Neuroprotective assessment of prolonged local hypothermia post-contusive spinal cord injury in rodent model

Publication date: Available online 23 October 2017
Source:The Spine Journal
Author(s): Daniel TEH Boon Loong, Soo Min CHUA, Ankshita PRASAD, Ioannis KAKKOS, Wenxuan JIANG, Yue MU, Xiaogang LIU, Angelo Homayoun ALL
Background ContextWhile general hypothermia is recognised as a clinically applicable neuroprotective intervention, acute moderate local hypothermia post-contusive Spinal Cord Injury (SCI) is being considered a more effective approach. Previously, we have investigated the feasibility and safety of inducing prolonged local hypothermia in the Central Nervous System of rodent model.PurposeHere, we aimed to verify the efficacy and neuroprotective effects of 5 and 8 hours local moderate hypothermia (30±0.5^°C) induced two hours after moderate thoracic contusive SCI in rats.Study DesignRats were induced with moderate SCI (12.5mm) at its T8 section. Local hypothermia (30 ± 0.5°C) was induced 2 hours after injury induction with an M-shaped copper tube with flow of cold water (12°C), from the T6 till T10 region. Experiment groups were divided into 5 hours and 8 hours hypothermia treatment respectively, while normothermia control group underwent no hypothermia treatment.MethodsThe neuroprotective effects were assessed through objective weekly Somatosensory Evoked Potential (SSEP) and motor behaviour (BBB scoring) monitoring. Histology on spinal cord was performed to at the end of Day 56. All authors declared no conflict of interest. This work was supported by the Singapore Institute for Neurotechnology Seed Fund (R-175-000-121-733), National University of Singapore, Ministry of Education, Tier 1 (R-172-000-414-112.).ResultsOur results show significant SSEP amplitudes recovery in local hypothermia groups starting from Day 14 post-injury onwards for 8 hours treatment group, which persisted up to Day 28 and 42, while 5 hours group showed significant improvement only at Day 42. The functional improvement plateaued after Day 42 as compared to control group of SCI with normothermia. This was supported by both 5 hours and 8 hours improvement in locomotion as measured by BBB scores. Local hypothermia also observe insignificant changes in its SSEP latency, as compared to control. In addition, 5 and 8 hours hypothermia rats spinal cord showed higher percentage of parenchyma preservation.ConclusionsEarly local moderate hypothermia can be induced for extended periods of time post-SCI in rodent model. Such intervention improves functional electrophysiological outcome and motor behaviour recovery for long-lasting till eight weeks.



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