Fatigue, Causes, Signs and Symptoms, Diagnosis and Treatment. скачать в хорошем качестве

Fatigue, Causes, Signs and Symptoms, Diagnosis and Treatment.

. Chapters 0:00 Introduction to fatigue 1:11 Causes of Fatigue 2:42 Symptoms of Fatigue 3:17 Diagnosis of Fatigue 4:18 Treatment of Fatigue Fatigue is a feeling of tiredness.[1] It may be sudden or gradual in onset. It is a normal phenomenon if it follows prolonged physical or mental activity, and resolves completely with rest. However, it may be a symptom of a medical condition if it is prolonged, severe, progressive, or occurs without provocation. Physical fatigue is the transient inability of muscles to maintain optimal physical performance, and is made more severe by intense physical exercise.[2][3][4] Mental fatigue is a transient decrease in maximal cognitive performance resulting from prolonged periods of cognitive activity. Mental fatigue can manifest as somnolence, lethargy, or directed attention fatigue.[5] Fatigue and 'feelings of fatigue' are sometimes confused.[6] Unlike weakness, fatigue can usually be alleviated by periods of rest. Physical fatigue, or muscle fatigue, is the temporary physical inability of muscles to perform optimally. The onset of muscle fatigue during physical activity is gradual, and depends upon an individual's level of physical fitness – other factors include sleep deprivation and overall health. Fatigue can be reversed by rest.[7] Physical fatigue can be caused by a lack of energy in the muscle, by a decrease of the efficiency of the neuromuscular junction or by a reduction of the drive originating from the central nervous system.[8] The central component of fatigue is triggered by an increase of the level of serotonin in the central nervous system.[9] During motor activity, serotonin released in synapses that contact motoneurons promotes muscle contraction.[10] During high level of motor activity, the amount of serotonin released increases and a spillover occurs. Serotonin binds to extrasynaptic receptors located on the axon initial segment of motoneurons with the result that nerve impulse initiation and thereby muscle contraction are inhibited.[11] Muscle strength testing can be used to determine the presence of a neuromuscular disease, but cannot determine its cause. Additional testing, such as electromyography, can provide diagnostic information, but information gained from muscle strength testing alone is not enough to diagnose most neuromuscular disorders.[12] People with multiple sclerosis experience a form of overwhelming lassitude or tiredness that can occur at any time of the day, for any duration, and that does not necessarily recur in a recognizable pattern for any given patient, referred to as "neurological fatigue".[13][14]