbidity factors that complicate the evolution of COPD. Recent publications have documented these systemic manifestations and co-morbidities and clarified somewhat the role of muscle dysfunction, nutritional anomalies, endocrine dysfunction, anaemia, osteoporosis and cardiovascular and metabolic disorders as well as lung cancer and psychological elements in this complex disease. Importantly, recent studies have shown that effort intolerance, exertional desaturation, loss of autonomy and reduced physical activity, loss of muscle mass and quadriceps strength as well as dyspnoea and impaired quality of life can be considered as independent predictive factors for survival in COPD. Use of these data may advance understanding of mechanisms; improve evaluation and thereby patient management in COPD.
3.
Mechanisms of functional loss in patients with chronic lung disease.
MacIntyre, NR
Respiratory care. 2008;(9):1177-84
Abstract
Functional loss (often quantified as exercise limitation) is common in patients with chronic lung disease. The factors involved are multiple and many may be present together in a given patient. Ventilatory factors involve an imbalance in load/capacity relationships. Specifically, breathing loads from abnormal respiratory-system mechanics and/or excessive ventilatory demand cannot be handled by respiratory muscles that are dysfunctional or malpositioned. Gas-exchange factors involve impaired ventilation-perfusion relationships that lead to hypoxemia, impaired oxygen delivery, and pulmonary hypertension. Cardiovascular factors involve coexisting intrinsic heart disease, right-ventricular overload from pulmonary vascular abnormalities, and simple deconditioning. Skeletal muscle (both respiratory and limb) factors involve direct inflammatory mediator effects on muscle function, malnutrition, blood-gas abnormalities, compromised oxygen delivery from right-heart dysfunction, electrolyte imbalances, drugs, and comorbid states. Other less well understood factors include excessive dyspnea, impaired motivation, orthopedic issues, and psychiatric issues.
4.
Structural and functional changes in the skeletal muscles of COPD patients: the "compartments" theory.
Gea, J, Orozco-Levi, M, Barreiro, E, Ferrer, A, Broquetas, J
Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace. 2001;(3):214-24
Abstract
This review focuses on the structural and functional changes occurring in respiratory as well as peripheral muscles in COPD patients. These changes are particular for each muscle territory or compartment. Respiratory muscles predominantly undergo structural adaptive changes. However, they have to do their job in unfavourable mechanical conditions and thus their function is impaired. Peripheral muscles have to be grouped in at least two different compartments: upper and lower limb muscles. The structure and function are relatively preserved in the former, due to the maintenance of some daily activities involving the arms or even the use of some of these muscles in the ventilatory effort. Lower limb muscles in contrast undergo involute structural changes which result in an impairment in their function and in the global exercise capacity of the individual. Deconditioning due to a reduction in daily activities secondary to ventilatory impairment is probably the driving factor for these changes. Although the level of activity appears to be the main determining factor in changes occurring in different territories, this would be modulated by other local and systemic factors, such as inflammation, oxidative stress, drugs and nutritional abnormalities.