Symptomatic Brainstem Compression Research Articles

Surgical and radiosurgical outcomes for Koos grade 3 vestibular schwannomas.

This study aimed to reveal the preferred initial treatment for Koos grade 3 vestibular schwannomas (VS). We performed a two-institutional retrospective study on 21 patients with Koos grade 3 VS undergoing resection at Yokohama Medical Center and 37 patients undergoing radiosurgery at Yokohama Rosai Hospital from 2010 to 2021. Tumor control, complications, and functional preservation were compared. The median pre-treatment volume and follow-up duration were 2845 mm3 and 57.0 months, respectively, in the resection group and 2127 mm3 and 81.7 months, respectively, in the radiosurgery group. In the resection group, 16 (76.2%) underwent gross total resection, and three patients (14.3%) experienced regrowth; however, no one required additional treatment. In the radiosurgery group, the tumor control rate was 86.5%, and three cases (8.1%) required surgical resection because of symptomatic brainstem compression. Kaplan-Meier analyses revealed that tumors with delayed continuous enlargement and large thin-walled cysts were significantly associated with poor prognostic factors (p = 0.0027, p < 0.001). The pre-radiosurgery growth rate was also associated with the volume increase (p = 0.013). Two cases (9.5%) required additional operation due to complications such as post-operative hematoma and cerebrospinal fluid leaks in the resection group, whereas temporary cranial neuropathies were observed in the radiosurgery group. Two patients (9.5%) had poor facial nerve function (House-Brackmann grading grade 3) in the resection group, while no one developed facial paresis in the radiosurgery group. Trigeminal neuropathy improved only in the resection group.Radiosurgery can be considered for the treatment of Koos grade 3 VS for functional preservation. However, resection may also be considered for patients with severe trigeminal neuropathy or a high risk of volume increments, such as large thin-walled cysts and rapid pre-treatment growth.

High-flow bypass for giant dolichoectatic vertebrobasilar aneurysms: illustrative cases

BACKGROUND Giant fusiform dolichoectatic vertebrobasilar artery aneurysms are challenging lesions with a poor natural history. When there is progressive brainstem compression from these lesions, endovascular treatment can be insufficient, and bypass surgery remains a possible salvage option. High-flow bypass surgery with proximal occlusion can potentially arrest aneurysm growth, promote aneurysm thrombosis, and reduce rupture risk. The authors describe their experience in two patients with giant fusiform dolichoectatic vertebrobasilar artery aneurysms treated with high-flow bypass. OBSERVATIONS Both patients presented with enlarging giant dolichoectatic vertebrobasilar aneurysms causing symptomatic brainstem compression. The authors performed staged treatment involving high-flow bypass from the external carotid artery to the posterior cerebral artery using a saphenous vein graft, Hunterian proximal vertebrobasilar occlusion, and finally posterior fossa decompression with or without direct aneurysm thrombectomy and debulking. Postoperative angiography revealed successful flow reversal, aneurysm exclusion, and no brainstem stroke. Clinically, one patient had improvement in their modified Rankin Scale (mRS) score from 3 preoperatively to 1 at 12-month follow-up. The second patient had a deterioration in their mRS score from 4 to 5 at 12-month follow-up. LESSONS High-flow bypass strategies remain high risk but can be a viable last resort in patients with neurological deficits and enlarging giant fusiform dolichoectatic vertebrobasilar artery aneurysms.

Partially thrombosed giant basilar artery aneurysm with attenuated contrast enhancement of the intraluminal thrombus on vessel wall MRI after flow diversion treatment: illustrative case.

The effect of vessel wall magnetic resonance imaging (VW-MRI) enhancement in partially thrombosed aneurysms has previously indicated aneurysmal instability and a rupture risk. However, whether the contrast effect of the wall changes before or after flow diversion treatment is still under investigation. The authors report a case of a partially thrombosed basilar artery aneurysm that increased in size over a short period, worsened brainstem compression symptoms, and was treated with a flow diverter stent with good results. In this case, VW-MRI after surgery showed a reduced contrast effect on the intraluminal thrombus within the aneurysm. The aneurysm thrombosed and markedly regressed over the next 5 months, with remarkable improvement in the brainstem compression symptoms. This finding on VW-MRI may indicate an attenuation of neovascularization in the thrombus wall and be a sign of aneurysm stabilization.

Early Postoperative Magnetic Resonance Imaging Findings Related to Electrocauterization for Cerebellar Reduction During Chiari Decompression Surgery.

Cerebellar tonsillar reduction or resection can be performed as part of the surgical management of Chiari type 1 malformation when it is accompanied by symptomatic brainstem compression or syringomyelia. The purpose of this study is to characterize the early postoperative magnetic resonance imaging (MRI) findings in patients with Chiari type 1 malformations who undergo cerebellar tonsillar reduction via electrocautery. The extent of cytotoxic edema and microhemorrhages demonstrated on MRI scans obtained within 9 days following surgery was assessed and correlated with neurological symptoms. Cytotoxic edema was found on all postoperative MRI examinations included in this series, with superimposed hemorrhage in 12 of 16 patients (75%) and was primarily located along the margins of the cauterized inferior cerebellum. Cytotoxic edema was present beyond the margins of the cauterized cerebellar tonsils in 5 of 16 patients (31%) and was associated with new focal neurological deficits in 4 of 5 patients (80%). Cytotoxic edema and hemorrhages along the cerebellar tonsil cautery margins can be expected findings in early postoperative MRI in patients who undergo Chiari decompression accompanied by tonsillar reduction. However, the presence of cytotoxic edema beyond these regions can be associated with new focal neurological symptoms.

Transcervical, retropharyngeal odontoidectomy - Anatomical considerations.

Anterior craniocervical junction lesions have always been a challenge for neurosurgeons. Presenting with lower cranial nerve dysfunction and symptoms of brainstem compression, decompression is often required. While posterior approaches offer indirect ventral brainstem decompression, direct decompression via odontoidectomy is necessary when they fail. The transoral and endoscopic endonasal approaches have been explored but come with their own limitations and risks. A novel retropharyngeal approach to the cervical spine has shown promising results with reduced complications. This study aims to explore the feasibility and potential advantages of the anterior retropharyngeal approach for accessing the odontoid process. To investigate the anatomical aspects of the anterior retropharyngeal approach, a paramedian skin incision was performed below the submandibular gland on two cadaveric specimens. The subcutaneous tissue followed by the platysma is dissected, and the superficial fascial layer is opened. The plane between the vascular sheath laterally and the pharyngeal structures medially is entered below the branching point of the facial vein and internal jugular vein. After reaching the prevertebral plane, further dissection cranially is done in a blunt fashion below the superior pharyngeal nerve and artery. Various anatomical aspects were highlighted during this approach. The anterior, submandibular retropharyngeal approach to the cervical spine was performed successfully on two cadavers highlighting relevant anatomical structures, including the carotid artery and the glossopharyngeal, hypoglossal, and vagus nerves. This approach offered wide exposure, avoidance of oropharyngeal contamination, and potential benefit in repairing cerebrospinal fluid fistulas. For accessing the craniocervical junction, the anterior retropharyngeal approach is a viable technique that offers many advantages. However, when employing this approach, surgeons must have adequate anatomical knowledge and technical proficiency to ensure better outcomes. Further studies are needed to enhance our anatomical variations understanding and reduce intraoperative risks.

Management of Chiari malformations: opinions from different centers-a review.

Surgical decision-making in Chiari malformation type I (CM-I) patients tends to depend on the presence of neurological signs and symptoms, syringomyelia, and/or scoliosis, but significant variability exists from center to center. Here, we review the symptoms of CM-I in children and provide an overview of the differences in opinion regarding surgical indications, preferred surgical techniques, and measures of outcome. A review of the literature was performed to identify publications relevant to the surgical management of pediatric CM-I patients. Most surgeons agree that asymptomatic patients without syringomyelia should not undergo prophylactic surgery, while symptoms of brainstem compression and/or lower cranial nerve dysfunction warrant surgery. Patients between these extremes, however, remain controversial, as does selection of the most appropriate surgical technique. The optimal surgical procedure for children with CM-I remains a point of contention, and widespread variability exists between and within centers.

Surgical treatment of large and giant vertebrobasilar aneurysms manifested by brainstem compression symptoms

The study included 8 patients operated on in the period between 2014 and 2017. All patients underwent intravascular intervention; two patients had open surgery at the second stage. Intravascular intervention, both alone and in combination with open surgery, is effective treatment of VB aneurysms whose clinical picture is manifested by brainstem compression symptoms. The use of flow-diverting stents in most cases has provided good radicalness in the long-term period, without worsening the functional outcome. Treatment of fusiform aneurysms of the basilar artery trunk requires separate consideration and an individual approach due to a high risk of thrombosis of short branches feeding the brainstem.

A new endovascular treatment of a recurrent giant proximal basilar aneurysm after coiling

BackgroundTreatment of giant basilar aneurysms is extremely challenging, especially recurrences after previous coiling.Case presentationA 20-year-old male was referred for a recurrent giant proximal basilar aneurysm 3 months after coiling, with headache, blurred vision, and brainstem compression symptoms. Angiography showed that the previously placed coils were compacted within the caudal portion of the 43 mm × 31 mm aneurysm, with spontaneous occlusion of the right vertebral artery and absence of the posterior communicating arteries. The diameter of the aneurismal neck, the afferent and efferent arteries was 6 mm, 3.5 mm and 4.1 mm, respectively. A balloon-expandable covered-stent of 3.5 mm × 10 mm was selected, matching the above 3 measurements; and deployed precisely across the aneurismal neck, immediately creating the “sub-complete reconstruction with intentional endoleak distal to aneurismal neck”. Subsequently, 2 self-expanding 4.5 mm × 37 mm stents were telescopically implanted within the covered-stent to adjust the angulation of the proximal basilar artery. After the procedure, the patient’s symptoms gradually disappeared. Catheter angiography at 18 days, 3 months and 15 months demonstrated complete aneurismal exclusion from the patent vertebrobasilar artery, with dramatic elimination of aneurismal volume and reconfiguration of the compacted coils. The patient was asymptomatic at 15-month follow-up.ConclusionsSub-complete reconstruction with intentional endoleak distal to aneurismal neck can be safely achieved after implantation of a covered-stent and conventional stents in the case of a recurrent post-coiling proximal giant basilar aneurysm, with complete vascular reconstruction subsequently.

Radiological evolution of peri-odontoid pannus in a patient with Chiari I malformation: a case-based review

The Chiari I malformation (CIM) is commonly encountered by neurosurgeons and can have different etiologies and clinical presentations. We report a CIM patient who presented with symptoms of ventral brain stem compression and was found to have a large peri-odontoid pannus. Posterior fossa decompression was performed with a planned second-stage odontoidectomy. However, at the 6-month follow-up, postoperative images demonstrated a mostly resolved pannus and improvement of the brain stem compression symptoms, and the patient progressed uneventfully without the need for odontoidectomy. This case illustrates the resolution of a significant and symptomatic peri-odontoid pannus in a patient with CIM without craniocervical fusion or odontoidectomy. Such a case indicates that not all peri-odontoid pannus formations in CIM patients are due to hypermobility at the craniocervical junction.

Long-Term Functional Outcome of Symptomatic Unruptured Intracranial Aneurysms in an Interdisciplinary Treatment Concept.

In symptomatic unruptured intracranial aneurysms (UIAs), data on long-term functional outcome are sparse in the literature, even in the light of modern interdisciplinary treatment decisions. We therefore analyzed our in-house database for prognostic factors and long-term outcome of neurologic symptoms after microsurgical/endovascular treatment. Patients treated between 2000 and 2016 after interdisciplinary vascular board decision were included. UIAs were categorized as symptomatic in cases of cranial nerve or brainstem compression. Symptoms were categorized as mild/severe. Long-term development of symptoms after treatment was assessed in a standardized and independent fashion. Of 98 symptomatic UIAs (microsurgery/endovascular 43/55), 84 patients presented with cranial nerve (NII-VI) compression and 14 patients with brainstem compression symptoms. Permanent morbidity occurred in 9% of patients. Of 119 symptoms (mild/severe 71/48), 60.4% recovered (full/partial 22%/39%) and 29% stabilized by the time of last follow-up; median follow-up was 19.5 months. Symptom recovery was higher in the long-term compared with that at discharge (P= 0.002). Optic nerve compression symptoms were less likely to improve compared with abducens nerve palsies and brainstem compression. Prognostic factors for recovery were duration and severity of symptoms, treatment modality (microsurgery) and absence of ischemia in the multivariate analysis. This recent study presents for the first time a detailed analysis of relevant prognostic factors for long-term recovery of cranial nerve/brainstem compression symptoms in an interdisciplinary treatment concept, which was excellent in most patients, with lowest recovery rates in optic nerve compression. Symptom recovery was remarkably higher in the long-term compared with recovery at discharge.

Symptomatic Ventrolateral Medulla Compression by Tortuous Vertebral Artery: A Case Report

Objective: Neurovascular compression syndrome of the vertebral artery with the medulla oblongata is a very rare condition manifesting with different neurological focal deficits. A video of the surgical procedure in a 36-year-old male with symptomatic brainstem compression by vertebral artery with particular attention to diagnostic protocol and nuances of the performed surgical procedure is presented.

Gamma Knife Radiosurgery as Primary Treatment for Large Vestibular Schwannomas: Clinical Results at Long-Term Follow-Up in a Series of 59 Patients

Gamma Knife radiosurgery (GKRS) represents a well-accepted treatment for small-medium vestibular schwannomas (VS); however, its application in larger VS is still controversial. Among the 523 patients treated at our institution for VS between 2001 and 2010, we included 59 patients with a VS larger than 25 mm, treated by GKRS as primary treatment, not affected by neurofibromatosis type 2, and with a clinical follow-up of at least 36 months. Five patients underwent ventriculoperitoneal shunt placement before radiosurgery. Clinical follow-up (mean, 79.4 months) was obtained in all patients. Patients' age ranged from 24 to 85 years (mean, 63.8 years). Mean tumor volume was 5.98 cm3 (maximum, 14.3 cm3) and median marginal dose was 13 Gy. A statistical analysis was performed to correlate clinical outcome with tumor radiologic features, dose-planning parameters, and patients' characteristics. Tumor control was achieved in 98.3% of cases. At last follow-up, 86.4% of VS showed volume reduction. Recorded complications were 3 cases (5.1%) of new permanent facial nerve deficit, 4 cases (6.8%) of new or worsened trigeminal impairment, and 10 new cases (18.5%) of hydrocephalus requiring ventriculoperitoneal shunt. Larger tumor size was significantly associated with a subsequent ventricular enlargement. Overall, functional hearing preservation rate was 31.3% (66.7% among patients with Gardner-Robertson I). Surgical resection remains the primary approach for large VS with symptomatic brainstem compression. GKRS can be considered a safe and effective option in particular in patients who are not good candidates for surgery.

Treatment of basilar invagination.

Basilar invagination is a rare craniocervical malformation which may lead to neurological deficits related to compression of brainstem and upper cervical cord as well as instability of the craniocervical junction. This study presents results of a treatment algorithm developed over a 20-year period focussing on anatomical findings, short-term and long-term outcomes. 69 patients with basilar invagination (mean age 41 ± 18 years, history 64 ± 85 months) were encountered. The clinical courses were documented with a score system for individual neurological symptoms for short-term results after 3 and 12 months. Long-term outcomes were analyzed with Kaplan-Meier statistics. Patients with (n = 31) or without (n = 38) ventral compression were distinguished. 25 patients declined an operation, while 44 patients underwent 48 operations. Surgical management depended on the presence of ventral compression and segmentation anomalies between occiput and C3, signs of instability and presence of caudal cranial nerve dysfunctions. 16 patients without ventral compression underwent foramen magnum decompressions without fusion. 19 patients with ventral compression and abnormalities of segmentation or evidence of instability underwent a foramen magnum decompression with craniocervical (n = 18) or C1/2 (n = 1) stabilization. In nine patients with severe ventral compression and caudal cranial nerve deficits, a transoral resection of the odontoid was combined with a posterior decompression and fusion. Within the first postoperative year neurological scores improved for all symptoms in each patient group. In the long-term, postoperative deteriorations were related exclusively to instabilities either becoming manifest after a foramen magnum decompression in three or as a result of hardware failures in two patients. The great majority of patients with basilar invagination report postoperative improvements with this management algorithm. Most patients without ventral compression can be managed by foramen magnum decompression alone. The majority of patients with ventral compression can be treated by posterior decompression, realignment and stabilization alone, reserving anterior decompressions for patients with profound, symptomatic brainstem compression.

Fatal Outcome after Delayed Pipeline Embolization Device Migration for the Treatment of a Giant Superior Cerebellar Artery Aneurysm: Technical Note for Complication Avoidance

Purpose: Flow diversion is a relatively novel technique to treat some intracranial aneurysms. With new techniques, unusual complications can occur. We described a case of Pipeline Embolization Device (PED) migration, strategy for its recognition, and a technical point to prevent its occurrence. Publication of these rare events is important to make physicians aware of potential complications. Methods: A patient with a previously coiled giant superior cerebellar aneurysm presented with brainstem compression symptoms. Imaging verified progressive aneurysm growth. A decision was made to treat the aneurysm with PED. Results: Development of new neurologic symptoms prompted a computed tomography that showed hydrocephalus. An angiogram also showed recanalization of the aneurysm secondary to upward migration/retraction of the flow diverter. A ventriculo-peritoneal shunt was implemented and planning for placement of a second flow diverter was made. Unfortunately, the patient expired while waiting for the endovacular intervention. Conclusions: PED migration may occur even after correct placement of the device. Early recognition of this complication is essential. When clinical changes occur, it is paramount that this uncommon, but potentially deadly, complication is suspected. Appropriate sizing and deployment technique are important for the long-term stability of the device.

Predictive Capability of the Spetzler-Martin versus Supplementary Grading Scale for Microsurgical Outcomes of Cerebellar Arteriovenous Malformations

The recently described supplementary grading scale may be superior to the widely used Spetzler-Martin grading scale in the prediction of microsurgical outcomes for cerebellar arteriovenous malformations (AVM). We report two cases of ruptured cerebellar AVMs with the same Spetzler-Martin grade but different supplementary grades treated with microsurgical resection. Both patients had symptomatic brainstem compression from cerebellar hematomas and subsequently underwent uncomplicated surgeries; however, their outcomes were significantly different. It has previously been proposed that AVMs distort cerebellar anatomy in a different manner than supratentorial cerebral anatomy thereby potentially resulting in misrepresentation when utilizing the Spetzler-Martin grading scale. However, the components of the supplementary grading scale are independent of cerebellar anatomy, which may explain why it has been shown to be better than the Spetzler-Martin grading scale for prediction of surgical outcomes. In addition, due to the smaller volume of the posterior fossa compared to the supratentorial compartment, rupture of cerebellar AVMs may result in rapid and catastrophic neurological compromise. Therefore, the role of microsurgery may be more critical for AVMs of the cerebellar than for those located elsewhere. Simple and effective grading systems are invaluable tools for clinical and surgical decision-making, although the decisions rendered should always be made in conjunction with the patient's presentation and the physician's experience.

Long-term follow-up studies of Gamma Knife surgery with a low margin dose for vestibular schwannoma

The aim of this study was to assess long-term clinical outcomes in patients who underwent Gamma Knife surgery (GKS) with a low margin dose-14 Gy or less-to treat vestibular schwannoma (VS) unrelated to neurofibromatosis Type II. Between December 1994 and December 2001, 200 patients with VSs underwent GKS, which was performed using the Leksell Gamma Knife model B. More than 10 years of follow-up is available in these patients. One hundred ninety patients (88 male and 102 female patients) were followed up using MRI (follow-up rate 95%). The mean age of these patients was 50.6 years (range 10-77 years). Gamma Knife surgery was the primary treatment for VS in 134 cases (70.5%) and was an adjunctive management approach in 56 cases (29.5%). The median tumor margin dose was 13.0 Gy (range 6.0-14.4 Gy), and the median maximum tumor dose was 28.0 Gy (range 15.0-60.0 Gy). The median tumor volume was 3.6 cm(3) (range 0.3-27.3 cm(3)). The median duration of follow-up in these patients was 109 months (range 8-195 months). In the 190 patients, the latest follow-up MRI studies demonstrated tumor regression in 122 patients (64.2%), stable tumor in 48 patients (25.3%), and tumor enlargement in 20 patients (10.5%). The total rate of tumor control was 89.5%. Using the Kaplan-Meier method, the authors found the estimated 3-, 5-, 10-, and 15-year tumor control rates to be 95%, 93%, 86%, and 79%, respectively; and the estimated 3-, 5-, and 10-year hearing preservation rates to be 96%, 92%, and 70%, respectively. Twenty-six patients (13.7%) exhibited transient mild facial palsy or facial spasm, and 2 patients (1.1%) suffered persistent mild facial palsy. Thirty-nine patients (20.5%) had transient trigeminal neuropathy, and 5 patients (2.6%) suffered from persistent mild facial numbness. The incidence of persistent severe facial and trigeminal neuropathy was 0.0%. With a low prescribed margin dose of 14 Gy or less, GKS was confirmed to provide long-term tumor control for small to medium-sized VSs and largely to prevent cranial nerves from iatrogenic injury. Based on the findings of this study, GKS is also a reasonable option for the treatment of large, heterogeneously enhancing tumors without symptomatic brainstem compression. Gamma Knife surgery can preserve a high quality of life for most patients with VS who do not have symptomatic brainstem compression. Long-term follow-up is required because of the risk of delayed recurrence of VS.

Long-term tumor control and cranial nerve outcomes following Gamma Knife surgery for larger-volume vestibular schwannomas

γ knife surgery (GKS) for vestibular schwannoma (VS) is an accepted treatment for small- to medium-sized tumors, generally smaller than 2.5 cm in the maximum posterior fossa dimension. The purpose of this study was to evaluate the efficacy and toxicity of GKS for larger tumors. Prospectively collected data were analyzed for 22 patients who had undergone GKS for VSs larger than 2.5 cm in the posterior fossa diameter between 1997 and 2006. No patient had symptomatic brainstem compression at the time of GKS. The median treated tumor volume was 9.4 cm(3) (range 5.3-19.1 cm(3)). The median maximum posterior fossa diameter was 2.8 cm (range 2.5-3.8 cm). The median tumor margin dose was 12 Gy (range 12-14 Gy). Serial imaging, audiometry (10 patients with serviceable hearing pre-GKS), and clinical follow-up were available for a median of 66 months (range 26-121 months). Tumor control failure was defined as either a progressive increase in tumor diameter of at least 2 mm in any dimension or a later resection. Four patients met the criteria for GKS failure, including 1 patient who demonstrated sarcomatous degeneration more than 7 years after GKS and died 3 months after microsurgical debulking. An enlarging cystic component was the surgical indication in 1 of the 2 patients who required resection, although 27% of tumors (6 lesions) were cystic before GKS. The 3-year actuarial rate of tumor control, freedom from new facial neuropathy, and preservation of functional hearing were 86%, 92%, and 47%, respectively. At 5 years post-GKS, these rates decreased to 82%, 85%, and 28%, respectively. At the most recent follow-up, 91% of tumors were smaller than at the time of GKS and the median maximum posterior fossa diameter reduction was 26%. On multivariate analysis, none of the following factors was associated with GKS failure, new facial weakness, new trigeminal neuropathy, or loss of serviceable hearing: patient age, tumor volume, tumor margin dose, and preoperative cranial nerve dysfunction. Single-session radiosurgery is a successful treatment for the majority of patients with larger VSs. Although tumor control rates are lower than those for smaller VSs managed with GKS, the cranial nerve morbidity of GKS is significantly lower than that typically achieved via resection of larger VSs.

Anatomical variation of the vertebral artery clinically mimicking myasthenia gravis

Cranial nerve palsy, most commonly trigeminal, abducens, or facial, caused by compression of an ectatic or elongated intracranial artery is a well-known phenomenon. Symptoms of brain stem compression by an abnormal artery have rarely been reported (Tomasello et al. Neurosurgery 56(suppl 1):117-124, 2005). The authors present a 59-year-old woman with intermittent ptosis of the right eye, diplopia and swallowing disturbances, enhanced after physical effort, implying myasthenia gravis. Typical diagnostic procedures, e.g. repetitive nerve stimulation tests, acetylcholine receptor antibodies level were within normal limit. Neurogenic changes from the orbicularis oculi muscle were found in EMG. MRI and angio-CT revealed anatomical variation of the vertebral artery (elongated and arcuate route), causing intermittent signs of brain stem lesion. We point out the similarity of the clinical symptoms of myasthenia gravis and vascular brain stem compression by abnormal vertebral artery. The two diseases require completely different therapeutic proceedings.

Skull Base Manifestations of Camurati-Engelmann Disease

To describe presenting symptoms, evaluation findings, and surgical management of cranial base hyperostosis in patients with Camurati-Engelmann disease (CED). Retrospective study and literature review. The Mayo Clinic, Rochester, Minnesota. A total of 306 patients diagnosed as having CED, including 12 primarily evaluated at our institution between 1968 and 2008, and 294 identified in the international literature. Presenting symptoms, methods of diagnosis, treatment strategies, and patient outcomes. One hundred seventy-three of 306 patients (56.5%) had radiographically proven skull base hyperostosis, whereas less than one-fourth were symptomatic. The most common manifestations of cranial base involvement were hearing loss (19.0%), headache (10.4%), exophthalmos (8.2%), and frontal bossing (7.2%); less common were vision changes, vertigo, facial weakness, symptomatic brainstem compression, facial numbness, and hyposmia. Although corticosteroids and bisphosphates may treat torso and extremity involvement, they demonstrate no benefit for symptomatic skull base disease. In select symptomatic patients, aggressive decompression surgery may provide the only means of treatment. Decompression surgery is more challenging with thick sclerotic bone, loss or obscuration of bony landmarks, and decreased supratentorial space. Patients must be counseled on the increased risks associated with surgery and the potential for redeposition of bone and recurrence of symptoms. Physicians should include CED in the differential diagnosis for patients with radiographic evidence of skull base thickening and synchronous cranial neuropathies or symptoms of elevated intracranial pressure. In mild forms of the disease, the clinical course of patients should be followed with serial examination, audiometric testing, and radiography. In select patients with progressive cranial base symptoms, aggressive wide decompression of involved neurovascular structures may provide benefit.

Gamma Knife Radiosurgery for Benign Tumors With Symptoms From Brainstem Compression

This study evaluated the role of radiosurgery in the management of symptomatic patients with brainstem compression from benign basal tumors. Over a 17-year, period 246 patients (202 vestibular schwannomas and 44 meningiomas) with brainstem compression from benign skull-base tumors were managed with Gamma Knife radiosurgery. Median tumor volumes were 3.9 cm(3) (range, 0.8-39.0 mL) and 6.6 mL (range, 1.6-25.1 mL) for vestibular schwannomas and meningiomas, respectively. For both tumors, a median marginal dose of 13 Gy was prescribed. Median follow-up of patients was 65 months for vestibular schwannomas and 60 months for meningiomas. Patients were categorized into four groups on the basis of the tumor-brainstem relationship on neuroimaging. Preservation of function was stratified according to grade of brainstem compression. We analyzed the effect of radiosurgery on symptoms of brainstem compression. The tumor control rate was 100 % for meningioma and 97% for vestibular schwannomas (although 5% required an additional procedure such as a ventriculoperitoneal shunt). In patients with vestibular schwannoma, serviceable hearing was preserved in 72.0%. Balance improved in 31.9%, remained unchanged in 56.5%, and deteriorated in 11.6% of patients who had imbalance at presentation. Balance improved significantly in patients who had less tumor compression (p = 0.0357) after radiosurgery. Symptoms improved in 43.2% of patients with meningioma. Radiosurgery is a minimally invasive option for patients with benign basal tumors that indent or distort the brainstem. A high tumor growth control rate and satisfactory rate of neurological preservation and symptom control can be obtained with radiosurgery.