Anti-Nogo-A Antibody Therapy Improves Functional Outcome Following Traumatic Brain Injury.

BACKGROUND: Traumatic brain injury (TBI) can cause sensorimotor deficits, and recovery is slow and incomplete. There are no effective pharmacological treatments for recovery from TBI, but research indicates potential for anti-Nogo-A antibody (Ab) therapy. This Ab neutralizes Nogo-A, an endogenous transmembrane protein that inhibits neuronal plasticity and regeneration. OBJECTIVE: We hypothesized that anti-Nogo-A Ab treatment following TBI results in disinhibited axonal growth from the contralesional cortex, the establishment of new compensatory neuronal connections, and improved function. METHODS: We modeled TBI in rats using the controlled cortical impact method, resulting in focal brain damage and motor deficits like those observed in humans with a moderate cortical TBI. Rats were trained on the skilled forelimb reaching task and the horizontal ladder rung walking task. They were then given a TBI, targeting the caudal forelimb motor cortex, and randomly divided into 3 groups: TBI-only, TBI + Anti-Nogo-A Ab, and TBI + Control Ab. Testing resumed 3 days after TBI and continued for 8 weeks, when rats received an injection of the anterograde neuronal tracer, biotinylated dextran amine (BDA), into the corresponding area contralateral to the TBI. RESULTS: We observed significant improvement in rats that received anti-Nogo-A Ab treatment post-TBI compared to controls. Analysis of BDA-positive axons revealed that anti-Nogo-A Ab treatment resulted in cortico-rubral plasticity to the deafferented red nucleus. Conclusions. Anti-Nogo-A Ab treatment may improve functional recovery via neuronal plasticity to brain areas important for skilled movements, and this treatment shows promise to improve outcomes in humans who have suffered a TBI.

Case report and review of literature: Isolated intramedullary spinal neurocysticercosis.

Background: Cases of isolated intramedullary spinal neurocysticercosis are extremely rare. Only 25 cases have been reported before 2022. Due to its rarity, the diagnosis of spinal neurocysticercosis may be missed. Case presentation: We describe a 37-year-old female patient who developed back pain and lower extremity weakness and was found to have an intramedullary thoracic spine cystic lesion. She was taken to the operating room for resection of the lesion. Pathology revealed a larval cyst wall consistent with neurocysticercosis. The patient was started on albendazole and dexamethasone. Her exam improved post-operatively, and she was able to ambulate with minimal difficulty at the time of follow up. Conclusion: The case provides insights on the diagnosis and treatment of isolated intramedullary spinal neurocysticercosis. Review of the literature suggests that combined surgical and medical intervention results in significant improvement in the patient's neurological exam, and decreases morbidity associated with the disease. We propose a treatment paradigm for this rare manifestation of neurocysticercosis.

Evaluation of Sagittal Spinopelvic Balance in Spinal Cord Stimulator Patients.

OBJECTIVE: Spinal cord stimulation (SCS) has become a popular nonopioid pain intervention. However, the treatment failure rate for SCS remains significantly high and many of these patients have poor sagittal spinopelvic balance, which has been found to correlate with increased pain and decreased quality of life. The purpose of this study was to determine if poor sagittal alignment is correlated with SCS treatment failure. MATERIALS AND METHODS: Comparative retrospective analysis was performed between two cohorts of patients who had undergone SCS placement, those who had either subsequent removal of their SCS system (representing a treatment failure cohort) and those that underwent generator replacement (representing a successful treatment cohort). The electronic medical record was used to collect demographic and surgical characteristics, which included radiographic measurements of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Also included were data on pain medication usage including opioid and nonopioid therapies. RESULTS: Eighty-one patients met inclusion criteria, 31 had complete removal, and 50 had generator replacements. Measurement of sagittal balance parameters demonstrated that many patients had poor alignment, with 34 outside normal range for LL (10 vs 24 in removal and replacement cohorts, respectively), 30 for PI (12 [38.7%] vs 18 [36.0%]), 46 for PT (18 [58.1%] vs 28 [56.0%]), 38 for SS (18 [58.1%] vs 20 [40.0%]), and 39 for PI-LL mismatch (14 [45.2%] vs 25 [50.0%]). There were no significant differences in sagittal alignment parameters between the two cohorts. CONCLUSIONS: This retrospective cohort analysis of SCS patients did not demonstrate any relationship between poor sagittal alignment and failure of SCS therapy. Further studies of larger databases should be performed to determine how many patients ultimately go on to have additional structural spinal surgery after failure of SCS and whether or not those patients go on to have positive outcomes.

Intraoperative Assessment of Coronal Balance with Long Cassette Radiographs in Adult Thoracolumbar Deformity Correction.

BACKGROUND: To describe the use of intraoperative anteroposterior long cassette radiographs (APLCRs) to guide kickstand rod application in adult spinal deformity. METHODS: A retrospective chart review was performed to identify patients with adult thoracolumbar and coronal plane deformity undergoing open segmental decompression with spinopelvic fixation and deformity correction between October 2017 and June 2019 who had APLCRs after rod placement. In patients with persistent intraoperative coronal deviations, a kickstand rod was placed. This supplemental rod was anchored to an iliac screw and to the construct via a pair of side-to-side connectors. A distractor was expended between a vice grip plyer on the kickstand and side-to-side connector to apply a lateralizing force to reduce the degree of deviation. RESULTS: Of 15 patients who underwent T3-ilium fusion with spinal deformity correction with intraoperative APLCRs, 7 underwent kickstand placement. Mean preoperative coronal deviation was similar between cohorts (4.3 cm vs. 2.2 cm, P = 0.09), but was greater intraoperatively in the kickstand cohort (4.3 cm vs. 0.6 cm, P < 0.001). Postoperative coronal deviation was similar between groups (2.1 cm vs. 1.8 cm, P = 0.37). Preoperative fractional lumbar curve was significantly greater in patients requiring a kickstand (23° vs. 35°, P = 0.02), but the major thoracolumbar curve was similar between groups (43° vs. 35°, P = 0.14). CONCLUSIONS: Intraoperative APLCRs can help guide application of a kickstand rod in adult thoracolumbar deformity correction. Patients with a greater fractional lumbar curve may derive greater benefit of kickstand usage, independent of major curve magnitude.

"The Circle" Predicts Extent of Fusion for Surgical Correction of Cervical Spinal Kyphotic Deformities: Proof of Concept.

BACKGROUND: Correction of kyphotic deformities of the spine is a common problem faced by spine surgeons. Unfortunately, there are no clear published guidelines available regarding the extent of spinal fusion required to achieve and maintain lasting deformity correction. We aim to share a set of novel radiographic parameters ("the Circle") that can be used as a guideline for determining the extent of fusion required in surgical correction of spinal kyphotic deformity. METHODS: A Google forms survey was distributed among spine surgeons and trainees to evaluate differences in recommended extent of posterior-approach fusions for cervical spinal kyphotic deformities before and after introduction to the Circle. Extent of fusion before and after use of the Circle were qualitatively and quantitatively analyzed. Data were anonymized and stored in a secure database. RESULTS: Twenty-seven neurosurgical attendings (n = 14), residents (n = 9), and fellows (n = 3) responded to the survey. Variance between predicted upper and lower instrumented vertebrae, and length of construct, was statistically significantly decreased after application of the Circle in almost all cases. Respondents rated the ease of use of the Circle an average of 4.2 out of 5 (5 = the most ease). The majority of participants (92 [6%]; n = 25 of 27) stated that they would or would likely use the Circle as a radiographic tool in the surgical planning for correction of cervical spinal kyphotic deformities in the future. CONCLUSIONS: The Circle is a novel set of radiographic parameters that may be used to educate and guide surgical plans and extent of fusion when aiming to correct spinal kyphotic deformities.

Surgical correction of pediatric spinal deformities with coexisting intraspinal pathology: A case report and literature review.

BACKGROUND: Surgical correction of spinal deformities with coexisting intraspinal pathology (SDCIP) requires special consideration to minimize risks of further injury to an already abnormal spinal cord. However, there is a paucity of literature on this topic. Here, the authors present a pediatric patient with a residual pilocytic astrocytoma and syringomyelia who underwent surgical correction of progressive postlaminectomy kyphoscoliosis. Techniques employed are compared to those in the literature to compile a set of guidelines for surgical correction of SDCIP. METHODS: A systematic MEDLINE search was conducted using the following keywords; "pediatric," "spinal tumor resection," "deformity correction," "postlaminectomy," "scoliosis correction," "intraspinal pathology," "tethered cord," "syringomyelia," or "diastematomyelia." Recommendations for surgical technique for pediatric SDCIP correction were reviewed. RESULTS: The presented case demonstrates recommendations that primarily compressive forces on the convexity of the coronal curve should be used when performing in situ correction of SDCIP. Undercorrection is favored to minimize risks of traction on the abnormal spinal cord. The literature yielded 13 articles describing various intraoperative techniques. Notably, seven articles described use of compressive forces on the convex side of the deformity as the primary mode of correction, while only five articles provided recommendations on how to safely and effectively surgically correct SDCIP. CONCLUSION: The authors demonstrated with their case analysis and literature review that there are no clear current guidelines regarding the safe and effective techniques for in situ correction and fusion for the management of pediatric SDCIP.

Improved Functional Outcome After Peripheral Nerve Stimulation of the Impaired Forelimb Post-stroke.

Lack of blood flow to the brain, i.e., ischemic stroke, results in loss of nerve cells and therefore loss of function in the effected brain regions. There is no effective treatment to improve lost function except restoring blood flow within the first several hours. Rehabilitation strategies are widely used with limited success. The purpose of this study was to examine the effect of electrical stimulation on the impaired upper extremity to improve functional recovery after stroke. We developed a rodent model using an electrode cuff implant onto a single peripheral nerve (median nerve) of the paretic forelimb and applied daily electrical stimulation. The skilled forelimb reaching test was used to evaluate functional outcome after stroke and electrical stimulation. Anterograde axonal tracing from layer V pyramidal neurons with biotinylated dextran amine was done to evaluate the formation of new neuronal connections from the contralesional cortex to the deafferented spinal cord. Rats receiving electrical stimulation on the median nerve showed significant improvement in the skilled forelimb reaching test in comparison with stroke only and stroke with sham stimulation. Rats that received electrical stimulation also exhibited significant improvement in the latency to initiate adhesive removal from the impaired forelimb, indicating better sensory recovery. Furthermore, axonal tracing analysis showed a significant higher midline fiber crossing index in the cervical spinal cord of rats receiving electrical stimulation. Our results indicate that direct peripheral nerve stimulation leads to improved sensorimotor recovery in the stroke-impaired forelimb, and may be a useful approach to improve post-stroke deficits in human patients.

Surgical management of atlantoaxial dislocation and cervical spinal cord injury in craniopagus twins.

A case of cervical spinal cord injury in 12-year-old angular craniopagus twins is presented, with a description of the planning and execution of surgical treatment along with subsequent clinical outcome. The injury occurred following a fall from a standing position, resulting in quadriparesis in one of the twins. Imaging revealed severe craniocervical stenosis resulting from a C1-2 dislocation, and T2-weighted hyperintensity of the cervical spinal cord. After custom halo fixation was obtained, a posterior approach was utilized to decompress and instrument the occiput, cervical, and upper thoracic spine with intraoperative reduction of the dislocation. Early neurological improvement was noted during the acute postoperative phase, and 27 months of follow-up demonstrated intact instrumentation with continued neurological improvement to near baseline. The complexity of managing such an injury, inclusive of the surgical, anesthetic, biomechanical, and ethical considerations, is described in detail.

Tarik Syndrome: Reversible Postoperative Blindness Secondary to Occipital Seizures.

BACKGROUND: Postoperative blindness is a devastating surgical complication. Although usually associated with prolonged cardiac and prone spinal operations, it may follow other procedures as well. Postoperative blindness is most commonly caused by a vascular etiology, but it can more rarely be caused by status epilepticus. We have previously reported a case of this phenomenon following a staged spinal deformity surgery. CASE DESCRIPTION: Here we report 2 additional cases following a skull base procedure and a single stage lumbar spine surgery. In all instances, rapid recognition that the patients' blindness was due to occipital seizures resulted in acute antiepileptiform treatment and full restoration of vision. CONCLUSIONS: Although a rare phenomenon, this syndrome, first recognized and described by Tarik F. Ibrahim, should be considered in any patient with postoperative visual impairment.

Cerebellar Hemorrhage Following an Uncomplicated Lumbar Spine Surgery: Case Report.

Remote cerebellar hemorrhage is rare but potentially fatal complication of cranial and spinal surgeries. The pathophysiology of this condition following spinal surgery is thought to be related to venous bleeding from cerebellar sagging and cerebrospinal fluid (CSF) hypotension. Most reported cases in the literature following spinal surgery involve intraoperative CSF leakage. We present a case of remote cerebellar hemorrhage following uncomplicated lumbar spinal decompression and fusion without CSF leakage.

Management of Adolescent Idiopathic Scoliosis: Institutional Experience, Integration into Neurosurgical Practice, and Impact on Resident Training.

OBJECTIVE: Management of adolescent idiopathic scoliosis (AIS) in neurosurgery residency training may have a significant impact on resident experience, even though few trainees are likely to pursue careers in the field of AIS. The impact of this exposure on resident knowledge in adult spinal disease management is the subject of our retrospective analysis. METHODS: An analysis was performed of all adolescent patients undergoing surgical correction of spinal deformity between 2006 and 2016. Patient characteristics, including age at operation, Cobb angles, length of stay, operative time, blood loss, and complications, were collected. Objective benchmarks were created for resident education in the management of AIS. A survey was sent to the last 7 years of graduates to assess the impact of exposure to AIS during neurosurgery training on their current practice. RESULTS: Nine male and 37 female patients ages 11 to 22 years were identified. Neurosurgical residents assisted in all procedures without fellows or surgical assistants. Average operative time was 336 minutes (range, 215-575 minutes), and blood loss per procedure was 603 mL (range, 200-4000 mL). The average Cobb angle correction was 72.2% (range, 35.3%-90.9%). Zero of the past 7 graduates currently treat AIS surgically. All 7 graduates agreed that exposure to AIS during residency enhanced their knowledge of adult spinal disease management. CONCLUSIONS: Treatment of AIS by surgeons with specialized training can be effective and safe. Resident exposure to these patients enhances their understanding of spinal biomechanics and deformity correction, which is applicable to treating AIS and adult spinal deformity.

Morphologic variations of the second cervical vertebra in Down syndrome compared with age-matched peers.

OBJECTIVEAtlantoaxial instability is an important cause of pain and neurological dysfunction in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. This study provides a quantitative analysis of C2 morphology in DS patients compared with their peers without DS to identify differences that must be considered for the safe placement of instrumentation.METHODSA retrospective chart review identified age-matched patients with and without DS with a CT scan of the cervical spine. Three-dimensional reconstructions of these scans were made with images along the axis of, and perpendicular to, the pars, lamina, facet, and transverse foramen of C2 bilaterally. Two of the authors performed independent measurements of anatomical structures using these images, and the average of the 2 raters' measurements was recorded. Pedicle height and width; pars axis length (the distance from the facet to the anterior vertebral body through the pars); pars rostrocaudal angle (angle of the pars axis length to the endplate of C2); pars axial angle (angle of the pars axis length to the median coronal plane); lamina height, length, and width; lamina angle (angle of the lamina length to the median coronal plane); and transverse foramen posterior distance (the distance from the posterior wall of the transverse foramen to the tangent of the posterior vertebral body) were measured bilaterally. Patients with and without DS were compared using a mixed-effects model accounting for patient height.RESULTSA total of 18 patients with and 20 patients without DS were included in the analysis. The groups were matched based on age and sex. The median height was 147 cm (IQR 142-160 cm) in the DS group and 165 cm (IQR 161-172 cm) in the non-DS group (p < 0.001). After accounting for variations in height, the mean pars rostrocaudal angle was greater (50.86° vs 45.54°, p = 0.004), the mean transverse foramen posterior distance was less (-1.5 mm vs +1.3 mm, p = 0.001), and the mean lamina width was less (6.2 mm vs 7.7 mm, p = 0.038) in patients with DS.CONCLUSIONSPatients with DS had a steeper rostrocaudal trajectory of the pars, a more posteriorly positioned transverse foramen posterior wall, and a narrower lamina compared with age- and sex-matched peers. These variations should be considered during surgical planning, as they may have implications to safe placement of instrumentation.

Reversible postoperative blindness caused by bilateral status epilepticus amauroticus following thoracolumbar deformity correction: case report.

Postoperative vision loss (POVL) is a devastating complication and has been reported after complex spine procedures. Anterior ischemic optic neuropathy and posterior optic neuropathy are the 2 most common causes of POVL. Bilateral occipital lobe seizures causing complete blindness are rare and have not been reported as a cause of POVL after spine surgery with the patient prone. The authors report the case of a 67-year-old man without a history of seizures who underwent a staged thoracolumbar deformity correction and developed POVL 6 hours after surgery. Imaging, laboratory, and ophthalmological examination results were nonrevealing. Routine electroencephalography study results were negative, but continuous electroencephalography captured bilateral occipital lobe seizures. The patient developed nonconvulsive status epilepticus despite initial treatment with benzodiazepines and loading doses of levetiracetam and lacosamide. He was therefore intubated for status epilepticus amauroticus and received a midazolam infusion. After electrographic seizure cessation for 48 hours, the patient was weaned off midazolam. The patient was maintained on levetiracetam and lacosamide without seizure recurrence and returned to his preoperative visual baseline status.

Biomechanical assessment of a PEEK rod system for semi-rigid fixation of lumbar fusion constructs.

The concept of semi-rigid fixation (SRF) has driven the development of spinal implants that utilize nonmetallic materials and novel rod geometries in an effort to promote fusion via a balance of stability, intra- and inter-level load sharing, and durability. The purpose of this study was to characterize the mechanical and biomechanical properties of a pedicle screw-based polyetheretherketone (PEEK) SRF system for the lumbar spine to compare its kinematic, structural, and durability performance profile against that of traditional lumbar fusion systems. Performance of the SRF system was characterized using a validated spectrum of experimental, computational, and in vitro testing. Finite element models were first used to optimize the size and shape of the polymeric rods and bound their performance parameters. Subsequently, benchtop tests determined the static and dynamic performance threshold of PEEK rods in relevant loading modes (flexion-extension (F/E), axial rotation (AR), and lateral bending (LB)). Numerical analyses evaluated the amount of anteroposterior column load sharing provided by both metallic and PEEK rods. Finally, a cadaveric spine simulator was used to determine the level of stability that PEEK rods provide. Under physiological loading conditions, a 6.35 mm nominal diameter oval PEEK rod construct unloads the bone-screw interface and increases anterior column load (approx. 75% anterior, 25% posterior) when compared to titanium (Ti) rod constructs. The PEEK construct's stiffness demonstrated a value lower than that of all the metallic rod systems, regardless of diameter or metallic composition (78% < 5.5 mm Ti; 66% < 4.5 mm Ti; 38% < 3.6 mm Ti). The endurance limit of the PEEK construct was comparable to that of clinically successful metallic rod systems (135N at 5 × 10(6) cycles). Compared to the intact state, cadaveric spines implanted with PEEK constructs demonstrated a significant reduction of range of motion in all three loading directions (> 80% reduction in F/E, p < 0.001; > 70% reduction in LB, p < 0.001; > 54% reduction in AR, p < 0.001). There was no statistically significant difference in the stability provided by the PEEK rods and titanium rods in any mode (p = 0.769 for F/E; p = 0.085 for LB; p = 0.633 for AR). The CD HORIZON(®) LEGACY(™) PEEK Rod System provided intervertebral stability comparable to currently marketed titanium lumbar fusion constructs. PEEK rods also more closely approximated the physiologic anteroposterior column load sharing compared to results with titanium rods. The durability, stability, strength, and biomechanical profile of PEEK rods were demonstrated and the potential advantages of SRF were highlighted.

The multiple benefits of minimally invasive spinal surgery: results comparing transforaminal lumbar interbody fusion and posterior lumbar fusion.

Minimally invasive transforaminal lumbar interbody fusion (TLIF) offers equivalent postoperative fusion rates compared to posterior lumbar fusion (PLF) and minimizes the amount of iatrogenic injury to the spinal muscles. The objective of this study was to examine the difference in pain perception, stress, mood disturbance, quality of life, and immunological indices throughout the perioperative course among patients undergoing TLIF and PLF. A prospective, nonrandomized descriptive design was used to evaluate these measures among patients undergoing TLIF (n = 17) or PLF (n = 18) at 1 week prior to surgery (T1), the day of surgery (T2), 24 hours postoperatively (T3), and 6 weeks postoperatively (T4). Among TLIF patients, pain, stress, fatigue, and mood disturbance were significantly decreased at the 6-week followup visit (T4) compared to patients who underwent PLF. The TLIF group also demonstrated significantly higher levels (near baseline) of CD8 cells at T4 than the PLF group. Interleukin-6 levels were significantly higher in the TLIF group as well, which may be an indicator of ongoing nerve regeneration and healing. Knowledge concerning the effect of pain and the psychological experience on immunity among individuals undergoing spinal fusion can help nurses tailor interventions to improve outcomes, regardless of the approach used.

Clinical outcomes of 90 isolated unilateral facet fractures, subluxations, and dislocations treated surgically and nonoperatively.

STUDY DESIGN: A retrospective outcomes study. OBJECTIVE: The purposes of this study were 1) to identify plausible patient and interventional variables that influence the outcome of unilateral facet injuries and 2) to determine if patients return to normal general health status after unilateral facet injuries. SUMMARY OF BACKGROUND DATA: The management of unilateral subaxial cervical facet fractures and dislocations lacks agreement on treatment options and the variables that influence outcome. METHODS: Injury data, radiographs, and outcomes (North American Spine Society Cervical Follow-up Questionnaire and Short Form-36) were collected from 9 centers and 13 surgeons, members of the Spine Trauma Study Group. RESULTS: Causally motor vehicle accidents (49%) and sports (31%) predominated. The C6-C7 level accounted for 60% of injuries and C5-C6 represented 17%. The mean SF-36 PCS score of the operative patients with follow-up >18 months was 6.70 points higher than the mean of the nonoperative patients (P = 0.017). The SF-36 Bodily Pain mean of all patients was 67.2 (SD = 27.6), significantly lower (more pain) than the normative mean of 75.2 (SD = 23.7) (P = 0.014). Nonoperative patients also reported a mean Bodily Pain score of 63.0 (SD = 30.5) that was significantly worse than normative values (P = 0.031). Similarly, the NASS PD mean score for all patients was 84.8 (SD = 17.9), significantly lower than the normative mean of 89.1 (SD = 15.5) (P = 0.014). CONCLUSION: To our knowledge this is the largest reported series of facet injuries to date and the only one using health-related quality of life instruments. Unilateral facet injuries of the subaxial cervical spine led to reported levels of pain and disability that are significantly worse than those of the healthy population. Although further study is required, we suggest that nonoperatively treated patients report worse outcomes than operatively treated patients, particularly at longer follow-up despite having a more benign fracture pattern. The presence of comorbidities, associated injuries, and advanced age adversely impact clinical outcomes.

Occipitocervical fusion with rigid internal fixation: long-term follow-up data in 69 patients.

OBJECT: Instability of the occipitocervical junction may result from degenerative disease, infection, tumor, and trauma. Surgical stabilization involving screw fixation and rigid implants has been found to be biomechanically superior to wire-based implants. To evaluate the long-term results in a large and diverse patient population, the authors prospectively studied a consecutive group of 69 patients. METHODS: All patients underwent occipitocervical fusion in which rigid posterior instrumentation included either plates or rods and screws. Patients ranged in age from 11 to 90 years (mean 51.4 years); there were 34 female and 35 male patients. The mean follow-up duration was 37 months (range 6-66 months). Fifty-seven (83%) of the 69 patients had long-standing occipitocervical anomalies, whereas the remainder presented with acute instability. Basilar invagination was present in 20 patients. RESULTS: Correction of a severe cervical kyphotic deformity was accomplished in six patients. There were no fatalities or medical complications associated with the procedures. During the follow-up period, 87% of the patients exhibited improvement in their myelopathic symptoms; in 13% the symptoms were unchanged. Complications were minimal. Stability was demonstrated on flexion/extension studies in all cases. There were no treatment-related deaths, although four patients died within the follow-up period, all due to progression of metastatic disease. CONCLUSIONS: The authors found that rigid internal fixation of the occipitocervical complex was safe, effective, and technically possible for spine surgeons familiar with occipital bone anatomy and lateral mass fixation.

Immune function, pain, and psychological stress in patients undergoing spinal surgery.

STUDY DESIGN: This study was an exploratory repeated measures design comparing patients undergoing two magnitudes of surgery in the lumbar spine: lumbar herniated disc repair and posterior lumbar fusion. OBJECTIVE: The present study evaluated and compared the effect of perceived pain, perceived stress, anxiety, and mood on natural killer cell activity (NKCA) and IL-6 production among adult patients undergoing lumbar surgery. SUMMARY OF BACKGROUND DATA: Presurgical stress and anxiety can lead to detrimental patient outcomes after surgery, such as increased infection rates. It has been hypothesized that such outcomes are due to stress-immune alterations, which may be further exacerbated by the extent of surgery. However, psychologic stress, anxiety, and mood have not been previously characterized in patients undergoing spinal surgery. METHODS: Pain, stress, anxiety, and mood were measured using self-report instruments at T1 (1 week before surgery), T2 (the day of surgery), T3 (the day after surgery), and T4 (6 weeks after surgery). Blood (30 mL) was collected for immune assessments at each time point. RESULTS: Pain, stress, anxiety, and mood state were elevated at baseline in both surgical groups and were associated with significant reduction in NKCA compared with the nonsurgical control group. A further decrease in NKCA was observed 24 hours after surgery in both surgical groups with a significant rise in stimulated IL-6 production, regardless of the magnitude of surgery. In the recovery period, NKCA increased to or above baseline values, which correlated with decreased levels of reported pain, perceived stress, anxiety, and mood state. CONCLUSIONS: This study demonstrated that patients undergoing elective spinal surgery are highly stressed and anxious, regardless of the magnitude of surgery and that such psychologic factors may mediate a reduction in NKCA.

Effect of prone positioning systems on hemodynamic and cardiac function during lumbar spine surgery: an echocardiographic study.

STUDY DESIGN: Prospective randomized study of patients undergoing spine surgery. OBJECTIVE: To compare changes in hemodynamic and cardiac function after prone positioning using different prone positioners. SUMMARY OF BACKGROUND DATA: Prone positioning decreases blood pressure and cardiac function. Several studies have evaluated changes in cardiac function after prone positioning, and linked them to reduced venous return and ventricular compliance. This study compares different prone positioners using transesophageal echocardiography, and determines their effect on cardiac function and hemodynamics. METHODS: After correction of fluid deficits with the patient under stable anesthesia, hemodynamic and cardiac performance was measured using transesophageal echocardiography. After prone positioning, repeat measurements were performed, and comparisons were made between prone and supine positions. RESULTS: No intergroup differences in demographics, fluid deficit, baseline hemodynamics, or differences from supine to prone position were noted. Cardiac output decreased with the Wilson (Union City, CA) and Siemens AG (Munich, Germany) frames, while cardiac index and stroke volume decreased with the Andrews (Hollywood, CA), Wilson, and Siemens systems. Cardiac preload decreased using the Andrews frame. The Jackson spine table (Hollywood, CA) and bolsters had the least effect on cardiac performance. CONCLUSION: Adequate fluid replacement reduced hypotension and hemodynamic instability after prone positioning. The Jackson spine table and longitudinal bolsters had minimal effects on cardiac function, and should be considered in patients with limited cardiac reserve.