The standardized exploration of the radial nerve during humeral shaft fixation reduces the incidence of iatrogenic palsy.

BACKGROUND: The purpose of this study is to determine if a standardized protocol for radial nerve handling during humeral shaft repair reduces the incidence of iatrogenic nerve palsy post operatively. METHODS: Seventy-three patients were identified who underwent acute or reconstructive humeral shaft repair with radial nerve exploration as part of the primary procedure for either humeral shaft fracture or nonunion. All patients exhibited intact radial nerve function pre-operatively. A retrospective chart review and analysis identified patients who developed a secondary radial nerve palsy post-operatively. In each case, the radial nerve was identified and mobilized for protection, regardless of whether the implant necessitated the extensile exposure. RESULTS: Fractures were classified according to AO/OTA guidelines and included 23 Type 12A, 11 Type 12B, and 3 Type 12C. Eight patients had periprosthetic fractures and 28 fractures could not be classified. All patients in the cohort were fixed with locking plates. Surgery was indicated for 36 patients with humeral nonunions and 37 patients with acute humeral shaft fractures. Of the 73 patients, 2 (2.7%) developed radial nerve palsy following surgery, one from the posterior approach and one from the anterolateral approach. Both patients exhibited complete recovery of radial nerve function by 6-month follow-up. No significant differences (p > 0.05) were found in any demographic or surgical details between those with and without radial nerve injury. CONCLUSIONS: Nerve exploration identification and protection leads to a low incidence of transient radial nerve palsy compared to the rate reported in the current literature (2.7% compared to 6-24%). Thus, radial nerve exploration and mobilization should be considered when approaching the humeral shaft for acute fracture and nonunion repairs. LEVEL OF EVIDENCE: Level III.

Risk Factors and Prevention of C5 Palsy After Anterior Cervical Decompression and Fusion: Similarity of the Pathomechanism With That After a Posterior Approach.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: The objective of this study was to review clinical and imaging findings after anterior cervical decompression and fusion, as a basis for prevention of C5 palsy. SUMMARY OF BACKGROUND DATA: C5 palsy is a common postoperative complication in spine surgery, but the mechanistic basis for this condition is unknown. MATERIALS AND METHODS: The subjects were 239 patients with cervical myelopathy who underwent anterior cervical decompression and fusion including at C4-C5 disk level at our hospital from 2001 to 2018. Twelve of these patients (5.0%) had C5 palsy postoperatively. Clinical features and imaging findings were compared in patients with and without C5 palsy. RESULTS: In patients with C5 palsy, the sagittal alignment of the cervical spine was kyphotic, the width of the C5 intervertebral foramen was narrower, and the lateral decompressed line was wider beyond the medial part of the Luschka joint. Age, sex, disease, the number of fused segments, decompression width, and anterior shift of the spinal cord did not differ significantly between patients with and without C5 palsy. CONCLUSIONS: These results indicate that the pathomechanism of C5 palsy may be dependent on the location of the lateral decompression line, especially in patients with cervical kyphosis and a narrow C5 intervertebral foramen. Excessive lateral decompression beyond the Luchka joint might lead to C5 root kinking between the intervertebral foramen and posterior edge of vertebra. This pathomechanism may be similar in anterior and posterior approaches. To prevent C5 palsy, the medial line of the Luschka joint should be confirmed intraoperatively and decompression should be performed within the Luschka joints. Alternatively, medial foraminotomy should be used in cases needing wide decompression, such as those with massive ossification of the posterior longitudinal ligament, lateral osteophytes, and symptomatic foraminal stenosis. LEVEL OF EVIDENCE: Level III.

Critical points and effectiveness of prophylactic C4/5 foraminotomy to prevent C5 palsy after posterior cervical spine surgery.

OBJECTIVE: The aim of this study was to clarify the cut-off values of the spinal canal parameters as risk factors for C5 palsy after posterior cervical spine surgery with and without foraminotomy. METHODS: One hundred three consecutive patients (67 males, 36 females; mean age = 66 years, age range = 27-87 years) with cervical myelopathy who underwent posterior cervical spine surgery at our institution were retrospectively reviewed and included in the study. The first consecutive 69 patients who underwent posterior cervical spine surgery with prophylactic bilateral C4/5 foraminotomy were designated as the F (+) group. The subsequent 34 consecutive patients who underwent posterior cervical spine surgery without prophylactic bilateral C4/5 foraminotomy were designated as the F (-) group. All patients were then divided into four subgroups. In the F (+) group, patients with C5 palsy were designated as the F (+) P (+) subgroup (n = 13), while those without C5 palsy were designated as the F (+) P (-) subgroup (n = 56). In the F (-) group, patients with C5 palsy were designated as the F (-) P (+) subgroup (n = 5), while those without C5 palsy were designated as the F (-)P(-) subgroup (n = 29). Receiver operating characteristic curves were used to investigate the cut-off values of the spinal canal parameters for the development of postoperative C5 palsy. The assessed spinal parameters were the gutter positions (GP), laminar inclination angles (LIA), and postoperative cross-sectional areas (CSA) of the dural sac. The risk ratios (RR) of the spinal canal parameters as risk factors for C5 palsy were evaluated. RESULTS: The incidence of C5 palsy was similar between the F (+) group (18.8%) and the F (-) group (14.7%). The cut-off values for each spinal canal parameter in the F (+) group (GP: 0.82-0.84, LIA: 58.9-62.4°, and CSA: 189.5-200 mm2 ) were similar to those in the F (-) group (0.81-0.89, 61.7-62.5°, and 197.5-199.5 mm2, respectively). In the RR results for C5 palsy, the LIA was highest in both groups. The F (+) P (-) subgroup had significantly larger mean CSA at C4/5 and C5/6 (202.3 mm2 and 200.9 mm2, respectively) than the F (-)P(-) subgroup (177.3 mm2 and 178.9 mm2, respectively) (P = 0.0181 and P = 0.0277, respectively). Prophylactic C4/5 foraminotomy did not specifically prevent postoperative C5 palsy due to foraminal stenosis at C4/5. CONCLUSION: C4/5 foraminotomy should not be recommended for avoidance of C5 palsy. Although the bony spinal parameters were similar between the F (+) and F (-) groups, the CSA in the F (+) group was significantly than that in the F (-) group in the patients without C5 palsy.

[Effect of prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery on postoperative C 5 nerve root palsy syndrome].

OBJECTIVE: To investigate the effect of prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery on postoperative C 5 nerve root palsy syndrome. METHODS: The clinical data of patients with cervical spondylotic myelopathy (cervical spinal cord compression segments were more than 3) who met the selection criteria between March 2016 and March 2019 were retrospectively analyzed. Among them, 40 patients underwent prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery (observation group) and 40 patients underwent simple posterior cervical open-door surgery (control group). There was no significant difference between the two groups ( P>0.05) in gender, age, disease duration, Nurick grade of spinal cord symptoms, and preoperative diameter of C 4, 5 intervertebral foramen, Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score. The occurrence of C 5 nerve root paralysis syndrome was recorded and compared between the two groups, including incidence, paralysis time, recovery time, and spinal cord drift. VAS and JOA scores were used to evaluate the improvement of pain and function before operation and at 12 months after operation. RESULTS: The incisions of the two groups healed by first intention, and there was no early postoperative complications such as cerebrospinal fluid leakage. Patients of both groups were followed up 12-23 months, with an average of 17.97 months. C 5 nerve root paralysis syndrome occurred in 8 cases in the observation group (3 cases on the right and 5 cases on the left) and 2 cases in the control group (both on the right). There was significant difference of the incidence (20% vs. 5%) between the two groups ( χ 2=4.114, P=0.043). Except for 1 case in the observation group who developed C 5 nerve root palsy syndrome at 5 days after operation, the rest patients all developed at 1 day after operation; the recovery time of the observation group and the control group were (3.87±2.85) months and (2.50±0.70) months respectively, showing no significant difference between the two groups ( t=-0.649, P=0.104). At 12 months after operation, the JOA score and VAS score of cervical spine in the two groups significantly improved when compared with those before operation ( P<0.05); there was no significant difference in the difference of the cervical spine JOA score and VAS score between at 12 months after operation and before operation and the degree of spinal cord drift between the two groups ( P>0.05). CONCLUSION: Prophylactic C 4, 5 foraminal dilatation can not effectively prevent and reduce the occurrence of postoperative C 5 root palsy, on the contrary, it may increase its incidence, so the clinical application of this procedure requires caution.

Beneficial Effects of Cyclic Ether 2-Butoxytetrahydrofuran from Sea Cucumber Holothuria scabra against Aß Aggregate Toxicity in Transgenic Caenorhabditis elegans and Potential Chemical Interaction.

The pathological finding of amyloid-ß (Aß) aggregates is thought to be a leading cause of untreated Alzheimer's disease (AD). In this study, we isolated 2-butoxytetrahydrofuran (2-BTHF), a small cyclic ether, from Holothuria scabra and demonstrated its therapeutic potential against AD through the attenuation of Aß aggregation in a transgenic Caenorhabditis elegans model. Our results revealed that amongst the five H. scabra isolated compounds, 2-BTHF was shown to be the most effective in suppressing worm paralysis caused by Aß toxicity and in expressing strong neuroprotection in CL4176 and CL2355 strains, respectively. An immunoblot analysis showed that CL4176 and CL2006 treated with 2-BTHF showed no effect on the level of Aß monomers but significantly reduced the toxic oligomeric form and the amount of 1,4-bis(3-carboxy-hydroxy-phenylethenyl)-benzene (X-34)-positive fibril deposits. This concurrently occurred with a reduction of reactive oxygen species (ROS) in the treated CL4176 worms. Mechanistically, heat shock factor 1 (HSF-1) (at residues histidine 63 (HIS63) and glutamine 72 (GLN72)) was shown to be 2-BTHF's potential target that might contribute to an increased expression of autophagy-related genes required for the breakdown of the Aß aggregate, thus attenuating its toxicity. In conclusion, 2-BTHF from H. scabra could protect C. elegans from Aß toxicity by suppressing its aggregation via an HSF-1-regulated autophagic pathway and has been implicated as a potential drug for AD.

Can prophylactic C4/5 foraminotomy prevent C5 palsy after cervical laminoplasty with and without posterior instrumented fusion with maximal expansion?

OBJECTIVE: To prospectively examine whether laminoplasty with maximal expansion induces C5 palsy, even with prophylactic bilateral C4/5 foraminotomy. METHODS: Thirty-five consecutive patients with cervical myelopathy underwent laminoplasty (n = 19: LP group) or posterior decompression and fusion (n = 16: PDF group) with maximal expansion. Prophylactic bilateral C4/5 foraminotomy was performed alternately in consecutive five patients undergoing each type of surgery. In each type of surgery, the first and third consecutive five patients did not undergo foraminotomy (NF subgroup: 20 patients), while the second and fourth consecutive five patients underwent foraminotomy (F subgroup: 15 patients). The widths between the gutters was equivalent to the diameter of the spinal canal, and an inclination angle of the lamina of approximately 90° was created during laminoplasty. The incidence and severity of postoperative C5 palsy were investigated. Patients with a manual muscle testing score for the deltoid muscle and/or biceps brachii muscle of ≤ 2 were diagnosed with severe palsy. RESULTS: The respective incidences of C5 palsy in the F and NF subgroups were 33% and 20% in the LP group and 50% and 20% in the PDF group. Severe palsy occurred in 67% and 0% of patients who had developed palsy in F and NF subgroups, respectively, in the LP group, and in 100% of patients in the PDF group. Furthermore, 40% of the patients with severe palsy took more than 6 months to recover. CONCLUSIONS: Laminoplasty with maximal expansion induced C5 palsy in both the LP and PDF groups, even with the addition of prophylactic bilateral C4/5 foraminotomy.

Hesperidin improves motor disability in rat spinal cord injury through anti-inflammatory and antioxidant mechanism via Nrf-2/HO-1 pathway.

Spinal cord injury (SCI) is associated with inflammation with concurrent oxidative stress and glial activation. The aim of this study was to evaluate whether hesperidin, a representative flavonoid in citrus fruits, ameliorates SCI-induced motor dysfunction and neuro-pathologic degeneration in rat model. Rats received hesperidin (100 mg/kg body weight/daily, oral administration) from 7 days prior to SCI to 7 days post SCI. Behavioral test was done on rats with SCI until 6 weeks. For the study of inflammatory molecules in SCI rats with hesperidin treatment, rats were sacrificed at day 4 post SCI, and spinal cords were collected and studied histopathologically. Behavioral tests on hind-limbs of rats with SCI revealed that treatment of hesperidin in rats with SCI significantly ameliorate the hind-limb paralysis beginning at day 21 post SCI. Hesperidin treatment in rats with SCI reduced the neuropathological changes (e.g., hemorrhage, inflammatory cell infiltration, and tissue loss) and pro-inflammatory cytokines including tumor necrotic factor-α and interleukin-1ß. In addition, oxidative stress related molecules including superoxide dismutase, catalase, nuclear factor erythroid 2-related factor-2 and heme oxygenase-1 were also increased by hesperidin treatment. Furthermore, Fe2+, bilirubin and p38 mitogen activated protein kinase, these by-product of heme catabolism in serum and spinal cord of rats with hesperidin-treatment groups were significantly increased compared with those of vehicle-treatment group. Collectively, this study implies that hesperidin accelerates recovery of locomotor function and tissue repair of damaged spinal cord, with concurrent upregulation of heme oxygenase-1 as far as rat SCI model is concerned.

Limited laminectomy and foraminal decompression combined with internal fixation for treating multi-segment cervical spondylotic myelopathy: Does it effectively improve neurological function and prevent C5 palsy?

Laminectomy is an effective surgical treatment for multi-segment cervical spondylotic myelopathy (M-CSM) but usually results in C5 palsy. Some surgical techniques to restore the spinal sequence, increase the intervertebral foramen diameter, and limit the spinal cord drift distance have been proposed; however, it is unclear whether these procedures can avoid this complication.To investigate the clinical efficacy of limited laminectomy and foraminal decompression with fixation (LLFDF) for improving neurological recovery and preventing C5 palsy.A total of 71 patients with M-CSM were retrospectively analyzed. Thirty-nine of them were treated with LLFDF (group A) and 32 with normal laminectomy with fixation (NLF; group B) after 3 months of formal conservative treatment. Pre- and postoperative neurological function, spinal cord drift distance, cervical curvature index (CCI), and number of C5 palsy cases were recorded and analyzed.There was no significant intergroup difference in the surgical time or intraoperative blood loss (P >.05). The laminectomy widths in groups A and B were 16.7 ±â€Š2.6 mm and 21.8 ±â€Š2.9 mm, respectively (P <.01), while the spinal cord drift distances were 2.3 ±â€Š0.4 mm and 3.6 ±â€Š0.7 mm, respectively (P <.01). The mean Japanese Orthopedic Association score of both groups increased significantly after surgery (P <.01), and no significant difference was noted at any observation time points (P >.05). Both groups demonstrated significant CCI improvements after surgery compared with those before surgery (P <.01). There were 2 cases of C5 palsy in group A (5.1%) and 8 cases in group B (25.0%), and the difference was significant (P <.05).LLFDF can relieve spinal compression and considerably promote neurological recovery. Moreover, it restricts excessive spinal cord back drifting and decreases the incidence of C5 palsy.

Arthroscopic Superior Capsule Reconstruction Can Eliminate Pseudoparalysis in Patients With Irreparable Rotator Cuff Tears.

BACKGROUND: Patients with pseudoparalysis and irreparable rotator cuff tears have very poor function. The authors developed a superior capsule reconstruction (SCR) technique for irreparable rotator cuff tears that restores shoulder stability and muscle balance, improving shoulder function and relieving pain. PURPOSE: To evaluate whether arthroscopic SCR reversed preoperative pseudoparalysis in patients with irreparable rotator cuff tears. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: One hundred consecutive patients with irreparable rotator cuff tears underwent arthroscopic SCR with fascia lata autografts; 7 patients with deltoid weakness from cervical or axillary nerve palsy and 5 with severe presurgical shoulder stiffness were excluded. The remaining 88 were allocated to 3 groups according to their preoperative active shoulder elevation: no pseudoparalysis (45 patients; mean age, 66.2 years; mean tear size, 3.5 cm), moderate pseudoparalysis (28 patients, 68.3 years, 3.5 cm), and severe pseudoparalysis (15 patients, 62.3 years, 4.9 cm). Clinical outcome, active shoulder range of motion, acromiohumeral distance, and healing rate were compared between patients with and without pseudoparalysis, as well as before surgery and at final follow-up (35-110 months). RESULTS: American Shoulder and Elbow Surgeons score, active elevation, active external rotation, and acromiohumeral distance increased significantly after arthroscopic SCR among all patients. Graft healing rates did not differ among the groups ( P = .73): 98% (44 of 45) for no pseudoparalysis, 96% (27 of 28) for moderate pseudoparalysis, and 87% (13 of 15) for severe pseudoparalysis. Pseudoparalysis was reversed in 96% (27 of 28) of patients with preoperative moderate pseudoparalysis and 93% (14 of 15) with preoperative severe pseudoparalysis. Both patients with residual pseudoparalysis postoperatively (1 of 28 with preoperative moderate pseudoparalysis, 1 of 15 with preoperative severe pseudoparalysis) had graft tears. CONCLUSION: Arthroscopic SCR restored superior glenohumeral stability and improved shoulder function among patients with or without pseudoparalysis who had previously irreparable rotator cuff tears. In the absence of postoperative graft tear, arthroscopic SCR reversed preoperative pseudoparalysis. Graft healing rates after arthroscopic SCR did not differ between patients with and without pseudoparalysis.

Operative technique for benign submandibular gland mass without identifying the mandibular branch of the facial nerve.

OBJECTIVE: The marginal mandibular branch of the facial nerve must be protected during surgery for benign diseases of submandibular gland. Methods for protecting the marginal mandibular branch include the nerve identification method and the non-identification method. METHODS: We performed submandibular gland surgery in 138 patients with benign submandibular gland diseases using the non-identification method to preserve the marginal mandibular branch. In brief, the submandibular gland capsule is incised at the inferior border of the gland and detached along the gland parenchyma. The nerve is protected by this procedure without the need for identification. RESULTS: Among 138 patients who underwent this surgical procedure, only 7 patients developed transient paralysis of the lower lip. CONCLUSION: This method of resecting the submandibular gland without identifying the marginal mandibular branch is an effective procedure associated with a low incidence of transient paralysis. Moreover, no patient developed paralysis due to procedural errors.

Does Surgical Intervention or Timing of Surgery Have an Effect on Neurological Recovery in the Setting of a Thoracolumbar Burst Fracture?

Traumatic thoracolumbar burst fractures are one of the most common forms of spinal trauma with the majority occurring at the junctional area where mechanical load is maximal (AOSpine Thoracolumbar Spine Injury Classification System Subtype A3 or A4). Burst fractures entail the involvement of the middle column, and therefore, they are typically associated with bone fragment in the spinal canal, which may cause compression of the spinal cord, conus medullaris, cauda equina, or a combination of these. Fortunately, approximately half of the patients with thoracolumbar burst fractures are neurologically intact due to the wide canal diameter. Recent evidences have revealed that functional outcomes in the long term may be equivalent between operative and nonoperative management for neurologically intact thoracolumbar burst fractures. Nevertheless, consensus has not been met regarding the optimal treatment strategy for those with neurological deficits. The present review article summarizes the contemporary evidences to discuss the role of nonoperative management in the presence of neurological deficits and the optimal timing of decompression surgery for neurological recovery. In summary, although operative management is generally recommended for thoracolumbar fracture with significant neurological deficits, the evidence is weak, and nonoperative management can also be an option for those with solitary radicular symptoms. With regards to timing of operative management, high-quality studies comparing early and delayed intervention are lacking. Extrapolating from the evidence in cervical spine injury leads to an assumption that early intervention would also be beneficial for neurological recovery, but further studies are warranted to answer these questions.

Do Formal Laminectomy and Timing of Decompression for Patients With Sacral Fracture and Neurologic Deficit Affect Outcome?

OBJECTIVES: To identify whether formal sacral decompression provides improvement in outcome for patients with neurologic deficit after sacral fracture compared with patients treated with indirect decompression and whether the timing of surgical decompression influences neurologic outcome? DATA SOURCES: MEDLINE was searched via PubMed using combinations of the following search terms: "Sacral fracture," "Traumatic Sacral fracture," "Sacral fracture decompression," "Sacral fracture time to decompression," "Sacral Decompression." Only clinical studies on human subjects and in the English language were included. STUDY SELECTION: Studies that did not provide sufficient detail to confirm the nature of the sacral injury, treatment rendered, and neurologic outcome were excluded. Studies using subjects less than 18 years of age, cadavers, nonhuman subjects, or laboratory simulations were excluded. All other relevant studies were reviewed in detail. DATA EXTRACTION: All studies were assigned a level of evidence using the grading tool described by the Centre for Evidence-Based Medicine and all studies were analyzed for bias. Both cohorts in articles comparing 2 groups of patients treated differently were included in the appropriate group. Early decompression was defined as before 72 hours. DATA SYNTHESIS: The effect of decompression technique and timing of decompression surgery on partial and complete neurologic recovery was estimated using a generalized linear mixed model to implement a logistic regression with a study-level random effect. CONCLUSIONS: There was no benefit to early decompression within 72 hours and no difference between formal laminectomy and indirect decompression with respect to neurologic recovery.

Cervical laminectomy of limited width prevents postoperative C5 palsy: a multivariate analysis of 263 muscle-preserving posterior decompression cases.

PURPOSE: Between 2006 and 2010, we performed wide laminectomy (wide LAM) alone, with decompression performed between the bilateral medial margin of the zygapophyseal joints, or double-door laminoplasty (DL) combined with wide LAM for cervical compressive myelopathy (CCM). From 2010, instead of wide LAM and DL, we began to perform narrow LAM, where the laminectomy width was no more than 2-3 mm wider than the spinal cord width (SW). This study aimed to elucidate the risk factors for C5 palsy by reviewing surgical outcomes. METHODS: The clinical features and radiological findings of 263 CCM patients with or without C5 palsy were compared. Risk factors for C5 palsy were assessed using logistic regression analysis. The decompression width (DW) was defined as the laminectomy width or the width between the bilateral medial margins of the bony gutters in DL. RESULTS: Narrow LAM reduced the incidence of C5 palsy from 9.2 to 1.2%. DL was performed more frequently in the C5 palsy group. The difference between the DW and the SW (DW - SW) was significantly greater in the C5 palsy group. Posterior spinal cord shift, aging, and the number of consecutive laminae surgically treated were significantly higher in the C5 palsy group. The diameter of the foramen (DF) at C4/5 was significantly smaller in the C5 palsy patients. The logistic regression analysis revealed that DL, DW - SW, DF, and aging were risk factors for C5 palsy. CONCLUSIONS: Cervical laminectomy of limited width prevented postoperative C5 palsy without compromising the functional recovery.

The Accuracy of Multimodality Intraoperative Neuromonitoring to Predict Postoperative Neurologic Deficits Following Cervical Laminoplasty.

BACKGROUND: Intraoperative neuromonitoring (IONM) has been reported to be sensitive and specific in the detection of neurologic injury during spinal surgery. The purpose of this study was to clarify the incidence of C5 palsy using multimodality IONM and to compare the accuracy of multimodality IONM to predict postoperative C5 palsy with isolated transcranial motor evoked potentials (MEPs). METHODS: We retrospectively reviewed 135 consecutive patients at a single institution with cervical spondylotic myelopathy who underwent open door laminoplasty using MEPs combined with somatosensory evoked potentials and free-running electromyography. RESULTS: Multimodality IONM was obtained in 131 cases. Ossification of the posterior longitudinal ligament was present in 19 patients (14.1%). Postoperative C5 palsy occurred in 3 patients (2.2%). Significant MEP alerts occurred in 12 patients. Significant somatosensory evoked potential change was not observed. To predict acute-onset C5 palsy, MEP alerts in the deltoid or biceps had 100% sensitivity and 98.4% specificity. Transient or persistent MEP alerts in the deltoid or biceps had same positive predictive value with sensitivity of 50.0% and specificity 99.2%. CONCLUSIONS: Incidence of any neurologic deficit, including C5 palsy, during laminoplasty while using multimodality IONM was relatively low. MEP alerts in the deltoids or biceps had 100% sensitivity and 98.4% specificity for predicting a postoperative deficit. Somatosensory evoked potentials did not appear to be helpful in predicting postoperative deficits.

Phrenic Nerve Palsy and Regional Anesthesia for Shoulder Surgery: Anatomical, Physiologic, and Clinical Considerations.

Regional anesthesia has an established role in providing perioperative analgesia for shoulder surgery. However, phrenic nerve palsy is a significant complication that potentially limits the use of regional anesthesia, particularly in high-risk patients. The authors describe the anatomical, physiologic, and clinical principles relevant to phrenic nerve palsy in this context. They also present a comprehensive review of the strategies for reducing phrenic nerve palsy and its clinical impact while ensuring adequate analgesia for shoulder surgery. The most important of these include limiting local anesthetic dose and injection volume and performing the injection further away from the C5-C6 nerve roots. Targeting peripheral nerves supplying the shoulder, such as the suprascapular and axillary nerves, may be an effective alternative to brachial plexus blockade in selected patients. The optimal regional anesthetic approach in shoulder surgery should be tailored to individual patients based on comorbidities, type of surgery, and the principles described in this article.

Ethyl pyruvate modulates delayed paralysis following thoracic aortic ischemia reperfusion in mice.

OBJECTIVE: Delayed paralysis is an unpredictable problem for patients undergoing complex repair of the thoracic/thoracoabdominal aorta. These experiments were designed to determine whether ethyl pyruvate (EP), a potent anti-inflammatory and antioxidant agent, might ameliorate delayed paralysis following thoracic aortic ischemia reperfusion (TAR). METHODS: C57BL6 mice were subjected to 5 minutes of thoracic aortic ischemia followed by reperfusion for up to 48 hours. Mice received either 300 mg/kg EP or lactated ringers (LR) at 30 minutes before ischemia and 3 hours after reperfusion. Neurologic function was assessed using an established rodent scale. Spinal cord tissue was analyzed for markers of inflammation (keratinocyte chemoattractant [KC], interleukin-6 [IL-6]), microglial activation (ionized calcium-binding adapter molecule-1 [Iba-1]), and apoptosis (Bcl-2, Bax, and terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL] staining) at 24 and 48 hours after TAR. Nissl body stained motor neurons were counted in the anterior horns sections from L1-L5 segments. RESULTS: Ninety-three percent of the LR mice developed dense delayed paralysis between 40 and 48 hours after TAR, whereas only 39% of EP mice developed delayed paralysis (P < .01). Bcl-2 expression was higher (P < .05) and Iba-1 expression was lower (P < .05) in the EP group only at 24 hours reperfusion. At 48 hours, the number of motor neurons was higher (P < .01) and the number and TUNEL-positive cells was lower (P < .001) in the EP-treated mice. EP decreased the expression of KC (P < .01) and IL-6 (P < .001) at 48 hours after TAR. CONCLUSIONS: The protection provided by EP against delayed paralysis correlated with preservation of motor neurons, higher expression of antiapoptotic molecules, decreased microglial cell activation, and decreased spinal cord inflammation. EP may be a treatment for humans at risk for delayed paralysis.

Moderate hypothermia increased the incidence of delayed paralysis through activation of the spinal microglia in an aortic cross-clamping rat model.

BACKGROUND: Hypothermia reduces immediate paralysis during surgical repair of aortic aneurysms. However, it is unknown what the impact of hypothermia is on delayed paralysis, a serious complication of this type of surgery. METHODS: Sprague-Dawley rats were subjected to occlusion of the descending aorta at different duration under normothermia (38.0±0.5) or hypothermia (33.0±0.5°). Neurologic function was assessed. Motor neuron number, glial activation, and cytokine expression in the spinal cord were examined. Minocycline was administered perioperatively by intraperitoneal injection in the rats subjected to the aorta occlusion. RESULTS: In contrast to normothermia conditions at which immediate paralysis occurred when the duration of aorta occlusion exceeded 11.5min, hypothermia did not induce immediate paralysis if the duration of aorta occlusion was less than 41min. However, delayed paralysis was developed when the duration of aorta occlusion exceeded 18min, and reached peak level when the duration of aorta occlusion was 40min at hypothermia condition. The number of motoneurons was significantly decreased (P<0.05) at 30h postoperation. In addition, microglia was activated, and interleukin-1ß and interleukin-6 levels were upregulated, both of which were co-localized in microglia at 24h postoperation in the hypothermia group. Minocycline treatment attenuated the incidence and degree of paralysis but did not decrease the mortality. CONCLUSIONS: Hypothermia, a neuroprotective strategy in cardiothoracic surgery, increased the incidence of delayed paralysis through activation of spinal microglia and cytokines. Blocking the activated microglia may be a potential intervention to prevent the incidence of delayed paralysis.

Functional Nerve Preservation in Extracranial Head and Neck Schwannoma Surgery.

IMPORTANCE: A schwannoma is an uncommon, benign neurogenic tumor of Schwann cells. Tumor enucleation is the recommended surgical method to preserve function of the original nerve, although enucleation does not guarantee completely intact nerve function after the operation. OBJECTIVE: To establish a strategy for functional preservation in extracranial head and neck schwannoma treatment by using an electromyographic (EMG) system during tumor resection. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study was conducted of 15 patients who underwent surgery for removal of schwannoma tumors between April 1, 2006, and March 31, 2015, at an academic tertiary referral center. Data analysis was conducted from April 3, 2006, to September 15, 2015. Neurogenic tumors were diagnosed according to preoperative findings, and during surgery tumors were exposed and given EMG-controlled electrical stimulation to analyze their origins. In motor nerve cases, the electrical activity of the muscle was measured and recorded by EMG. The tumor was then enucleated by incision along tumor fibers mapped using EMG stimulation. If a nerve bundle was visible, we incised along there and enucleated the tumor. INTERVENTIONS: A strategy using electrical stimulation to improve preservation of nerve function in extracranial head and neck schwannoma operations. MAIN OUTCOMES AND MEASURES: Frequency and duration of postoperative neurologic complications associated with functional preservation surgery with tumor enucleation was evaluated using EMG monitoring according to tumor origin. RESULTS: Of the 15 patients with extracranial schwannoma, 9 (60%) were women (mean [SD] age, 36.3 [15.3] years). All 15 patients underwent surgery using a transcervical approach. The most common nerves of origin were the vagus nerve and the sympathetic chain. In sensory or sympathetic nerve cases, the EMG response was absent. Two of 5 patients with vagus schwannoma had postoperative temporary vocal nerve palsy. These symptoms showed improvement after 1 year. There was no tumor recurrence during the follow-up period in any patient. CONCLUSIONS AND RELEVANCE: The strategy used here demonstrated a method of diagnosis and nerve preservation surgery for extracranial schwannomas. Nerve functionality was preserved in all vagus schwannoma cases. However, preservation of nerve function in sympathetic nerve schwannoma cases remains problematic and needs further investigation.

Significant reduction in the incidence of C5 palsy after cervical laminoplasty using chilled irrigation water.

AIMS: The aim of this study was to determine whether chilled irrigation saline decreases the incidence of clinical upper limb palsy (ULP; a reduction of one grade or more on manual muscle testing; MMT), based on the idea that ULP results from thermal damage to the nerve roots by heat generated by friction during bone drilling. METHODS: Irrigation saline for drilling was used at room temperature (RT, 25.6°C) in open-door laminoplasty in 400 patients (RT group) and chilled to a mean temperature of 12.1°C during operations for 400 patients (low-temperature (LT) group). We assessed deltoid, biceps, and triceps brachii muscle strength by MMT. ULP occurring within two days post-operatively was categorised as early-onset palsy. RESULTS: The incidence of ULP (4.0% vs 9.5%, p = 0.003), especially early-onset palsy (1.0% vs 5.5%, p < 0.001), was significantly lower for the LT group than for the RT group. Multivariate analysis indicated that RT irrigation saline use, concomitant foraminotomy, and opened side were significant predictors for ULP. DISCUSSION: Using chilled irrigation saline during bone drilling significantly decreased the ULP incidence, particularly the early-onset type, and shortened the recovery period for ULP. Chilled irrigation saline can thus be recommended as a simple method for preventing ULP. TAKE HOME MESSAGE: Chilled irrigation during laminoplasty reduces C5 palsy.