Establishment of an animal model of extra-vertebral foramen cervical nerve entrapment by local electrical stimulation and selection of suitable stimulation parameters

A rat model of extra-vertebral foramen cervical nerve entrapment was established according to the following parameters： stimulation intensity 20 V; frequency 50 Hz; pulse width 200 μs; duration 333 ms/s for a total of 8 hours. After the electrical stimulation, rats exhibited mild muscle fiber atrophy, mild inflammatory exudates, connective tissue local fibrosis and chondrocyte metaplasia. Mean muscle fiber cross-sectional area was reduced. The nerve myelin sheath continuity was partially demyelinated. The microstructure of nerve cells was disrupted and these symptoms worsened with prolongation of the stimulation. The shoulder, neck and upper extremity muscles on the tested side demonstrated positive sharp waves and fibrillations. The severity increased with continuation of the stimulation. High amplitude and polyphasic motor unit potentials gradually appeared. Similar findings were seen in the contralateral side, but at a less severe level.

THE RELATIONSHIP BETWEEN THE INVASION OF PARAPHARYNGEAL SPACES AND THE INVOLVEMENT OF CERVICAL NODES AND POSTERIOR GROUP CRANIAL NERVES IN NASOPHARYNGEAL CARCINOMA

Two hundred cates of nasopharyngeal carcinoma (NPC) admitted to this department from Feb. 1985 to May. 1988 were analysed according to the CT scanning and clinical findings of the primary lesions prior to radiotherapy. The results showed that involvement of parapharyngeal space was very common in NPC, about 80% (160/200 cases) ; particularly unilateral or bilateral retro-styloid spaces, about 69.5% (139/200 cases). It was proposed that patients with NPC had a high Incidence of ipsilateral cervical node metastasis. Contralateral cervical node metastasis was rare. The development of cervical node metastasto in NPC has two modes: one Is direct Infiltration of the retro-stylold space by the lesion; the other Is along the nasopharyngeal lymphatic rete. The data also showed that patients with NPC who presented symptoms of Ⅸ- Ⅲ cranial nerve paralyses always had ipsilateral or bilateral retro- styloid space Infiltrations.

DIAGNOSTIC VALUE OF NERVE ROOT STIMULATION METHOD IN CERVICAL RADICULOPATHY

By means of cervical nerve root stimulation(CRS) method, the amplitudes and latencies of compound motor action potential(CMAP) of brachial biceps and brachial triceps muscles in 41 patients with clinical symptoms and signs of cervical radiculopathy were observed. The amplitudes of CMAPs on the affected side in the patients were obviously lower than on the healthy side and control group, latencies of CMAPs on the affected side were also significantly prolonged. The results showed that CRS was a sensitive method for making a direct determination of proximal nerve roit cinductiin function, and a good aid for diagnosing cervical radiculopathy.

Neuroinflammation Mediates Faster Brachial Plexus Regeneration in Subjects with Cerebral Injury

Our previous investigation suggested that faster seventh cervical nerve(C7)regeneration occurs in patients with cerebral injury undergoing contralateral C7 transfer.This finding needed further verification,and the mechanism remained largely unknown.Here,Tinel’s test revealed faster C7 regeneration in patients with cerebral injury,which was further confirmed in mice by electrophysiological recordings and histological analysis.Furthermore,we identified an altered systemic inflammatory response that led to the transformation of macrophage polarization as a mechanism underlying the increased nerve regeneration in patients with cerebral injury.In mice,we showed that,as a contributing factor,serum amyloid protein A1(SAA1)promoted C7 regeneration and interfered with macrophage polarization in vivo.Our results indicate that altered inflammation promotes the regenerative capacity of the C7 nerve by altering macrophage behavior.SAA1 may be a therapeutic target to improve the recovery of injured peripheral nerves.