Ido Strauss

Where are we with surgical therapies for Parkinson's disease?

Surgical therapies are now widely accepted in the treatment of medically refractory Parkinsons disease or levodopa-related side effects. Neuromodulation using deep brain stimulation (DBS) is currently the most well known surgical treatment, however other developing technologies are emerging. We briefly review active research areas in the field of DBS including timing of surgery, target selection and localization under general anesthesia and developments in closed loop stimulation systems. We then describe other evolving modalities such as lesioning using MR guided focused ultrasound and biological therapies.

Critical appraisal of endovascular treatment of brain arteriovenous malformation using Onyx in a series of 92 consecutive patients

BackgroundThe introduction of Onyx has led us to adopt a new treatment approach for brain arteriovenous malformation (AVM), using endovascular embolization with Onyx as the first line treatment with a curative intent. The aim of the present report is to evaluate our results using this strategy, with special emphasis on angiographic characteristics affecting treatment risks and success rates.MethodsFrom October 2006 to December 2009, 92 consecutive patients harboring brain AVM were treated with Onyx during 177 procedures.ResultsEndovascular treatments were completed in 68 out of 92 patients. Median number of procedures was two. Complete obliteration using embolization exclusively was achieved in 25 patients, resulting in a 37xa0% cure rate in patients who concluded treatments (25/68), and 27xa0% in the cohort. In Spetzler-Martin grades 1 & 2 AVMs, complete obliteration was achieved in 48xa0% of the cases. Complete obliteration rates were significantly higher in lesions with superficial big feeding arteries. There were 15 bleeding complications during 177 embolization sessions (8.4xa0% per procedure); seven cases resolved in less than 3xa0months. Permanent disability rate was 6.5xa0%; mortality rate was 2.2xa0%. Bleeding was related to the use of the microcatheter/guidewire in six cases and to the use of the embolization material in nine, the amount of Onyx injected was significantly higher in those nine cases.ConclusionsEmbolization of brain AVM using Onyx and detachable tip microcatheters results in a relatively high rate of complete obliteration. Angioarchitecture of the lesion can predict treatment success. Higher amounts of Onyx injected per session increase the bleeding risk.

Silk flow diverter in the treatment of complex intracranial aneurysms: a single-center experience with 60 patients

BackgroundFlow diverters are used to treat complex aneurysms that are not amenable to coiling. The aim of the present work was to retrospectively evaluate our experience with the Silk flow diverter. Technical nuances and complications are specifically discussed.MethodsRetrospectively data was collected on patients treated with Silk between October 2008 and October 2013.ResultsSixty patients harboring 67 aneurysms were treated using the Silk. Fifteen aneurysms were located in the posterior circulation and 52 in the anterior. A good angiographic result was achieved in 88xa0% (53/60) of the aneurysms available for imaging follow-up. There were ten treatment-related complications, 80xa0% were ischemic. Risk of complications increased with aneurysm size and in aneurysms of the posterior circulation.ConclusionsSilk flow diverters are a good treatment option for aneurysms of the anterior circulation. Additional stents may be required in specific cases due to the Silk’s low radial resistance. Treatment of giant fusiform aneurysms of the posterior circulation with Silk flow diverters is associated with a high rate of severe complications.

Craniectomy Versus Craniotomy for Posterior Fossa Metastases: Complication Profile

OBJECTIVEnSurgical resection of posterior fossa metastases (PFM) includes either suboccipital craniotomy or suboccipital craniectomy. The optimal surgical technique is yet to be defined. We examined the association between the chosen surgical approach and the occurrence of postoperative complications.nnnMETHODSnWe retrospectively evaluated medical records and imaging characteristics of patients who underwent resection of newly diagnosed PFM between 2003 and 2014 in our medical center to identify covariates that significantly affected postoperative complications.nnnRESULTSnOf 917 patients with brain metastases, 88 patients underwent surgery for PFM and were included in the study. Craniectomy was performed in 54 cases (61%). Urgent postoperative posterior fossa decompression or cerebrospinal fluid diversion was performed in 4 patients (4.5%). Postoperative complications included postoperative central nervous system infection (nxa0= 10 [12%]), cerebrospinal fluid leak (nxa0= 3 [4%]), wound dehiscence (nxa0= 6 [7%]), and long-term pseudomeningocele (nxa0= 12 [14%]). The perioperative mortality rate was 2.3% (nxa0= 2). Multivariate analysis that included patient baseline characteristics, imaging study parameters, and surgical approaches demonstrated that suboccipital craniectomy was associated with more postoperative complications (Pxa0= 0.03, odds ratioxa0= 4.48, 95% confidence intervalxa0= 1.14-17.6). There was no correlation between patient baseline characteristics or surgical technique with the need for urgent postoperative posterior fossa decompression or cerebrospinal fluid diversion.nnnCONCLUSIONSnSuboccipital craniotomy may be associated with a lower incidence of postoperative morbidity compared with suboccipital craniectomy and should be considered as the preferred approach for the resection of PFM.

Age-Related Changes in Diffusion Tensor Imaging Metrics of Fornix Subregions in Healthy Humans

Objective: White matter diffusivity measures of the fornix change with aging, which likely relates to changes in memory and cognition in older adults. Subregional variations in forniceal diffusivity may exist, given its heterogeneous anatomy and connectivity; however, these have not been closely examined in vivo. We examined diffusivity parameters (fractional anisotropy, FA; radial diffusivity, RD; axial diffusivity, AD) in forniceal subregions of healthy subjects and correlated them with age and hippocampal volume. Methods: Diffusion-weighted imaging and streamline tractography of the fornix were performed on 20 healthy, right-handed females (23-66 years). Six anatomical subregions were defined: midline (body, column, precommissural fornix) or lateral (fimbria, crura, postcommissural fornix). Regression analysis was performed comparing diffusivities against age. Hippocampal and ventricular volumes were also compared. Results: Diffusivity values revealed statistical changes with age in both midline and lateralized subregions. The fornix body and left crus showed age-related alterations in all metrics (FA, RD, AD), whereas only right crus FA was altered. There was no significant change in hippocampal volumes, suggesting that forniceal changes may precede hippocampal age-related changes. Conclusions: Age-related changes in fornix diffusivity measures appear subregion dependent and asymmetrical. Specific subregion diffusivity measures may be a more sensitive aging marker than hippocampal volume change.

Spinal Dural Arteriovenous Fistula: A Review

Spinal dural arteriovenous fistula (SDAVF) is a rare disease, the etiology of which is not entirely clear. It is the most common vascular malformation of the spinal cord, comprising 60-80 % of the cases. The clinical presentation and imaging findings may be nonspecific and misleading, often mistaking it for other entities like demyelinating or degenerative diseases of the spine.This chapter describes the imaging findings, clinical signs, and symptoms of this disease and also the available treatment options according to the current literature.Angiography is still considered the gold standard for diagnosis; however, MRI/MRA is increasingly used as a screening tool. Modern endovascular techniques are becoming increasingly more effective in treating SDAVF offering a less invasive treatment option; however, they still lag behind surgical success rates which approach 100 %. The outcome of both treatment options is similar if complete obliteration of the fistula is obtained and depends mainly on the severity of neurological dysfunction before treatment.Heightened awareness by radiologists and clinicians to this rare entity is essential to make a timely diagnosis of this treatable disease. A multidisciplinary treatment approach is required in order to make appropriate treatment decisions.

Patterns of Failure after Stereotactic Radiosurgery of the Resection Cavity Following Surgical Removal of Brain Metastases

BACKGROUNDnWhole brain radiation treatment (WBRT) is considered standard treatment for BM. However, exposing large volumes of normal brain tissue to irradiation can cause neurotoxicity. This study describes our experience with 100 consecutive patients with brain metastases who were managed with surgical extirpation followed by stereotactic radiosurgery (SRS) to the resection cavity.nnnMETHODSnPatients with 1-3 brain metastases (BM), who underwent resection of 1-2 BM between June 2005 and December 2013, were treated with SRS directed to the tumor cavity and for any synchronous BM. Local and distant treatment failures were determined based on neuroimaging. Kaplan-Meier curves were generated for local and distant failure rates and overall survival.nnnRESULTSnOne hundred and two resection cavities were treated with SRS in 100 consecutive patients. Thirty-two additional synchronous metastases were treated in 27 patients during the same session. The median overall survival was 18.9 months. Local control rate at 1 year was 84%. Longer delays between surgery and SRS were associated with increased risk of local failure (hazard ratio, -1.46; P = 0.02). Distant progression occurred in 44% of the patients at a mean of 8.8 ± 6.6 months after SRS treatment. Ten cases of leptomeningeal spread occurred around the resection cavities (9.8%). Central nervous system failure was not significantly associated with survival. Multivariate Cox regression analysis showed that recursive partitioning analysis and active systemic disease were significantly associated with survival.nnnCONCLUSIONnThe strategy described provides acceptable local disease control when compared with WBRT following surgery. This approach can delay and even annul WBRT in the majority of selected BM patients, especially recursive partitioning analysis class I patients. SRS should be scheduled as soon as possible after surgery.

Regression of intracranial meningioma following treatment with nivolumab: Case report and review of the literature

The treatment of refractory meningiomas remains a challenge for both neurosurgeons and neuro-oncologists. There have been no clinical reports of the use or effects of anti-PD-1 therapy in patients with meningioma. We describe a patient whose intracranial meningioma decreased significantly in size after treatment with nivolumab, a monoclonal antibody targeting PD-1, for a concomitant advanced lung cancer. This is the first clinical report suggesting that antibodies targeting PD-1 are effective in treating meningioma. It should encourage further research into the use of checkpoint inhibitors in meningioma.

Gliomas of the posterior fossa in adults

Infratentorial gliomas are relatively rare tumors compared to their supratentorial counterparts. As such they have not been extensively characterized as a group and are usually excluded from clinical studies. Using our database we aimed to characterize adult gliomas involving the posterior fossa with respect to their clinical behavior and prognostic factors. We reviewed our neurosurgical and neuro-oncological data bases for adult patients diagnosed with gliomas involving the posterior fossa between 1996 and 2010. Of 1,283 glioma patients, 57 patients with gliomas involving the posterior fossa were identified (4.4xa0%). Tumors were further classified by location as primary brainstem (nxa0=xa021) and primary cerebellar (nxa0=xa018) tumors. On univariate analysis survival was correlated to tumor grade and KPS. In addition we have identified a unique group of patients (nxa0=xa018) with previously diagnosed supratentorial gliomas who subsequently developed noncontiguous secondary infratentorial extension of their tumors with subsequent rapid clinical deterioration. Gliomas of the posterior fossa comprise a heterogeneous group of tumors. Histological grade of the tumor was found to be the main prognostic factor. Survival of primary cerebellar gliomas is comparable to supra-tentorial gliomas, while brainstem gliomas in adults fare better than in the pediatric population. Secondary extension of supratentorial gliomas to the posterior fossa signifies a grave prognosis.

Impact of Onyx Embolization on Radiosurgical Management of Cerebral Arteriovenous Malformations: Treatment and Outcome

BACKGROUNDnStereotactic radiosurgery (SRS) is a well-established treatment modality for cerebral arteriovenous malformations (AVMs). The main limiting factor in the radiosurgical treatment of AVMs is the volume of the nidus, with high-grade lesions often requiring combined treatment to reduce the SRS target volume. To overcome this limitation, we have been using a combined treatment approach consisting of endovascular embolization with Onyx followed by SRS.nnnOBJECTIVEnTo evaluate our clinical experience for safety and feasibility of this multimodality treatment approach.nnnMETHODSnThis is a retrospective review of all adult patients with cerebral AVMs who received SRS treatment to their AVM after endovascular embolization with Onyx between June 2007 and Junexa02014.nnnRESULTSnThirty-five consecutive patients were identified. The mean follow-up period was 52.4 ± 22.6 months (range 18-97 months). We confirmed 18 (51.4%) complete nidus closures at a median time of 49.5 months (range 6.5-81 months) from SRS. High-resolution Magnetic resonance imaging/magnetic resonance angiography was performed routinely in all patients until closure of the nidus. Digital subtraction angiography was performed to confirm complete obliteration in 5 of the patients (28%); 13 patients are either planned for digital subtraction angiography or have refused it. In 6 patients (17%) a significant flow reduction was noted after a mean of 32 ± 16 months. No significant improvement was observed in 9 patients (26%) during the follow-up period. Two patients were lost to follow-up.nnnCONCLUSIONSnThe multimodality treatment of cerebral AVMs using embolization with Onyx followed by SRS is feasible and safe. The use of Onyx significantly reduced the SRS treatment target volume.