Protocol paper: kainic acid excitotoxicity-induced spinal cord injury paraplegia in Sprague-Dawley rats

BACKGROUND: Excitotoxicity-induced in vivo injury models are vital to reflect the pathophysiological features of acute spinal cord injury (SCI) in humans. The duration and concentration of chemical treatment controls the extent of neuronal cell damage. The extent of injury is explained in relation to locomotor and behavioural activity. Several SCI in vivo methods have been reported and studied extensively, particularly contusion, compression, and transection models. These models depict similar pathophysiology to that in humans but are extremely expensive (contusion) and require expertise (compression). Chemical excitotoxicity-induced SCI models are simple and easy while producing similar clinical manifestations. The kainic acid (KA) excitotoxicity model is a convenient, low-cost, and highly reproducible animal model of SCI in the laboratory. The basic impactor approximately cost between 10,000 and 20,000 USD, while the kainic acid only cost between 300 and 500 USD, which is quite cheap as compared to traditional SCI method. METHODS: In this study, 0.05 mM KA was administered at dose of 10 µL/100 g body weight, at a rate of 10 µL/min, to induce spinal injury by intra-spinal injection between the T12 and T13 thoracic vertebrae. In this protocol, detailed description of a dorsal laminectomy was explained to expose the spinal cord, following intra-spinal kainic acid administration at desired location. The dose, rate and technique to administer kainic acid were explained extensively to reflect a successful paraplegia and spinal cord injury in rats. The postoperative care and complication post injury of paraplegic laboratory animals were also explained, and necessary requirements to overcome these complications were also described to help researcher. RESULTS: This injury model produced impaired hind limb locomotor function with mild seizure. Hence this protocol will help researchers to induce spinal cord injury in laboratories at extremely low cost and also will help to determine the necessary supplies, methods for producing SCI in rats and treatments designed to mitigate post-injury impairment. CONCLUSIONS: Kainic acid intra-spinal injection at the concentration of 0.05 mM, and rate 10 µL/min, is an effective method create spinal injury in rats, however more potent concentrations of kainic acid need to be studied in order to create severe spinal injuries.

Clinical study of acute spinal spontaneous hematoma / 中华急诊医学杂志

Objective To evaluate the etiology, pathogenesis, clinical manifestation, imaging features, treatments and factors related to prognosis of acute spinal spontaneous hematoma.Methods The clinical data of 38 patients with acute spinal hematoma treated in our hospital from 2011 till now were analyzed retrospectively.Duration of follow-up was 6 months.The factors influencing the prognosis were analyzed.Results Acute epidural hematomas (n=29) were much more common than subdural (n=5), subarachnoid (n=1) and intramedullary (n=3).Most hematomas were located in the cervical and thoracic vertebra regions.The etiology of acute spinal spontaneous hematoma was unknown in most patients.Twenty-nine patients were dealt with surgical intervention and 9 patients were treated conservatively.After 6-month follow up, recovery rate measured by JOA score in patients of spinal injury ASIA level A and B was (51.26 ±38.97), and level C, D and E was (80.33 ±25.83), P<0.05.Recovery rate in patients with hematoma discovered in less then 24 hours treated with surgical decompression was (64.79 ±36.10), and that in those with hematoma present over 24 hours was (34.54 ±30.17), P<0.05.Conclusions Acute spinal hematoma always caused by unknown etiology, and usually manifests itself in a sudden onset of pain and neurological deficits.The early diagnosis mainly depends on MRI.Patients presenting with severe neurologic dysfunction or showing signs of progressive deficit should have immediate surgical intervention. The status of neurological deficits before surgery and the length of interval between onset and surgical intervention are associated with recovery.

Microsurgery of intra-spinal tumor via the quadrant pathway / 西安交通大学学报(医学版)

Objective To investigate the indications,surgical principles and advantages and disadvantages of microsurgery of intra-spinal tumor via the quadrant pathway.Methods We made a retrospective analysis of the clinical data of patients with spinal canal tumors treated via the quadrant pathway from October 2014 to July 201 5. Results Totally 1 6 patients were included.Their tumors were fully removed by microscopic resection,in which there were three epidural cases,twelve subdural extra-medullar cases,and one intra-medullar case.In terms of stage,there were three cases of cervical segment (C3 - C7 ),four cases of thoracic (T1 - T10 ),nine cases of thoracic and lumbar ones (T1 1 - S2 ). In pathology, there were nine cases of neurilemmoma, two cases of neurofibroma,four cases of meningeal tumor and one case of neuroepithelial cyst.The postoperative symptoms and signs of the patients were significantly improved,and no recurrence or complications occurred in the follow-up 2-10 months.Conclusion Quadrant pathway can be used in removing spinal epidural and subdural tumor,which is shorter than two vertebral segments in length,and the cross-sectional area is less than 2/3 of the spinal cord. However,surgery with extensive adhesion and intra-medullary lesions should be performed carefully,and the surgical techniques are more demanding and a longer learning curve is needed.

Retained Intraspinal Bullet: A Rare Case in a Visitor to Malaysia - A Case Report

Firearm injuries to the spine commonly present with acute neurology caused by direct penetration or indirectly from concussive effects of bullet impact on the vertebral column. We report a case of delayed neurologic presentation of retained intra-spinal bullet in a 42 year-old African who had chronic low back pain and sciatica with a past history of gunshot injury to the spine and radiograph revealed a bullet at the L4-5 disc level. Intra-operative exploration showed a fibrous mass around the bullet compressing on the L4 existing nerve root and L5 traversing nerve root. Removal of the retained bullet resulted in a good clinical outcome with complete resolution of symptoms.

Lesiones intramedulares que simulan tumor / Spinal cord lesions that mimic neoplasms

Objetivo. Analizar las características clínicas y neurorradiológicas de las distintas lesiones intramedulares con la finalidad de poder diferenciar las lesiones no-tumorales de las tumorales y reservar la exploración quirúrgica sólo para aquellos pacientes sin diagnósticoy con sintomatología rápidamente progresiva. Material y métodos. Se revisaron las historias clínicas de 44 pacientes operados consecutivamente con diagnóstico presuntivo de tumor intramedular entre enero de 1988 y diciembre de 2007. No se incluyeron en el análisis los tumores bulbomedulares ni los del cono y filum ni tampoco los lipomas, teratomas y quistes dermoides.Resultados. Se identificaron 4 pacientes (9.1%), 3 masculinos y 1 femenino, con edad media de 9 años, que presentaban deterioro neurológico progresivo e IRM espinal compatible con tumor intramedular. El resultado histopatológico confirmó en los cuatro casos lesiones no tumorales: infiltrado inflamatorio inespecífico, edema, micosis y gliosis respectivamente.Conclusiones. El minucioso análisis clínico, de laboratorio y el estudio de las imágenes en IRM puede ayudar a la correcta distinción entre tumores y lesiones no-tumorales evitando la exploración quirúrgica que sólo está justificada en los casos muy dudososacompañados de rápido deterioro neurológico funcional del paciente.

Objective. To analyze the clinic and neuro-imaging characteristicsof the intra spinal lesions in order to differentiate the non-neoplasticlesions from neoplastic lesions and to spare surgical exploration only for non-diagnosed patients with rapid deterioration. Materials and method. Fourty-four medical charts of patientsoperated on spinal cord lesions between January 1988 and December 2007 have been analyzed. Results. In four patients (3 male, 1 female – mean age: 9 years)who were operated with diagnosis of intra-spinal tumor, their lesions turned out to be non-neoplastic: non-specific inflammation, edema, mycosis and gliosis, respectively. Conclusions. The thorough clinical and laboratory investigation together with the study of the imaging can help distinguishbetween non-neoplastic lesions from neoplastic lesions in order to avoid surgical exploration which is only suitable in very doubtful cases with rapid deterioration.

Microsurgical Treatment of Recurrent Intra-spinal Canal Tumors / 中国医师杂志

Objective To explore the microneurosurgical treatment of recurrent intra-spinal canal tumors. Methods The clinical data on the microsurgical parameters, operative procedures, operative efficacy and post-operative complications of 16 cases with recurrent intra-spinal canal tumors from June 1993 to June 2002 were reviewed retrospectively. Results Under the operative microscope, the tumors were totally removed in 10 cases, subtotally in 4 cases, and partially in 2 cases. Fllowed up from 5 months to 8 years, 11 cases recovered well, 4 cases suffered from moderate disability, and 1 case died. Preoperative CT or MRI scan, knowledge of the anatomy and structures, and skillful operative techinique all were important to microsurgical treatment of recurrent intra-spinal canal tumors. Conclusion Once diagnosis of recurrent intra-spinal canal tumors, the operative treatment is effective. Radiation therapy for the malignant tumors or incompletely removed recurrent tumors is necessary.