Cervical spondylotic myelopathy and driving abilities: defining the prevalence and long-term postoperative outcomes using the Quality Outcomes Database.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) can cause significant difficulty with driving and a subsequent reduction in an individual's quality of life due to neurological deterioration. The positive impact of surgery on postoperative patient-reported driving capabilities has been seldom explored. METHODS: The CSM module of the Quality Outcomes Database was utilized. Patient-reported driving ability was assessed via the driving section of the Neck Disability Index (NDI) questionnaire. This is an ordinal scale in which 0 represents the absence of symptoms while driving and 5 represents a complete inability to drive due to symptoms. Patients were considered to have an impairment in their driving ability if they reported an NDI driving score of 3 or higher (signifying impairment in driving duration due to symptoms). Multivariable logistic regression models were fitted to evaluate mediators of baseline impairment and improvement at 24 months after surgery, which was defined as an NDI driving score < 3. RESULTS: A total of 1128 patients who underwent surgical intervention for CSM were included, of whom 354 (31.4%) had baseline driving impairment due to CSM. Moderate (OR 2.3) and severe (OR 6.3) neck pain, severe arm pain (OR 1.6), mild-moderate (OR 2.1) and severe (OR 2.5) impairment in hand/arm dexterity, severe impairment in leg use/walking (OR 1.9), and severe impairment of urinary function (OR 1.8) were associated with impaired driving ability at baseline. Of the 291 patients with baseline impairment and available 24-month follow-up data, 209 (71.8%) reported postoperative improvement in their driving ability. This improvement seemed to be mediated particularly through the achievement of the minimal clinically important difference (MCID) in neck pain and improvement in leg function/walking. Patients with improved driving at 24 months noted higher postoperative satisfaction (88.5% vs 62.2%, p < 0.01) and were more likely to achieve a clinically significant improvement in their quality of life (50.7% vs 37.8%, p < 0.01). CONCLUSIONS: Nearly one-third of patients with CSM report impaired driving ability at presentation. Seventy-two percent of these patients reported improvements in their driving ability within 24 months of surgery. Surgical management of CSM can significantly improve patients' driving abilities at 24 months and hence patients' quality of life.

Methylprednisolone Following Minimally Invasive Lumbar Decompression: A Large Prospective Single-Institution Study.

STUDY DESIGN: Prospective randomized. OBJECTIVE: Intraoperative methylprednisolone is a common adjunct following microscopic laminectomy/microdiscectomy. The goal of epidural instillation is a rapid symptomatic reduction in irritation of neural elements. There is inconsistent data supporting its use intraoperatively. To understand whether this maneuver results in any clinical effect, we performed a multiyear prospective study. SUMMARY OF BACKGROUND DATA: Previous work has demonstrated equivocal effects on pain with a suggestion of an increased risk of complication. These studies tend to suffer from small sample sizes and short follow-ups. MATERIALS AND METHODS: Study obtained IRB approval. During the study period from 2013 to 2019, nearly equivalent numbers of patients who had received steroids during MIS decompressions were followed. Primary outcomes included pain (visual analog scale) and disability [Oswestry Disability Index (ODI)] at 2 weeks and 4 months. Secondary outcomes included complications, readmissions, and reoperation rates during the study period. RESULTS: Four hundred eighty-six patients were followed for a mean follow-up of 5.17 years. The index case was more likely to be a revision surgery in the steroid group. Across all patients, there was no difference in pain at 2 weeks or 4 months. Disability was reduced at 2 weeks in the steroid group (ODI: 16.71 vs . 21.02, P = 0.04) but not at 4 months. By subgroup analysis, this is largely explained by ODI reduction in patients with high preoperative ODI (13.00 vs . 43.43, P = 0.03). Patients in the steroid cohort were more likely to undergo subsequent spinal surgery during the study period. CONCLUSION: Methylprednisolone instillation is associated with a large, transient reduction in ODI for patients with high preoperative ODI; there is no measurable effect on pain. There is equivocal effect on risk of subsequent reoperation. This issue was clarified in peer review but changes did not make it to the abstract. Therefore, the technique is likely best reserved for patients with significant preoperative disability.

Does diabetes affect outcome or reoperation rate after lumbar decompression or arthrodesis? A matched analysis of the Quality Outcomes Database data set.

OBJECTIVE: Diabetes mellitus (DM) is a known risk factor for postsurgical and systemic complications after lumbar spinal surgery. Smaller studies have also demonstrated diminished improvements in patient-reported outcomes (PROs), with increased reoperation and readmission rates after lumbar surgery in patients with DM. The authors aimed to examine longer-term PROs in patients with DM undergoing lumbar decompression and/or arthrodesis for degenerative pathology. METHODS: The Quality Outcomes Database was queried for patients undergoing elective lumbar decompression and/or arthrodesis for degenerative pathology. Patients were grouped into DM and non-DM groups and optimally matched in a 1:1 ratio on 31 baseline variables, including the number of operated levels. Outcomes of interest were readmissions and reoperations at 30 and 90 days after surgery in addition to improvements in Oswestry Disability Index, back pain, and leg pain scores and quality-adjusted life-years at 90 days after surgery. RESULTS: The matched decompression cohort comprised 7836 patients (3236 [41.3] females) with a mean age of 63.5 ± 12.6 years, and the matched arthrodesis cohort comprised 7336 patients (3907 [53.3%] females) with a mean age of 64.8 ± 10.3 years. In patients undergoing lumbar decompression, no significant differences in nonroutine discharge, length of stay (LOS), readmissions, reoperations, and PROs were observed. In patients undergoing lumbar arthrodesis, nonroutine discharge (15.7% vs 13.4%, p < 0.01), LOS (3.2 ± 2.0 vs 3.0 ± 3.5 days, p < 0.01), 30-day (6.5% vs 4.4%, p < 0.01) and 90-day (9.1% vs 7.0%, p < 0.01) readmission rates, and the 90-day reoperation rate (4.3% vs 3.2%, p = 0.01) were all significantly higher in the DM group. For DM patients undergoing lumbar arthrodesis, subgroup analyses demonstrated a significantly higher risk of poor surgical outcomes with the open approach. CONCLUSIONS: Patients with and without DM undergoing lumbar spinal decompression alone have comparable readmission and reoperation rates, while those undergoing arthrodesis procedures have a higher risk of poor surgical outcomes up to 90 days after surgery. Surgeons should target optimal DM control preoperatively, particularly for patients undergoing elective lumbar arthrodesis.

Impact of Educational Background on Preoperative Disease Severity and Postoperative Outcomes Among Patients With Cervical Spondylotic Myelopathy.

STUDY DESIGN: Retrospective review of a prospectively maintained database. OBJECTIVE: Assess differences in preoperative status and postoperative outcomes among patients of different educational backgrounds undergoing surgical management of cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Patient education level (EL) has been suggested to correlate with health literacy, disease perception, socioeconomic status (SES), and access to health care. METHODS: The CSM data set of the Quality Outcomes Database (QOD) was queried for patients undergoing surgical management of CSM. EL was grouped as high school or below, graduate-level, and postgraduate level. The association of EL with baseline disease severity (per patient-reported outcome measures), symptoms >3 or ≤3 months, and 24-month patient-reported outcome measures were evaluated. RESULTS: Among 1141 patients with CSM, 509 (44.6%) had an EL of high school or below, 471 (41.3%) had a graduate degree, and 161 (14.1%) had obtained postgraduate education. Lower EL was statistically significantly associated with symptom duration of >3 months (odds ratio=1.68), higher arm pain numeric rating scale (NRS) (coefficient=0.5), and higher neck pain NRS (coefficient=0.79). Patients with postgraduate education had statistically significantly lower Neck Disability Index (NDI) scores (coefficient=-7.17), lower arm pain scores (coefficient=-1), and higher quality-adjusted life-years (QALY) scores (coefficient=0.06). Twenty-four months after surgery, patients of lower EL had higher NDI scores, higher pain NRS scores, and lower QALY scores ( P <0.05 in all analyses). CONCLUSIONS: Among patients undergoing surgical management for CSM, those reporting a lower educational level tended to present with longer symptom duration, more disease-inflicted disability and pain, and lower QALY scores. As such, patients of a lower EL are a potentially vulnerable subpopulation, and their health literacy and access to care should be prioritized.

Minimally-invasive tubular resection of thoracolumbar intradural schwannoma.

Minimally invasive surgical (MIS) approaches to the spine are increasingly adopted for intradural pathology. In this setting, they may especially be useful to minimize risk of CSF leakage due to the decreased disruption to paraspinal musculature and minimal dead space. Herein, the authors demonstrate their technique for the resection of an intradural thoracolumbar schwannoma in a 30-year-old woman via an MIS approach using a nonexpandable tubular retractor. Salient points include the use of bayonetted instruments and the technique for dural closure in a small corridor. Indications for this technique are discussed in the context of a series of patients with intradural extramedullary lesions.

Sleep Disturbances in Cervical Spondylotic Myelopathy: Prevalence and Postoperative Outcomes-an Analysis From the Quality Outcomes Database.

STUDY DESIGN: Prospective observational study, level of evidence 1 for prognostic investigations. OBJECTIVES: To evaluate the prevalence of sleep impairment and predictors of improved sleep quality 24 months postoperatively in cervical spondylotic myelopathy (CSM) using the quality outcomes database. SUMMARY OF BACKGROUND DATA: Sleep disturbances are a common yet understudied symptom in CSM. MATERIALS AND METHODS: The quality outcomes database was queried for patients with CSM, and sleep quality was assessed through the neck disability index sleep component at baseline and 24 months postoperatively. Multivariable logistic regressions were performed to identify risk factors of failure to improve sleep impairment and symptoms causing lingering sleep dysfunction 24 months after surgery. RESULTS: Among 1135 patients with CSM, 904 (79.5%) had some degree of sleep dysfunction at baseline. At 24 months postoperatively, 72.8% of the patients with baseline sleep symptoms experienced improvement, with 42.5% reporting complete resolution. Patients who did not improve were more like to be smokers [adjusted odds ratio (aOR): 1.85], have osteoarthritis (aOR: 1.72), report baseline radicular paresthesia (aOR: 1.51), and have neck pain of ≥4/10 on a numeric rating scale. Patients with improved sleep noted higher satisfaction with surgery (88.8% vs 72.9%, aOR: 1.66) independent of improvement in other functional areas. In a multivariable analysis including pain scores and several myelopathy-related symptoms, lingering sleep dysfunction at 24 months was associated with neck pain (aOR: 1.47) and upper (aOR: 1.45) and lower (aOR: 1.52) extremity paresthesias. CONCLUSION: The majority of patients presenting with CSM have associated sleep disturbances. Most patients experience sustained improvement after surgery, with almost half reporting complete resolution. Smoking, osteoarthritis, radicular paresthesia, and neck pain ≥4/10 numeric rating scale score are baseline risk factors of failure to improve sleep dysfunction. Improvement in sleep symptoms is a major driver of patient-reported satisfaction. Incomplete resolution of sleep impairment is likely due to neck pain and extremity paresthesia.

Cervical Epidural Electrical Stimulation Increases Respiratory Activity through Somatostatin-Expressing Neurons in the Dorsal Cervical Spinal Cord in Rats.

We tested the hypothesis that dorsal cervical epidural electrical stimulation (CEES) increases respiratory activity in male and female anesthetized rats. Respiratory frequency and minute ventilation were significantly increased when CEES was applied dorsally to the C2-C6 region of the cervical spinal cord. By injecting pseudorabies virus into the diaphragm and using c-Fos activity to identify neurons activated during CEES, we found neurons in the dorsal horn of the cervical spinal cord in which c-Fos and pseudorabies were co-localized, and these neurons expressed somatostatin (SST). Using dual viral infection to express the inhibitory Designer Receptors Exclusively Activated by Designer Drugs (DREADD), hM4D(Gi), selectively in SST-positive cells, we inhibited SST-expressing neurons by administering Clozapine N-oxide (CNO). During CNO-mediated inhibition of SST-expressing cervical spinal neurons, the respiratory excitation elicited by CEES was diminished. Thus, dorsal cervical epidural stimulation activated SST-expressing neurons in the cervical spinal cord, likely interneurons, that communicated with the respiratory pattern generating network to effect changes in ventilation.SIGNIFICANCE STATEMENT A network of pontomedullary neurons within the brainstem generates respiratory behaviors that are susceptible to modulation by a variety of inputs; spinal sensory and motor circuits modulate and adapt this output to meet the demands placed on the respiratory system. We explored dorsal cervical epidural electrical stimulation (CEES) excitation of spinal circuits to increase ventilation in rats. We identified dorsal somatostatin (SST)-expressing neurons in the cervical spinal cord that were activated (c-Fos-positive) by CEES. CEES no longer stimulated ventilation during inhibition of SST-expressing spinal neuronal activity, thereby demonstrating that spinal SST neurons participate in the activation of respiratory circuits affected by CEES. This work establishes a mechanistic foundation to repurpose a clinically accessible neuromodulatory therapy to activate respiratory circuits and stimulate ventilation.

Epidural electrical stimulation of the cervical spinal cord opposes opioid-induced respiratory depression.

Opioid overdose suppresses brainstem respiratory circuits, causes apnoea and may result in death. Epidural electrical stimulation (EES) at the cervical spinal cord facilitated motor activity in rodents and humans, and we hypothesized that EES of the cervical spinal cord could antagonize opioid-induced respiratory depression in humans. Eighteen patients requiring surgical access to the dorsal surface of the spinal cord between C2 and C7 received EES or sham stimulation for up to 90 s at 5 or 30 Hz during complete (OFF-State) or partial suppression (ON-State) of respiration induced by remifentanil. During the ON-State, 30 Hz EES at C4 and 5 Hz EES at C3/4 increased tidal volume and decreased the end-tidal carbon dioxide level compared to pre-stimulation control levels. EES of 5 Hz at C5 and C7 increased respiratory frequency compared to pre-stimulation control levels. In the OFF-State, 30 Hz cervical EES at C3/4 terminated apnoea and induced rhythmic breathing. In cadaveric tissue obtained from a brain bank, more neurons expressed both the neurokinin 1 receptor (NK1R) and somatostatin (SST) in the cervical spinal levels responsive to EES (C3/4, C6 and C7) compared to a region non-responsive to EES (C2). Thus, the capacity of cervical EES to oppose opioid depression of respiration may be mediated by NK1R+/SST+ neurons in the dorsal cervical spinal cord. This study provides proof of principle that cervical EES may provide a novel therapeutic approach to augment respiratory activity when the neural function of the central respiratory circuits is compromised by opioids or other pathological conditions. KEY POINTS: Epidural electrical stimulation (EES) using an implanted spinal cord stimulator (SCS) is an FDA-approved method to manage chronic pain. We tested the hypothesis that cervical EES facilitates respiration during administration of opioids in 18 human subjects who were treated with low-dose remifentanil that suppressed respiration (ON-State) or high-dose remifentanil that completely inhibited breathing (OFF-State) during the course of cervical surgery. Dorsal cervical EES of the spinal cord augmented the respiratory tidal volume or increased the respiratory frequency, and the response to EES varied as a function of the stimulation frequency (5 or 30 Hz) and the cervical level stimulated (C2-C7). Short, continuous cervical EES restored a cyclic breathing pattern (eupnoea) in the OFF-State, suggesting that cervical EES reversed the opioid-induced respiratory depression. These findings add to our understanding of respiratory pattern modulation and suggest a novel mechanism to oppose the respiratory depression caused by opioids.

Neurosurgical Management of Interspinous Device Complications: A Case Series.

Background: Best practice guidelines for treating lumbar stenosis include a multidisciplinary approach, ranging from conservative management with physical therapy, medication, and epidural steroid injections to surgical decompression with or without instrumentation. Marketed as an outpatient alternative to a traditional lumbar decompression, interspinous process devices (IPDs) have gained popularity as a minimally invasive stabilization procedure. IPDs have been embraced by non-surgical providers, including physiatrists and anesthesia interventional pain specialists. In the interest of patient safety, it is imperative to formally profile its safety and identify its role in the treatment paradigm for lumbar stenosis. Case Description: We carried out a retrospective review at our institution of neurosurgical consultations for patients with hardware complications following the interspinous device placement procedure. Eight cases within a 3-year period were identified, and patient characteristics and management are illustrated. The series describes the migration of hardware, spinous process fracture, and worsening post-procedural back pain. Conclusions: IPD placement carries procedural risk and requires a careful pre-operative evaluation of patient imaging and surgical candidacy. We recommend neurosurgical consultation and supervision for higher-risk IPD cases.

C2 translaminar screw fixation in pediatric occipitocervical fusion.

PURPOSE: Rigid occipitocervical (O-C) instrumentation can reduce the anterior pathology and has a high fusion rate in children with craniovertebral instability. Typically, axis (C2) screw fixation utilizes C1-C2 transarticular screws or C2 pars screws. However, anatomic variation may preclude these screw types due to the size of fixation elements or by placing the vertebral artery at risk for injury. Pediatric C2 translaminar screw fixation has low risk of vertebral artery injury and may be used when the anatomy is otherwise unsuitable for C1-C2 transarticular screws or C2 pars screws. METHODS: We retrospectively reviewed a neurosurgical database at UCSF Benioff Children's Hospital Oakland for patients who had undergone a cervical spinal fusion that utilized translaminar screws for occipitocervical instrumentation between 2002 and 2020. We then reviewed the operative records to determine the parameters of C2 screw fixations performed. Demographic and all other relevant clinical data were then recorded. RESULTS: Twenty-five patients ranging from 2 to 18 years of age underwent O-C fusion, with a total of 43 translaminar screws at C2 placed. Twenty-three patients were fused (92%) after initial surgery with a mean follow-up of 43 months. Two patients, both with Down syndrome, had a nonunion. Another 2 patients had a superficial wound dehiscence that required wound revision. One patient died of unknown cause 7 months after surgery. One patient developed an adjacent-level kyphosis. CONCLUSION: When performing occipitocervical instrumentation in the pediatric population, C2 translaminar screw fixation is an effective option to other methods of C2 screw fixation dependent on anatomic feasibility.

A novel endoscope-assisted technique for lateral lumbar interbody fusion: feasibility study, technical note, and operative video.

The lateral approach to the spine is generally well tolerated, but reports of debilitating injury to the lumbar plexus, iliac vessels, ureter, and abdominal viscera are increasingly recognized, likely related to the lack of direct visualization of these nearby structures. To minimize this complication profile, the authors describe here a novel, minimally invasive, endoscope-assisted technique for the LLIF and evaluate its clinical feasibility. Seven consecutive endoscope-assisted lateral lumbar interbody fusion (LLIF) procedures by the senior authors were reviewed for the incidence of approach-related complications. One patient had a postoperative approach-related complication. This patient developed transient ipsilateral thigh hip flexion weakness that resolved spontaneously by the 3-month follow-up. No patient experienced visceral, urological, or vascular injury, and no patient sustained a permanent neurological injury related to the procedure. The authors' preliminary experience suggests that this endoscope-assisted LLIF technique may be clinically feasible to mitigate vascular, urological, and visceral injury, especially in patients with previous abdominal surgery, anomalous anatomy, and revision operations. It provides direct visualization of at-risk structures without significant additional operative time. A larger series is needed to determine whether it reduces the incidence of lumbar plexopathy or visceral injury compared with traditional lateral approaches.

Cell Therapy for Chronic TBI: Interim Analysis of the Randomized Controlled STEMTRA Trial.

OBJECTIVE: To determine if chronic motor deficits secondary to traumatic brain injury (TBI) can be improved by implantation of allogeneic modified bone marrow-derived mesenchymal stromal/stem cells (SB623). METHODS: This 6-month interim analysis of the 1-year double-blind, randomized, surgical sham-controlled, phase 2 STEMTRA trial (NCT02416492) evaluated safety and efficacy of the stereotactic intracranial implantation of SB623 in patients with stable chronic motor deficits secondary to TBI. Patients in this multi-center trial (N = 63) underwent randomization in a 1:1:1:1 ratio to 2.5 × 106, 5.0 × 106, 10 × 106 SB623 cells or control. Safety was assessed in patients who underwent surgery (N = 61), and efficacy in the modified intent-to-treat population of randomized patients who underwent surgery (N = 61; SB623 = 46, control = 15). RESULTS: The primary efficacy endpoint of significant improvement from baseline of Fugl-Meyer Motor Scale score at 6 months for SB623-treated patients was achieved. SB623-treated patients improved by (LS mean [SE]) +8.3 (1.4) vs +2.3 (2.5) for control at 6 months, the LS mean difference was 6.0 (95% CI: 0.3-11.8); p = 0.040. Secondary efficacy endpoints improved from baseline, but were not statistically significant vs control at 6 months. There were no dose-limiting toxicities or deaths, and 100% of SB623-treated patients experienced treatment-emergent adverse events vs 93.3% of control patients (p = 0.25). CONCLUSIONS: SB623 cell implantation appeared to be safe and well tolerated, and patients implanted with SB623 experienced significant improvement from baseline motor status at 6 months compared to controls. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that implantation of SB623 was well tolerated and associated with improvement in motor status.

Laminoplasty for Cervical Spinal Cord Stimulator Implantation in Patients With Cervical Spondylosis and Fusion: A Technical Note.

Background: Epidural spinal cord stimulator (SCS) implantation is a commonly used strategy for treating refractory neuropathic pain, but the literature on the technical aspects of cervical SCS surgery remains scarce. Degenerative cervical stenosis and prior fusion surgery are relatively frequent conditions in this population, and the optimal method for cervical lead placement among such patients has not been established. Decompressive laminectomy may be required for cervical SCS placement in the presence of spinal stenosis. However, extensive decompression may increase the rate of lead migration and destabilize the spine, especially when performed above an existing fusion. Case Series: We present a surgical technique for cervical SCS implantation and the cases of 3 patients with significant spinal stenosis and/or prior fusion. In these patients, the paddle lead placement was safely achieved using cervical laminoplasty techniques. Conclusion: In addition to stabilizing the epidural paddle lead, laminoplasty offers several potential advantages compared to decompression alone.

Minimally Invasive Decompression and Physiotherapy for Lumbar Spinal Stenosis in Geriatric Patients.

Background Lumbar spinal stenosis (LSS) is the most common indication for spine surgery among the geriatric population. Although decompressive surgery is effective, older patients do not benefit as much as younger patients, and they are frequently excluded from studies assessing postoperative physiotherapy. We sought to evaluate the long-term outcomes after surgery when a novel postoperative physiotherapy regimen was included. Methods We performed a retrospective review of patients with LSS greater than 70 years old who underwent lumbar decompressive surgery by the senior author over the past five years. We evaluated patients who participated in a novel postoperative physiotherapy regimen involving four phases of rehabilitation aimed at progressively independent ambulation. The visual analog scale (VAS), lower extremity motor strength, and functional independence measure (FIM) were collected preoperatively and after physiotherapy to measure outcomes. Results Ten consecutive patients with an average age of 83 years (range: 71 - 96) met the inclusion criteria. Nine patients underwent minimally invasive laminotomies at L4-L5 and one underwent a laminotomy at L3-L4. The average follow-up time was 41.9 months. The preoperative mean VAS was 7.35, and at the end of the study, it was 1.7 (p = 0.005). Three of the four patients with preoperative motor deficits improved. The median transfer and locomotion subscores of the FIM were six preoperatively and increased to seven postoperatively. Neither of these improvements was significant. Conclusions Patients older than 70 years undergoing decompressive surgery and a novel postoperative physiotherapy regimen experienced significant reductions in pain. Independence also increased; however, this did not reach statistical significance.

Aspiration of sterile post-operative spinal fluid collections using low-dose computed tomography guidance.

Sterile postoperative seromas can develop after posterior spinal surgery and cause pain, weakness, and numbness. Management typically involves operative evacuation. We propose that these collections can be managed with percutaneous computed tomography (CT) guided aspiration, potentially saving the patient an additional surgery. Here, we evaluate the safety and efficacy of this approach. Patients who developed symptomatic postoperative seromas within 60 days following surgery for spinal canal stenosis and had stable neurologic exams were considered for CT-guided percutaneous aspiration. To be considered for this approach, patients had to have pre-procedural evidence of radiographic spinal cord or cauda equina compression, hemodynamic stability, and low suspicion for infection. A total of 16 symptomatic collections were aspirated among 15 patients. The mean volume of fluid removed was 32.0 mL. There were no peri- or post-procedural complications. Eight (50%) had resolution or substantial improvement of their symptoms (p = 0.0002 when compared to the null hypothesis). One patient had short interval improvement but return of their initial symptoms 12 h following aspiration, 3/16 (19%) had minimal improvement, and 4/16 (25%) had no change in symptoms. Fluid collections that appeared denser on the pre-procedural CT were associated with retrieval of more sanguineous appearing fluid (p = 0.08). Neither the amount nor quality of fluid aspirated was associated with outcome. We conclude that percutaneous CT-guided aspiration of postoperative seromas is safe and should be considered as an alternative to open surgical evacuation in patients with stable neurologic exams.

Identifying predictors for postoperative clinical outcome in lumbar spinal stenosis patients using smart-shoe technology.

BACKGROUND: Approximately 33% of the patients with lumbar spinal stenosis (LSS) who undergo surgery are not satisfied with their postoperative clinical outcomes. Therefore, identifying predictors for postoperative outcome and groups of patients who will benefit from the surgical intervention is of significant clinical benefit. However, many of the studied predictors to date suffer from subjective recall bias, lack fine digital measures, and yield poor correlation to outcomes. METHODS: This study utilized smart-shoes to capture gait parameters extracted preoperatively during a 10 m self-paced walking test, which was hypothesized to provide objective, digital measurements regarding the level of gait impairment caused by LSS symptoms, with the goal of predicting postoperative outcomes in a cohort of LSS patients who received lumbar decompression and/or fusion surgery. The Oswestry Disability Index (ODI) and predominant pain level measured via the Visual Analogue Scale (VAS) were used as the postoperative clinical outcome variables. RESULTS: The gait parameters extracted from the smart-shoes made statistically significant predictions of the postoperative improvement in ODI (RMSE =0.13, r=0.93, and p<3.92×10-7) and predominant pain level (RMSE =0.19, r=0.83, and p<1.28×10-4). Additionally, the gait parameters produced greater prediction accuracy compared to the clinical variables that had been previously investigated. CONCLUSIONS: The reported results herein support the hypothesis that the measurement of gait characteristics by our smart-shoe system can provide accurate predictions of the surgical outcomes, assisting clinicians in identifying which LSS patient population can benefit from the surgical intervention and optimize treatment strategies.

Aquaporin-1 Expression in Herniated Human Lumbar Intervertebral Discs.

STUDY DESIGN: Case series. OBJECTIVE: Intervertebral disc (IVD) degeneration is the cause of spondylosis. The pathogenesis is poorly understood, but disc dehydration often plays a role. In this study, we aim to identify and quantify aquaporin-1 (AQP1) in ex vivo human degenerated IVDs obtained intraoperatively and to investigate the relationship between AQP1 levels and magnetic resonance imaging (MRI) T2 intensity of the disc. METHODS: Ex vivo samples of nucleus pulposus (NP) tissue from lumbar IVDs were obtained from 18 consecutive patients who underwent surgery for disc herniation at L4/5 and L5/S1 level. Immunohistochemistry was performed to determine the presence of AQP1 expression, and this was quantified by Western blot analysis. AQP1 expression was compared to preoperative IVD signal intensity on T2-weighted MRI. RESULTS: NP tissue was obtained from 18 patients (9 for L4/5 level and 9 for L5/S1 level). AQP1 expression was detected in all samples by Western blot and immunohistochemistry. AQP1 expression had a linear correlation with the preoperative IVD signal intensity on T2-weighted MRI at L4/5 level (R2 = 0.90) and at L5/S1 level (R2 = 0.92). AQP1 expression was 52.2 ± 59.0 at L5/S1 level and 15.9 ± 20.6 at L4/5 (P = .10). CONCLUSIONS: Our results show that AQP1 can be detected in IVD obtained from live human subjects. Increased AQP1 expression is associated with greater disc hydration as measured by signal intensity on T2-weighted MRI. AQP1 may have a role in the dehydration associated with disc degeneration.

Primary lung metastasis of glioblastoma multiforme with epidural spinal metastasis: Case report.

Extracranial metastasis of glioblastoma multiforme (GBM) is rare, but has recently been reported with increasing frequency. GBM metastases typically present after a biopsy or resection of the primary tumor. An otherwise healthy 54year-old woman presented with recurring pleural effusions originally believed to be from a primary lung malignancy. The patient subsequently experienced a generalized tonic clonic seizure and a right temporal brain mass was discovered. The patient later developed weakness and radiculopathy, and an extramedullary extradural mass spreading from C7 to T6 was discovered. She underwent resection of both central nervous system lesions as well as a lung biopsy, and all pathologic specimens were consistent with GBM. The case presented is unique in that the patient's initial symptoms were related to her metastasis. Furthermore, a purely epidural spread of GBM that respects the leptomeninges and intramedullary parenchyma is highly unusual.

Minimally invasive surgery for lumbar synovial cysts with coexisting degenerative spondylolisthesis.

BACKGROUND: About one third of lumbar synovial cysts are associated with degenerative spondylolisthesis. Segmental instability is thought to contribute to the pathogenesis and recurrence of synovial cysts and lumbar fusion has been advocated as a treatment of choice in the presence of spondylolisthesis. In patients with spondylolisthesis, minimally invasive resection of lumbar synovial cysts, without fusion, could minimize surgically induced segmental instability while providing good pain relief. METHODS: Clinical and radiological outcomes of lumbar synovial cyst patients with and without spondylolisthesis were retrospectively compared. Pain outcomes were assessed with modified Macnab criteria. RESULTS: Fifty-three patients (18 with grade 1 spondylolisthesis) underwent minimally invasive synovial cyst resection and all had either excellent or good pain outcome at ≤ 8 post- operative weeks (P = 1.000, n = 53). At > 8 post-operative weeks (mean (SD) follow-up of 200 (175) weeks), excellent or good outcomes were noted in 89% of patients without spondylolisthesis and in 75% of patients with spondylolisthesis (P = 0.425, n = 40). Four patients developed a new grade 1 spondylolisthesis at a mean follow-up of 2.6 ± 2.1 years. Nine patients were assessed for spondylolisthesis measurements at 1.2 ± 1.3 years of follow up and no significant difference was observed (5 ± 0 vs 5 ± 1 mm; P = 0.791). Two patients without spondylolisthesis and none of the patients with spondylolisthesis had a synovial cyst recurrence. CONCLUSION: Patients with concomitant lumbar degenerative spondylolisthesis and synovial cyst can have good short- and long-term clinical outcomes with minimally invasive surgery without fusion. Post-operative segmental instability does not appear to be significant in patients with spondylolisthesis. All patients included in this article signed an informed consent for the use of their medical information for research.

Postoperative Cerebrospinal Fluid Leak Rates with Subfascial Epidural Drain Placement after Intentional Durotomy in Spine Surgery.

Study Design Retrospective chart review. Objective Postoperative cerebrospinal fluid (CSF) leak is a known complication of intraoperative durotomy. Intraoperative placement of subfascial epidural drains following primary dural repair has been proposed as a potential management strategy to prevent formation of CSF cutaneous fistula and symptomatic pseudomeningocele. Here we describe our experience with subfascial drain after intentional durotomy. Methods Medical records of patients who underwent placement of subfascial epidural drains during spinal procedures with intentional intraoperative durotomies over a 4-year period at two institutions were retrospectively reviewed. Primary outcomes of interest were postoperative CSF cutaneous fistula or symptomatic pseudomeningocele formation. Results Twenty-five patients were included. Mean length of follow-up was 9.5 months. Twelve patients (48%) underwent simultaneous arthrodesis. The average duration of the drain was 5.3 days with average daily output of 126.5 mL. Subgroup analyses revealed that average drain duration for the arthrodesis group was 6.33 days, which is significantly greater than that of the nonfused group, which was 3.7 days (p = 0.016). Similarly, the average daily drain output for the arthrodesis subgroup at 153.1 mL was significantly higher than that of the nonfused subgroup (86.8 mL, p = 0.04). No patient developed postoperative CSF cutaneous fistula or symptomatic pseudomeningocele or had negative sequelae associated with overdrainage of CSF. One patient had a delayed wound infection. Conclusions The intraoperative placement of subfascial epidural drains was not associated with postoperative development of CSF cutaneous fistula, symptomatic pseudomeningocele, overdrainage, or subdural hematoma in the cases reviewed. Subfascial closed wound drain placement is a safe and efficacious management method after intentional spinal durotomies. It is particularly helpful in those who undergo simultaneous arthrodesis, as those patients have statistically higher daily drain output and longer drain durations.