ЭТИОЛОГИЯ ПАРЕЗОВ И ПАРАЛИЧЕЙ ДИАФРАГМЫ

Приобретенная релаксация диафрагмы (у взрослых) ПАРЕЗЫ И ПАРАЛИЧИ ДИАФРАГМЫ ОПРЕДЕЛЕНИЕ И ВСТУПЛЕНИЕ ПО ПРОБЛЕМЕ ПАРЕЗОВ И ПАРАЛИЧЕЙ ДИАФРАГМЫ ФИЗИОЛОГИЯ И ПАТОФИЗИОЛОГИЯ ДИАФРАГМЫ ЭТИОЛОГИЯ ПАРЕЗОВ И ПАРАЛИЧЕЙ ДИАФРАГМЫ КЛИНИЧЕСКИЕ ПРОЯВЛЕНИЯ ПАРЕЗОВ И ПАРАЛИЧЕЙ ДИАФРАГМЫ ПАРАЛИЧ ДИАФРАГМЫ И СОН ДИАГНОСТИКА ПАРАЛИЧЕЙ ДИАФРАГМЫ ЛЕЧЕНИЕ ПАРАЛИЧЕЙ И ПАРЕЗОВ ДИАФРАГМЫ

Парез и паралич диафрагмы может развиться в результате дефекта на любом участке нейромышечной оси:

• Спинной мозг
• Диафрагмальный нерв
• Нейромышечное соединение
• Мышца

Спинной мозг

Cerebrovascular accidents may lead to decreased electrical activity of the diaphragm.5,6 In one study of 34 patients with acute cerebrovascular accidents, 41% had decreased diaphragmatic excursion. Hemiplegic patients were found to have more hypoxia and hypocapnia.7
Spinal cord lesions above the take-off of the phrenic nerve at C3-C5 can lead to diaphragm paralysis. In fact, high spinal cord lesions have severe clinical consequences because most of the accessory muscles of respiration, including the intercostals and abdominal muscles, are paralyzed as well. In these cases, only the sternocleidomastoids and trapezii are intact.8 Hypertrophy of the remaining muscles with glossopharyngeal breathing follows in these cases.9
The anterior horn cells are the motor neurons of the spinal cord. They receive information from descending pathways. Because anterior horn cells at C3-C5 give rise to the phrenic nerves, motor neuron disease can lead to diaphragmatic weakness. Diseases of the motor neuron include amyotrophic lateral sclerosis (ALS), spinal muscular atrophy, and poliomyelitis.

Диафрагмальный нерв

Because the diaphragm is innervated solely by the phrenic nerves, damage of any type to the latter can lead to diaphragmatic weakness. The phrenic nerves run from the cervical spine in the neck through the mediastinum to the diaphragms. Therefore, they are susceptible to damage from thoracic surgeries or tumors as well as chest trauma. Neuropathies such as Guillain-Barré syndrome and herpes zoster can affect the phrenic nerves, leading to diaphragmatic weakness. Isolated phrenic neuropathies can also be idiopathic.

Нейро-мышечное соединение

Activation of the diaphragm by the phrenic nerve depends on transmission of the signal across the neuromuscular junction. The machinery that accomplishes this can be impaired by several diseases, including myasthenia gravis, Lambert-Eaton syndrome, and botulism toxicity.

Мышца

The diaphragm muscle itself can be affected by myopathies or metabolic disorders that weaken muscles systemically. Processes that affect the diaphragm itself include muscular dystrophies, thyroid disorders, and polymyositis/dermatomyositis.
The position of the diaphragm at rest or FRC is a function of the inward recoil of the lung and the outward recoil of the chest wall. Disorders of the chest wall and obstructive lung diseases can alter FRC, which affects the length of the diaphragm at rest. The strength of the diaphragm, as with any muscle, depends on its length. Obstructive lung disease involves decreased lung recoil leading to hyperinflation, which places the diaphragm on a suboptimal point on its length-tension curve. Chest wall disorders affect diaphragmatic strength both by altering the length of the diaphragm and by affecting the integrity of the zone of apposition and the way in which the chest wall responds to diaphragmatic contraction.9