Chondromyxoid Fibroma of the Sacral Spine.

Background and Importance. Chondromyxoid fibromas are rare tumors of cartilaginous origin typically found in long bones. They usually present during the second and third decades of life. In this case report, we describe the case of a 60-year-old male who presented with back pain and was later found to have a sacral mass. Further immunohistochemical analysis determined that the mass was a chondromyxoid fibroma. Clinical Presentation. A 60-year-old male presented with worsening lower back pain over the course of 2 years. Magnetic resonance imaging demonstrated a destructive mass centered at S4 with heterogeneous enhancement. The patient underwent an S3-to-Co1 laminectomy for gross total resection of the tumor. Histology demonstrated a biphasic, lobulated appearance, characteristic of a chondromyxoid fibroma. The tissue stained faintly positive for multicytokeratin, and it was negative for markers S-100 protein and brachyury, indicating that it was not a chordoma. Conclusion. Only 8 cases have documented sacral chondromyxoid fibroma. As these are exceedingly rare tumors, especially within the sacral spine, the differential diagnosis includes other malignant tumors more likely to be found in the spine, particularly chordomas and chondrosarcomas. Immunohistochemistry and histology are essential in making a definitive diagnosis. This case provides a comprehensive illustration of the clinical presentation, radiographic findings, and immunohistochemistry of sacral chondromyxoid fibroma.

Parasitic infections of the spine: case series and review of the literature.

OBJECTIVEAlthough parasitic infections are endemic to parts of the developing world and are more common in areas with developing economies and poor sanitary conditions, rare cases may occur in developed regions of the world.METHODSArticles eligible for the authors' literature review were initially searched using PubMed with the phrases "parasitic infections" and "spine." After the authors developed a list of parasites associated with spinal cord infections from the initial search, they expanded it to include individual diagnoses, using search terms including "neurocysticercosis," "schistosomiasis," "echinococcosis," and "toxoplasmosis."RESULTSTwo recent cases of parasitic spinal infections from the authors' institution are included.CONCLUSIONSKey findings on imaging modalities, laboratory studies suggestive of parasitic infection, and most importantly a thorough patient history are required to correctly diagnose parasitic spinal infections.

The effect of prophylactic vancomycin powder on infections following spinal surgeries: a systematic review.

OBJECTIVEThe use of vancomycin powder in spine surgery for prophylaxis against surgical site infections (SSIs) is well debated in the literature, with the majority of studies demonstrating improvement and some studies demonstrating no significant reduction in infection rate. It is well known in certain populations that vancomycin powder reduces the general rate of infection, but its effects on reducing the rate of infection due to gram-negative pathogens are not well reviewed. The goal of this paper was to review studies that investigated the efficacy of vancomycin powder as a prophylactic agent against SSI and demonstrate whether the rate of infections by gram-negative pathogens is impacted.METHODSAn electronic search of the published literature was performed using PubMed and Google Scholar in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A variety of combinations of the search terms "vancomycin powder," "infection," "spine," "gram-negative," "prophylaxis," and "surgical site" was used. Inclusion criteria were studies that 1) described an experimental group that received intraoperative intrawound vancomycin powder; 2) included adequately controlled groups that did not receive intraoperative intrawound vancomycin powder; 3) included the number of patients in both the experimental and control groups who developed infection after their spine surgery; and 4) identified the pathogen-causing infection. Studies not directly related to this review's investigation were excluded from the initial screen. Among the studies that met the criteria of the initial screen, additional reasons for exclusion from the systematic review included lack of a control group, unspecified size of control groups, and inconsistent use of vancomycin powder in the experimental group.RESULTSThis systematic review includes 21 studies with control groups. Vancomycin powder significantly reduced the relative risk of developing an SSI (RR 0.55, 95% CI 0.45-0.67, p < 0.0001). In addition, the use of vancomycin powder did not significantly increase the risk of infection by gram-negative pathogens (RR 1.11, 95% CI 0.66-1.86, p = 0.701).CONCLUSIONSThe results of this systematic review suggest that intrawound vancomycin powder is protective against SSI. It is less clear if this treatment increases the risk of gram-negative infection. Further studies are required to investigate whether rates of infection due to gram-negative pathogens are affected by the use of vancomycin powder.

Hemorrhagic Complications of External Ventriculostomy in the Aspirin and P2Y12 Response Assay Era.

OBJECTIVE: Hemorrhagic complications reported from external ventricular drain (EVD) placement range from 10% to 44%. There remains limited literature investigating the incidence, risk factors, and mechanisms to prevent its occurrence, especially in the setting of antiplatelet agent use. We investigated EVD-related hemorrhagic complications after the implementation of VerifyNow platelet inhibition assays at our institution. METHODS: Medical records from 445 patients requiring EVD placement during a 2-year period during which our institution used the assays were reviewed. In total 345 patients were included, and 208 of them underwent assay testing. Indications for EVD included complications of cerebrovascular disease (n = 215), traumatic brain injury (n = 74), primary hydrocephalus (n = 23), and tumor (n = 33). Hemorrhage was defined as any new area of hyperdensity adjacent to or immediately along the catheter trajectory on computed tomography. RESULTS: There was no significant decrease in catheter-induced hemorrhage (CIH) between patients who underwent the VerifyNow assay and those who did not. Platelet transfusion did not significantly decrease the risk of CIH. CIH occurred in 17.7% of patients, significantly decreased when compared with our previously published incidence of 33% before platelet inhibition assay use (P < 0.05). Patients with cerebrovascular disease complications exhibited a significant decrease in CIH, 20% versus 39%, before assay use (P < 0.01). CONCLUSIONS: The incidence of hemorrhage is lower in our new cohort when compared with that of our previously published cohort. Despite the overall decreased rate of hemorrhage, there was no significant difference in hemorrhage rates between patients who did or did not undergo the assay. Platelet transfusion did not decrease the incidence of hemorrhage in patients with inhibited platelet function.

Lung adenocarcinoma presenting as intramedullary spinal cord metastasis: Case report and review of literature.

Intramedullary spinal cord metastasis (IMSCM) is a rare entity which lacks well-defined treatment guidelines, yet sees rising incidence. We report a case of a 67-year-old man who presented with severe neck pain and numbness in his right fourth and fifth digits, and was found to have a C5-7 IMSCM of previously unknown lung adenocarcinoma. He underwent gross total resection of the IMSCM, afatinib, and radiation treatment. He had full reversal of his pain and sensory deficit, and remained ambulatory without any focal neurological deficit. Additionally, we conducted a literature review of original case series of IMSCM published between 1983 and 2016, representing 138 unique cases, and discuss various treatments with a focus on surgical resection and general treatment of stage IV lung adenocarcinoma. 18.75% of cases of IMSCM were an initial presentation of underlying malignancy. Rapidly progressive pain and weakness was the most common presentation, often compromising ambulatory status. Median survival ranged from 3.8 to 11.6 months after treatment in patients who were deceased at time of publication. Treatments included corticosteroids, chemotherapy, various radiotherapies, and surgical resection. Surgical resection was found to greatly improve symptoms and preserve ambulatory status, and was associated with increased survival time up to double that of non-surgical treatments. Most authors recommended surgical resection only in symptomatic patients with reversible deficits, to palliate symptoms and preserve ambulation. IMSCM can herald an underlying malignancy, and surgical resection can preserve ambulatory status and palliate symptoms as well increase survival time in a subset of patients.

Direct Midline Posterior Corpectomy and Fusion of a Lumbar Burst Fracture with Retrospondyloptosis.

BACKGROUND: Traumatic burst fractures of the lumbar spine can result in significant neurologic injury and mechanical instability. The ideal surgical approach for the treatment of unstable lumbar spine burst fractures remains debatable. CASE DESCRIPTION: A 37-year-old man presented with severe neurologic injury including loss of motor function below the level of the iliopsoas muscles bilaterally, saddle anesthesia, and absent rectal tone, after a fall from 18.28 m (60 ft). Computed tomography showed an L4 vertebral body comminuted burst fracture with complete posterior translation of L4 over L5. The patient was taken to the operating room for an L4 corpectomy and L2-S1 posterior fusion. The L4 vertebral body was visualized posterior to the posterior elements of L5 and resected in a piecemeal fashion. Because the thecal sac had been completely transected, a visible path down the L3-L4 and L4-L5 disk spaces was apparent, allowing direct posterior discectomies at these levels and completion of the L4 segment resection. The use of a direct posterior approach resulted in minimal blood loss, correction of sagittal alignment, and satisfactory outcomes comparable with the standard posterior transpedicular approach. Construct stability and solid bony fusion have been maintained for 4 years postoperatively. CONCLUSIONS: The use of a direct midline posterior corpectomy approach may be considered for patients with lumbar burst fractures, high-grade neurologic injury, and transection of the thecal sac.

First report of major vascular injury due to lateral transpsoas approach leading to fatality.

Extreme lateral interbody fusion (XLIF) has gained popularity among spine surgeons for treating multiple conditions of the lumbar spine. In contrast to the anterior lumbar interbody fusion (ALIF) approach, the minimally invasive XLIF approach affords wide access to the lumbar disc space without an access surgeon and causes minimal tissue disruption. The XLIF approach offers many advantages over other lumbar spine approaches, with a reportedly low complication profile. The authors describe the first fatality reported in the literature following an XLIF approach. They describe the case of a 50-year-old woman who suffered a fatal intraoperative injury to the great vessels during a lateral transpsoas approach to the L4-5 disc space.

Progressive multifocal leukoencephalopathy: a rare cause of cerebellar edema and atypical mass effect. A case report.

Progressive multifocal leukoencephalopathy (PML) is an opportunistic demyelinating disease of the CNS caused by the JC papovavirus (JCV). Demyelination due to oligodendrocyte death leads to multifocal, asymmetric lesions. MRI is a valuable tool for detecting and differentiating PML from other neuropathies. Radiographically, PML classically presents as bilateral, subcortical white matter lesions with a lack of brain atrophy. As the disease progresses, lesions become larger and coalesce to become confluent. Minor edema and mass effect are infrequently described and the presence of significant mass effect suggests an alternative diagnosis. In our case, a patient demonstrated atypical marked infratentorial mass effect. Bilaterally, cerebellar lesions with associated mass effect were observed, as well as effacement of cerebellar folia and partial effacement of the fourth ventricle. The diagnosis of PML was confirmed with a biopsy of the right cerebellar lesion showing classic PML histology, with JCV DNA detection by polymerase chain reaction in the biopsy material.

Titanium mesh-assisted dural tenting for an expansile suboccipital cranioplasty in the treatment of Chiari 1 malformation.

Cerebellar ptosis and dural prolapse are known complications after posterior craniocervical decompression of Chiari 1 malformation (CM1), and are associated with larger craniectomies, epidural scarring and intradural adhesions. Although management of these complications has been well documented, little has been reported in regards to their prevention. We describe our variation of the posterior fossa decompression technique for CM1 using a titanium mesh-assisted dural tenting expansile cranioplasty to prevent both cerebellar ptosis and dural prolapse. A watertight dural augmentation patch is performed after posterior craniocervical decompression. A titanium mesh cranioplasty is performed to cover the superior aspect of the craniectomy. The duraplasty is then tented to the titanium mesh plate with several interrupted sutures. The titanium mesh plate was intended to prevent postoperative cerebellar ptosis or sag, while the dural tenting was performed to prevent delayed collapse and restenosis of the cistern magna. Four patients with CM1 underwent this technique without complication. Postoperative MRI did not demonstrate cerebellar ptosis, restenosis or collapse of the cisterna magna. The expansile suboccipital cranioplasty with titanium mesh-assisted dural tenting technique is a simple and efficient strategy that may be useful to prevent cerebellar ptosis and dural prolapse and maintain the patency of the surgically created neo-cisterna magna.

The history of brain retractors throughout the development of neurological surgery.

Early neurosurgical procedures dealt mainly with treatment of head trauma, especially skull fractures. Since the early medical writings by Hippocrates, a great deal of respect was given to the dura mater, and many other surgeons warned against violating the dura. It was not until the 19th century that neurosurgeons started venturing beneath the dura, deep into the brain parenchyma. With this advancement, brain retraction became an essential component of intracranial surgery. Over the years brain retractors have been created pragmatically to provide better visualization, increased articulations and degrees of freedom, greater stability, less brain retraction injury, and less user effort. Brain retractors have evolved from simple handheld retractors to intricate brain-retraction systems with hand-rest stabilizers. This paper will focus on the history of brain retractors, the different types of retractors, and the progression from one form to another.

The history of craniotomy for headache treatment.

Both the history of headache and the practice of craniotomy can be traced to antiquity. From ancient times through the present day, numerous civilizations and scholars have performed craniotomy in attempts to treat headache. Today, surgical intervention for headache management is becoming increasingly more common due to improved technology and greater understanding of headache. By tracing the evolution of the understanding of headache alongside the practice of craniotomy, investigators can better evaluate the mechanisms of headache and the therapeutic treatments used today.

Prevalence of asymptomatic incidental aneurysms: a review of 2,685 computed tomographic angiograms.

OBJECTIVE: Intracranial aneurysms are a public health issue with a potential for rupturing, causing significant morbidity/mortality. The prevalence of unruptured intracranial aneurysms, including those that are asymptomatic, varies widely, as it has been determined through autopsy studies as well as conventional angiography. However, computed tomography angiography, a less invasive procedure, has replaced the use of conventional angiography in the recent decades. The objective of the present study is to determine the prevalence of incidental aneurysms. METHODS: The present study reviews all computed tomography angiography cases within the past decade at a single institution. RESULTS: Of 2195 cases included in the study, 39 (1.8%) were found to have asymptomatic unruptured aneurysms. CONCLUSIONS: The numbers of asymptomatic incidental aneurysms have increased.

Treatment of a supratentorial primitive neuroectodermal tumor using magnetic resonance-guided laser-induced thermal therapy.

Supratentorial primitive neuroectodermal tumors (PNETs) are rare tumors that carry a poorer prognosis than those arising from the infratentorial compartment (such as medulloblastoma). The overall prognosis for these patients depends on several factors including the extent of resection, age at diagnosis, CSF dissemination, and site in the supratentorial space. The authors present the first case of a patient with a newly diagnosed supratentorial PNET in which cytoreduction was achieved with MR-guided laser-induced thermal therapy. A 10-year-old girl presented with left-sided facial weakness and a large right thalamic mass extending into the right midbrain. The diagnosis of supratentorial PNET was made after stereotactic biopsy. Therapeutic options for this lesion were limited because of the risks of postoperative neurological deficits with resection. The patient underwent MR-guided laser-induced thermal ablation of her tumor. Under real-time MR thermometry, thermal energy was delivered to the tumor at a core temperature of 90°C for a total of 960 seconds. The patient underwent follow-up MR imaging at regular intervals to evaluate the tumor response to the thermal ablation procedure. Initial postoperative scans showed an increase in the size of the lesion as well as the amount of the associated edema. Both the size of the lesion and the edema stabilized by 1 week and then decreased below preablation levels at the 3-month postsurgical follow-up. There was a slight increase in the size of the lesion and associated edema at the 6-month follow-up scan, presumably due to concomitant radiation she received as part of her postoperative care. The patient tolerated the procedure well and has had resolution of her symptoms since surgery. Further study is needed to assess the role of laser-induced thermal therapy for the treatment of intracranial tumors. As such, it is a promising tool in the neurosurgical armamentarium. Postoperative imaging has shown no evidence of definitive recurrence at the 6-month follow-up period, but longer-term follow-up is required to assess for late recurrence.

Ossification of the ligamentum flavum: a unique report of a Hispanic woman.

Ossification of the ligamentum flavum (OLF) is a disease of ectopic bone formation within the ligamentum flavum, which may result in mass effect and neurological compromise. The low thoracic region is the most common region of occurrence, and this is followed by the cervical, then lumbar, spine. The prevalence of OLF is significantly higher in the Japanese population compared with other nationalities and has a male preponderance. Ossification of the ligamentum flavum has been reported in association with the more common ligamentous pathological entities--ossification of the posterior longitudinal ligament and diffuse idiopathic skeletal hyperostosis. These latter two conditions have been linked to several metabolic processes, and a possible genetic basis has been hypothesized. Here, the authors present a unique case of OLF of the cervical spine in a patient with idiopathic hypercalcemia.

The effects of intrathecal hypotension on tissue perfusion and pathophysiological outcome after acute spinal cord injury.

OBJECT: Venous stasis and intrathecal hypertension are believed to play a significant role in the hypoperfusion present in the spinal cord following injury. Lowering the intrathecal pressure via cerebrospinal fluid (CSF) drainage has been effective in treating spinal cord ischemia during aorta surgery. The purpose of the present study was to determine whether CSF drainage increases spinal cord perfusion and improves outcome after spinal injury in an animal model. METHODS: Anesthetized adult rabbits were subjected to a severe contusion spinal cord injury (SCI). Cerebrospinal fluid was then drained via a catheter to lower the intrathecal pressure by 10 mm Hg. Tissue perfusion was assessed at the site of injury, and values obtained before and after CSF drainage were compared. Two other cohorts of animals were subjected to SCI: 1 group subsequently underwent CSF drainage and the other did not. Results of histological analysis, motor evoked potential and motor function testing were compared between the 2 cohorts at 4 weeks postinjury. RESULTS: Cerebrospinal fluid drainage led to no significant improvement in spinal cord tissue perfusion. Four weeks after injury, the animals that underwent CSF drainage demonstrated significantly smaller areas of tissue damage at the injury site. There were no differences in motor evoked potentials or motor score outcomes at 4 weeks postinjury. CONCLUSIONS: Cerebrospinal fluid drainage effectively lowers intrathecal pressure and decreases the amount of tissue damage in an animal model of spinal cord injury. Further studies are needed to determine whether different draining regimens can improve motor or electrophysiological outcomes.

Activated autologous macrophage implantation in a large-animal model of spinal cord injury.

OBJECT: Axonal regeneration may be hindered following spinal cord injury (SCI) by a limited immune response and insufficient macrophage recruitment. This limitation has been partially surmounted in small-mammal models of SCI by implanting activated autologous macrophages (AAMs). The authors sought to replicate these results in a canine model of partial SCI. METHODS: Six dogs underwent left T-13 spinal cord hemisection. The AAMs were implanted at both ends of the lesion in 4 dogs, and 2 other dogs received sham implantations of cell media. Cortical motor evoked potentials (MEPs) were used to assess electrophysiological recovery. Functional motor recovery was assessed with a modified Tarlov Scale. After 9 months, animals were injected with wheat germ agglutinin-horseradish peroxidase at L-2 and killed for histological assessment. RESULTS: Three of the 4 dogs that received AAM implants and 1 of the 2 negative control dogs showed clear recovery of MEP response. Behavioral assessment showed no difference in motor function between the AAM-treated and control groups. Histological investigation with an axonal retrograde tracer showed neither local fiber crossing nor significant uptake in the contralateral red nucleus in both implanted and negative control groups. CONCLUSIONS: In a large-animal model of partial SCI treated with implanted AAMs, the authors saw no morphological or histological evidence of axonal regeneration. Although they observed partial electrophysiological and functional motor recovery in all dogs, this recovery was not enhanced in animals treated with implanted AAMs. Furthermore, there was no morphological or histological evidence of axonal regeneration in animals with implants that accounted for the observed recovery. The explanation for this finding is probably multifactorial, but the authors believe that the AAM implantation does not produce axonal regeneration, and therefore is a technology that requires further investigation before it can be clinically relied on to ameliorate SCI.

Prospective serial proton MR spectroscopic assessment of response to tamoxifen for recurrent malignant glioma.

OBJECTIVE: Early prediction of imminent failure during chemotherapy for malignant glioma has the potential to guide proactive alterations in treatment before frank tumor progression. We prospectively followed patients with recurrent malignant glioma receiving tamoxifen chemotherapy using proton magnetic resonance spectroscopic imaging ((1)H-MRSI) to identify intratumoral metabolic changes preceding clinical and radiological failure. METHODS: We performed serial (1)H-MRSI examinations to assess intratumoral metabolite intensities in 16 patients receiving high-dose oral tamoxifen monotherapy for recurrent malignant glioma (WHO grade III or IV) as part of a phase II clinical trial. Patients were followed until treatment failure, death, or trial termination. RESULTS: Patients were officially classified as responders (7 patients) or non-responders (9 patients) 8 weeks into treatment. At 8 weeks, responders and non-responders had different intratumoral intensities across all measured metabolites except choline. Beyond 8 weeks, metabolite intensities remained stable in all responders, but changed again with approaching disease progression. Choline, lipid, choline/NAA, and lactate/NAA were significantly elevated (P < 0.02), while creatine (P < 0.04) was significantly reduced, compared to stabilized levels on average 4 weeks prior to failure. Lactate was significantly elevated (P = 0.036) fully 8 weeks prior to failure. In one patient who was still responding to tamoxifen at the conclusion of the trial, metabolite intensities never deviated from 8-week levels for the duration of follow-up. CONCLUSIONS: Characteristic global intratumoral metabolic changes, detectable on serial (1)H-MRSI studies, occur in response to chemotherapy for malignant glioma and may predict imminent treatment failure before actual clinical and radiological disease progression.

Neurosurgical implications of mannitol accumulation within a meningioma and its peritumoral region demonstrated by magnetic resonance spectroscopy: case report.

Mannitol is widely considered the hyperosmolar therapy of choice in routine neurosurgical practice for the reduction of intracranial pressure (ICP). The authors present a unique case of a patient with a large meningioma treated with mannitol, in which mannitol accumulation within the tumor and its surrounding parenchyma was shown using in vivo magnetic resonance spectroscopy (MRS). This rare appearance of mannitol on MRS was characterized by a wide-based peak at 3.8 ppm, which remained detectable several hours after the last dose. These findings provide the first in vivo evidence in support of the prevailing theory that mannitol leakage into the peritumoral edematous region may contribute to rebound increases in ICP and suggest that this phenomenon has the potential to occur in extraaxial tumors. Judicious use of mannitol in the setting of elevated ICP due to tumor may be indicated to avoid potentially deleterious side effects caused by its accumulation.