Object. An electrical field cathode (negative pole) has trophic and tropic effects on injured spinal cord axons in in vitro and in vivo models of sea lamprey, rodent, and canine spinal cord injury (SCI) and it improves functional outcome. A human oscillating field stimulator (OFS) was built, a Food and Drug Administration (FDA) exemption number was obtained, and institutional review board approval was given for a Phase 1 trial to study 10 humans with complete motor and sensory SCI. Methods. Entry criteria were complete SCI between C-5 and T-10 in patients 18 to 65 years of age and no transection demonstrated on magnetic resonance imaging. All participants received the National Acute Spinal Cord Injury Study (NASCIS) III methylprednisilone protocol. Cord compression and/or vertebral instability was treated before study entry. After treatment complete SCI (according to the American Spinal Injury Association [ASIA] score) remained in all patients with no somatosensory evoked potentials (SSEPs) below the injury level after surgery or for 48 hours. All patients underwent implantation of the OFS within 18 days. Patients underwent evaluation every 2 weeks postimplantation; the OFS was explanted at 15 weeks. Independent neurological status was assessed based on the ASIA score, visual analog scale (VAS) pain score, and SSEPs at 6 weeks, 6 months, and 1 year. Statistical analyses were performed using the two-tailed Wilcoxon test and analysis of variance (ANOVA). There were no complications at insertion of the OFS; there was one case of wound infection after explantation (5% infection rate). One patient was lost to follow up after 6 months. In all 10 patients the mean VAS pain score was 8 at implantation, 2 at 6 months, and in the nine attending follow up for 1 year it remained 2. At 1 year, the mean improvement in light touch was 25.5 points (ANOVA p < 0.001, Wilcoxon test p = 0.02), the mean improvement in pinprick sensation was 20.4 points (ANOVA p < 0.001, Wilcoxon test p = 0.02), and the mean improvement in motor status was 6.3 points (ANOVA p < 0.01, Wilcoxon test p = 0.02). Of five cases involving cervical cord injuries, bilateral upper-extremity SSEPs were normal in one, unilateral upper-extremity SSEPs were recovered in four, bilateral upper-extremity SSEPs were recovered in one, and abnormal lower-extremity SSEPs resolved in one case. In one of the five cases involving thoracic injuries an abnormal lower-extremity SSEP resolved. Conclusions. The use of OFS treatment in patients with SCI is safe, reliable, and easy. Compared with the outcomes obtained in compliant NASCIS III plegic patients, the results of the present study indicate efficacy, and the FDA has given permission for enrollment of 10 additional patients.

Object. Thoracic fracture dislocations reportedly lead to complete paraplegia in 80% of cases. It is rare for these dislocations not to cause neurological deficits, as evidenced by the mere 11 well-documented neurologically intact cases in the English-language literature. Methods. The authors report four cases of thoracic fracture dislocation that remained neurologically intact and discuss 11 other previously published well-documented cases. Overall there were 10 men and five women with a mean age of 34 years (range 17–66 years). Mechanisms of injury included car crash in six, motorcycle crash in seven, plane crash in one, and fall from a horse in one. On admission, neurological deficits were absent in 11 patients, intercostal neuralgia was present in two, and mild lower-extremity weakness/numbness was demonstrated in two. All suffered significant thoracic pain, with 14 patients having sustained rib fractures and eight a hemothorax. The levels of dislocation were T3–4 in two, T5–6 in four, T6–7 in four, T7–8 in two, T8–9 in one, and T9–10 in two. All suffered some degree of lateral translation (mean 12 mm, range 3–27 mm). There were six cases of well-documented anterior subluxation in addition to translation (mean 12 mm, range 4–23 mm), and all involved some degree of fracture imploding of one vertebral body (VB) into an adjacent VB. There were six cases of burst fracture with translation (mean kyphotic angle 38°, range 28–50°). Bilateral pedicle shear fractures were present in all 15 cases at the site of subluxation, thus separating the anterior from the posterior elements and preserving the spinal canal. Only two of the 15 patients suffered complete spondylolisthesis. Five patients underwent successful nonoperative management with prolonged bed rest; at follow-up examination, neurological status remained normal in all five, lesions were radiographically unchanged in three, and there was less subluxation but not anatomical alignment in two. Ten patients underwent successful internal fixation via anterior approaches (two cases), posterior approaches (five cases), and combined approaches (three cases). Neurological status either improved to normal or remained normal except in one case with persistent intercostal neuralgia. Surgery resulted in no change in alignment in three, improved but not anatomical alignment in 11, and normal alignment in one patient. All patients ambulated unassisted by 6 months. Conclusions. In cases in which bilateral pedicle fractures occur at the site of significant thoracic subluxation and/or translation, preservation of the spinal canal and spinal cord neurological function can rarely occur when both the lamina and spinal cord do not dislocate along with the anterior VBs. In these instances, perfect anatomical reduction may require forces that unnecessarily put neurological function at risk and the results appear to justify internal fixation with some or no reduction of deformity.

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Membrane disruption following mechanical injury likely plays a critical role in the pathology of spinal cord trauma. It is known that intracellular calcium is a key factor that is essential to membrane resealing. However, the differential role of calcium influx through the injury site and through voltage dependent calcium channels (VDCC) has not been examined in detail. Using a well-established ex vivo guinea-pig spinal cord white matter preparation, we have found that axonal membrane resealing was significantly inhibited following transection or compression in the presence of cadmium, a non-specific calcium channel blocker, or nimodipine, a specific L-type calcium channel blocker. Membrane resealing was assessed by the changes of membrane potential and compound action potential (CAP), and exclusion of horseradish peroxidase 60 min following trauma. Furthermore, 1 microM BayK 8644, a VDCC agonist, significantly enhanced membrane resealing. Interestingly, this effect was completely abolished when the concentration of BayK 8644 was increased to 30 microM. These data suggest that VDCC play a critical role in membrane resealing. Further, there is likely an appropriate range of calcium influx through VDCC which ensures effective axonal membrane resealing. Since elevated intracellular calcium has also been linked to axonal deterioration, blockage of VDCC is proposed to be a clinical treatment for various injuries. The knowledge gained in this study will likely help us better understand the role of calcium in various CNS trauma, which is critical for designing new approaches or perhaps optimizing the effectiveness of existing methods in the treatment of CNS trauma.

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The interhemispheric, transcallosal, subchoroidal, fornix-sparing approach to gross-total resection of colloid cysts is safe and led to a zero recurrence rate with no permanent neurological sequelae including epilepsy, and these results are superior to any reported results with endoscopy.

Recent studies have demonstrated excellent results in treating isthmic spondylolisthesis via an anterior lumbar interbody fusion (ALIF). The authors describe 3 patients with isthmic spondylolisthesis at L5–S1 who experienced sacral fractures after insertion of a unique, stand-alone anterior interbody fixation device. Three consecutive patients at a single institution were treated for Grade I spondylolisthesis at L5–S1 via a standalone ALIF with insertion of a novel biomechanical interbody device. This device is made of polyetheretherketone and has an integrated system for internal fixation into the vertebral bodies. In each patient a bone morphogenetic protein–soaked sponge was placed for the fusion. The indications for treatment in each patient were back and radicular pain that had been unsuccessfully treated with conservative measures. All 3 patients had reduction of their spondylolisthesis and resolution of their unilateral radiculopathies immediately postoperatively. Within 1 month of surgery, all 3 patients had failure of the device and recurrence of their symptoms. In each case the failure was due to fracture of the anterior portion of the S-1 body. Each patient underwent reduction and pedicle screw fixation at L5–S1. In all cases, there was successful reduction in their recurrent spondylolisthesis and resolution of their radiculopathies. Treatment of Grade I isthmic spondylolisthesis at L5–S1 with stand-alone ALIF and fixation can lead to sacral fracture from high stress loads at that level in the spine, and consideration should be made either for supplemental pedicle screw fixation or a completely posterior approach.