Efficacy of high dose amino acid solution on spinal cord injury induced by focal Nd : YAG laser irradiation

Abstract

In this experimental study, a neodymium:yttrium-aluminium-garnet (Nd:YAG) laser was used to induce highly reproducible focal spinal cord lesions in anaesthetized guinea pigs. The efficacy of high dose amino acid solution (HDAAS) on this injury is investigated. Experiments were performed on 36 animals divided into three groups; sham operated controls, laser irradiated surgical controls, and amino acid groups. Acute responses to injury were evaluated with somatosensory (SSEP) and motor evoked potentials (MEP) and functional recovery was assessed for 8 weeks using the inclined plane technique. In the laser irradiated surgical control group, MEP disappeared one hour after the laser injury, but SSEP revealed changes of amplitude and latency. In this group, the average value of the inclined plane at 24 hours after the laser application was 45.3 +/- 1.4 degrees. In the amino acid group, at the sixth hour of injury, MEP and SSEP changes improved with infusion of HDAAS for 4 hours. This improvement was statistically significant (for latency of SSEP U = 140 p < 0.05). Inclined plane value at 24 hours after the laser application was 65.5 +/- 1.2 degrees in this group. This study showed that application of Nd:YAG laser irradiation on the spinal cord induced spinal cord injury which presented as paraparesis, HDAAS may provide significant therapeutic protection in secondary damage following this injury and may have a potential role in the treatment of acute spinal cord injury.

New Animal Model to Mimic Spastic Cerebral Palsy: The Brain-Damaged Pig Preparation

“… To elicit abnormally propagated electromyographic (EMG) polysynaptic current spreading, three to four segments surrounding the stimulated L4 nerve and the creation of an upper motor lesion (14,15) that is not present in the normal central nervous system of either animals (5) or humans (7). To investigate if there are differences of threshold between both damaged and nondamaged sides. To compare the latencies of motor‐evoked potentials (MEP) in normal specimens and both sides of the brain in damaged specimen preparations. Because latencies of MEPs are strongly dependent on conduction speed that is roughly the same in pigs and humans, we felt that the pig model was a good experimental approach that would closely mimic human clinical conditions (16). …”

“…Because latencies of MEPs are strongly dependent on conduction speed that is roughly the same in pigs and humans, we felt that the pig model was a good experimental approach that would closely mimic human clinical conditions (16).…”