The effects of intrathecal ketamine on improving sensory-motor function in a rat model of compression spinal cord injury

Abstract

Introduction: The major secondary complications of spinal cord injury (SCI) are neuropathic pain and motor dysfunction, which remained medical challenges for clinicians. Due to the major role of glutamate in excitotoxicity and central sensitization, the present experiment was to evaluate the effects of ketamine (KET), an n-methyl-D-aspartate (NMDA) receptor blocker, on sensory-motor functions in a rat model of clip compression SCI. Methods: Wistar rats were divided into sham, SCI and KET-treated groups. The sham group received laminectomy without any compression lesion. KET and SCI groups were subjected to severe compression injury for 1min with an aneurysm clip and then treated with KET (10mg/kg) or 5% dimethyl sulfoxide (as vehicle), respectively. The rats were assessed by pain-related and motor behavioral tests inclusive of von Frey, acetone drop, hot plate, inclined plane and Basso-Beattie-Bresnahan on day 0 prior to the injury and the 7th, 14th, 21st and 28th days following SCI. Results: KET group compared with the SCI group showed a significant decline in the mechanical allodynia on the 21st and 28th days, and in cold allodynia from the 1st week to the 4th week post-injury. KET treatment improved the motor function but not weight loss and auricle temperature rise during the 4 weeks of follow up from the 1st week until the 4th week. Conclusion: It was ultimately attained that the advantageous effects of intrathecal KET on sensory-motor dysfunction of SCI rats could provide new approaches for KET as a neuroprotective agent toward clinical applications.