膈神经传导以及膈运动诱发电位对呼吸功能障碍评价的初步探讨

Preliminary exploration of significance of phrenic nerve conduction and diaphragmatic MEP on respiratory dysfunction.

目的：初步探讨膈神经传导（ＰＮＣ）及膈运动诱发电位（ＭＥＰ）对评价各种呼吸功能障碍的价值。方法：对３４例病人（各种神经肌肉疾病１９例、呼吸系统疾病１５例）在胸锁乳突肌后缘中点用电刺激膈神经，于第７—８肋间和剑突处记录膈肌复合动作电位；用磁圈置于对侧头皮进行刺激，在深吸气状态下记录膈ＭＥＰ。结果：肌病患者的ＰＮＣ均正常；格林巴利综合征、重症肌无力危象以及遗传性运动感觉神经病者的ＰＮＣ均异常，动态观察结果均表现为ＰＮＣ与呼吸功能障碍显著相关；７例睡眠呼吸暂停综合征中４例ＰＮＣ异常；３例慢性阻塞性肺病有２例主要表现为膈肌电位波幅低；憋气、平卧时呼吸困难者患者５例中仅１例表现为单侧膈肌电位波幅低；５例作ＭＥＰ的睡眠呼吸暂停综合征者３例异常、３例慢性阻塞性肺病者的隔ＭＥＰ均正常。结论：ＰＮＣ不仅可客观地评价神经肌肉性呼吸功能障碍、预示疾病过程，而且还可为呼吸系统病变所致呼吸功能障碍提供膈肌功能障碍的其它信息；结合ＰＮＣ及隔ＭＥＰ两者的结果可能有助于判断睡眠呼吸暂停综合征的病变类型。

Objectives:To explore preliminarily the significance of phrenic nerve conduction (PNC) and diaphragmatic motor evoked potentials (MEP) in the evaluation on various respiratory dysfunctions (RDFs). Methods:Thirty four patients (19 patients with neuromuscular disease and 15 with respiratory disorder) were studied. The phrenic nerve was stimulated electrically at the midpoint of the posterior border of the sternomastoid muscle, and the diaphragmatic muscle compound action potential (DCAP) was recorded between the 7th and 8th intercostal space and xiphoid process. MEP were recorded under deep inspiration during magnetic transcranial stimulation (MTS) of the cortex. Results:PNC in patients with myopathy was normal, and that in patients with Guillain Barre syndrome (GBS),hereditary motor and sensory neuropathy (HMSN) and myasthenic crisis was abnormal. PNC in patients with GBS and MG was closely correlated with RDF. Four of 7 patients with sleep apnea syndrome (SAS) had abnormal PNC; Two of three with chronic obstructive pulmonary disease (COPD) showed mainly a decrease in DCAP amplitude; one of five with chest tightness or breathlessness on the supine position showed a low unilateral DCAP amplitude; three of five with SAS showed abnormal MEP and three with COPD had normal MEP. Conclusions:PNC could not only evaluate the neuromuscular RDF objectively and predict the course of the disease, but also provide additional information of diaphragmatic dysfunction for RDF caused by respiratory disease. The combined results of PNC and diaphragmatic MEP might be helpful in judging SAS type.