Hypothermia Therapy for Traumatic Spinal Cord Injury: An Updated Review

Abstract

Although hypothermia has shown to protect against ischemic and traumatic neuronal death, its potential role in neurologic recovery following traumatic spinal cord injury (TSCI) remains incompletely understood. Herein, we systematically review the safety and efficacy of hypothermia therapy for TSCI. The English medical literature was reviewed using PRISMA guidelines to identify preclinical and clinical studies examining the safety and efficacy of hypothermia following TSCI. Fifty-seven articles met full-text review criteria, of which twenty-eight were included. The main outcomes of interest were neurological recovery and postoperative complications. Among the 24 preclinical studies, both systemic and local hypothermia significantly improved neurologic recovery. In aggregate, the 4 clinical studies enrolled 60 patients for treatment, with 35 receiving systemic hypothermia and 25 local hypothermia. The most frequent complications were respiratory in nature. No patients suffered neurologic deterioration because of hypothermia treatment. Rates of American Spinal Injury Association (AIS) grade conversion after systemic hypothermia (35.5%) were higher when compared to multiple SCI database control studies (26.1%). However, no statistical conclusions could be drawn regarding the efficacy of hypothermia in humans. These limited clinical trials show promise and suggest therapeutic hypothermia to be safe in TSCI patients, though its effect on neurological recovery remains unclear. The preclinical literature supports the efficacy of hypothermia after TSCI. Further clinical trials are warranted to conclusively determine the effects of hypothermia on neurological recovery as well as the ideal means of administration necessary for achieving efficacy in TSCI.

Updates in Neuroanesthesia

“…Acutely, hypothermia induced either by cold IV saline or local cooling during spinal decompression has been shown to improve functional outcomes in animal models in preliminary studies in the late 60s but little traction was gained in the clinical world after these studies were published. However, following the successful treatment of NFL player Kevin Everett with cooling therapy in the field after a devastating C4 spinal cord injury leaving him paralyzed from the neck down, the clinical literature has begun to examine the possibility of utilizing systemic cooling or localized cooling intraoperatively to improve patient outcomes [65]. While the majority of the research currently is pre-clinical, some small cohort studies have also been published on the topic and so far, the data has largely been supportive of some degree of clinically significant improvement [65].…”

“…However, following the successful treatment of NFL player Kevin Everett with cooling therapy in the field after a devastating C4 spinal cord injury leaving him paralyzed from the neck down, the clinical literature has begun to examine the possibility of utilizing systemic cooling or localized cooling intraoperatively to improve patient outcomes [65]. While the majority of the research currently is pre-clinical, some small cohort studies have also been published on the topic and so far, the data has largely been supportive of some degree of clinically significant improvement [65]. However randomized clinical trials with large sample sizes are still required before this becomes a regular part of clinical practice.…”

Meta-Analysis on the Effect of Hypothermia in Acute Spinal Cord Injury

“…Although the result of an experimental study varies depending on the protocol of the study, hypothermia for acute SCI has shown generally beneficial effects in experimental animal models [ 8 , 21 - 25 ]. Ok et al [ 21 ] reported that both local (28°C for 48 hours) and systemic hypothermia (32°C for 48 hours) had neuroprotective effects after acute SCI in rats, and systemic hypothermia showed a higher neuroprotective effect due to antiapoptotic and anti-inflammatory effects.…”

“…It can be induced as local and systemic hypothermia, and each has its pros and cons. While systemic hypothermia can lead to rapid and persistent hypothermic status through surface cooling, endovascular heat exchange catheters, or cold intravenous infusions, local hypothermia has the advantage of direct irrigation to the intradural or extradural space with cold saline without the risk of systemic consequences [ 8 ]. However, human investigations on the effects of hypothermia have yielded inconsistent results, depending on the clinical circumstances and methods of hypothermia, although animal studies have showed usually positive results.…”

Clinical Trials Targeting Secondary Damage after Traumatic Spinal Cord Injury

“…A case report published in 2010 described the details of how systemic TH was applied, the performance of DS approximately 3 h after SCI, and how the patient made an impressive recovery, converting from AIS A to AIS D four months after the initial injury [ 79 ]. At least three unique clinical trials since 2010, including around 70 patients, have applied systemic TH administration within an average of 8 h after SCI for durations of 12–48 h and reported that around half of the patients improved by at least one AIS grade within several days of SCI [ 32 , 33 , 34 , 80 ]. However, due to the low number of patients and injury heterogeneity, it is not clear whether this level of recovery truly represents improvement compared to the untreated SCI population [ 80 ].…”