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Background Context: Total removal of spinal schwannomas is ideal but it sometimes requires tumor-involved root resection, which increases the risk of postoperative motor deterioration (PMD). Therefore, it is important for clinicians to predict the impact of tumor-involved root resection on motor function in spinal schwannomas.Purpose: To investigate the role of intraoperative electromyographic (EMG) techniques in decision-making of tumor-involved root resection for treating spinal schwannomas.Study Design: A retrospective analysis PATIENT SAMPLE: Sixty-eight patients with spinal schwannomas arising from C5-T1 or L3-S1 roots underwent total resection of schwannoma, including tumoral root.Outcome Measures: Nerve root activation threshold, free-running EMG signals, visual analogue scale, and American Spinal Injury Association scale.Methods: During evoked EMG, nerve root activation threshold for tumoral root stimulation was recorded from muscles anatomically corresponding to tumoral root. During free-running EMG, abnormal EMG signals were identified as irregularly recurrent, monomorphic signals, low frequency (<5 Hz) or absent discharges recorded from muscles innervated by tumoral root. Clinical assessments were performed before, 3 to 5 day's and six months' after operation.Results: Sixteen (16 of 68, 23.5%) patients showed PMD, and muscle strength improved or was not affected in the other 52 patients. Absent myogenic responses were observed in 19 patients with non-PMD, and nerve root activation threshold in non-PMD group was higher than that in PMD group (p<.05). Receiver operating characteristic curve revealed that cut-off value of nerve root activation threshold for distinguishing functional and nonfunctional roots was 11.8 mA. A larger number of patients without PMD than with PMD showed abnormal free-running EMG signals (p<.05). At postoperative 6-months' follow-up, ten patients with muscle weakness after tumor-involved root resection showed functional recovery (full vs. partial recovery: 5 vs. 5), and intraoperative nerve root activation threshold in these patients was higher than that in the other patients without functional recovery (p<.05). Furthermore, there is negative relationship between the duration for full recovery and nerve root activation threshold (p<.05).Conclusions: Both evoked and free-running EMG can be used as supplementary tests for differentiating functional and nonfunctional tumoral roots in spinal schwannomas, and nerve root activation threshold may be also related to prognosis of patients with muscle weakness caused by tumor-involved root resection. Therefore, intraoperative EMG techniques may provide additional references in decision-making of tumor-involved root resection. [ABSTRACT FROM AUTHOR]

Background Context: Both open surgical resection (OSR) and radiofrequency ablation (RFA) have been reported for spinal osteoid osteoma (OO).Purpose: To verify the clinical safety and efficiency of RFA with OSR in treating spinal OO.Study Design: Retrospective cohort study.Patient Sample: Twenty-eight consecutive patients with spinal OO who underwent either RFA or OSR in our institute between September 2006 and December 2016.Outcome Measures: The age, gender, lesion distribution, surgical time, estimated blood loss, complications, local recurrence, visual analogue scale (VAS), and the modified Frankel grade were documented.Methods: We retrospectively reviewed 28 patients with spinal OO who had been treated in our hospital from September 2006 to December 2016. Patients were followed at 3, 6, 12, and 24 months after the index surgery. The minimum follow-up period was 12 months. This study was funded by Peking University Third Hospital (Y71508-01) (¥ 400,000).Results: Twelve and 16 patients were treated with CT-guided percutaneous RFA and OSR, respectively. Spinal OO locations were cervical in 4, thoracic in 4, lumbar in 3, and sacral vertebra in 1 in the RFA group and cervical in 12, thoracic in 1, and lumber in 3 in the OSR group. RFA showed shorter operating time, less blood loss, and less in-hospital stay than open surgery [105.0 ± 33.8 minutes vs. 186.4 ± 53.5 minutes (p < .001), 1 (0 to 5) ml vs. 125 (30-1200) ml (p < .001) and 1 (1-3) days vs. 6 (3-10) days (p < .001), respectively]. At last follow-up, one patient underwent a secondary RFA for recurrence. VAS improvement was 7.5 (3-10) and 6.5 (4-9) (p = .945) in the RFA and OSR groups, respectively. The overall complication rate was 8.3% (1/12) and 18.8% (3/16) in the RFA and OSR groups, respectively.Conclusions: If there is sufficient cerebrospinal fluid between the spinal OO lesion and spinal cord/nerve root (more than 1 mm), RFA is effective and safe for treatment of well-selected spinal OO, showing reduced operating time, blood loss, in-hospital stay, and complications compared to OSR. However, OSR is still recommended in cases with spinal cord/nerve root compression. [ABSTRACT FROM AUTHOR]

Background: The iatrogenic injuries to the lumbar nerves during the fixation the sacroiliac (SI) joint fractures with anterior plates were often reported. No specific method had been reported to avoid it. This study was done to find a safer way of placing the anterior plates and screws for treating the sacroiliac (SI) joint fracture and/or dislocation.Methods: The research was performed using 8 male and 7 female normal corpse pelvic specimens preserved by 10% formalin solution. Try by measuring the horizontal distance from L4, L5 nerve roots to the sacroiliac joint and perpendicular distance from L4, L5 nerve roots to the ala sacralis, the length of L4, L5 nerve roots from intervertebral foramen to the edge of true pelvis, the diameter of L4, L5 nerve roots. The angles between the sacroiliac joint and sagittal plane were measured on the CT images.Results: The horizontal distance between the lateral side of the anterior branches of L4, L5 nerve roots and the sacroiliac joint decreased gradually from the top to the bottom. The widest distances for L4,5 were 2.1 cm (range, 1.74-2.40) and 2.7 cm (range, 2.34-3.02 cm), respectively. The smallest distances for L4, 5 were 1.2 cm (range, 0.82-1.48 cm) and 1.5 cm (range, 1.08-1.74 cm), respectively. On CT images, the angle between the sacroiliac joint and sagittal plane was about 30°.Conclusions: If we use two anterior plates to fix the sacroiliac joint, It is recommended to place one plate on the superior one third part of the joint, with exposing medially no more than 2.5 cm and the other in the middle one third part of the joint, with elevating periosteum medially no more than 1.5 cm. The screws in the sacrum are advised to incline medially about 30° directing to the true pelvis. [ABSTRACT FROM AUTHOR]

Background context The posterior cervical foraminotomy (PCF) may be performed using an open or minimally-invasive (MIS) approach using a tubular retractor. Although there are theoretical advantages such as less blood loss and shorter hospitalizations, there is no consensus in the literature regarding the best approach for treatment. Purpose To assess clinical outcomes of PCF treated with either an open or an MIS approach using a tubular retractor. Study design Systematic literature review and meta-analysis of English language studies for the treatment of cervical radiculopathy treated with foraminotomy. Patient sample Pooled patient results from Level I studies and Level IV retrospective studies. Outcome measures Meta-analysis for clinical success as determined by Odom and Prolo criteria, and visual analog scale scores for arm and neck pain. Methods A literature search of three databases was performed to identify investigations performed in the treatment of PCF with an open or MIS approach. The pooled results were performed by calculating the effect size based on the logit event rate. Studies were weighted by the inverse of the variance, which included both within and between-study errors. Confidence intervals (CIs) were reported at 95%. Heterogeneity was assessed using the Q statistic and I-squared, where I-squared is the estimate of the percentage of error due to between-study variation. Results The initial literature search resulted in 195 articles, of which, 20 were determined as relevant on abstract review. An open foraminotomy approach was performed in six; similarly, an MIS approach was performed in three studies. The pooled clinical success rate was 92.7% (CI: 88.9, 95.3) for open foraminotomy and 94.9% (CI: 90.5, 97.4) for MIS foraminotomy, which was not statistically significant (p=.418). The open group demonstrated relative homogeneity with Q value of 7.6 and I 2 value of 34.3%; similarly, the MIS group demonstrated moderate study heterogeneity with Q value of 4.44 and I 2 value of 54.94%. Conclusions Patients with symptomatic cervical radiculopathy from foraminal stenosis can be effectively managed with either a traditional open or an MIS foraminotomy. There is no significant difference in the pooled outcomes between the two groups. [ABSTRACT FROM AUTHOR]

Abstract: Background context: Decompressive procedures such as laminectomy, facetectomy, and costotransversectomy are routinely performed for various pathologies in the thoracic spine. The thoracic spine is unique, in part, because of the sternocostovertebral articulations that provide additional strength to the region relative to the cervical and lumbar spines. During decompressive surgeries, stability is compromised at a presently unknown point. Purpose: To evaluate thoracic spinal stability after common surgical decompressive procedures in thoracic spines with intact sternocostovertebral articulations. Study design: Biomechanical cadaveric study. Methods: Fresh-frozen human cadaveric spine specimens with intact rib cages, C7–L1 (n=9), were used. An industrial robot tested all spines in axial rotation (AR), lateral bending (LB), and flexion-extension (FE) by applying pure moments (±5 Nm). The specimens were first tested in their intact state and then tested after each of the following sequential surgical decompressive procedures at T4–T5 consisting of laminectomy; unilateral facetectomy; unilateral costotransversectomy, and subsequently instrumented fusion from T3–T7. Results: We found that in all three planes of motion, the sequential decompressive procedures caused no statistically significant change in motion between T3–T7 or T1–T12 when compared with intact. In comparing between intact and instrumented specimens, our study found that instrumentation reduced global range of motion (ROM) between T1–T12 by 16.3% (p=.001), 12% (p=.002), and 18.4% (p=.0004) for AR, FE, and LB, respectively. Age showed a negative correlation with motion in FE (r=−0.78, p=.01) and AR (r=−0.7, p=.04). Conclusions: Thoracic spine stability was not significantly affected by sequential decompressive procedures in thoracic segments at the level of the true ribs in all three planes of motion in intact thoracic specimens. Age appeared to negatively correlate with ROM of the specimen. Our study suggests that thoracic spinal stability is maintained immediately after unilateral decompression at the level of the true ribs. These preliminary observations, however, do not depict the long-term sequelae of such procedures and warrant further investigation. [Copyright &y& Elsevier]

Abstract: The relationship between pain severity and the extent of injury to a peripheral nerve remains elusive. In this study, we compared the pain behavior resulting from partial (1/3–1/2 thickness) and full L5 spinal nerve ligation (SNL) in rats. The decrease in paw withdrawal threshold (PWT) to mechanical stimuli in the hindpaw ipsilateral to the injury was comparable in the two groups on days 3–21 post-injury. However, the decreased PWT recovered earlier in the partial SNL group than in the full SNL group. These observations suggest that the duration of neuropathic pain behavior, but not the early development of mechanical allodynia, is dependent on the extent of nerve injury. On days 6 and 15 post-injury, when the mechanical allodynia was similar in the two groups, systemic morphine induced a greater reduction of mechanical allodynia in the partial SNL group than in the full SNL group. Furthermore, in partial SNL rats, at post-injury time points when they had largely recovered from the neuropathic pain state, systemic administration of naloxone hydrochloride (day 53) or naloxone methiodide (a non-selective peripherally acting opioid receptor antagonist; day 64) or intra-plantar injection of naloxone methiodide rekindled mechanical pain hypersensitivity in the ipsilateral hindpaw, suggesting a prolonged activation of endogenous opioidergic pain-inhibition. Therefore, partial SNL in rats may represent an efficient model for studying the mechanisms of neuropathic pain, testing effects of analgesic/antihyperalgesic drugs, and understanding endogenous pain-inhibitory mechanisms that lead to reversal of the pain behavior with time. [Copyright &y& Elsevier]

Spinal cord injury results not only in motor and sensory dysfunctions, but also in loss of normal urinary bladder functions. A number of clinical studies were focused on the strategies for improvement of functions of the bladder. Completely dorsal root rhizotomy or selective specific S2-4 dorsal root rhizotomy suppress autonomic hyper-reflexia but have the same defects: it could cause detrusor and sphincter over-relaxation and loss of reflexive erection in males. So precise operation needs to be considered. We designed an experimental trail to test the possibility on the basis of previous study. We found that different dorsal rootlets which conduct impulses from the detrusor or sphincter can be distinguished by electro-stimulation in SD rats. Highly selective rhizotomy of specific dorsal rootlets could change the intravesical pressure and urethral perfusion pressure respectively. We hypothese that for neurogenic bladder following spinal cord injury, highly selective rhizotomy of specific dorsal rootlets maybe improve the bladder capacity and the detrusor sphincter dyssynergia, and at the same time, the function of other pelvic organ could be maximize retainment. [ABSTRACT FROM AUTHOR]

Background: Medically refractory trigeminal neuralgia (TN) has been treated with a variety of minimally invasive techniques, all of which have been compared with microvascular decompression. For patients not considered good surgical candidates, percutaneous retrogasserian glycerol rhizotomy (GR) and gamma knife (GK) radiosurgery are two minimally invasive techniques in common practice worldwide and used routinely at Jefferson Hospital for Neuroscience. Using a common pain scale outcomes questionnaire, we sought to analyze efficacies and morbidities of both treatments.Methods and Materials: Between June 1994 and December 2002, 79 patients were treated with GR and 109 patients underwent GK for the treatment of TN. GR was performed with fluoroscopic guidance as an overnight inpatient procedure. GK was performed using a single 4-mm shot positioned at the root exit zone of the trigeminal nerve. Radiation doses of 70-90 Gy prescribed to the 100% isodose line were used. Treatment outcomes including pain response, pain recurrence, treatment failure, treatment-related side effects, and overall patient satisfaction with GK and GR were compared using a common outcomes scale. Using the Barrow Neurologic Institute pain scale, patients were asked to define their level of pain both before and after treatment: I, no pain and no pain medication required; I, occasional pain not requiring medication; IIIa, no pain and pain medication used; IIIb, some pain adequately controlled with medication; IV, some pain not adequately controlled with medication; and V, severe pain with no relief with medication. We used posttreatment scores of I, II, IIIa, and IIIb to identify treatment success, whereas scores of IV and V were considered treatment failure. Results were compiled from respondents and analyzed using SAS software. Statistical comparisons used log-rank test, univariate and multivariate logistic regression, Fisher's exact test, and Wilcoxon test with significance established at p < 0.05.Results: There were 63 evaluable GK patients and 36 evaluable GR patients. The median follow-up time was 34 and 29 months for the GR and GK groups, respectively. The median age was 69 and 70 years and the median number of years with TN pain was 6 and 7 years in the GR and GK groups, respectively. Thirty-one GR (86%) and 58 GK (92%) patients achieved a successful treatment outcome (p = 0.49). The median time to pain relief was < or = 24 h in the GR group and 3 weeks in the GK group (p < 0.001, ordinal logistic regression). Nineteen GR and 26 GK patients experienced pain recurrence or pain never relieved (p = 0.30). The median time to pain recurrence was 5 and 8 months in the GR and GK groups, respectively (p = 0.22). At last follow-up, however, a statistically significant greater number of GR vs. GK patients had failed treatment. Twelve or 33% of GR patients, whereas 8 or 13% of GK patients, had BNI scores of 4 or 5 (p = 0.019, Fisher's exact test). When both initial and late treatment failures were combined, the overall rate of treatment failures was 39% in the GR group and 24% in the GK group (p = 0.023, log-rank). More GR patients developed facial numbness and facial numbness morbidity than GK patients: 19 GR (54%) and 17 GK patients (30%) developed new facial numbness and 12 GR and 7 GK patients reported either somewhat or very bothersome facial numbness (p = 0.018). On multivariate analysis, only treatment with GK and severity of pain before treatment significantly predicted treatment response. GK patients were more likely to have a lower pain score at last follow-up than were GR patients (p = 0.005, OR = 4.3), and patients with pretreatment pain scores of 5 were more likely to have lower posttreatment pain scores than patients with pretreatment pain scores of 4 and lower (p = 0.003, OR = 4.0).Conclusion: Despite greater facial numbness morbidity and a higher failure rate, GR provided more immediate pain relief than GK. GR therefore should be considered in patients with disabling trigeminal pain requiring urgent pain relief. For all other patients, GK provides better long-term pain relief with less treatment-related morbidity, and should therefore be considered the preferred treatment for patients with medically refractory trigeminal neuralgia who are not suitable candidates for microvascular nerve decompression. [ABSTRACT FROM AUTHOR]

Commentary On: Klement MR, Kleeman LT, Blizzard DJ, Gallizzi MA, Eure M, Brown CR. C5 palsy after cervical laminectomy and fusion: does width of laminectomy matter? Spine J 2016:16:462-7 (in this issue). [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to describe the anatomic trajectory of the extracranial needle for percutaneous rhizotomy and correlate this with structures at risk during such a procedure. Methods Six sides from 3 frozen fresh Caucasian heads were used in this study. Hartel anatomic landmarks for percutaneous trigeminal rhizotomy procedures were used. A free hand technique was then used, and intraprocedural visualization of the needle was performed with fluoroscopy. When the procedure was completed, the face was dissected along with the needle pathway up to the foramen ovale in order to evaluate for any damaged structures. Results On all sides, the needle passed lateral to the buccinator muscle and near the parotid duct to then pierce the superior head of the lateral pterygoid muscle to enter the infratemporal fossa. This placed the needle near the buccal nerve on all sides, although no direct injury was noted. Although very near, no branches of the facial nerve or artery were damaged. On 1 side, the maxillary artery was pierced. Conclusions To our knowledge, this is the first study to describe the detailed extracranial anatomic needle pathway using the Hartel approach. Such data might help surgeons better recognize potential complications from such procedures. [ABSTRACT FROM AUTHOR]