Molecular hydrogen therapy for neurological diseases: a review of current evidence

Reactive oxygen species and other free radicals cause oxidative stress which is the underlying pathogenesis of cellular injury in various neurological diseases. Molecular hydrogen therapy with its unique biological property of selectively scavenging pathological free radicals has demonstrated therapeutic potential in innumerable animal studies and some clinical trials. These studies have implicated several cellular pathways affected by hydrogen therapy in explaining its anti-inflammatory and antioxidative effects. This article reviews relevant animal and clinical studies that demonstrate neuroprotective effects of hydrogen therapy in stroke, neurodegenerative diseases, neurotrauma, and global brain injury.

Response to intravenous racemic ketamine after switch from intranasal (S)-ketamine on symptoms of treatment-resistant depression and post-traumatic stress disorder in Veterans: A retrospective case series

BACKGROUND

Racemic (R,S)-ketamine is a glutamatergic drug with potent and rapid acting antidepressant effects. An intranasal formulation of (S)-ketamine was recently approved by the US Food and Drug Administration (FDA) to be used in individuals with treatment-resistant depression (TRD). There are no data directly comparing outcomes on depression or other comorbidities between these two formulations of ketamine. However, recent meta-analyses have suggested that IV racemic ketamine may be more potent than IN-(S)-ketamine.

METHODS

We retrospectively analyzed clinical outcomes in 15 Veterans with comorbid TRD and post-traumatic stress disorder (PTSD) who underwent ketamine treatment at the VA San Diego Neuromodulation Clinic. All Veterans included in this analysis were given at least 6 intranasal (IN)-(S)-ketamine treatments prior to switching to treatment with IV racemic ketamine.

RESULTS

Veterans receiving ketamine treatment ( across both IN-(S)-ketamine and IV-(R,S)-ketamine) showed significant reductions in both the Patient Health Questionnaire-9 (PHQ-9), a self-report scale measuring depression symptoms (rm ANOVA F(14,42) = 12.6, p < 0.0001), and in the PTSD checklist for DSM-5 (PCL-5), a self-report scale measuring PSTD symptoms (rm ANOVA F(13,39) = 5.9, p = 0.006). Post hoc testing revealed that PHQ-9 scores were reduced by an average of 2.4 ± 1.2 compared to baseline after (S)-ketamine treatments (p = 0.1) and by an average of 5.6 ± 1 after IV-ketamine treatments (p = 0.0003) compared to pretreatment baseline scores. PCL-5 scores were reduced by an average of 4.3 ± 3.3 after IN (S)-ketamine treatments (p = 0.6) and 11.8 ± 3.5 after IV-ketamine treatments (p = 0.03) compared to pretreatment baseline scores.

CONCLUSIONS

This work suggests that off-label IV-(R,S)-ketamine could be considered a reasonable next step in patients who do not respond adequately to the FDA-approved IN-(S)-ketamine. Further double-blinded, randomized controlled trials are warranted to assess whether IV racemic ketamine is more effective than IN-(S)-ketamine.

Management of a ruptured and unruptured pial arteriovenous fistula during and after pregnancy

We present the case of a 16-week pregnant 19-year-old female who presented with hemiplegia due to a ruptured right frontal pial arteriovenous fistula (PAVF). She was also found to have an unruptured right temporal PAVF and a family history of brain hemorrhage. The patient was managed with Onyx embolization of the ruptured fistula, followed by surgical excision and hematoma evacuation. At 35 weeks gestation, she underwent cesarean section to prevent rupture of the second fistula in the setting of peripartum hypervolemia and increasing headaches. The child was delivered healthy. Subsequently, the right temporal AV fistula, supplied by a middle cerebral artery and posterior cerebral artery branch, underwent staged embolization resulting in complete occlusion. The patient recovered to a modified Rankin score of two, with a left foot drop as only persistent significant motor deficit.

Periprosthetic Osteolysis in Cervical Total Disc Arthroplasty: A Single Institutional Experience

BACKGROUND

Cervical disc arthroplasty (CDA) affords an excellent alternative to cervical fusion for the treatment of symptomatic patients with degenerative disc disease. As more surgeons perform CDAs, an understanding of the complications associated with this technique is crucial. Periprosthetic osteolysis (PO) is a rare potential complication associated with CDA.

OBJECTIVE

To highlight potential complications associated with CDA.

METHODS

A retrospective chart review of patients who underwent CDA at our institution was performed. Patient outcomes and relevant clinical and radiographical data were analyzed in addition to associated complications. Explanted devices were subjected to macroscopic and microscopic analyses.

RESULTS

A total of 88 patients were included: 68 patients underwent 1-level CDA and 20 patients had 2-level CDA. Implants used in this series included Mobi-C (Zimmer Biomet), Prestige LP (Medtronic), Secure C (Globus), Advent (Orthofix), and ProDisc C (DePuy). One patient demonstrated symptoms of myeloradiculopathy that correlated with radiographical periprosthetic osteolysis and required surgical intervention in the form of disc explantation, corpectomy, and cervical instrumented fusion. Device retrieval analysis demonstrated evidence of elevated oxidation levels and increased wear in the presence of high concentrations of metal ions and debris in the surrounding tissue. The tissue did not exhibit any immune response, infection, or acute inflammation.

CONCLUSION

PO is a potential complication of CDA that occurs irrespective of the type of implant used. We describe its occurrence and management and highlight the importance of being aware of this understated phenomenon.

Review of Atypical and Anaplastic Meningiomas: Classification, Molecular Biology, and Management

Although the majority of meningiomas are slow-growing and benign, atypical and anaplastic meningiomas behave aggressively with a penchant for recurrence. Standard of care includes surgical resection followed by adjuvant radiation in anaplastic and partially resected atypical meningiomas; however, the role of adjuvant radiation for incompletely resected atypical meningiomas remains debated. Despite maximum treatment, atypical, and anaplastic meningiomas have a strong proclivity for recurrence. Accumulating mutations over time, recurrent tumors behave more aggressively and often become refractory or no longer amenable to further surgical resection or radiation. Chemotherapy and other medical therapies are available as salvage treatment once standard options are exhausted; however, efficacy of these agents remains limited. This review discusses the risk factors, classification, and molecular biology of meningiomas as well as the current management strategies, novel therapeutic approaches, and future directions for managing atypical and anaplastic meningiomas.

Tailoring the surgical corridor to the basilar apex in the pretemporal transcavernous approach: morphometric analyses of different neurovascular mobilization maneuvers

BACKGROUND

The pretemporal transcavernous approach (PTA) provides optimal exposure and access to the basilar artery (BA); however, the PTA can be invasive when vital neurovascular structures are mobilized. The goal of this study was to evaluate mobilization strategies to tailor approaches to the BA.

METHODS

After an orbitozygomatic craniotomy, 10 sides of 5 cadaveric heads were used to assess the surgical access to the BA via the opticocarotid triangle (OCT), carotid-oculomotor triangle (COT), and oculomotor-tentorial triangle (OTT). Measurements were obtained, and morphometric analyses were performed for natural neurovascular positions and after each stepwise expansion maneuver. An imaginary line connecting the midpoints of the limbus sphenoidale and dorsum sellae was used as a reference to normalize the measurements of BA exposure and to facilitate the clinical applicability of this technique.

RESULTS

In the OCT, the exposed BA segment ranged from - 1 ± 3.9 to + 6 ± 2.0 mm in length in its natural position. In the COT, the accessible BA segment ranged from - 4 ± 2.3 to - 2 ± 3.0 mm in length in its natural position. Via the OTT, the accessible BA segment ranged from - 7 ± 2.6 to - 5 ± 2.8 mm in length in its natural position. In the OCT, COT, and OTT, a posterior clinoidectomy extended the exposure down to - 6 ± 2.7, - 8 ± 2.5, and - 9 ± 2.9 mm, respectively.

CONCLUSIONS

This study quantitatively evaluated the need for the expansion maneuvers in the PTA to reach BA aneurysms according to the patient's anatomical characteristics.

The anterior incisural width as a preoperative indicator for intradural space evaluation: An anatomical investigation

Background:

The opticocarotid triangle (OCT) and the carotico-oculomotor triangle (COT) are two anatomical triangles used in accessing the interpeduncular region. Our objective is to evaluate if the anterior incisural width (AIW) is an indicator to predict the intraoperative exposure through both triangles.

Methods:

Twenty sides of 10 cadaveric heads were dissected and analyzed. The heads were divided into the following: Group A – narrow anterior incisura and Group B – wide anterior incisura – using 26.6 mm as a cutoff distance of the AIW. Subsequently, the area of the COT and the OCT in the transsylvian approach was measured, along with the maximum widths through the two trajectories in modified superior transcavernous approach.

Results:

The COT in the wide group was shown to have a significantly larger area compared with the COT in the narrow group (38.4 ± 12.64 vs. 58.3 ± 15.72 mm, P < 0.01). No difference between the two groups was reported in terms of the area of the OCT (50.9 ± 19.22 mm vs. 63.5 ± 15.53 mm, P = 0.20), the maximum width of the OCT (6.6 ± 1.89 vs. 6.5 ± 1.38 mm, P = 1.00), or the maximum width of the COT (11.7 ± 2.06 vs. 12.2 ± 2.32 mm, P = 0.50). Clinical cases were included.

Conclusion:

An AIW <26.6 mm is an unfavorable factor related to a limited COT area in a transsylvian approach for pathologies at the interpeduncular fossa. Preoperative identification and measurement of a narrow AIW can suggest the need to add a transcavernous approach.

High flow bypass for right giant cavernous internal carotid artery aneurysm with fibromuscular dysplasia of cervical internal carotid artery: microsurgical 2-D video

Background

It is well known that intracranial aneurysms can be associated to fibromuscular dysplasia (FMD). Nevertheless, it is not clear the best treatment strategy when there is an association of giant symptomatic cavernous carotid aneurysm with extensive cervical internal carotid artery (ICA) FMD.

Case Description

We present the case of 63 year-old right-handed female with hypothyroidism, 1 month history of right-sided pulsatile headache and visual disturbances with feeling of fullness sensation and blurry vision. Her neurological exam showed partial right oculomotor nerve palsy with mild ptosis, asymmetric pupils (right 5 mm and left 3mm, both reactive), and mild exotropia, normal visual acuity. Computed tomography angiogram and conventional angiogram showed 2.5 × 2.6 × 2.6 cm non-ruptured aneurysm arising from cavernous segment of the right ICA. She had right hypoplastic posterior communicant artery, and collateral flow through anterior communicant artery during balloon test occlusion and the presence of right cervical ICA FMD. The patient was started on aspirin. After lengthy discussion of treatment options in our neurovascular department, between observations, endovascular treatment with flow diverter device, or high flow bypass, recommendation was to perform high flow bypass and patient consented for the procedure. We performed right-sided pterional trans-sylvian microsurgical approach and right neck dissection at common carotid bifurcation under electrophysiology monitoring (somatosensory evoked potentials and electroencephalography); while vascular surgery department assisted with the radial artery graft harvesting. The radial artery graft was passed through preauricular tunnel, cranially was anastomosed at superior trunk of middle cerebral artery, and caudally at external carotid artery (Video). Intraoperative angiogram showed adequate bypass patency and lack of flow within aneurysm. The patient was extubated postoperatively and discharged home with aspirin in postoperative day 5. Improvement on oculomotor deficit was complete 3 weeks after surgery.

Conclusion

Nowadays, endovascular therapy can manage small to large cavernous ICA aneurysms even if associated to FMD, although giant symptomatic cavernous carotid aneurysms impose a different challenge. Here, we present the management for the association of symptomatic giant cavernous ICA aneurysm and cervical ICA FMD with high flow bypass. We consider important to keep the skills in the cerebrovascular neurosurgeon armamentarium for the safe management of these lesions.

Headache Relief Is Maintained 7 Years After Anterior Cervical Spine Surgery: Post Hoc Analysis From a Multicenter Randomized Clinical Trial and Cervicogenic Headache Hypothesis

OBJECTIVE

To evaluate whether anterior cervical spine surgery offers sustained (7 years) relief in patients with cervicogenic headaches (CGHs), and evaluate the difference between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) for 1 and 2-level surgeries from a multicenter randomized clinical trial.

METHODS

A post hoc analysis was performed of 575 patients who underwent one or 2-level CDA or ACDF for symptomatic cervical spondylosis as part of a prospective randomized clinical trial. Assessment of pain and functional outcome was done with the Neck Disability Index (NDI) in the trial. We used the NDI headache component to assess headache outcome.

RESULTS

For both 1- and 2-level CDA and ACDF groups, there was significant headache improvement from preoperative baseline out to 7 years (p < 0.0001). For 1-level surgeries, headache improvement was similar for both groups at the 7-year point. For 2-level treatment, CDA patients had significantly improved headache scores versus ACDF patients at the 7-year point (p = 0.016).

CONCLUSION

The headache improvement noted at early follow-up was sustained over the long-term period with ACDF and CDA populations. In the case of 2-level operations, CDA patients demonstrated significantly greater benefit compared to ACDF patients over the long-term. Sinuvertebral nerve irritation at the unco-vasculo-radicular junction and anterior dura may be the cause of CGH. Therefore, it is possible that improved cervical kinematics and preservation of range of motion at adjacent uncovertebral joints in CDA may contribute to the observed difference between the groups.

Mechanical Thrombectomy for Sequential Bilateral Middle Cerebral Artery Occlusions in a Patient With Recurrent Cryptogenic Strokes: A Case Report

Recurrent sequential mechanical thrombectomy for cryptogenic large vessel occlusion (LVO) can lead to excellent clinical outcome. A 68-year-old right-handed male presented with an acute proximal right middle cerebral artery (MCA) ischemic syndrome and underwent successful revascularization by mechanical thrombectomy with normal functional recovery. He was treated with dual antiplatelet therapy for 2 months following discharge, however later discontinued clopidogrel due to side effects. He then developed a recurrent, contralateral MCA occlusion 16 months later and once again received emergent endovascular reperfusion therapy with excellent neurological outcome. He has remained on off-label empiric oral anticoagulation since and has not had recurrent stroke nor evidence of cerebral ischemia. Favorable clinical outcomes can be achieved in patients despite recurrent LVO who underwent emergent mechanical thrombectomy. Optimal antithrombotic secondary stroke prevention strategies following embolic stroke of unknown source remains uncertain as recent evidence does not support rivaroxaban or dabigatran over aspirin. The benefit of apixaban over aspirin for the prevention of recurrent cerebral ischemia is under current investigation.

Combined petrosal approach for resection of petroclival chondrosarcoma: Microsurgical 2-D video

Background:

Petroclival lesions pose a significant neurosurgical challenge due to involvement or close proximity to important neurovascular structures. Chondrosarcomas are rare lesions that can affect these areas.

Case Description:

A 24-year-old male with 3 months history of poor coordination, imbalance, left-sided face hypoesthesia, facial palsy House-Brackmann Grade 2, and 6^th cranial nerve palsy with diplopia. Hearing was preserved. Preoperative images showed a 5.5 cm multilobulated enhancing extra-axial mass centered in the left petroclival region with extension into middle and posterior fossa causing severe (Stage 3) brainstem compression.^[1] After a lengthy discussion of treatment options, the patient consented for the procedure. We performed a presigmoid retrolabyrinthine combined petrosal approach. We used cranial nerves monitoring (VII, VIII, IX, X, XI, XII), frameless stereotaxy, and a lumbar drain. Due to the tumor size and location (petroclival region with extension into the posterior and middle cranial fossa), we chose this approach to achieve a maximal safe resection of the tumor and preserve hearing. Alternative approaches of use are expanded middle fossa with transcavernous extension or expanded endonasal approach. The selected approach achieved wide exposure of the tumor which was highly vascular. The tumor was carefully dissected off the brainstem, cranial nerves (IV, V, VI, VII, VIII), and basilar artery trunk. A gross total resection was achieved (Multimedia 1). The patient did well after surgery and was extubated on postoperative day (POD) 1 and the lumbar drain removed on POD 5. Pathology reported low-grade chondrosarcoma (WHO grade I). At 3 months follow-up, the patient improved neurologically, including facial nerve weakness (House-Brackmann Grade 1) except for his left 6^th cranial nerve palsy which mildly improved.

Conclusion:

Petroclival chondrosarcomas are rare tumors that are usually treated with surgical resection followed by stereotactic radiosurgery. The tumor size, location, and extension dictate approach selection. For lesions involving the petroclival region with extension into the middle fossa and posterior fossa, the combined petrosal approach is reasonable.

Stem and progenitor cell microenvironment for bone regeneration and repair

Stem cells reside in their native microenvironment, which provides dynamic physical and chemical cues essential to their survival, proliferation and function. A typical cell-based therapeutic approach requires the mesenchymal stem cells (MSC) to depart their native microenvironment, transplant to in-vivo environment, differentiate toward multiple lineages and participate in bone formation. The long-term survival, function and fate of MSC are dependent on the microenvironment in which they are transplanted. Transplantation of morselized autologous bone, which contains both stem cells and their native microenvironment, results in a good clinical outcome. However, implantation of bone graft substitutes does not provide the complete and dynamic microenvironment for MSC. Current bone graft therapeutics may need to be improved further to provide an optimal engineered MSC microenvironment.

Disseminated Coccidioidomycosis to the Spine-Case Series and Review of Literature

Coccidioidomycosis is a fungal infectious disease caused by the Coccidioides species endemic to Southwestern United States. Symptomatic patients typically present as community-acquired pneumonia. Uncommonly, in about 1% of infections, hematogenous extra pulmonary systemic dissemination involving skin, musculoskeletal system, and meninges occur. Disseminated spinal infection is treated with antifungal drugs and/or surgical treatment. A retrospective review of medical records at our institution was done between January 2009 to December 2018 and we present three cases of spinal coccidioidomycosis and review the current literature. Disseminated coccidioidomycosis can lead to spondylitis that can present as discitis or a localized spinal or paraspinal abscess. Spinal coccidioidomycosis is typically managed with antifungal treatments but can include surgical treatment in the setting poor response to medical therapy, intractable pain, presence of neurological deficits due to compression, or structural spinal instability.

DuraSeal Exact Is a Safe Adjunctive Treatment for Durotomy in Spine: Postapproval Study

STUDY DESIGN

A nonrandomized, two-armed prospective study.

OBJECTIVE

Water-tight dural closure is paramount to the prevention of cerebrospinal fluid (CSF) leakage and associated complications. Synthetic polyethylene glycol (PEG) hydrogel has been used as an adjunct to sutured dural repair; however, its expansion postoperatively is a concern for neurological complications. A low-swell formulation of PEG sealant was introduced as DuraSeal Exact Spine Sealant System (DESS). A Post-Approval Study was performed primarily to evaluate the safety and efficacy of DESS for spinal dural repair compared to current alternatives, in a large patient population, reflecting a real-world practice.

METHODS

A total of 36 sites in the United States enrolled 429 patients treated with DESS as an adjunct to dural repair in the spinal sealant group and 406 patients treated with all other modalities in the control arm, from October 2011 to June 2016. The primary endpoint was the incidence of CSF leak within 90 days of operation. The secondary endpoints evaluated were deep surgical site infection and neurological serious adverse events.

RESULTS

The CSF leakage in the DESS group (6.6%) was not significantly different from the control group (6.5%) (p = .83), and there was no significant difference in the time to first leak. The two groups had no significant differences in deep surgical site infection (1.6% versus control 2.1%, p = .61) or proportion of subjects with neurological serious adverse events (2.9% versus control 1.6%, p = .516).

CONCLUSIONS

DuraSeal Exact Spinal Sealant is safe when compared to current alternatives for spinal dural repair.

Adult Thoracic Intradural Exophytic Mature Teratoma: Case Report and Literature Review

Mature thoracic intraspinal teratomas are rare tumors in adults. In this case study, we present a case of intradural, extramedullary teratoma, which was surgically resected. A 50 year old man presented with progressive bilateral leg pain, severe myelopathy and weakness. Magnetic Resonance Imaging (MRI) revealed a cystic mass lesion in the T11-12 region region. Microsurgical resection of the tumor using CO² laser with neuromonitoring was performed. Postoperatively, the patient had a remarkable clinical improvement. Mature spinal teratomas are rare, slow growing spinal tumors. Surgical resection provides excellent recovery, and recurrence rates are low.

Abstract TP101: CaMKII Reverts After Stem Cell Treatment in Ischemic Stroke

Background: Loss of calcium/calmodulin-dependent kinase II (CaMKII) after ischemic stroke exacerbates cell death by sensitizing vulnerable neurons to excitotoxic glutamate signaling and inducing neurotoxicity. Our recent study demonstrated the potential of human umbilical cord blood-derived mesenchymal stem cells (HUCB-MSCs) treatment in inhibiting apoptosis after ischemic stroke. In this study, we aimed to investigate the effect of focal cerebral ischemia and/or reperfusion on CaMKII expression and the role of HUCB-MSCs treatment on CaMKII regulation. To our knowledge this is the first study that demonstrates the possible involvement of CaMKII in HUCB-MSCs-mediated neuroprotection after ischemic stroke.

Methods: Male Sprague-Dawley rats were obtained and randomly assigned to various groups. Rats were subjected to a two-hour middle cerebral artery occlusion (MCAO) procedure followed by seven days reperfusion. HUCB-MSCs (0.25x106cells/animal) were intravenously injected via tail vein 24 hours post-MCAO to designated animals. Rats brain tissues obtained seven days after reperfusion from various groups were subjected to real-time PCR, immunoblot and immunofluorescence analysis.

Results: CaMKII protein expression did not change in animals subjected to 1h, 2h, and 4h of ischemia without reperfusion. However, CaMKII expression is significantly reduced when the animals were subjected to ischemia followed by one day reperfusion. The loss of CaMKII was persistent until 14 days after reperfusion. All CaMKII isoforms (CaMKIIα, CaMKIIγ and CaMKIIδ), except CaMKIIβ, were downregulated. CaMKII expression in neurons was also reduced in the ischemic hemisphere. HUCB-MSCs treatment 24h after reperfusion revert CaMKII mRNA and protein expression. Significant co-localization of CaMKII with neurons was also noticed in rats subjected to stem cell treatment.

Conclusions: HUCB-MSCs-mediated neuroprotection after ischemic stroke could be mediated by upregulation of neuronal CaMKII expression.

Radial Artery Bypass for Intractable Vertebrobasilar Insufficiency: Case Series and Review of the Literature

BACKGROUND

Vertebrobasilar insufficiency resulting from embolism, atherosclerosis, or arterial dissection has long been a challenge for successful management and outcomes. The main treatment options include medical therapy, angioplasty and stenting, and surgical revascularization. Unlike cardiac or peripheral vascular revascularization, large randomized trials with cerebrorevascularization have not revealed favorable outcomes. In patients who have failed maximal medical therapy, and having persistent debilitating symptomology, cerebral revascularization may still be a viable option.

METHODS

We report 3 patients who presented with symptoms of vertebrobasilar ischemia. The diagnosis was verified by computerized tomographic arteriography and digital subtraction angiography.

RESULTS

These patients subsequently underwent revascularization with a radial artery graft. We also present a comprehensive review of the literature of treatment for vertebrobasilar insufficiency.

CONCLUSIONS

Surgical revascularization should be considered in the posterior circulation in the rare subset of patients with VBI, who remain symptomatic despite having a protracted course of maximal medical therapy with large- and medium-sized vessel occlusions and poor collateral circulation.

Intraventricular tissue plasminogen activator for the prevention of vasospasm and hydrocephalus after aneurysmal subarachnoid hemorrhage

BACKGROUND

The sequelae of aneurysmal subarachnoid hemorrhage (SAH) include vasospasm and hydrocephalus.

OBJECTIVE

To assess whether intraventricular tissue plasminogen activator (tPA) results in less vasospasm, fewer angioplasties, or fewer cerebrospinal fluid shunting procedures.

METHODS

41 patients (tPA group, Hunt and Hess 3, 4, 5) from 2007 to 2008 received intraventricular tPA and lumbar drainage for a minimum of 5 days (range 5-7 days) and were compared to a matched group of 35 patients from 2006 to 2007 (Control, HH 3, 4, 5). Statistical comparison was done by t test analysis or Fisher exact tests and data are expressed as average+/-standard error of the mean.

RESULTS

There were no significant differences in demographic data, although the tPA group had a trend toward more surgical patients. The tPA group of patients had a significantly higher modified Fisher grade than controls (P<.001) and had a significantly better Hunt and Hess grade than controls (P<.03). The angioplasty rate was significantly lower among the tPA patients (15.0%+/-5.6) than controls (40.0%+/-8.5, P=.019). The number of days spent in severe vasospasm normalized over the 14-day monitoring period by transcranial Doppler was significantly lower in the tPA group (0.09+/-0.02) than controls (0.17+/-0.03). The shunt rate was significantly lower among tPA patients (17.5%+/-6.0) than controls (42.8%+/-8.6). There were 2 clinically silent tract hemorrhages in the tPA group (4.8%).

CONCLUSION

Intraventricular tPA is a safe and effective treatment for reducing both angioplasty and shunting rates in patients with SAH H&H Grades 3 to 5. A randomized trial is indicated.

Management of spinal epidural arteriovenous fistulas: interventional techniques and results

BACKGROUND

Spinal epidural arteriovenous fistulas (SEDAVF) are rare and poorly understood clinical entities.

MATERIALS AND METHODS

We report a series of five (three men, two women) consecutive cases treated at our center to analyze their characteristic and treatment strategies in their management. We report a successful technique of percutaneous embolization of fistulas in a patient with failed previous attempts.

RESULTS

All five patients were symptomatic; three patients presented with a history of back pain, which progressed to myelopathic symptoms, one patient had symptoms of persistent back pain, and one patient had intermittent numbness of the left arm and thigh. Of the three patients who had myelopathic symptoms, two were successfully treated with transarterial embolizations with Onyx copolymer. The third patient who had a prominent epidural venous pouch with numerous arterial feeders was embolized percutaneously with a flat detector CT guided navigation (XperCT) and real time fluoroscopic monitoring of the injected n-butyl cyanoacrylate glue, after previous unsuccessful attempts with surgery and arterial embolizations. All three myelopathic treated patients had complete angiographic remission of the fistulas and symptoms on follow-up (mean 7.2 months).

CONCLUSIONS

The diagnosis and treatment of SEDAVF can be challenging due to their rarity and intricate pathomechanics. Patients with severe pain or progression of symptoms or myelopathic symptoms need to be treated at the earliest opportunity, while asymptomatic patients can be closely monitored. Percutaneous embolization is an effective strategy to embolize SEDAVF associated venous pouch.

Surgical resection of cavernous malformations of the brainstem: evolution of a minimally invasive technique

OBJECTIVE

The purpose of this study is to provide an institutional retrospective review of surgically treated brainstem cavernous malformations.

METHODS

Between 2005 and 2010, 22 consecutive patients with brainstem cavernous malformations (15 female and 7 male) with a mean age of 43 years underwent surgical treatment. Mean volume of the resected cavernous malformations was 0.65 cm(3). A minimally invasive resection technique was used for these cases, in conjunction with skull base approaches.

RESULTS

The mean follow-up period was 26.6 months (range, 4-68 months). Of the 22 patients, 9% did not have clear evidence of hemorrhage at the time of presentation. Of the remainder, 22% had two or more instances of hemorrhage documented by magnetic resonance imaging. After resection and during follow-up, 54% of patients had an improvement in their modified Rankin scale, whereas 14% were worse compared with their preoperative presentation; 32% were unchanged and 9% of patients were found to have residual cavernoma post-surgery.

CONCLUSION

Our longitudinal experience has guided us to emphasize minimally invasive approaches during resection of the brainstem cavernous malformations, occasionally at the expense of achieving a complete resection, to improve patient outcomes.

Cerebral bypasses for complex aneurysms and tumors: long-term results and graft management strategies

BACKGROUND

Various techniques of cerebral bypasses are used to treat aneurysms and tumors.

OBJECTIVE

To study long-term clinical and radiological outcome of various bypass types and to analyze techniques used in the management of long-term graft problems.

METHODS

A consecutive series of patients who underwent revascularization during a 5-year period were analyzed for indications, graft patency, and neurological outcomes. Potential risk factors for bypass problems and the management of bypass stenosis were studied.

RESULTS

A total of 80 patients (69 with aneurysms and 11 with tumors) underwent 88 bypasses (59 extracranial-to-intracranial [EC-IC] bypasses [10 low flow, 49 high flow], 9 intracranial-to-intracranial [IC-IC] bypasses [3 long, 6 short], and 20 local bypasses), with mean radiological follow-up of 32 months (range, 1-53 months). At late follow-up, 5 of 9 (56%) IC-IC (5 short, 0 long grafts), 8 of 9 (90%) EC-IC low-flow, 44 of 48 (92%) EC-IC high-flow, and all local bypasses were patent. Four patients with EC-IC high-flow bypass occlusions were asymptomatic, but transient ischemic attacks were noted in 3 of 6 patients with graft stenosis. None of the risk factors evaluated were significantly predictive of EC-IC graft occlusions or stenosis. EC-IC HF graft stenoses were permanently corrected by microsurgery (n = 4) or endovascular surgery (n = 1).

CONCLUSION

The EC-IC and local bypasses have higher long-term patency rates (91% and 100%) compared with IC-IC bypasses (66%, 0% long graft). Some EC-IC bypasses may occlude asymptomatically (9%) or develop graft stenosis (13%) over the long term. Microsurgical and endovascular surgical techniques have been developed to treat graft stenosis.

Petrous bone epidermoid cyst caused by penetrating injury to the external ear: Case report and review of literature

Epidermoid cysts are histologically benign, slow-growing congenital neoplasms of the central nervous system that may arise from retained ectodermal implants. The epidermoid lesions are generally caused during the 3^rd to 5^th week of gestation by an incomplete cleavage of the neural tissue from the cutaneous ectoderm, though it can also happen later in life due to introduction of skin elements by skin puncture, trauma or surgery. We present this unique case of a petromastoid epidermoid cyst associated with ipsilateral cerebellar abscesses, presenting 20 years after a penetrating trauma to the external auditory canal. Radical excision of both lesions and revision of the previous fistulous tract was performed. We present the diagnostic challenge and the operative treatment of this unique case, which to our knowledge is the first where an epidermoid cyst and an adjacent brain abscess occurred as a result of a single traumatic event.

Evolution and future of skull base surgery: the paradigm of skull base meningiomas

BACKGROUND

Skull base meningiomas represent the paradigm for the evolution of skull base surgery within the past 50 years into a distinct neurosurgical subspecialty.

METHODS

From 2005 to 2011, 117 patients with cranial base meningiomas underwent surgical resection. Extent of resection, histologic grade, complications, functional status, and recurrence-free and overall survival data are presented.

RESULTS

The summary rate of gross total resection was 53.0%. The surgical complication and mortality rates were 17.9% and 0.9%, respectively. Five-year recurrence-free survival was 88.0% for grade I meningiomas. A total of 90.3% of patients had a Karnofsky performance score ≥ 80 at last follow-up.

CONCLUSIONS

A large contemporary series of skull base meningiomas is presented. In addition, the evolution of surgical approaches to skull base meningiomas is reviewed, together with the current issues regarding radiation therapy, management of cavernous sinus tumor, oncologic management of atypical and malignant subtypes, molecular genetics, and future therapeutic options.

Current comprehensive management of cranial base chordomas: 10-year meta-analysis of observational studies

OBJECT

The role of surgery and adjuvant radiation therapy for cranial base chordomas is not well established. This meta-analysis measures the relationship of complete resection and type of adjuvant radiation therapy to 5-year progression-free survival (PFS) and overall survival (OS) of cranial base chordomas.

METHODS

A systematic MEDLINE search (1999-present) yielded 23 observational studies and 807 patients who fit inclusion criteria. The following analyses were performed: 1) Kaplan-Meier 5-year PFS and OS compared based on the extent of resection and type of adjuvant radiation therapy using the log-rank method; 2) a random-effects model comparing 5-year PFS with complete or incomplete resection; and 3) paired z-test comparisons of weighted average 5-year OS and PFS grouped by type of adjuvant radiation therapy.

RESULTS

The weighted average follow-up was 53.6 months. The weighted average 5-year PFS and OS were 50.8% and 78.4%, respectively. Complete resection conferred a higher 5-year PFS than incomplete resection from the random effects model (mean difference in PFS 20.7%; 95% CI 6.57%-34.91%). Patients with incomplete resection were 3.83 times more likely to experience a recurrence (95% CI 1.63-9.00) and 5.85 times more likely to die (95% CI 1.40-24.5) at 5 years versus patients with complete resection. There was no difference in 5-year OS by type of adjuvant radiation, although 5-year PFS was lower in patients receiving Gamma Knife surgery relative to carbon ion radiotherapy (p = 0.042) on paired z-test. No survival difference occurred between radiation therapy techniques on Kaplan-Meier analysis of compiled patient data.

CONCLUSIONS

Patients with complete resection of cranial base chordomas have a prolonged 5-year PFS and OS. Adjuvant proton-beam, carbon ion, and modern fractionated photon radiation therapy techniques offered a similar rate of PFS and OS at 5 years.

Endovascular management of cerebral bypass graft problems: an analysis of technique and results

BACKGROUND AND PURPOSE

Cerebral bypass grafts may develop generalized graft narrowing or focal stenosis during the perioperative period or later. Endovascular techniques such as PTA and stent placement of graft vessels are potential treatment options. Our objective was to review the safety, indications, technique, and results of endovascular management of graft problems.

MATERIALS AND METHODS

All patients with cerebral bypass procedures by using graft vessels from 2005 to 2009 were identified from a prospective registry and were studied retrospectively. Patient characteristics, bypass procedures, indications for endovascular interventions, graft patency, and clinical outcomes were reviewed from medical charts and imaging records.

RESULTS

A total of 79 patients underwent bypass procedures by using graft vessels. Seven patients of this group underwent endovascular interventions for the treatment of graft narrowing. Four of the 7 patients were treated for graft narrowing in the perioperative period (<1 month) with PTA; and 3 of the 7 patients, for late stenosis, 2 with PTA alone and 1 with PTA followed by stent placement. All procedures were immediately successful in improving flow through the graft. In late stenosis, PTA alone provided temporary improvement followed by recurrence, whereas PTA with a stent procedure was effective in the 1 patient long term.

CONCLUSIONS

PTA is safe and effective in the management of graft spasm in the perioperative period. For late graft stenosis, PTA alone provides only temporary respite, while PTA with stent placement may be an effective solution.

Intracranial in situ side-to-side microvascular anastomosis: principles, operative technique, and applications

OBJECTIVE

Side-to-Side microvascular anastomosis is a revascularization technique used to create an artificial conduit between two similar adjacent vessels. This technique is used for microsurgical clipping of aneurysms, when indicated. It is important to study the angiographic results, both immediate and long term, along with the clinical outcomes and indications of the procedure.

METHODS

Fifteen patients who had this procedure over a fourteen-year period were reviewed for patency of bypass by intra-arterial digital subtraction angiography (DSA) and computed tomographic arteriograms (CTA) and their clinical outcomes were studied. The mean age of the study group was 53.4 years and mean angiographic follow up period was 14 months.

RESULTS

All surviving patients (14 patients) had patent anastomosis with good clinical outcomes. None of the patients developed a clinically manifested stroke due to the procedure, while one had a small asymptomatic infarct detected post operatively.

CONCLUSION

This technique is a useful and durable solution for correcting critical stenosis or complete occlusion of the vessels, while clipping intracranial aneurysms.

Management of the asymptomatic primary in the palliative treatment of metastatic colorectal cancer

OBJECTIVE

The management of the asymptomatic primary in stage IV colorectal cancer presents a dilemma. There is an increased morbidity and mortality from surgical resection. Nonresectional management of the primary is associated with the risks of obstruction, perforation or haemorrhage. Our practice in patients with stage IV disease is palliative chemotherapy and symptom control. We reviewed our nonoperatively managed patients with colorectal liver metastases in order to identify the percentage of patients requiring urgent operative interventions for symptoms related to the primary. SUBJECTS/PATIENTS AND METHOD: A retrospective review of all patients treated for stage IV disease at our institution from 2003-2006 was undertaken. Patients were identified from multidisciplinary team (MDT) records. Demographic detail, treatment, and follow-up data were extracted from hospital records. These were analysed with Microsoft Excel.

RESULTS

Thirty-seven patients were identified. 26 Male:11 Female. Median age 63 years (range 38-78). The median survival from diagnosis was 14 months. Three (8%) patients developed obstruction whilst having palliative chemotherapy. Two required a defunctioning stoma, and one was treated by means of a stent. There were no similarities between these three patients in terms of age, sex, site or stage of primary, volume of liver metastases, and alkaline phosphatase (ALP) or carcinoembryonic antigen (CEA) levels.

CONCLUSION

Of 37 patients initially treated palliatively for stage IV colorectal cancer, 92% required no surgical treatment of their primary. Therefore it is the experience of this MDT that it is acceptable to treat such patients in an expectant manner. It is not possible to predict those patients, likely to require surgical intervention.