Magnesium efficacy in a rat spinal cord injury model.

OBJECT: Magnesium has been shown to have neuroprotective properties in short-term spinal cord injury (SCI) studies. The authors evaluated the efficacy of magnesium, methylprednisolone, and magnesium plus methylprednisolone in a rat SCI model. METHODS: A moderate-to-severe SCI was produced at T9-10 in rats, which then received saline, magnesium, methylprednisolone, or magnesium plus methylprednisolone within 10 minutes of injury. The Basso-Beattie-Bresnahan (BBB) motor score was evaluated weekly, beginning on postinjury Day 1. After 4 weeks, the rats' spinal cords were evaluated histologically to determine myelin index and gross white matter sparing. A second experiment was conducted to evaluate the effect of delayed administration (8, 12, or 24 hours postinjury) of magnesium on recovery. RESULTS: The mean BBB scores at 4 weeks showed that rats in which magnesium was administered (BBB Score 6.9 +/- 3.9) recovered better than controls (4.2 +/- 2.0, p < 0.01). Insufficient numbers of animals receiving methylprednisolone were available for analysis because of severe weight loss. The rats given magnesium within 8 hours of injury had better motor recovery at 4 weeks than control animals (13.8 +/- 3.7 vs 8.6 +/- 5.1, p < 0.01) or animals in which magnesium was administered at 12 or 24 hours after injury (p < 0.01). Steroids (30.2%), magnesium (32.3%), and a combination of these (42.3%) had a significant effect on white matter sparing (p < 0.05), but the effect was not synergistic (p > 0.8). Neither steroids nor magnesium had a significant effect on the myelin index (p > 0.1). CONCLUSIONS: The rats receiving magnesium had significantly better BBB motor scores and white matter sparing 4 weeks after moderate-to-severe SCI than control animals. In addition, the groups given steroids only or magnesium and steroids had improved white matter sparing, although the limited numbers of animals reaching the study end point makes it difficult to draw firm conclusions about the utility of steroids in this model. The optimal timing of magnesium administration appears to be within 8 hours of injury.

Paraparesis in a black man brought on by ossification of the ligamentum flavum: case report and review of the literature.

We present the second case of paraparesis secondary to ossification of the ligamentum flavum at the midthoracic region in a black man. Ossification of the ligamentum flavum is frequently described in the Japanese population where the presentation is often in the lower thoracic region. The patient is a 37-year-old black man who, over the 6 months before admission, noticed progressive paraparesis. CT myelogram revealed severe thoracic stenosis by an ossified ligamentum flavum from T4 to T7 with most severe involvement at the T5, T6, and T7 levels. The patient underwent multilevel laminectomies and medial facetectomies from T4 to T7. Over the past decade, ossification of the ligamentum flavum has been reported with increasing frequency in non-Asian patients. This is the third case report in a black man. In addition, ossification of the ligamentum flavum in this particular location is rarely reported. The increased use of advanced neuroimaging techniques in the evaluation of "back pain" may reveal that the prevalence of this condition is higher than expected in non-Asian populations. Improvement in neurologic symptoms secondary to decompressive laminectomies will depend on the degree and duration of spinal cord compression.

Triage for the neurosurgeon.

Triage for the neurosurgeon is a misnomer. The neurosurgeon's role within a mass-casualty situation is one of a subspecialist surgeon instead of a triage officer. Unfortunately because of the events of September 11, 2001, civilian neurosurgeons and other medical specialists have been questioning their role within a mass-casualty situation or, worse, a situation created by biological, chemical, or nuclear weapons. There is no single triage system used exclusively within the United States, and different systems have differing sensitivities, specificities, and labeling methods. The purpose of this article is to discuss varying aspects of triage for both military personnel and civilians and suggest how the neurosurgeon may help shape this process within his or her community. Furthermore, the effects of biological, chemical, and nuclear weapons will be discussed in relation to the triage system.