Peer-reviewed journal articles seldom, if ever, identify by name the patients reported in their published research. Two very recent entries are no exception - but stay tuned.
Released today online, a paper in the Proceedings of the National Academy of Sciences (PNAS) is titled: "Functional reorganization and stability of somatosensory-motor cortical topography in a tetraplegic subject with late neurological recovery." Its senior author is neurologist John McDonald, at the Washington University School of Medicine in St. Louis. The paper's first author is clinical and research neurologist Maurizio Corbetta.
Just three months earlier, the September issue of the Journal of Neurosurgery: Spine ran a story headed: "Late recovery following spinal cord injury: Case report and review of the literature." Its senior author, too, is Washington U's John McDonald.
Who, then, are these two anonymous "subjects?" They are one and the same victim of a neck-breaking accident, namely, the celebrated movie actor Christopher Reeve.
A university press release dated Sept. 20, 2002, lifts the veil by announcing the Spine article under the headline: "Christopher Reeve is first case of partial recovery more than two years after spinal cord injury." Seven years ago, in May 1995, Reeve's horse threw him at a jump. The star sustained a broken neck and severely damaged spinal cord, leaving him quadriplegic - unable to move arms or legs, and with only limited ability to breathe.
"The main message of today's PNAS paper," Corbetta told BioWorld Today, "is that the brain responses after spinal cord injury, and lack of sensation and movement for five years, before we began treating him two years ago, show both evidence for reorganization and stability of the brain activity. Some sensory motor areas of the brain seem to be normally organized, so there appears to be a stability of cortical representations - after the longtime spinal lack of input and output. That surprised us."
Comparisons With Primates, Amputees
"We also found evidence," Corbetta continued, "of the cortical reorganization, which goes along with what has been reported previously in primates and people suffering amputations. So there is both stability and reorganization, which is in the PNAS paper's title. The most far-reaching implication is to enhance the function of surviving fibers in the spinal cord. Our results suggest that in that case the brain might be ready to receive these new inputs. So the question now," he went on, "is whether somebody, some day, will be able with some trick - maybe stem cells - to enhance this connectivity in the spinal cord. And these findings may suggest that the cortex is ready to receive such new input, so that presumably its function may be restored - the dream for the future."
In that future, Corbetta speculated on possible therapeutic approaches developed out of these preliminary spinal wakeup-call findings: " I'm collaborating with people who are closely working on the therapy of spinal cord injury - specifically Dr. McDonald's team here at Washington U. They're really doing the bench work on the treatment side, both clinical and bench. On the clinical side," he added, "they are doing a lot on this original activity-dependent treatment described in the PNAS report.
"The idea," Corbetta explained, "is training patients to sustain physiologically organized muscle activity. So McDonald's co-authors used specially designed stationary bicycles in which electrodes were placed on the thighs of subjects and hooked up to a computer. The electrode firing pattern was synchronized by the computer to release a biking movement in the lower extremities. Our subject actually biked for an hour a day three times a week. In animal studies this pattern of activity has maintained representation, and elicited synaptic axonal sprouting.
"We've done three sets of magnetic resonance imaging experiments," Corbetta recounted. "The first were anatomical, 3-dimensional reconstructions to characterize the site of the lesion."
Electronic MRI-Stimulated Phrenology?
"The second test sets were functional MRI scans," he went on. "We measured the amounts of deoxygenated hemoglobin in the blood, which maps neuronal activity in the human brain. We did these scans when injured subject and uninjured control subject were performing two different sets of tasks, some sensory, some motor. In the sensory tasks we had a modified massage vibrator applied either to the palm of the subject's hand or the sole of his foot. In the foot and the hand we were able to get a good idea of the sensory cortex topography.
"The motor tasks had the subjects visually following a tennis ball projected on a computer screen, either with their tongue movements tracking the ball bouncing back and forth, or with the left forefinger. The face tracked muscle groups above the lesion, and the finger movements below the injury. Our basic idea was to make a map of the topography of the sensory motor cortex in the normal subject and in the subject with spinal cord lesions. The basic results were that the motor system topography was near normal - a surprise because the subject did not move for almost five years. The last couple of years he seemed to regain some function, initially spontaneous. He's been coming here regularly for follow-ups.
"His recovery has been accelerated since we started to do this rehabilitation," Corbetta observed, "although in this paper we don't make any claim regarding possible linkage between his recovery and this therapy. Our purpose here was to describe the brain responses. One surprising finding on the sensory side was in his foot area representation, which was normal both in level of activation and location. We might speculate as to why this stability in the foot. One possible reason is that the foot cannot be reorganized because it's too far away from the face representation. The second theory is that the foot area might have been trained by the biking treatment, and that's why it's more normal than the hand area, which had not been trained as much.
"The fact that there is stability in the brain despite a lack of input from the body," Corbetta summed up, "is very good news. However, longer studies with more patients will be conducted," he concluded, "to learn more about what this means for recovery after spinal cord injury."