Search Results

You are looking at 1 - 10 of 28 items for

  • Author or Editor: R. John Hurlbert x
Clear All Modify Search
Restricted access

R. John Hurlbert

Object. Since publication in 1990, results from the National Acute Spinal Cord Injury Study II (NASCIS II) trial have changed the way patients suffering an acute spinal cord injury (SCI) are treated. More recently, recommendations from NASCIS III are being adopted by institutions around the world. The purpose of this paper is to reevaluate carefully the results and conclusions of these studies to determine the role they should play in influencing decisions about care of the acutely spinal cord—injured patient.

Methods. Published results from NASCIS II and III were reviewed in the context of the original study design, including primary outcomes compared with post-hoc comparisons. Data were retroconverted from tabular form back to raw form to allow direct inspection of changes in treatment groups. These findings were further analyzed with respect to justification of practice standards.

Although well-designed and well-executed, both NASCIS II and III failed to demonstrate improvement in primary outcome measures as a result of the administration of methylprednisolone. Post-hoc comparisons, although interesting, did not provide compelling data to establish a new standard of care in the treatment of patients with acute SCI.

Conclusions. The use of methylprednisolone administration in the treatment of acute SCI is not proven as a standard of care, nor can it be considered a recommended treatment. Evidence of the drug's efficacy and impact is weak and may only represent random events. In the strictest sense, 24-hour administration of methylprednisolone must still be considered experimental for use in clinical SCI. Forty-eight-hour therapy is not recommended. These conclusions are important to consider in the design of future trials and in the medicolegal arena.

Restricted access
Restricted access
Full access

Taro Kaibara, R. John Hurlbert and Garnette R. Sutherland

Object

Because transoral decompression of the cervicomedullary junction is compromised by a narrow surgical corridor, the adequacy of decompression/resection may be difficult to determine. This is problematic as spinal hardware may obscure postoperative radiological assessment, or the patient may require reoperation. The authors report three patients in whom high-field intraoperative magnetic resonance (MR) images were acquired at various stages during the transoral resection of C-2 lesions causing craniocervical junction compression.

Methods

In all three patients the lesions involved the cervicomedullary junction: one case each of plasmacytoma and metastatic breast carcinoma involving the odontoid process and C-2 vertebral body, and one case of basilar invagination with a Chiari type I malformation. All three patients presented with progressive myelopathy. Surgery-planning MR imaging studies, performed after the induction of anesthesia, demonstrated the lesion and its relationship to the planned surgical corridor. Transoral exposure was achieved through placement of a Crockard retractor system. In one case the soft palate was divided. Interdissection MR imaging revealed that adequate decompression had been achieved in all cases. In the two patients with carcinoma, posterior instrumentation was placed to achieve spinal stabilization. Planned suboccipital decompression and fixation was averted in the third case because MR imaging demonstrated that excellent decompression had been achieved.

Conclusions

Intraoperatively acquired MR images were instrumental in determining the adequacy of surgical decompression. In one patient the MR images changed the planned surgical procedure. Importantly, the acquisition of intraoperative MR images did not adversely affect operative time or neurosurgical techniques, including the instrumentation procedure.

Restricted access

Taro Kaibara, R. John Hurlbert and Garnette R. Sutherland

✓ Transoral decompression of the cervicomedullary junction may be compromised by a narrow corridor in which surgery is performed, and thus the adequacy of surgical decompression/resection may be difficult to determine. This is problematic as the presence of spinal instrumentation may obscure the accuracy of postoperative radiological assessment, or the patient may require reoperation. The authors describe three patients in whom high-field intraoperative magnetic resonance (MR) images were acquired at various stages during the transoral resection of C-2 disease that had caused craniocervical junction compression.

All three patients harbored different lesions involving the cervicomedullary junction: one each of plasmacytoma and metastatic breast carcinoma involving the odontoid process and C-2 vertebral body, and basilar invagination with a Chiari I malformation. All patients presented with progressive myelopathy. Surgical planning MR imaging studies performed after the induction of anesthesia demonstrated the lesion and its relationship to the planned surgical corridor. Transoral exposure was achieved through placement of a Crockard retractor system. In one case the soft palate was divided. Interdissection MR imaging revealed that adequate decompression had been achieved in all cases. The two patients with carcinoma required placement of posterior instrumentation for stabilization. Planned suboccipital decompression and placement of instrumentation were averted in the third case as the intraoperative MR images demonstrated that excellent decompression had been achieved.

Intraoperatively acquired MR images were instrumental in determining the adequacy of the decompressive surgery. In one of the three cases, examination of the images led the authors to change the planned surgical procedure. Importantly, the acquisition of intraoperative MR images did not adversely affect operating time or neurosurgical techniques, including instrumentation requirements.

Restricted access

Mark J. Winder, Kelly Brett and R. John Hurlbert

Spinal cord concussion (SCC) is an uncommon injury resulting in transient quadriplegia. The pathophysiology of SCC has been related to underlying spinal canal stenosis in many cases, yet is not always identified. The authors present the case of a professional ice hockey player, without evidence of canal compromise, who sustained an SCC during a regulation game after being struck by a puck in the upper cervical spine. The unusual mechanism of injury is discussed along with a comprehensive review of the literature.

Restricted access

R. John Hurlbert, Charles H. Tator and Elizabeth Theriault

✓ Electrical stimulation of the mammalian central nervous system (CNS) can result in extensive destruction of tissue unless applied within specific stimulation parameters. Classically, unbalanced or monopolar currents have been avoided in order to minimize these harmful effects. However, direct current (DC) fields have recently been proposed for the treatment of spinal cord injury. Until now, no rigorous analysis has been made of the safety of these fields in the mammalian CNS. The purpose of this study was to determine the amount of chronically applied DC current that can be tolerated by the normal rodent spinal cord stimulated with metal disc electrodes.

Thirty-five normal rats underwent implantation of DC stimulating devices and were allowed to recover for a period of 2 to 12 weeks. The stimulators delivered constant currents of 0 to 50 µA through two disc-shaped platinum/iridium electrodes positioned extradurally at the C-7 and T-3 levels. Following sacrifice of the animals, serial 8-µm cross sections of the spinal cord at the electrode sites were examined microscopically. Evidence of demyelination presumed due to the physical presence of the rostral electrode was seen in animals from most groups including control animals. Pathological changes directly attributable to the applied fields were seen with current as low as 3 µA. It was concluded that DC's of 3 µA or more are harmful to the mammalian CNS with this method of stimulation. In addition, the data suggest that the maximum current density tolerated by the rodent spinal cord is in the order of 75 µA/sq cm. These findings have important implications for the use of chronic DC stimulation in the mammalian CNS.

Restricted access