Choi I, et al. J Korean Med Sci. 2016 Apr;31(4):479-488. http://dx.doi.org/10.3346/jkms.2016.31.4.479

Earlier reports have revealed that the incidence of posttraumatic hydrocephalus (PTH) is higher among patients who underwent decompressive craniectomy (DC). The aim of this study was to determine the influencing factors for the development of PTH after DC. A total of 693 head trauma patients admitted in our hospital between March 2004 and May 2007 were reviewed. Among thee, we analyzed 55 patients with severe traumatic brain injury who underwent DC. We excluded patients who had confounding variables. The 33 patients were finally enrolled in the study and data were collected retrospectively for these patients. The patients were divided into two groups: non-hydrocephalus group (Group I) and hydrocephalus group (Group II). Related factors assessed were individual Glasgow Coma Score (GCS), age, sex, radiological findings, type of operation, re-operation and outcome. Of the 693 patients with head trauma, 28 (4.0%) developed PTH. Fifty-five patients underwent DC and 13 (23.6%) developed PTH. Eleven of the 33 study patients (30.3%) who had no confounding factors were diagnosed with PTH. Significant differences in the type of craniectomy and re-operation were found between Group I and II. It is suggested that the size of DC and repeated operation may promote posttraumatic hydrocephalus in severe head trauma patients who underwent DC.

Choi I, et al. Yonsei Med J. 2014 Jul;55(4):1063-1071. http://dx.doi.org/10.3349/ymj.2014.55.4.1063

Background: To evaluate paraspinal back muscles of asymptomatic subjects using qualitative and quantitative analysis on CT and MRI and correlate the results with demographic data.Methods: Twenty-nine asymptomatic subjects were enrolled prospectively (age: mean 34.31, range 23–50; 14 men, 15 women) from August 2016 to April 2017. Qualitative analysis of muscles was done using Goutallier’s system on CT and MRI. Quantitative analysis entailed cross sectional area (CSA) on CT and MRI, Hounsfield unit (HU) on CT, fat fraction using two-point Dixon technique on MRI. Three readers independently analyzed the images; intra- and inter-observer agreements were measured. Linear regression and Spearman’s analyses were used for correlation with demographic data.Results: CSA values were significantly higher in men (p < 0.001). Fat fraction was higher (22.53% vs. 14.35%) and HU lower (36.00 vs. 47.43) in women (p < 0.001). Intra- and inter-observer reliabilities of the two methods were greater than 0.8, except for CSA of L5/S1 on MRI; however, regarding quantitative analysis, decreasing HU and increasing fat fraction were correlated with increasing age, female gender and lower lumbar segment (p < 0.001).Conclusion: MRI and CT can be reliably used for qualitative and quantitative analysis of paraspinal back muscles, regarding fat content. Fat fraction and HU showed highest reliabilities.

Spinal cord injury (SCI) is one of the most devastating conditions and many SCI patients suffer neurological sequelae. Stem cell therapies are expected to be beneficial for many patients with central nervous system injuries, including SCI. Adult stem cells (ASCs) are not associated with the risks which embryonic stem cells have such as malignant transformation, or ethical problems, and can be obtained relatively easily. Consequently, many researchers are currently studying the effects of ASCs in clinical trials. The environment of transplanted cells applied in the injured spinal cord differs between the phases of SCI; therefore, many researchers have investigated these phases to determine the optimal time window for stem cell therapy in animals. In addition, the results of clinical trials should be evaluated according to the phase in which stem cells are transplanted. In general, the subacute phase is considered to be optimal for stem cell transplantation. Among various candidates of transplantable ASCs, mesenchymal stem cells (MSCs) are most widely studied due to their clinical safety. MSCs are also less immunogenic than neural stem/progenitor cells and consequently immunosuppressants are rarely required. Attempts have been made to enhance the effects of stem cells using scaffolds, trophic factors, cytokines, and other drugs in animal and/or human clinical studies. Over the past decade, several clinical trials have suggested that transplantation of MSCs into the injured spinal cord elicits therapeutic effects on SCI and is safe; however, the clinical effects are limited at present. Therefore, new therapeutic agents, such as genetically enhanced stem cells which effectively secrete neurotrophic factors or cytokines, must be developed based on the safety of pure MSCs.