NEW YORK (Reuters Health) Apr 12 - Repair of damage caused by stroke, cerebral palsy and spinal cord injury may soon be possible, according to two presentations at the American Academy of Neurology's 58th Annual Meeting in San Diego.

Dr Cesar Borlongan, from the Medical College of Georgia in Augusta, and his associates tested the use of bone marrow cells for treating rat models of stroke and cerebral palsy

"We implanted the cells directly into the injured brains at 7 days after injury”, Dr Borlongan explained at a press briefing.

"We've now followed the animals for 56 days, in which they've continued to demonstrate functional improvements," he added. He noted that they observed approximately 25% functional recovery.

"Twenty-five percent recovery may mean that you can get a bedridden stroke patient into a wheelchair, or a wheelchair-bound patient to use a walker," he pointed out. "Those are all significant functional improvements."

He and his associates were puzzled because they observed that only about 1% of the implanted cells survived.

They found that "cells along the rim of injured but living cells around the core of dead tissue remain viable if treated appropriately, and that treatment with bone marrow cells increased survival.

Moreover, the animals did not require immunosuppression, since the bone marrow cells are stem cells.

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In a second presentation, Dr Norbert Weidner, from the University of Regensburg in Germany, described some of the problems that researchers have encountered when using stem cells to treat spinal cord injuries.

"The only way to get recovery is if you can get axons to pass by or through the lesion to connect to the distal spinal cord and reinnvervate target neurons," he explained. In previous attempts at axon regrowth, axons have grown back into the injured area, forming large cysts, or to the sides, with no reattachment to axons beyond the lesion.

To address this problem, Dr Weidner and associates generated “scaffolds” (a complex compound), developed by colleagues at his University.

They then tested the “scaffold” in an animal. They transected rats' spinal cords at the cervical level and then immediately introduced the “scaffold”. The axons grew longitudinally into the material, all the way through the gel in 6 weeks. The researchers add that they have to observe the animals for longer periods to ensure that the axons do in fact reconnect to the distal spinal cord and reconnect to target neurons.

Edited version. Reuters Health Information 2006. © 2006 Reuters Ltd