Different Strokes for Different
Folks
Here are some promising entrants in the race to restore nerve function to
people with spinal cord injuries:
- Experts at the Functional Electrical Stimulation Center
at the Cleveland Veterans
Affairs Medical Center and Case Western Reserve University in Cleveland have
taken a non-biological approach to nerve regeneration. Using miniaturized
computers, sensors and electrodes, they have replaced the damaged nervous
system with silicon and copper -- a technique known as "neural prostheses."
These nerve substitutes help paraplegics stand and walk, and help
quadriplegics reach and grasp objects. An implanted stimulator, similar to a
cardiac pacemaker, generates electrical impulses that mimic natural movement
patterns. The impulses are transmitted along electrodes to the paralyzed
muscles.
- Since so much nerve destruction occurs during the inflammation that
follows injury, the
Multicenter Animal
Spinal Cord Injury Study, is assessing medicines that might protect
nerves after injury. The fast-track effort will compare methylprednisolone,
a chemical that reduces damage by protecting neurons' cell membranes and is
considered the "gold standard" of treatment for spinal cord injury, to four
other drugs. Under the direction of Wise Young of New York University, the
project is treating rats with various types of spinal cord injuries with
varying dosages of the five drugs.
Protecting neurons in the spinal cord is even more important now that
scientists are learning to rejuvenate cells that are alive but not
functioning, says Douglas Anderson of the University of Florida. "The more
cells you preserve up front, the more you have to turn back on with a graft"
or other technique.
- Acorda, a New York biotechnology firm specializing in spinal-cord
medicines, is about to embark on a trial of the effectiveness of 4-amino
pyradine. 4-AP, one of many pyradine rings with pharmacological properties,
increases the ability of a damaged axon to transmit electrical signals. Ron
Cohen, Acorda's president, says about 70 people with spinal-cord injury have
received it over the past five years. Although, with so many experimental designs, it's not difficult to
tabulate results, he says there has been a striking reduction in a phantom
but excruciating pain that's often felt in the paralyzed zone. The drug has
also reduced severe spasticity, and some patients have regained sensory or
motor functions. The upcoming trials will test various dosing schedules and check for
long-term side effects. Since the drug only compensates for demyelination of
axons, it must be given every day. Although the drug is not perfect, Cohen
says it is "the first therapy ever to appear to restore some neurological
function in people with damaged spinal cord nerves."
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