Clinical Study On Evaluation Of Characteristic Changes In Phrenic Nerve Electrophysiology And Inspiratory Function In Patients With Stroke

Objective: To observe the characteristic changes in phrenic nerve electrophysiology and inspiratory function in patients with stroke.To explore the neurophysiological mechanisms of respiratory dysfunction in Patients with Stroke,and provide a basis for assessment of respiratory function and long-term prognosis in patients with stroke.Methods: Examination of Phrenic nerve motor conduction and inspiratory function were performed in 42 healthy subjects and 86 patients with 2 weeks-5 years after stroke aged 38-80.The phrenic nerve motor conduction indexes such as latency,amplitude,minimum electrical stimulation intensity and inspiratory function indexes: mean and maximum of the muscle strength index,the inspiratory peak velocity and the inspiratory volume were recorded,as well as basic information such as gender,age,height,weight,chest circumference,smoking history were collected to analyze the changes of electrophysiological test and inspiratory function between both sides of patients and healthy subjects.Results:(1)There were no statistical differences in general information between stroke and control group.(2)Inspiratory function: compared with control group,the muscle strength index,inspiratory peak velocity and inspiratory volume of stroke group decreased significantly(P<0.05).(3)Phrenic nerve motor conduction in stroke group: compared with the unaffected side,the latency of motor conduction on affected side was prolonged and the CMAP amplitude was decreased(P<0.05).(4)Phrenic nerve motor conduction in control group: there was no significant difference between left and right sides(P>0.05).Male,smokers showed higher latency and amplitude(P<0.05).(5)Phrenic nerve motor conduction in both groups: The latency on affected side of stroke group was prolonged obviously than control group(P<0.05),but there was no significant difference in amplitude(P>0.05).The amplitude on unaffected side was higher obviously than control group(P<0.05),but there was no difference in latency(P>0.05).The minimum electrical stimulation intensity needed for maxmum amplitude of CMAP of stroke group was higher than control group(P<0.05).(6)There were no further changes of phrenic nerve conduction and inspiratory function between less than 3 months,3-6 months and more than 6 months of the course of stroke.Conclusions: Stroke patients showed decresed inspiratory function,prolonged latency and decreased excitability of phrenic nerve motor conduction,The electrophysiological test may provide objective evidence for diaphragmatic function evaluation after stroke.