Pablo F. Recinos

Cavernous malformations: natural history, diagnosis and treatment

Cavernous malformations (CMs) consist of dilated vascular channels that have a characteristic appearance on MRI. CMs are usually found intracranially, although such lesions can also affect the spinal cord. Individuals with CMs can present with epilepsy and focal neurological deficits or acute intracranial hemorrhage. In many cases, however, patients with such lesions are asymptomatic at diagnosis. Furthermore, several natural history studies have documented that a substantial proportion of asymptomatic CMs follow a benign course. Surgical resection is recommended for CMs that require intervention. Radiosurgery has been advocated for many lesions that have not been easily accessible by conventional surgery. The outcomes of radiosurgery and surgery for deep lesions, however, vary widely between studies, rendering treatment recommendations for such CMs difficult to make. In addition to reviewing the literature, this article will discuss the current understanding of lesion pathophysiology and explore the controversial issues in the management of CMs, such as when to use radiosurgery or surgery in deep-seated lesions, the treatment of epilepsy, and the safety of anticoagulation.

Laser interstitial thermal therapy for focal cerebral radiation necrosis: a case report and literature review.

Whole-brain radiotherapy and stereotactic radiosurgery (SRS) play a central role in the treatment of metastatic brain tumors. Radiation necrosis occurs in 5% of patients and can be very difficult to treat. The available treatment options for radiation necrosis include prolonged high-dose corticosteroids, hyperbaric oxygen, anticoagulation, bevacizumab, and surgical resection. We present the first report and results using laser-interstitial thermal therapy (LITT) for medically refractory radionecrosis. A 74-year-old diabetic patient who had a history of non-small cell lung cancer with brain metastases and subsequent treatment with SRS, presented with a focal lesion in the left centrum semiovale with progressively worsening edema. Image findings were consistent with radiation necrosis that was refractory despite prolonged, high-dose steroid therapy. His associated comorbidities obviated alternative interventions and the lesion was not in a location amenable to surgical resection. We used laser thermal ablation to treat the biopsy-proven radionecrosis. The procedure was tolerated well and the patient was discharged 48 hours postoperatively. Imaging at 7-week follow-up showed near complete resolution of the edema and associated mass effect. Additionally, the patient was completely weaned off steroids. To our knowledge this is the first report using LITT for the treatment of focal radiation necrosis. LITT may be an effective treatment modality for patients with medically refractory radiation necrosis with lesions not amenable to surgical decompression.

Systemic administration of simvastatin after the onset of experimental subarachnoid hemorrhage attenuates cerebral vasospasm.

OBJECTIVE:Experimental evidence suggests that intercellular adhesion molecule-1 mediated leukocyte extravasation contributes to the pathogenesis of cerebral vasospasm. Simvastatin, an HMG-CoA reductase inhibitor, decreases intercellular adhesion molecule-1 expression and competitively inhibits leukocyte intercellular adhesion molecule-1 binding. We hypothesized that administration of simvastatin after the onset of subarachnoid hemorrhage (SAH) would attenuate perivascular granulocyte migration and ameliorate cerebral vasospasm in a rabbit model of SAH. METHODS:New Zealand white rabbits (n = 15) underwent injection of autologous blood into the cisterna magna or sham surgery followed by subcutaneous injection of simvastatin (40 mg/kg) or vehicle 30 minutes, 24 hours, and 48 hours after SAH or sham surgery. Seventy-two hours later, basilar artery lumen diameter was measured by in situ perfusion/fixation and image analysis. CD-18 monoclonal antibody stained perivascular granulocytes and macrophages were counted under light microscopy. RESULTS:In vehicle treated rabbits, mean ± standard deviation basilar artery diameter was reduced 3 days after SAH (n = 5) versus sham (n = 5) rabbits (0.49 ± 0.08 mm versus 0.75 ± 0.03 mm, P < 0.01). After SAH, mean ± standard deviation basilar artery diameter was greater in simvastatin (n = 5) treated rabbits versus vehicle (n = 5) (0.63 ± 0.04 mm versus 0.49 ± 0.08 mm, P < 0.01). In vehicle treated rabbits, SAH resulted in an increase in the mean ± standard deviation perivascular CD18 cell count (sham-vehicle, 2.8 ± 2; SAH-vehicle 90 ± 27; P < 0.01). Subcutaneous administration of simvastatin attenuated this increase in perivascular CD18-positive cells after SAH (SAH statin, 41.6 ± 13; SAH vehicle, 90 ± 27; P < 0.001). CONCLUSION:Subcutaneous administration of simvastatin after the onset of SAH attenuates perivascular granulocyte migration and ameliorates basilar artery vasospasm after experimental SAH in rabbits. 5-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, such as simvastatin, may potentially serve as agents in the prevention of cerebral vasospasm after SAH.

Brainstem Tumors: Where Are We Today?

Brainstem tumors comprise 10–20% of all pediatric central nervous system tumors. The management of these tumors has evolved dramatically in the past century. Once considered uniformly fatal, it is now known that brainstem tumors have distinguishing characteristics and do not behave identically. The focality and location of the lesion is determined from the clinical history, presentation, and associated imaging. Based on these findings, it is possible to predict the behavior of the tumor and choose an appropriate intervention. Focal lesions have a good prognosis and are treated operatively while diffuse lesions have a poor prognosis and are managed medically. This article reviews the current classification of brainstem tumors, current management options and future directions for the treatment of these rare tumors.

Use of a minimally invasive tubular retraction system for deep-seated tumors in pediatric patients: Technical note

OBJECT Microsurgical removal is the preferred treatment for most deep-seated, intraaxial tumors in the pediatric population. The feasibility of surgery as an option has improved with advances in surgical technology and technique. Tubular retractors disperse retraction forces over a greater surface area than do conventional retractors, which can lower the risk of ischemic complications. The authors describe their experience utilizing a new tubular retractor system specifically designed for cranial applications in conjunction with frameless neuronavigation. METHODS The Vycor ViewSite retractor was used in 4 pediatric patients (ages 15 months and 9, 10, and 16 years) with deep-seated intraaxial tumors. The lesions included a papillary tumor of the pineal region, a low-grade astrocytoma in the occipital lobe, a dysembryoplastic neuroepithelial tumor arising from the basal ganglia, and an intraventricular low-grade glioma. The extent of white matter damage along the surgical trajectory (based on T2 or FLAIR and diffusion restriction/apparent diffusion coefficient signals) and the extent of resection were assessed on postoperative imaging. RESULTS Satisfactory resection or biopsy was achieved in all patients. A comparison of pre- and postoperative MR imaging studies revealed evidence of white matter damage along the surgical trajectory in 1 patient. None of the patients demonstrated new neurological deficits postoperatively. CONCLUSIONS Obtaining surgical access to deep-seated, intraaxial tumors is challenging. In this small series of pediatric patients, the combination of the ViewSite tubular retractor and frameless neuronavigation facilitated the surgical approach. The combination of these technologies adds to the armamentarium to safely approach tumors in deep locations.

Minimally invasive trans-portal resection of deep intracranial lesions.

BACKGROUND The surgical management of deep intra-axial lesions still requires microsurgical approaches that utilize retraction of deep white matter to obtain adequate visualization. We report our experience with a new tubular retractor system, designed specifically for intracranial applications, linked with frameless neuronavigation for a cohort of intraventricular and deep intra-axial tumors. METHODS The ViewSite Brain Access System (Vycor, Inc) was used in a series of 9 adult and pediatric patients with a variety of pathologies. Histological diagnoses either resected or biopsied with the system included: colloid cyst, DNET, papillary pineal tumor, anaplastic astrocytoma, toxoplasmosis and lymphoma. The locations of the lesions approached include: lateral ventricle, basal ganglia, pulvinar/posterior thalamus and insular cortex. Post-operative imaging was assessed to determine extent of resection and extent of white matter damage along the surgical trajectory (based on T (2)/FLAIR and diffusion restriction/ADC signal). RESULTS Satisfactory resection or biopsy was obtained in all patients. Radiographic analysis demonstrated evidence of white matter damage along the surgical trajectory in one patient. None of the patients experienced neurological deficits as a result of white matter retraction/manipulation. CONCLUSION Based on a retrospective review of our experience, we feel that this access system, when used in conjunction with frameless neuronavigational systems, provides adequate visualization for tumor resection while permitting the use of standard microsurgical techniques through minimally invasive craniotomies. Our initial data indicate that this system may minimize white matter injury, but further studies are necessary.

Role of Gamma Knife surgery in patients with 5 or more brain metastases

OBJECT The authors evaluated overall survival and factors predicting outcome in patients with ≥ 5 brain metastases who were treated with Gamma Knife surgery (GKS). METHODS Medical records from patients with ≥ 5 brain metastases treated with GKS between 1997 and 2010 at the Cleveland Clinic Gamma Knife Center were retrospectively reviewed. Patient demographics, tumor characteristics, treatment-related factors, and outcome data were evaluated. RESULTS One hundred seventy patients were identified, with a median age of 58 years. The female/male ratio was 1.2:1. Gamma Knife surgery was used as an upfront treatment in 35% of patients and as salvage treatment in 65% of patients with multiple brain metastases. The median overall survival after GKS was 6.7 months (95% CI 5.5-8.1). At the time of GKS, 128 patients (75%) had concurrent extracranial metastases, and in 69 patients (41%) multiple extracranial sites were involved. Ninety-two patients (54%) had a history of whole-brain radiation therapy, and 158 patients (93%) had a Karnofsky Performance Scale (KPS) score ≥ 70. The median total intracranial disease volume was 3.2 cm(3) (range 0.2-37.2 cm(3)). A total intracranial tumor volume ≥ 10 cm(3) was observed in 32 patients (19%). Lower KPS score at the time of treatment (p < 0.0001), patient age > 60 years (p = 0.004), multiple extracranial metastases (p = 0.0001), and greater intracranial burden of disease (p = 0.03) were prognostic factors for poor outcome in the univariate and multivariate analyses. CONCLUSIONS In this study, GKS was safe and effective for upfront and salvage treatment in patients with ≥ 5 brain metastases. Gamma Knife surgery should be considered as an additional treatment modality for these patients, especially in the subset of patients with favorable prognostic factors.

Surgical outcomes of trigeminal neuralgia in patients with multiple sclerosis.

BACKGROUND Trigeminal neuralgia (TN) is relatively frequent in multiple sclerosis (MS) patients and can be extremely disabling. Surgical interventions are less effective for the treatment of MS-related TN compared with classic TN, and higher recurrence rates are observed. OBJECTIVE To evaluate initial pain-free response (IPFR), duration of pain-free intervals (PFIs), and factors predictive of outcome in different surgical modalities used to treat MS-related TN. METHODS A total of 96 MS patients underwent 277 procedures (range, 1-11 procedures per patient) to treat TN at our institution from 1995 to 2011. Of these, 89 percutaneous retrogasserian glycerol rhizotomies, 82 balloon compressions, 52 stereotactic radiosurgeries, 28 peripheral neurectomies, 15 percutaneous radiofrequency rhizotomies, and 10 microvascular decompressions were performed as upfront or repeat treatments. RESULTS Bilateral pain was observed in 10% of patients during the course of disease. During the follow-up period (median, 5.7 years), recurrence of symptoms was seen in 66% of patients, and 181 procedures were performed for symptom recurrence. As an initial procedure, balloon compression had the highest IPFR (95%; P = .006) and median PFI (28 months; P = .05), followed by percutaneous retrogasserian glycerol rhizotomy (IPFR, 74%, P = .04; median PFI, 9 months; P = .05). In general, repeat procedures had lower effectiveness compared with initial procedures, with no statistically significant difference seen across the various treatment modalities. CONCLUSION Treatment failure occurs in most of the MS-related TN patients independently of the type of treatment. However, balloon compression had the highest rate of IPFR and PFI compared with other modalities in the initial treatment of MS-related TN.

Vein of Galen Malformations: Epidemiology, Clinical Presentations, Management

The vein of Galen aneurysmal malformation is a congenital vascular malformation that comprises 30% of the pediatric vascular and 1% of all pediatric congenital anomalies. Treatment is dependent on the timing of presentation and clinical manifestations. With the development of endovascular techniques, treatment paradigms have changed and clinical outcomes have significantly improved. In this article, the developmental embryology, clinical features and pathophysiology, diagnostic workup, and management strategies are reviewed.

Intramedullary spinal cord tumor resection.

The authors present a case of a 27-year-old patient who presented with spastic gait and worsening difficulty walking over a 6 month period. Spinal MR imaging revealed a heterogeneously enhancing intramedullary spinal cord tumor (IMSCT) with associated syrinx in the cervical spine. The lesion was resected through posterior en bloc laminotomy, durotomy, and microscopic resection of the intramedullary component followed by laminoplasty reconstruction. Surgical resections with a goal of gross total resection can significantly improve overall survival and progression free survival in patients with low-grade IMSCT. The procedure is presented in an edited, high-definition format with accompanying narrative. The video can be found here: http://youtu.be/Ui9bn82PtP8 .