| Objectives.1. To investigate the influence of the motor evoked potentials of the diaphragm after upper cervical cord injuries to the variant extent and the value that the prognosis of the respiratory function after upper cervical cord injuries is evaluated by MEP.2. To study the diagnosis and prognostic evaluation of diaphragm function in the patients with upper cervical spinal cord injuries with magnetic stimulated MEP.Methods.1. Forty SD rats, male, weighed 250-270 grams. They were anesthetized with 3% sodium pentobarbital injecting into the abdominal cavity with a dosage at 40mg/Kg. The four limbs were stretched and fixed. A posterior cervical median incision was made. The lamina was removed under the operating microscope. The C3 and C4 spinal cord was injured with modified Allen's method at the level of 10 grams. A 3 mm X 2mm curve cushion was placed over the cervical spinal co so that the injury energy was distributed evenly. Group A (3cm), Group B (5cm), Group C (8cm) and Group D (10cm) were divided according to the height of falling objects. Each group contained 10 rats.The magnetic stimulator of type Mag I (Dantec, Denmark) and the S70 coil with the external diameter of 8.4 cm and the maximal output intensity of the magnetic field of 2.5 Tesla were used. The coil was placed horizontally over the heads of the rats, the external order of the coil was directed to the external occipital protuperance. The stimulating intensity was that of 80% of the maximum. Each time the experiment was repeated two times to attain the stable waves. The electrode was inserted into the diaphragm along the superior border of the 8th rib and the anterior axial line. The land line was placed into the sternum. The impedance of the electrodes were less than 5 k . The filtration wave was 20-200 Hz. And the analyzing time period was 50ms. The signals was magnified, and recorded for further analysis. Each group 'was performed7Allen's injury mode after the control value was measured. The MEPs of the diaphragm were observed at instant (15min), Ihrs, 6hrs, 24hrs, 1 weeks and 4 weeks after injuries.An incision of the right groin was made. The right femoral artery was exposed. A specially designed soft silicon tube was inserted proximally. The arterial blood of 0.2 ml was drawn before and 15min,lhrs, 6hrs, 24hrs, 1 weeks and 4weeks after injury of the C3 and C4. The PH value, the partial pressure of oxygen, partial pressure of carbon dioxide, and the saturation of the blood oxygen were mornitored with type ABL50 blood gas analyzer (Denmark). The index of the blood gas of the rats was observed after upper cervical spinal cords injuries.2. 12 patients with upper cervical spinal cord injuries, including 8 male and 4 female were admitted. The age ranged from 16 years to 59 years with a mean age of 38.7 years. The heights averaged 169 cm with a range from 153 cm to 178 cm. The injured level was Cl in 1 patients, C2 in 3 patients, C3 in 4 cases and C4 in 4 patients. 5 was caused by traffic accidents and 4 were fall from a height. 1 was injured when diving and the other 2 was paralyzed after the operation of the upper cervical spine. The other 10 healthy volunteers were as control group including 7 male and 3 female. They averaged 41.3 years with a range from 21 years to 55 years. The height range was from 156 cm to 177 cm and the average height was 168 cm. None was with limbs numbness, radiculopathy and nervous diseases.All patients were evaluated according to the American Spinal Injury Association (ASIA). The ASIA scorings were Grade B in 6, Grade C in 4 and Grade D in 2. The sense of sacral nerves (the sense of the mucous membrane of the anus) and the motor function (the contraction of the external sphincter muscle of anus) was ranked as the clinical criteria to evaluate whether it was incomplete or complete spinal paralysis. The former included paralysis and tetraplegia and the latter was composed of the central spinal injuries, the Brown-Sequard syndrome, the syndrome of the anterior funiculus injuries and the syndrome of c...
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