Paraplegia causes spinal cord shrinkage

Spinal cord injury leads to tissue degradation

07/03/2013

Already 40 days after paraplegia sufferers have less nerve tissue in the spinal cord. Researchers at the University of Zurich and the University Hospital Balgrist have found this out thanks to a new imaging measurement method. In the future, the process could more quickly and better control the efficacy of treatments or rehabilitation.

After 40 days, changes in the spinal cord and brain occur
An injury to the spinal cord changes the spinal cord and brain. So far, however, it was not known how fast the anatomical changes in paraplegic people develop. Researchers at the University of Zurich and the University Hospital Balgrist, in collaboration with colleagues from University College London, have now shown that the changes are already beginning 40 days of acute injury. After twelve months, the spinal cord had even shrunk by seven percent. The researchers published their research results in the journal „Lancet Neurology“.

There has already been an earlier investigation in which the researchers showed that the spinal cord had receded by one third after 14 years of spinal cord injury. The researchers showed that they were surprised, as they had assumed that many years had to pass for the development of such damage above the injury.

Extent of changes in the spinal cord correlates with disease progression
For their current study, the researchers studied 13 acute paraplegic patients and 18 control subjects. Within a year, the subjects were examined every third month by means of magnetic resonance imaging (MRI). The researchers found a rapid decline in the spinal cord, which made seven percent after twelve months. Even with the ascending motor nerve pathways and nerve cells in the sensorimotor cortex, there was a, albeit small, volume loss, the scientists report. The size of the degenerative changes depended on the course of the disease. „Thus, patients with greater loss of nerve tissue recovered less well from injury than those with less“, explained Patrick Freund, Research Assistant at the Center for Paraplegia Balgrist.

The chances of a successful treatment of paraplegia, which leads to the regeneration of the spinal cord, are so far very low. Those affected usually stay paralyzed for a lifetime. However, Freund points out that the new imaging process can quickly reveal the effects of treatments and rehabilitative measures. New therapies could also be better tested for their effectiveness.

Neurorehabilitation method successfully used in paraplegic rats
Another Swiss research team led by Grégoire Courtine of the Swiss Federal Institute of Technology in Lausanne (EPFL) attracted attention last year with a new procedure that allowed paraplegic rats to run again. The neurorehabilitation procedure is based, among other things, on running training and the electrical and chemical stimulation of sleeping neurons in the spinal cord, which receive no information from the brain after an injury or complete transection below the incision.

So far, the method has only been tested on rats. Whether it can actually be used in humans, must be checked in further investigations. The researchers published their findings in the journal „Science“. (Ag)

Image: Dieter Schütz