Spinal Schwannoma; Analysis of 40 Cases

Objective

This study is to report our experience of 40 cases of spinal schwannoma.

Methods

From 1995 to 2006, medical records were retrospectively reviewed in 40 cases of spinal schwannoma.

Results

We treated 40 spinal schwannomas in 38 (22 male and 16 female) patients. The mean age was 50.2. Four cases were sited in the cervical spine, 11 cases in the thoracic spine, and 25 cases in the lumbar spine. Two patients showed recurrences. Thirty-eight cases were intradural-extramedullary type and 2 cases were extradural. Two cases (5%) including 1 recurred case had no postoperative motor improvement. Ninety-five percents of patients improved on postoperative motor grade.

Conclusion

Spinal schwannoma is mostly benign and extramedullary tumor. There were 2 recurred cases (5%) that had history of previous subtotal removal at first operation and had shown worse prognosis compared with the cases without recurrence. To reduce the recurrence of spinal schannoma, total excision of tumor mass should be done.     

Conventional Posterior Approach without Far Lateral Approach for Ventral Foramen Magnum Meningiomas

Objective

We present our experience of conventional posterior approach without fat lateral approach for ventral foramen magnum (FM) meningioma (FM meningioma) and tried to evaluate the approach is applicable to ventral FM meningioma.

Methods

From January 1999 to March 2011, 11 patients with a ventral FM meningioma underwent a conventional posterior approach without further extension of lateral bony window. The tumor was removed through a working space between the dura and arachnoid membrane at the cervicomedullary junction with minimal retraction of medulla, spinal cord or cerebellum. Care should be taken not to violate arachnoid membrane.

Results

Preoperatively, six patients were of Nurick grade 1, three were of grade 2, and two were of grade 3. Median follow-up period was 55 months (range, 20-163 months). The extent of resection was Simpson grade I in one case and Simpson grade II in remaining 10 cases. Clinical symptoms improved in eight patients and stable in three patients. There were no recurrences during the follow-up period. Postoperative morbidities included one pseudomeningocele and one transient dysphagia with dysarthria.

Conclusion

Ventral FM meningiomas can be removed gross totally using a posterior approach without fat lateral approach. The arachnoid membrane can then be exploited as an anatomical barrier. However, this approach should be taken with a thorough understanding of its anatomical limitation.     

Occipital Neuralgia as the Only Presenting Symptom of Foramen Magnum Meningioma

Background

Occipital neuralgia (ON) is a condition characterized by a paroxysmal stabbing pain in the area of the greater or lesser occipital nerves; it is usually regarded by clinicians as idiopathic. Some have suggested that ON can be induced by trauma or injury of the occipital nerves or their roots, but tumor has rarely been reported as a cause of ON.

Case Report

We report herein a case of foramen magnum meningioma in a 55-year-old woman who presented with ON triggered by head motion as the only symptom without any signs of myelopathy.

Conclusions

This case indicates that it is important to consider the underlying causes of ON. Precise neurologic and radiological evaluations such as cervical spine magnetic resonance imaging are needed.     

The Jugular Foramen Schwannomas: Review of the Large Surgical Series

Objective

Jugular foramen schwannomas are uncommon pathological conditions. This article is constituted for screening these tumors in a wide perspective.

Materials

One-hundred-and-ninty-nine patients published in 19 articles between 1984 to 2007 years was collected from Medline/Index Medicus.

Results

The series consist of 83 male and 98 female. The mean age of 199 operated patients was 40.4 years. The lesion located on the right side in 32 patients and on the left side in 60 patients. The most common presenting clinical symptoms were hearing loss, tinnitus, disphagia, ataxia, and hoarseness. Complete tumor removal was achieved in 159 patients. In fourteen patients tumor reappeared unexpectedly. The tumor was thought to originate from the glossopharyngeal nerve in forty seven cases; vagal nerve in twenty six cases; and cranial accessory nerve in eleven cases. The most common postoperative complications were lower cranial nerve palsy and facial nerve palsy. Cerebrospinal fluid leakage, meningitis, aspiration pneumonia and mastoiditis were seen as other complications.

Conclusion

This review shows that jugular foramen schwannomas still have prominently high morbidity and those complications caused by postoperative lower cranial nerve injury are life threat.     

Preoperative Identification of Facial Nerve in Vestibular Schwannomas Surgery Using Diffusion Tensor Tractography

Objective

Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve.

Methods

We prospectively collected data from 11 patients with VS, who underwent preoperative DTT for facial nerve. Imaging results were correlated with intraoperative findings. Postoperative DTT was performed at postoperative 3 month. Facial nerve function was clinically evaluated according to the House-Brackmann (HB) facial nerve grading system.

Results

Facial nerve courses on preoperative tractography were entirely correlated with intraoperative findings in all patients. Facial nerve was located on the anterior of the tumor surface in 5 cases, on anteroinferior in 3 cases, on anterosuperior in 2 cases, and on posteroinferior in 1 case. In postoperative facial nerve tractography, preservation of facial nerve was confirmed in all patients. No patient had severe facial paralysis at postoperative one year.

Conclusion

This study shows that DTT for preoperative identification of facial nerve in VS surgery could be a very accurate and useful radiological method and could help to improve facial nerve preservation.     

Clinical Outcome of Treatment for Patients with Giant Cell Tumor in Spine

Objective

The treatment of giant cell tumor (GCT) is mainly performed surgically. However, GCT in spine seems difficult to treat because of the limited surgical accessibility and proximity. In this report, we analyzed the outcome of GCT treatment in spine.

Methods

Between 2000 and 2012, 19 patients received treatment for GCT in spine. Median age at their first diagnosis was 31 years, 10 patients were male, and 9 female. Fourteen tumors were located in the sacrum, 1 in cervical, 1 in thoracic and 3 in lumbar spine. As primary treatment, gross total removal (GTR) was done in 6 patients, and subtotal removal (STR) in 13 patients. Radiation therapy (RT) as an adjuvant therapy was performed in 2 cases in GTR group and 10 cases in STR group.

Results

During the follow-up, 7 patients had local recurrence (36.8%). The average period until recurrence after primary treatment was 14 months. No recurrence was detected in GTR group. Recurrence was noted in 7 out of 13 patients who underwent STR. These differences were statistically significant (p=0.024). A median of recurrence free period (RFP) was 84 months. Also average RFP of the RT group was 112 months, and non-RT group was 65 months. These differences were statistically significant (p=0.041).

Conclusion

Treatment of choice for GCT in spine is a complete removal of tumor without neurological deficits. In case of incomplete removal, radiation therapy may be a useful adjuvant treatment modality.     

Surgical Treatment of Craniovertebral Junction Instability : Clinical Outcomes and Effectiveness in Personal Experience

Objective

Craniovertebral junction (CVJ) consists of the occipital bone that surrounds the foramen magnum, the atlas and the axis vertebrae. The mortality and morbidity is high for irreducible CVJ lesion with cervico-medullary compression. In a clinical retrospective study, the authors reviewed clinical and radiographic results of occipitocervical fusion using a various methods in 32 patients with CVJ instability.

Methods

Thirty-two CVJ lesions (18 male and 14 female) were treated in our department for 12 years. Instability resulted from trauma (14 cases), rheumatoid arthritis (8 cases), assimilation of atlas (4 cases), tumor (2 cases), basilar invagination (2 cases) and miscellaneous (2 cases). Thirty-two patients were internally fixed with 7 anterior and posterior decompression with occipitocervical fusion, 15 posterior decompression and occipitocervical fusion with wire-rod, 5 C1-2 transarticular screw fixation, and 5 C1 lateral mass-C2 transpedicular screw. Outcome (mean follow-up period, 38 months) was based on clinical and radiographic review. The clinical outcome was assessed by Japanese Orthopedic Association (JOA) score.

Results

Nine neurologically intact patients remained same after surgery. Among 23 patients with cervical myelopathy, clinical improvement was noted in 18 cases (78.3%). One patient died 2 months after the surgery because of pneumonia and sepsis. Fusion was achieved in 27 patients (93%) at last follow-up. No patient developed evidence of new, recurrent, or progressive instability.

Conclusion

The authors conclude that early occipitocervical fusion to be recommended in case of reducible CVJ lesion and the appropriate decompression and occipitocervical fusion are recommended in case of irreducible craniovertebral junction lesion.     

The Influence of Pituitary Adenoma Size on Vision and Visual Outcomes after Trans-Sphenoidal Adenectomy: A Report of 78 Cases

Objective

The aims of this study were to investigate the quantitative relationship between pituitary macroadenoma size and degree of visual impairment, and assess visual improvement after surgical resection of the tumor.

Methods

The medical records of patients with pituitary adenoma, who had undergone trans-sphenoidal adenectomy between January 2009 and January 2011, were reviewed. Patients underwent an ocular examination and brain MRI before and after surgery. The visual impairment score (VIS) was derived by combining the scores of best-corrected visual acuity and visual field. The relationship between VIS and tumor size/tumor type/position of the optic chiasm was assessed.

Results

Seventy-eight patients were included (41 male, 37 female). Thirty-two (41%) patients experienced blurred vision or visual field defect as an initial symptom. Receiver operating characteristic curve analysis showed that tumors <2.2 cm tended to cause minimal or no visual impairment. Statistical analysis showed that 1) poor preoperative vision is related to tumor size, displacement of the optic chiasm in the sagittal view on MRI and optic atrophy, and 2) poorer visual prognosis is associated with greater preoperative VIS. In multivariate analysis the only factor significantly related to VIS improvement was increasing pituitary adenoma size, which predicted decreased improvement.

Conclusion

Results from this study show that pituitary adenomas larger than 2 cm cause defects in vision while adenomas 2 cm or smaller do not cause significant visual impairment. Patients with a large macroadenoma or giant adenoma should undergo surgical resection as soon as possible to prevent permanent visual loss.     

Thoracic Myelopathy Caused by Ossification of the Ligamentum Flavum

Objective

Ossification of the ligamentum flavum (OLF) is a rare cause of thoracic myelopathy. The aim of this study was to identify factors associated with the surgical outcome on the basis of preoperative clinical and radiological findings.

Methods

Data obtained in 26 patients whot underwent posterior decompression for thoracic myelopathy, caused by thoracic OLF, were analyzed retrospectively. Patient age, duration of symptoms, OLF type, preoperative and postoperative neurological status using the Japanese Orthopedic Association (JOA) scoring system, surgical outcome, and other factors were reviewed. We compared the various factors and postoperative prognosis. All patients had undergone decompressive laminectomy and excision of the OLF.

Results

Using the JOA score, the functional improvement was excellent in 8 patients, good in 14, fair in 2, and unchanged in 2. A mean preoperative JOA score of 6.65 improved to 8.17 after an average of 27.3 months. According to our analysis, age, gender, duration of symptoms, the involved spinal level, coexisting spinal disorders, associated trauma, intramedullary signal change, and dural adhesions were not related to the surgical outcome. However, the preoperative JOA score and type of OLF were the most important predictors of the surgical outcome.

Conclusion

Early diagnosis and sufficient surgical decompression could improve the functional prognosis for thoracic OLF. The postoperative results were found to be significantly associated with the preoperative severity of myelopathy and type of OLF.     

Feasibility of Endoscopic Endonasal Approach for Recurrent Pituitary Adenomas after Microscopic Trans-Sphenoidal Approach

Objective

The surgical approach for recurrent pituitary adenoma after trans-sphenoidal approach (TSA) is challenging. We report the outcomes of the endoscopic TSA for recurrent pituitary adenoma after microscopic TSA.

Methods

From February 2010 to February 2013, endoscopic TSA was performed for removal of 30 recurrent pituitary adenomas after microscopic TSA. Twenty-seven (90%) patients had a clinically non-functioning pituitary adenoma. Twenty-four (80%) patients suffered from a visual disturbance related to tumor growth. The clinical features and surgical outcomes were retrospectively analyzed for the ophthalmological, endocrinological, and oncological aspects.

Results

The mean tumor volume was 11.7 cm³, and gross total resection was achieved in 50% of patients. The volumetric analysis based on the postoperative MR showed that the mean extent of resection rates were 90%. Vision was improved in 19 (79%) of 24 patients with visual symptoms, and endocrinological cure was achieved in all of three functioning pituitary adenomas; however, the post-operative follow-up endocrinological examination revealed a new endocrinological deficit in one patient. Two patients required antibiotics management for post-operative meningitis.

Conclusion

The endoscopic TSA can be an effective treatment option for recurrent pituitary adenoma after microscopic TSA with acceptable outcome.     

Postoperative Survival and Ambulatory Outcome in Metastatic Spinal Tumors : Prognostic Factor Analysis

Objective

The purposes of this study are to estimate postoperative survival and ambulatory outcome and to identify prognostic factors thereafter of metastatic spinal tumors in a single institute.

Methods

We reviewed the medical records of 182 patients who underwent surgery for a metastatic spinal tumor from January 1987 to January 2009 retrospectively. Twelve potential prognostic factors (age, gender, primary tumor, extent and location of spinal metastases, interval between primary tumor diagnosis and metastatic spinal cord compression, preoperative treatment, surgical approach and extent, preoperative Eastern Cooperative Oncology Group (ECOG) performance status, Nurick score, Tokuhashi and Tomita score) were investigated.

Results

The median survival of the entire patients was 8 months. Of the 182 patients, 80 (44%) died within 6 months after surgery, 113 (62%) died within 1 year after surgery, 138 (76%) died within 2 years after surgery. Postoperatively 47 (26%) patients had improvement in ambulatory function, 126 (69%) had no change, and 9 (5%) had deterioration. On multivariate analysis, better ambulatory outcome was associated with being ambulatory before surgery (p=0.026) and lower preoperative ECOG score (p=0.016). Survival rate was affected by preoperative ECOG performance status (p<0.001) and Tomita score (p<0.001).

Conclusion

Survival after metastatic spinal tumor surgery was dependent on preoperative ECOG performance status and Tomita score. The ambulatory functional outcomes after surgery were dependent on preoperative ambulatory status and preoperative ECOG performance status. Thus, prompt decompressive surgery may be warranted to improve patient''s survival and gait, before general condition and ambulatory function of patient become worse.     

Clinical Analysis of Intracranial Hemangiopericytoma

Objective

Intracranial hemangiopericytomas (HPCs) are rare tumors with aggressive behavior, including local recurrence and distant metastasis. We conducted this retrospective study to evaluate the efficacy of grossly total resection and adjuvant radiotherapy (RT) for these tumors.

Methods

A total of 13 patients treated for intracranial HPC from January 1995 through May 2013 were included in this retrospective study. We analyzed the clinical presentations, radiologic appearances, treatment results, and follow-up outcomes, as well as reviewed other studies.

Results

The ages of the patients at the time of diagnosis ranged from 26 to 73 years (mean : 48 years). The majority of the patients were male (92.3%), and the majority of the tumors were located in the parasagittal and falx. The ratio of intracranial HPCs to meningiomas was 13 : 598 in same period, or 2.2%. Seven patients (53.8%) had anaplastic HPCs. Nine patients (69.2%) underwent gross total tumor resection in the first operation without mortality. Eleven patients (84.6%) underwent postoperative adjuvant RT. Follow-up period ranged from 13 to 185 months (mean : 54.3 months). The local recurrence rate was 46.2% (6/13), and there were no distant metastases. The 10-year survival rate after initial surgery was 83.9%. The initial mean Karnofsky performance scale (KPS) was 70.8 and the final mean KPS was 64.6.

Conclusion

Gross total tumor resection upon initial surgery is very important. We believe that adjuvant RT is helpful even with maximal tumor resection. Molecular biologic analyses and chemotherapy studies are required to achieve better outcomes in recurrent intracranial HPCs.     

Is the Complete Resection of Craniopharyngiomas in Adults Feasible Considering Both the Oncologic and Functional Outcomes?

Objective

To assess the impact of the complete resection of craniopharyngioma (CP) in adults on oncologic and functional outcomes.

Methods

We retrospectively analyzed 82 patients with CP who were surgically treated by the same neurosurgeon at our institution between January 1994 and December 2012.

Results

Gross total resection (GTR) was achieved in 71 patients (86.6%), near total resection (NTR) in 7 patients (8.5%), and subtotal resection (STR) in 3 patients (3.7%). The disease-specific overall survival rate was 100% with the exclusion of 2 surgery-related mortalities. The overall recurrence rate was 12.2% (10 of 82 patients), however the recurrence rate according to extent of resection (EOR) was 9.9% (7 of 71 patients) after GTR, 14.3% (1 of 7 patients) after NTR, and 66.7% (2 of 3 patients) after STR. The overall recurrence-free survival (RFS) rates at 5 and 10 years were 87.0% and 76.8%, respectively. Postoperatively, most patients (86.3%) needed hormone replacement for at least 1 hypothalamic-pituitary axis. Vision improved in 56.4% of the patients with preoperative abnormal vision, but deteriorated in 27.4% of patients. Hypothalamic dysfunction developed in 32.9% of patients. There were no significant differences in the risks of pituitary dysfunction, visual deterioration, or hypothalamic dysfunction between the groups with complete vs. incomplete removal. The overall rate of postoperative complications was 22.0%, which did not differ between groups (p=0.053).

Conclusion

The complete removal of a CP at first surgery can provide a chance for a cure with acceptable morbidity and mortality risks.     

Surgical Experience of Infratentorial Meningiomas : Clinical Series at a Single Institution during the 20-Year Period

Objective

Based on surgical outcomes of patients with infratentorial meningiomas surgically treated at our institution, we analyzed the predictors for surgical resection, recurrence, complication, and survival.

Methods

Of surgically treated 782 patients with intracranial meningioma, 158 (20.2%) consecutive cases of infratentorial location operated on between April 1993 and May 2013 at out institute were reviewed retrospectively. The patients had a median age of 57.1 years (range, 16--77 years), a female predominance of 79.7%, and a mean follow-up duration of 48.4 months (range, 0.8--242.2 months).

Results

Gross total resection (Simpson''s grade I & II) was achieved in 81.6% (129/158) of patients. Non-skull base location was an independent factor for complete resection. The recurrence rate was 13.3% (21/158) and the 5-, 10-, and 15-year recurrence rates were 8.2%, 12.0%, and 13.3%, respectively. Benign pathology, postoperative KPS over than 90, low peritumoral edema, and complete resection were significantly associated with longer recurrence-free survival rate. The 5-, 10-, and 15-year survival rates were 96.2%, 94.9%, and 94.9%, respectively. Benign pathology, postoperative KPS over than 90 and complete resection were significantly associated with a longer survival rate. The permanent complication rate was 13% (21/158). Skull base location and postoperative KPS less than 90 were independent factors for the occurrence of permanent complication.

Conclusion

Our experience shows that infratentorial meningiomas represent a continuing challenge for contemporary neurosurgeons. Various factors are related with resection degree, complications, recurrence and survival.     

Surgical Treatment of Primary Spinal Tumors in the Conus Medullaris

Objective

The objective of this study was to evaluate the characteristics and surgical outcome of the conus medullaris tumors.

Methods

We retrospectively reviewed 26 patients who underwent surgery for conus medullaris tumor from August 1986 to July 2007. We analyzed clinical manifestation, preoperative MRI findings, extent of surgical resection, histopathologic type, adjuvant therapy, and outcomes.

Results

There were ependymoma (13), hemangioblastoma (3), lipoma (3), astrocytoma (3), primitive neuroectodermal tumor (PNET) (2), mature teratoma (1), and capillary hemangioma (1) on histopathologic type. Leg pain was the most common symptom and was seen in 80.8% of patients. Pain or sensory change in the saddle area was seen in 50% of patients and 2 patients had severe pain in the perineum and genitalia. Gross total or complete tumor resection was obtained in 80.8% of patients. On surgical outcome, modified JOA score worsened in 26.9% of patients, improved in 34.6%, and remained stable in 38.5%. The mean VAS score was improved from 5.4 to 1.8 among 21 patients who had lower back pain and leg pain.

Conclusion

The surgical outcome of conus medullaris tumor mainly depends on preoperative neurological condition and pathological type. The surgical treatment of conus medullaris tumor needs understanding the anatomical and functional characteristics of conus meudllaris tumor for better outcome.     

Brachial Plexus Tumors in a Consecutive Series of Twenty One Patients

Objective

This is a retrospective review of 22 surgically treated benign and malignant tumors of brachial plexus region to describe clinical presentation, the characteristics of brachial plexus tumor and clinical outcomes with a literature review.

Methods

Twenty-one patients with consecutive 22 surgeries for primary brachial plexus tumors were enrolled between February 2002 and November 2011 were included in this study. The medical records of all patients were reviewed.

Results

Eleven male and 10 female patients were enrolled. Mean age was 39 years. Three patients had brachial plexus tumor associated with neurofibromatosis (13.6%). Presenting signs and symptoms included parenthesis and numbness (54.5%), radiating pain (22.7%), direct tenderness and pain (27.2%), palpable mass (77.3%). Twelve patients presented preoperative sensory deficit (54.5%) and 9 patients presented preoperative motor deficit (40.9%). Twenty tumors (90.9%) were benign and 2 tumors (9.1%) were malignant. Benign tumors included 15 schwannomas (68.2%), 4 neurofibromas (18.2%) and 1 granular cell tumor (4.5%). There were 1 malignant peripheral nerve sheath tumor (MPNST) and 1 malignant granular cell tumor. Gross total resection was achieved in 16 patients (72.7%), including all schwannomas, 1 neurofibroma. Subtotal resection was performed in 6 tumors (27.3%), including 3 neurofibromatosis associated with brachial plexus neurofibromas, 1 MPNST and 2 granular cell tumor in one patient.

Conclusion

Resection of tumor is the choice of tumor in the most of benign and malignant brachial plexus tumors. Postoperative outcomes are related to grade of resection at surgery and pathological features of tumor.     

Transventricular Biopsy of Brain Tumor without Hydrocephalus Using Neuroendoscopy with Navigation

Objective

It is usually difficult to perform the neuroendoscopic procedure in patients without hydrocephalus due to difficulties with ventricular cannulation. The purpose of this study was to find out the value of navigation guided neuroendoscopic biopsy in patients with peri- or intraventricular tumors without hydrocephalus.

Methods

Six patients with brain tumors without hydrocephalus underwent navigation-guided neuroendoscopic biopsy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by chemotherapy and/or radiotherapy as the first line treatment, or establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy.

Results

Under the guidance of navigation, targeted lesion was successfully approached in all patients. Navigational tracking was especially helpful in entering small ventricles and in approaching the third ventricle through narrow foramen Monro. The histopathologic diagnosis was established in all of 6 patients : 2 germinomas, 2 astrocytomas, 1 dysembryoplastic neuroepithelial tumor and 1 pineocytoma. The tumor biopsy sites were pineal gland (n = 2), suprasellar area (n = 2), subcallosal area (n = 1) and thalamus (n = 1). There were no operative complications related to the endoscopic procedure.

Conclusion

Endoscopic biopsy or resection of peri- or intraventricular tumors in patients without hydrocephalus is feasible. Image-guided neuroendoscopic procedure improved the accuracy of the endoscopic approach and minimized brain trauma. The absence of ventriculomegaly in patients with brain tumor may not be served as a contraindication to endoscopic tumor biopsy.     

Surgical Outcome of Spinal Cord Hemangioblastomas

Objective

Spinal cord hemangioblastomas are rare tumors. Despite their benign, slow-growing nature, they can cause severe neurological consequences. The purpose of this study was to evaluate variable factors, including clinical features, tumor findings, the extent of resection, and its recurrence or progression, which determine postoperative functional outcomes.

Methods

This study included sixteen patients at our institute who underwent microsurgical resection for sporadic spinal intramedullary hemangioblastomas and spinal intramedullary hemangioblastomas associated with von Hippel-Lindau (VHL) disease, between June 2003 and March 2012.

Results

A total of 30 operations were performed. Total resection (TR) of the tumor was achieved in 10 patients, and subtotal resection (STR) was achieved in 6. Postoperatively, the initial presenting symptoms were improved in 18.7% of the patients and were unchanged in 56.3%, but 25% were worse. Stable postoperative neurological functions were found in 83% of patients with preoperative McCormick grade I, and TR was achieved in 75% of these patients. In the STR group, poorer neurological status was observed in one patient, despite multiple operations. There were no poorer outcomes in the four cases of VHL disease. Various factors were analyzed, but only a correlation between the pre- and postoperative neurological status was verified in the TR-group patients.

Conclusion

Preoperative focal neurological impairment and meticulous microsurgical manipulation may be predictors of favorable outcomes for solitary hemangioblastomas. In addition, the preservation of function is more important than the extent of resection in VHL disease.     

Microvascular Decompression for Primary Trigeminal Neuralgia : Short-Term Follow-Up Results and Prognostic Factors

Objective

The aim of this prospective study was to demonstrate the influence of some factors on the prognosis of microvascular decompression in 37 patients with trigeminal neuralgia.

Methods

The results of microvascular decompression (MVD) in 37 patients with trigeminal neuralgia were evaluated at 6 months after surgery and were compared with clinical and operative findings.

Results

The sex of the patient, the patient''s age at surgery, the side of the pain, and the duration of symptoms before surgery did not play any significant roles in prognosis. Also, the visual analogue scale (VAS) of the patient, the duration of each pain attack, and the frequency of pain over 24 hours did not play any significant roles in prognosis. In addition, intraoperative detection of the type of conflicting vessel, the degree of severity of conflict, and the location of the conflict around the circumference of the root did not play any roles in prognosis. The only factors affecting the prognosis in MVD surgery were intraoperative detection of the site of the conflict along the root and neuroradiological compression signs on preoperative magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA).

Conclusion

These findings demonstrated that if neurovascular compression is seen on preoperative MRI/MRA and/or compression is found intraoperative at the root entry zone, then the patient will most likely benefit from MVD surgery.     

Role of “major” and “minor” lambdoid arch sutures in posterior cranial fossa changes: mechanism of cerebellar tonsillar herniation in infants with multisutural craniosynostosis

Purpose

This study aimed to explain the functional role of lambdoid arch sutures in the development of cerebellar tonsillar herniation. Posterior cranial fossa (PCF) changes were investigated in infants with premature synostosis of the major and minor sutures of the lambdoid arch without premature synostosis of the PCF synchondroses.

Methods

Morphometric and volumetric PCF measurements were performed on preoperative high-resolution CT studies in 12 infants with multisutural craniosynostosis involving the lambdoid arch and compared with those of 12 age-matched healthy subjects.

Results

All 12 patients had hypoplasia of PCF bone structures and normal volumes of the PCF and neural structures. PCF hypoplasia was related to exocciput length in infants with isolated involvement of major sutures, while it was related to posterior skull base hemifossae in infants with isolated involvement of minor lambdoid arch sutures. Foramen magnum AP diameter was reduced in babies with major suture involvement and tonsillar herniation, while foramen magnum AP and LL diameters were reduced in babies with minor suture involvement without tonsillar herniation. Right and left jugular foramen (JF) areas differed in all infants; however, the area of the smaller JF was significantly reduced only in infants with involvement of minor lambdoid arch sutures.

Conclusion

Hypoplasia of PCF bone structures due to sutural synostosis of the lambdoid arch is a required predisposing but not sufficient factor for the development of cerebellar tonsillar herniation through the foramen magnum. Normal PCF volume and foramen magnum anatomy may partly explain the development of cerebellar tonsil herniation in infants with lambdoid arch synostosis.