Efficacy of Anal Needle Electrodes for Intraoperative Spinal Cord Monitoring with Transcranial Muscle Action Potentials

Study Design Retrospective study. Purpose To examine the relationship between postoperative bowel bladder disorder (BBD) and the efficacy of needle electrodes for the external anal sphincter (EAS) in intraoperative spinal cord monitoring with transcranial muscle action potentials (Tc-MsEP). Overview of Literature Spinal surgery for spina bifida, spinal cord tumor, and spinal tethered cord syndrome has a high rate of postoperative BBD. Monitoring of the EAS with Tc-MsEP is frequently performed during spinal surgery. We initially used plug-surface electrodes for this purpose, but have more recently switched to needle electrodes for the monitoring of the EAS. To date, there has been no comparison between the utility of these electrodes. Methods Waveform derivation, exacerbation of postoperative BBD, and sensitivity and specificity for prediction of BBD by 70% amplitude reduction of EAS activity using needle and plug-surface electrodes were investigated in 239 spine surgeries. The cut-off for the % drop in amplitude for BBD prediction was determined for EAS monitoring using a needle electrode. Results The overall rate of postoperative BBD aggravation was 7.1% (17/239 cases), with the individual rates using needle and plug-surface electrodes being 6.9% (8/116) and 7.3% (9/123), respectively. The waveform derivation rate was significantly higher using needle electrodes (91.3% [106/116] vs. 76.4% [94/123], p <0.01). In patients with baseline waveform detection, the sensitivity and specificity for postoperative BBD were similar in the two groups. With needle electrodes, a cutoff amplitude of Tc-MsEP for the EAS at the end of surgery of 25% of the baseline amplitude had a sensitivity of 89% and specificity of 82% for the prediction of postoperative BBD aggravation. Conclusions The significantly higher waveform derivation rate using needle electrodes suggests that these electrodes are effective for monitoring the EAS in spinal surgery in cases with preoperative BBD

Fusion surgery with instrumentation following carbon ion radiotherapy for primary lumbar tumors: A case series.

Carbon-ion radiotherapy (CIRT) is a useful modality for treatment of primary spinal sarcoma, but osteonecrosis after CIRT may cause pseudoarthrosis that can make subsequent reconstruction surgery difficult. The patients were a 68-year-old man (case 1), a 30-year-old woman (case 2), and a 49-year-old man (case 3) with lumbar lesions. After CIRT, cases 1 and 3 were treated with instrumented spondylectomy and case 2 underwent posterior decompression and instrumentation surgery. Cases 1 and 2 required several salvage procedures because of failure of instrumentation (rod breakage) before bone union was achieved. After multiple revision surgeries, these cases did achieve bone union without tumor recurrence. In contrast, in case 3, only spondylectomy using a pedicle screw system at 20 months after CIRT was required for fusion. At follow-up 11 years postoperatively, CT showed bone union with invasion of autograft bone from the iliac crest into adjacent vertebra. Collapse or a finding of viable tumor cells after CIRT requires surgery such as spondylectomy with reconstruction. Instrumented fixation following CIRT for a lumbar primary tumor should be performed with multilevel anterior support using a sufficient amount of bone graft in posterior fusion levels

A case of delayed hydrocephalus from cerebrospinal fluid leak after resection of a cervical spinal schwannoma

A 39-year old man underwent surgery for recurrence of a cervical schwannoma. At 6 months postoperatively, severe headache appeared and head CT showed marked ventricular dilation that was diagnosed as delayed hydrocephalus. Dural repair surgery using a fascia patch of the tensor fasciae latae muscle was performed after VP shunt. This case shows the importance of awareness of the possibility of delayed hydrocephalus in a patient with severe headache

Utility of the Serum Cystatin C Level for Diagnosis of Osteoporosis among Middle-Aged and Elderly People

Purpose. Osteoporosis is a common age-related disorder leading to increased bone fragility and risk of fracture. Early diagnosis of osteoporosis is a vital step in providing early therapeutic intervention. Serum cystatin C is a marker of early renal dysfunction, a predictor of cardiovascular and inflammatory diseases, and an inhibitor of the differentiation of osteoclast precursor cells. The purpose of this study was to evaluate the relationship between serum cystatin C and osteoporosis. Methods. We enrolled 46 subjects who attended a health checkup and underwent measurement of bone status by quantitative ultrasound and determination of the level of serum cystatin C. A comparative study was conducted between those with and without osteoporosis for all subjects collectively and in two subgroups aged <65 and ≥65 years. Results. Serum cystatin C levels were strongly correlated with age, creatinine, and bone status data, with significant negative correlations with stiffness, T-score, and percentage of young adult mean. Among patients with osteoporosis, serum cystatin C was significantly higher even after adjustment for age and sex, whereas no significant difference was noted in creatinine. For patients aged ≥ 65 years, serum cystatin C was significantly higher in subjects with osteoporosis, although there was no significant difference in age between normal subjects and those with osteoporosis. Conclusions. To the best of our knowledge, this is the first study to demonstrate an association between serum cystatin C and osteoporosis. Serum cystatin C is significantly higher in osteoporosis and in particular may be a useful marker for osteoporosis among middle and elderly people aged ≥ 65 years. Measurement of serum cystatin C can be carried out easily and may contribute to early diagnosis and treatment of osteoporosis