Damned if you monitor, damned if you don't: medical malpractice and intraoperative neuromonitoring for spinal surgery.

OBJECTIVE: The aim of this study was to identify trends in medical malpractice litigation related to intraoperative neuromonitoring. METHODS: The Westlaw Edge legal research service was queried for malpractice litigation related to neuromonitoring in spine surgery. Cases were reviewed to determine if the plaintiff's assertion of negligence was due to either failure to use neuromonitoring or negligent monitoring. Comparative statistics and a detailed qualitative analysis of the resulting cases were performed. RESULTS: Twenty-six cases related to neuromonitoring were identified. Spinal fusion was the procedure in question in all cases, and defendants were nearly evenly divided between orthopedic surgeons and neurosurgeons. Defense verdicts were most common (54%), followed by settlements (27%) and plaintiff verdicts (19%). Settlements resulted in a mean $7,575,000 damage award, while plaintiff verdicts resulted in a mean $4,180,213 damage award. The basis for litigation was failure to monitor in 54% of the cases and negligent monitoring in 46%. There were no significant differences in case outcomes between the two allegations of negligence. CONCLUSIONS: The use and interpretation of intraoperative neuromonitoring findings can be the basis for a medical malpractice litigation. Spine surgeons can face malpractice risks by not monitoring when required by the standard of care and by interpreting or reacting to neuromonitoring findings inappropriately.

Spinal neurovascular complications with anterior thoracolumbar spine surgery: a systematic review and review of thoracolumbar vascular anatomy.

OBJECTIVE: Spinal cord infarction due to interruption of the spinal vascular supply during anterior thoracolumbar surgery is a rare but devastating complication. Here, the authors sought to summarize the data on this complication in terms of its incidence, risk factors, and operative considerations. They also sought to summarize the relevant spinal vascular anatomy. METHODS: They performed a systematic literature review of the PubMed, Scopus, and Embase databases to identify reports of spinal cord vascular injury related to anterior thoracolumbar spine procedures as well as operative adjuncts and considerations related to management of the segmental artery ligation during such anterior procedures. Titles and abstracts were screened, and studies meeting inclusion criteria were reviewed in full. RESULTS: Of 1200 articles identified on the initial screening, 16 met the inclusion criteria and consisted of 2 prospective cohort studies, 10 retrospective cohort studies, and 4 case reports. Four studies reported on the incidence of spinal cord ischemia with anterior thoracolumbar surgery, which ranged from 0% to 0.75%. Eight studies presented patient-level data for 13 cases of spinal cord ischemia after anterior thoracolumbar spine surgery. Proposed risk factors for vasculogenic spinal injury with anterior thoracolumbar surgery included hyperkyphosis, prior spinal deformity surgery, combined anterior-posterior procedures, left-sided approaches, operating on the concavity side of a scoliotic curve, and intra- or postoperative hypotension. In addition, eight studies analyzed operative considerations to reduce spinal cord ischemic complications in anterior thoracolumbar surgery, including intraoperative neuromonitoring and preoperative spinal angiography. CONCLUSIONS: While spinal cord infarction related to anterior thoracolumbar surgery is rare, it warrants proper consideration in the pre-, intra-, and postoperative periods. The spine surgeon must be aware of the relevant risk factors as well as the pre- and intraoperative adjuncts that can minimize these risks. Most importantly, an understanding of the relevant spinal vascular anatomy is critical to minimizing the risks associated with anterior thoracolumbar spine surgery.

Vulnerability of the L5 nerve root during anterior lumbar interbody fusion at L5-S1: case series and review of the literature.

OBJECTIVE: Nerve root injuries associated with anterior lumbar interbody fusion (ALIF) are uncommonly reported in the literature. This case series and review aims to describe the etiology of L5 nerve root injury following ALIF at L5-S1. METHODS: The authors performed a single-center retrospective review of prospectively collected data of patients who underwent surgery between 2017 and 2019 who had postoperative L5 nerve root injuries after stand-alone L5-S1 ALIF. They also reviewed the literature with regard to nerve root injuries after ALIF procedures. RESULTS: The authors report on 3 patients with postoperative L5 radiculopathy. All 3 patients had pain that improved. Two of the 3 patients had a neurological deficit, one of which improved. CONCLUSIONS: Stretch neuropraxia from overdistraction is an important cause of postoperative L5 radiculopathy after L5-S1 ALIF. Judicious use of implants and careful preoperative planning to determine optimal implant sizes are paramount.

Surgical treatment of epilepsy in Vietnam: program development and international collaboration.

OBJECTIVE: The purpose of this report was to describe an international collaboration model to facilitate the surgical treatment of children with epilepsy in Vietnam. METHODS: This model uses three complementary methods to achieve a meaningful expansion in epilepsy surgery capacity: US-based providers visiting Hanoi, Vietnam; Vietnamese providers visiting the US; and ongoing telecollaboration, including case review and real-time mentorship using internet-based communication platforms. RESULTS: Introductions took place during a US neurosurgeon's visit to Vietnam in 2014. Given the Vietnamese surgeon's expertise in intraventricular tumor surgery, the focus of the initial visit was corpus callosotomy. After two operations performed jointly, the Vietnamese surgeon went on to perform 10 more callosotomy procedures in the ensuing 6 months with excellent results. The collaborative work grew and matured in 2016-2017, with 40 pediatric epilepsy surgeries performed from 2015 through 2017. Because pediatric epilepsy care requires far more than neurosurgery, teams traveling to Vietnam included a pediatric neurologist and an electroencephalography (EEG) technologist. Also, in 2016-2017, a neurosurgeon, two neurologists, and an EEG nurse from Vietnam completed 2- to 3-month fellowships at Children's of Alabama (COA) in the US. These experiences improved EEG capabilities and facilitated the development of intraoperative electrocorticography (ECoG), making nonlesional epilepsy treatment more feasible. The final component has been ongoing, i.e., regular communication. The Vietnamese team regularly sends case summaries for discussion to the COA epilepsy conference. Three patients in Vietnam have undergone resection guided by ECoG without the US team present, although there was communication via internet-based telecollaboration tools between Vietnamese and US EEG technologists. To date, two of these three patients remain seizure free. The Vietnamese team has presented the results of their epilepsy experience at two international functional and epilepsy surgery scientific meetings. CONCLUSIONS: Ongoing international collaboration has improved the surgical care of epilepsy in Vietnam. Experience suggests that the combination of in-country and US-based training, augmented by long-distance telecollaboration, is an effective paradigm for increasing the capacity for highly subspecialized, multidisciplinary neurosurgical care.

The vagus afferent network: emerging role in translational connectomics.

Vagus nerve stimulation (VNS) is increasingly considered for the treatment of intractable epilepsy and holds potential for the management of a variety of neuropsychiatric conditions. The emergence of the field of connectomics and the introduction of large-scale modeling of neural networks has helped elucidate the underlying neurobiology of VNS, which may be variably expressed in patient populations and related to responsiveness to stimulation. In this report, the authors outline current data on the underlying neural circuitry believed to be implicated in VNS responsiveness in what the authors term the "vagus afferent network." The emerging role of biomarkers to predict treatment effect is further discussed and important avenues for future work are highlighted.

Intraoperative neuromonitoring alerts in a pediatric deformity center.

OBJECTIVE Intraoperative neuromonitoring (IONM) involves the use of somatosensory evoked potentials (SSEPs) and transcranial electric motor evoked potentials (TceMEPs). In this retrospective study the authors examined the sensitivity and specificity of both SSEPs and TceMEPs during pediatric spinal deformity surgeries. METHODS The authors performed a retrospective quantitative analysis of data obtained in 806 patients (197 males and 609 females) treated from December 2011 until October 2015. All patients were diagnosed with scoliosis that was classified as one of the following: adolescent idiopathic scoliosis (AIS) (38%), congenital scoliosis (22%), or syndromic scoliosis (40%). Also, 53 patients underwent vertebral column resection (VCR). All surgeries were monitored by high-level neuromonitoring specialists and were performed with total intravenous anesthesia. Alerts were described as a decrease in amplitude by 50% or greater (bilateral or unilateral) in SSEPs, TceMEPs, or both. RESULTS True-positive alerts for TceMEPs were observed in 60 of the 806 patients (7.4%). True-positive alerts for SSEPs were observed in 7 of the 806 patients (0.9%). In contrast, there were no false-positive or false-negative outcomes. Only 1 case (0.1%) was reported with a permanent postoperative deficit. No reported false negatives or false positives were observed, and thus sensitivity was 100% and specificity was 93%-100% for TceMEPs. The rate of sensitivity was 13.2% and the rate of specificity was 100% for SSEPs. The breakdown of total alert was as follows: 6.6% in AIS cases, 24.5% in congenital scoliosis cases, and 10.2% in syndromic scoliosis cases. Neurological injury rates were significantly lower than in previous studies, as there were 0% for AIS cases (p = 0.12), 0.6% for congenital scoliosis cases (p = 0.17), and 0% for syndromic scoliosis cases (p = 0.07). One injury in a patient with congenital scoliosis occurred during a VCR procedure, which brought the injury rate to 1.9% (p < 0.005). IONM alerts occurred during 34% of rod/correction cases, 25% of thoracic screw placements, 20% of the osteotomies, 17% of the resections, 3% of the cage insertions, and 2% of the sublaminar wiring procedures. CONCLUSIONS The authors hypothesize that the results of this study will support the necessity, as a standard of care, of multimodality neuromonitoring during high-risk pediatric spinal deformity surgery because of the decrease in postoperative deficits. Their data suggest that the TceMEPs are more sensitive than SSEPs, but when used in combination, they offer the patient a level of safety that would otherwise not exist. Last, these findings support the notion that better outcomes are achieved with high-level IONM professionals.

Electrophysiological monitoring during preoperative angiography to guide decisions regarding permanent occlusion of major radicular arteries in patients undergoing total en bloc spondylectomy.

OBJECTIVE Preoperative embolization is performed before spine tumor surgery when significant intraoperative hemorrhage is anticipated. Occlusion of radicular and segmental arteries may result in spinal ischemia. The goal of this study was to check whether neurophysiological monitoring during preoperative angiography in patients scheduled for total en bloc spondylectomy (TES) of spine tumors improves the safety of vessel occlusion. METHODS This was a case series study of patients who underwent tumor embolization under somatosensory evoked potential (SSEP) and motor evoked potential (MEP) monitoring in preparation for TES in treating spine tumors. The angiography findings, the embolized vessels, and the results are presented. RESULTS Five patients whose ages ranged from 33 to 75 years and who had thoracic spine tumors are reported. Four patients suffered from primary tumor and 1 patient had a metastatic tumor. Radicular arteries at the tumor level, 1 level above, and 1 level below were permanently occluded when SSEPs and MEPs were preserved during temporary occlusion. No complications were encountered during or after the angiography procedure and embolization. CONCLUSIONS Temporary occlusion with electrophysiological monitoring during preoperative angiography may improve the safety of permanent radicular artery occlusion, including the artery of Adamkiewicz in patients undergoing TES for the treatment of spine tumors.

The role of intraoperative MRI in resective epilepsy surgery for peri-eloquent cortex cortical dysplasias and heterotopias in pediatric patients.

OBJECTIVE: Previous studies have demonstrated that an important factor in seizure freedom following surgery for lesional epilepsy in the peri-eloquent cortex is completeness of resection. However, aggressive resection of epileptic tissue localized to this region must be balanced with the competing objective of retaining postoperative neurological functioning. The objective of this study was to investigate the role of intraoperative MRI (iMRI) as a complement to existing epilepsy protocol techniques and to compare rates of seizure freedom and neurological deficit in pediatric patients undergoing resection of perieloquent lesions. METHODS: The authors retrospectively reviewed the medical records of pediatric patients who underwent resection of focal cortical dysplasia (FCD) or heterotopia localized to eloquent cortex regions at the Children's National Health System between March 2005 and August 2015. Patients were grouped into two categories depending on whether they underwent conventional resection (n = 18) or iMRI-assisted resection (n = 11). Patient records were reviewed for factors including demographics, length of hospitalization, postoperative seizure freedom, postoperative neurological deficit, and need for reoperation. Postsurgical seizure outcome was assessed at the last postoperative follow-up evaluation using the Engel Epilepsy Surgery Outcome Scale. RESULTS: At the time of the last postoperative follow-up examination, 9 (82%) of the 11 patients in the iMRI resection group were seizure free (Engel Class I), compared with 7 (39%) of the 18 patients in the control resection group (p = 0.05). Ten (91%) of the 11 patients in the iMRI cohort achieved gross-total resection (GTR), compared with 8 (44%) of 18 patients in the conventional resection cohort (p = 0.02). One patient in the iMRI-assisted resection group underwent successful reoperation at a later date for residual dysplasia, compared with 7 patients in the conventional resection cohort (with 2/7 achieving complete resection). Four (36%) of the patients in the iMRI cohort developed postoperative neurological deficits, compared with 15 patients (83%) in the conventional resection cohort (p = 0.02). CONCLUSIONS: These results suggest that in comparison with a conventional surgical protocol and technique for resection of epileptic lesions in peri-eloquent cortex, the incorporation of iMRI led to elevated rates of GTR and postoperative seizure freedom. Furthermore, this study suggests that iMRI-assisted surgeries are associated with a reduction in neurological deficits due to intraoperative damage of eloquent cortex.

Safe use of subdermal needles for intraoperative monitoring with MRI.

OBJECTIVE: The purpose of this study was to develop safe, site-specific procedures for placing and leaving subdermal needle leads for intraoperative monitoring (IOM) during intraoperative MRI procedures. METHODS: The authors tested a variety of standard subdermal needle electrodes designed and FDA-approved for IOM in the conventional operating room. Testing was used to determine the conditions necessary to avoid thermal injury and significant image artifacts with minimal disruption of IOM and MRI procedures. Phantom testing was performed with a fiber optic (lead) temperature monitoring system and was followed by testing of leads placed in a healthy volunteer. The volunteer testing used electrode placements typical of standard IOM cases, together with radiofrequency (RF) coil placement and imaging sequences routinely employed for these case types. Lead length was investigated to assess heating effects for electrodes placed within the RF coil. RESULTS: The authors found that conventional stainless steel (SS) and platinum/iridium (Pt/Ir) subdermal needles can be used safely without significant heating when placed outside the RF coil, and this accounts for the majority or entirety of electrode placements. When placed within the RF coil, Pt/Ir leads produced minimal image artifacts, while SS leads produced potentially significant artifacts. In phantom testing, significant heating was demonstrated in both SS and Pt/Ir leads placed within the RF coil, but only during high-resolution T2-weighted scanning. This problem was largely, but not completely, eliminated when leads were shortened to 25 cm. Human testing was unremarkable except for nonpainful heating detected in a few electrodes during thin-slice (1.5 mm) FLAIR scanning. Transient irritation (skin reddening along the needle tract) was noted at 2 of the electrodes with detectable heating. CONCLUSIONS: The authors were satisfied with the safety of their site-specific procedures and have begun with off-label use (following institutional review board approval and obtaining patient informed consent) of tested monitoring leads in cases that combine IOM and MRI. The authors recommend that all facilities perform their own site-specific testing of monitoring leads before proceeding with their routine use.

Psychometric analysis and critical appraisal of the original, revised, and modified versions of the Japanese Orthopaedic Association score in the assessment of patients with cervical spondylotic myelopathy.

OBJECTIVE Cervical spondylotic myelopathy (CSM) is the most common cause of nontraumatic spinal cord impairment and disability in the world. Given that the Japanese Orthopaedic Association (JOA) score is the most frequently used outcome measure in clinical research and practice for treating patients with CSM, this review was undertaken to comprehensively and critically evaluate the psychometric properties of the JOA score. METHODS The authors identified studies (published in the period of January 1975 to November 2015) on the psychometric properties of the original, revised, and modified versions of the JOA score in Medline, PsycINFO, Excerpta Medica dataBASE (EMBASE), American College of Physicians Journal Club, and Cochrane Database of Systematic Reviews. Additional publications were captured in a secondary search of the bibliographies in both original research articles and literature reviews identified in the original search. The JOA scores were evaluated for item generation and reduction, internal consistency, reliability, validity, and responsiveness. This review included all those versions of the JOA score whose psychometric properties had been reported in at least 2 published studies. RESULTS The primary search strategy identified 59 studies, of which 9 fulfilled the inclusion and exclusion criteria. An additional 18 publications were captured in the secondary search and included in the analysis. The key findings from the 27 studies analyzed indicated the following: 1) the original JOA score (1975) was the source for the revised JOA score (1994) and 3 modified versions (1991, 1993, and 1999 JOA scores) reported or used in at least 2 published studies; 2) the revised and modified versions of the JOA score are markedly different from each other; 3) only the revised JOA score (1994) was validated with the original JOA score; and 4) the 1975 JOA score is the most appropriate instrument for assessing patients in Asian populations (especially from Japan) because of its psychometric attributes, and the 1991 JOA score is the most appropriate version for use in Western populations. CONCLUSIONS The authors' results indicate that the original (1975), revised (1994), and modified (1991, 1993, and 1999) versions of the JOA score are substantially different from each other in terms of their content and have been incompletely examined for their psychometric properties and cultural sensitivity. Whereas the 1975 JOA score is the most appropriate version for assessing individuals from Asian populations (particularly those eating with chopsticks), the 1991 JOA score is most suitable for evaluating patients in Western populations. Nonetheless, further investigation of the psychometric properties of the 1975 and 1991 JOA scores is recommended because of a paucity of studies reporting on the responsiveness of these 2 scoring instruments.

Intraoperative neurophysiological mapping and monitoring in spinal tumor surgery: sirens or indispensable tools?

Spinal tumor (ST) surgery carries the risk of new neurological deficits in the postoperative period. Intraoperative neurophysiological monitoring and mapping (IONM) represents an effective method of identifying and monitoring in real time the functional integrity of both the spinal cord (SC) and the nerve roots (NRs). Despite consensus favoring the use of IONM in ST surgery, in this era of evidence-based medicine, there is still a need to demonstrate the effective role of IONM in ST surgery in achieving an oncological cure, optimizing patient safety, and considering medicolegal aspects. Thus, neurosurgeons are asked to establish which techniques are considered indispensable. In the present study, the authors focused on the rationale for and the accuracy (sensitivity, specificity, and positive and negative predictive values) of IONM in ST surgery in light of more recent evidence in the literature, with specific emphasis on the role of IONM in reducing the incidence of postoperative neurological deficits. This review confirms the role of IONM as a useful tool in the workup for ST surgery. Individual monitoring and mapping techniques are clearly not sufficient to account for the complex function of the SC and NRs. Conversely, multimodal IONM is highly sensitive and specific for anticipating neurological injury during ST surgery and represents an important tool for preserving neuronal structures and achieving an optimal postoperative functional outcome.

Immediate complications associated with high-flow cerebrospinal fluid egress during endoscopic endonasal skull base surgery.

Endoscopic expanded endonasal approaches (EEAs) to the skull base are increasingly being used to address a variety of skull base pathologies. Postoperative CSF leakage from the large skull base defects has been well described as one of the most common complications of EEAs. There are reports of associated formation of delayed subdural hematoma and tension pneumocephalus from approximately 1 week to 3 months postoperatively. However, there have been no reports of immediate complications of high-volume CSF leakage from EEA skull base surgery. The authors describe two cases of EEAs in which complications related to rapid, large-volume CSF egress through the skull base surgical defect were detected in the immediate postoperative period. Preventive measures to reduce the likelihood of these immediate complications are presented.

Intraoperative monopolar mapping during 5-ALA-guided resections of glioblastomas adjacent to motor eloquent areas: evaluation of resection rates and neurological outcome.

OBJECT: Resection of glioblastoma adjacent to motor cortex or subcortical motor pathways carries a high risk of both incomplete resection and postoperative motor deficits. Although the strategy of maximum safe resection is widely accepted, the rates of complete resection of enhancing tumor (CRET) and the exact causes for motor deficits (mechanical vs vascular) are not always known. The authors report the results of their concept of combining monopolar mapping and 5-aminolevulinic acid (5-ALA)-guided surgery in patients with glioblastoma adjacent to eloquent tissue. METHODS: The authors prospectively studied 72 consecutive patients who underwent 5-ALA-guided surgery for a glioblastoma adjacent to the corticospinal tract (CST; < 10 mm) with continuous dynamic monopolar motor mapping (short-train interstimulus interval 4.0 msec, pulse duration 500 µsec) coupled to an acoustic motor evoked potential (MEP) alarm. The extent of resection was determined based on early (< 48 hours) postoperative MRI findings. Motor function was assessed 1 day after surgery, at discharge, and at 3 months. RESULTS: Five patients were excluded because of nonadherence to protocol; thus, 67 patients were evaluated. The lowest motor threshold reached during individual surgery was as follows (motor threshold, number of patients): > 20 mA, n = 8; 11-20 mA, n = 13; 6-10 mA, n = 10; 4-5 mA, n = 13; and 1-3 mA, n = 23. Motor deterioration at postsurgical Day 1 and at discharge occurred in 30% (n = 20) and 10% (n = 7) of patients, respectively. At 3 months, 3 patients (4%) had a persisting postoperative motor deficit, 2 caused by vascular injury and 1 by mechanical injury. The rates of intra- and postoperative seizures were 1% and 0%, respectively. Complete resection of enhancing tumor was achieved in 73% of patients (49/67) despite proximity to the CST. CONCLUSIONS: A rather high rate of CRET can be achieved in glioblastomas in motor eloquent areas via a combination of 5-ALA for tumor identification and intraoperative mapping for distinguishing between presumed and actual motor eloquent tissues. Continuous dynamic mapping was found to be a very ergonomic technique that localizes the motor tissue early and reliably.

Primary germinoma of the medulla oblongata: illustrative case.

BACKGROUND: Primary central nervous system germinomas of the medulla oblongata are extremely rare and usually have been found in young female Asian patients. The authors present an illustrative case of a patient who presented with severe medullary and posterior cord syndrome, the first South American case published to date, to the authors' knowledge. OBSERVATIONS: Initially, the radiological differential diagnosis did not include this entity. The lesion was located at the obex and exhibited a well-delineated contrast enhancement without hydrocephalus. An emergency decompressive partial resection following functional limits was performed. After histological confirmation, radiotherapy was indicated, with complete remission achieved at a 6-month follow-up. The patient, however, continued to have a severe proprioceptive disorder. The literature review identified 21 other such patients. The mean age for this location was 23 years, with a strong female and Asian origin predilection. All tumors exhibited contrast enhancement, and only one presented with hydrocephalus. LESSONS: In the absence of elevated tumor markers, radiological clues such as a well-delineated, contrast-enhanced lesion arising from the obex, without hydrocephalus, associated with demographic features such as young age, female sex, and Asian heritage, should evoke a high level of suspicion for this diagnosis. Gross total resection must not be attempted, because this tumor is potentially curable with high-dose radiotherapy.

Nerve preservation during partial sacrectomy by two-stage anterior and posterior approach: illustrative case.

BACKGROUND: Preserving the neurological function of sacral nerves during total or partial sacrectomy is challenging. OBSERVATIONS: The authors describe a case of an osseous desmoplastic fibroma of the sacrum in a 51-year-old woman. The patient attended the authors' institution with loss of muscle strength and sensitivity impairment in both legs, gait instability, bowel constipation, urinary incontinence, and weight loss. Preoperative magnetic resonance imaging and positron emission tomography/computed tomography showed intrapelvic and posterior extension of the tumor but sparing of S1 and the sacroiliac and lumbosacral joints. After a multidisciplinary discussion of the case, a staged anterior-posterior approach to the sacrum was chosen. The abdominal approach allowed full mobilization of the uterus, ovaries, bladder, and colon and protection of iliac vessels. After tumor resection, a synthetic surgical mesh was placed over the sacrum to minimize soft tissue defects. Then, the posterior stage allowed the authors to perform a bicortical osteotomy, achieving wide tumor excision with minimal nerve root injury. Spinopelvic fixation was not necessary, because both sacroiliac and lumbosacral joints remained intact. A few days after the surgery, the patient restarted ambulation and recovered sphincter control. LESSONS: Multidisciplinary planning and a staged abdominal and posterior approach for partial sacrectomy were fundamental to preserve neurological function in this case.

Cloward's approach for Pancoast neurogenic tumors: illustrative cases.

BACKGROUND: Pancoast tumors are a wide range of tumors located in the apex of the lung. Traditional surgery for Pancoast neurogenic tumors frequently involves extensive approaches, whether anterior or posterior or a combination, in which osteotomies are sometimes required. In this study, the authors proposed a less invasive surgical strategy using the standard Cloward's approach for complete resection of a schwannoma arising from the T1 nerve root. OBSERVATIONS: Two patients, each harboring a large T1 tumor, one on each side, underwent Cloward's approach with and without thoracoscopic surgery. Both patients had complete resection of the tumor. Considering the benign and encapsulated nature of neurogenic tumors, Cloward's approach under neuromonitoring, which is a common procedure for anterior cervical discectomy for most neurosurgeons, is a safe and less invasive alternative for Pancoast neurogenic tumors. For patients whose tumor cannot be removed completely via Cloward's approach, video-assisted thoracoscopic surgery is a viable backup plan with minimal invasiveness. LESSONS: Cloward's approach is a viable option for Pancoast neurogenic tumors.

Functional neurological disorders in patients undergoing spinal surgery: illustrative case.

BACKGROUND: "Conversion disorder" refers to bodily dysfunction characterized by either sensory or motor neurological symptoms that are unexplainable by a medical condition. Given their somatosensory context, such disorders often require extensive medical evaluation, and the diagnosis can only be made after structural disease is excluded or fails to account for the severity and/or spectrum of the patient's deficits. OBSERVATIONS: The authors briefly review functional psychiatric disorders and discuss the comprehensive workup of a patient with a functional postoperative neurological deficit, drawing from their recent experience with a patient who presented with conversion disorder immediately after undergoing anterior cervical discectomy and fusion. LESSONS: Conversion disorder has been found to be associated with bodily stress, requiring surgeons to be aware of this condition in the postoperative setting. This is especially true in neurosurgery, given the overlap of true neurological pathology, postoperative complications, and manifestations of conversion disorder. Although accurately diagnosing and managing patients with conversion disorder remains challenging, an understanding of the multifactorial nature of its etiology can help clinicians develop a methodical approach to this condition.

The efficacy of somatosensory evoked potentials in evaluating new neurological deficits after spinal thoracic fusion and decompression.

OBJECTIVE: Posterior thoracic fusion (PTF) is used as a surgical treatment for a wide range of pathologies. The monitoring of somatosensory evoked potentials (SSEPs) is used to detect and prevent injury during many neurological surgeries. The authors conducted a study to evaluate the efficacy of SSEPs in predicting perioperative lower-extremity (LE) neurological deficits during spinal thoracic fusion surgery. METHODS: The authors included patients who underwent PTF with SSEP monitoring performed throughout the entire surgery from 2010 to 2015 at the University of Pittsburgh Medical Center (UPMC). The sensitivity, specificity, odds ratio, and receiver operating characteristic curve were calculated to evaluate the diagnostic accuracy of SSEP changes in predicting postoperative deficits. Univariate analysis was completed to determine the impact of age exceeding 65 years, sex, obesity, abnormal baseline testing, surgery type, and neurological deficits on the development of intraoperative changes. RESULTS: From 2010 to 2015, 771 eligible patients underwent SSEP monitoring during PTF at UPMC. Univariate and linear regression analyses showed that LE SSEP changes significantly predicted LE neurological deficits. Significant changes in LE SSEPs had a sensitivity and specificity of 19% and 96%, respectively, in predicting LE neurological deficits. The diagnostic odds ratio for patients with new LE neurological deficits who had significant changes in LE SSEPs was 5.86 (95% CI 2.74-12.5). However, the results showed that a loss of LE waveforms had a poor predictive value for perioperative LE deficits (diagnostic OR 1.58 [95% CI 0.19-12.83]). CONCLUSIONS: Patients with new postoperative LE neurological deficits are 5.9 times more likely to have significant changes in LE SSEPs during PTF. Surgeon awareness of an LE SSEP loss may alter surgical strategy and positively impact rates of postoperative LE neurological deficit status. The relatively poor sensitivity of LE SSEP monitoring may indicate a need for multimodal neurophysiological monitoring, including motor evoked potentials, in thoracic fusion surgery.

Management of an odontoid synchondrosis fracture causing chronic translational anterior atlanto-axial subluxation in a child with autism: case report.

The authors report an unusual case of an odontoid synchondrosis fracture causing chronic translational anterior atlanto-axial subluxation and present a discussion of the unique management of this case. Traumatic translational anterior atlanto-axial subluxation is a rare manifestation within pediatrics. Patients with preexisting abnormalities in ligamentous or bony structures may present with unusual symptomatology, which could result in delay of treatment. A 6-year-old male patient with autism who presented with acute respiratory arrest was noted to have an odontoid synchondrosis fracture and severe anterior translational atlanto-axial subluxation. Initial attempts at reduction with halo traction were tried for first-line treatment. However, because of concern regarding possible inadvertent worsening of the impingement, the presence of comorbid macrocephaly, and possible instability with only C1-2 fusion, a posterior C1 laminectomy was performed. Further release of the C1-2 complex and odontoid peg from extensive fibrous tissue allowed for complete reduction. Acute injuries of the C1-2 complex may not present as expected, and the presence of pain is not a reliable symptom. Halo traction is an appropriate initial treatment, but some patients may require surgical realignment and stabilization.

The efficacy of intraoperative multimodal monitoring in pedicle subtraction osteotomies of the lumbar spine.

OBJECTIVE: Iatrogenic spine injury remains one of the most dreaded complications of pedicle subtraction osteotomies (PSOs) and spine deformity surgeries. Thus, intraoperative multimodal monitoring (IOM), which has the potential to provide real-time feedback on spinal cord signal transmission, has become the gold standard in such operations. However, while the benefits of IOM are well established in PSOs of the thoracic spine and scoliosis surgery, its utility in PSOs of the lumbar spine has not been robustly documented. The authors' aim was to determine the impact of IOM on outcomes in patients undergoing PSO of the lumbar spine. METHODS: All patients older than 18 years who underwent lumbar PSOs at the authors' institution from 2007 to 2017 were analyzed via retrospective chart review and categorized into one of two groups: those who had IOM guidance and those who did not. Perioperative complications were designated as the primary outcome measure and postoperative quality of life (QOL) scores, specifically the Parkinson's Disease Questionnaire-39 (PDQ-39) and Patient Health Questionnaire-9 (PHQ-9), were designated as secondary outcome measures. Data on patient demographics, surgical and monitoring parameters, and outcomes were gathered, and statistical analysis was performed to compare the development of perioperative complications and QOL scores between the two cohorts. In addition, the proportion of patients who reached minimal clinically important difference (MCID), defined as an increase of 4.72 points in the PDQ-39 score or a decrease of 5 points in the PHQ-9 score, in the two cohorts was also determined. RESULTS: A total of 95 patients were included in the final analysis. IOM was not found to significantly impact the development of new postoperative deficits (p = 0.107). However, the presence of preoperative neurological comorbidities was found to significantly correlate with postoperative neurological complications (p = 0.009). Univariate analysis showed that age was positively correlated with MCID achievement 3 months after surgery (p = 0.018), but this significance disappeared at the 12-month postoperative time point (p = 0.858). IOM was not found to significantly impact MCID achievement at either the 3- or 12-month postoperative period as measured by PDQ-39 (p = 0.398 and p = 0.156, respectively). Similarly, IOM was not found to significantly impact MCID achievement at either the 3- or 12-month postoperative period, as measured by PHQ-9 (p = 0.230 and p = 0.542, respectively). Multivariate analysis showed that female sex was significantly correlated with MCID achievement (p = 0.024), but this significance disappeared at the 12-month postoperative time point (p = 0.064). IOM was not found to independently correlate with MCID achievement in PDQ-39 scores at either the 3- or 12-month postoperative time points (p = 0.220 and p = 0.097, respectively). CONCLUSIONS: In this particular cohort, IOM did not lead to statistically significant improvement in outcomes in patients undergoing PSOs of the lumbar spine (p = 0.220). The existing clinical equipoise, however, indicates that future studies in this arena are necessary to achieve systematic guidelines on IOM usage in PSOs of the lumbar spine.