Spectroscopy-supported frame-based image-guided stereotactic biopsy of parenchymal brain lesions: Comparative evaluation of diagnostic yield and diagnostic accuracy

Objective

Comparative evaluation of diagnostic efficacy of stereotactic brain biopsy performed with and without additional use of spectroscopic imaging (¹H-MRS) for target selection was done.

Methods

From 2002 to 2006, 30 patients with parenchymal brain lesions underwent ¹H-MRS-supported frame-based stereotactic biopsy, whereas in 39 others MRI-guided technique was used. Comparison of diagnostic yield of the procedure in these two groups was performed. Additionally, the diagnostic accuracy was evaluated in 37 lesions, which were surgically resected within 1 month thereafter.

Results

Stereotactic biopsy permitted establishment of a definitive histopathological diagnosis in 57 cases and diagnosis of low-grade glioma without specific tumor typing in 8 cases. In 4 cases tissue sampling was non-diagnostic. In 5 out of 8 cases with incomplete diagnosis and in all non-diagnostic cases target selection was performed without the use of ¹H-MRS (P = 0.2073). The diagnostic yields of ¹H-MRS-supported and MRI-guided procedures were 100% and 90%, respectively (P = 0.1268). Comparison of the histopathological diagnoses after stereotactic biopsy and surgical resection revealed complete diagnostic agreement in 13 cases, minor disagreement in 14 cases, and major disagreement in 10 cases. Among these last 10 cases, initial undergrading of non-enhancing WHO grade III gliomas was the most common (7 cases). The diagnostic accuracy of ¹H-MRS-supported and MRI-guided procedures was 67% and 79%, respectively (P = 0.4756).

Conclusion

While in the present study the diagnostic yield of ¹H-MRS-supported frame-based stereotactic brain biopsy was 100%, its statistically significant diagnostic advantages over MRI-guided technique were not proved. Optimal selection of the spectroscopic target for tissue sampling remains unclear.     

Usefulness of thallium-201 SPECT for prediction of early progression in low-grade astrocytomas diagnosed by stereotactic biopsy

Objective

To establish the value of thallium-201 single-photon emission computed tomography (²⁰¹Tl-SPECT) as a predictor of early progression in low-grade astrocytomas (LGAs).

Methods

We studied 57 consecutive patients who underwent 201 Tl-SPECT before stereotactic biopsy (n = 33) or surgical resection (n = 24). The value of radiologic and histopathological variables (²⁰¹Tl index and MIB-1 index) in predicting progression free survival (PFS) was examined in each group of patients.

Results

During a median follow up of 55 months (range, 11–101), progression of the primary lesion was identified in 46 patients (80.7%). Based on Cox's proportional hazards model, the increased thallium uptake was associated with a short PFS in both biopsy and resection groups, whereas the MIB-1 index was significant only in the resection group. Considering the cut-off value, ²⁰¹Tl index > 1.7 was statistically significant for reduced PFS in the biopsy group; however, MIB-1 index was not directly related to the PFS at any level. For the surgical resection group, both a ²⁰¹Tl index > 1.9 and a MIB-1 index > 6% were associated with short PFS.

Conclusion

²⁰¹Tl SPECT may play a role in prediction of early tumor progression not only in resected LGAs, but also in biopsy-proven LGAs. Therefore, we suggest that patients with LGAs established from biopsy should be considered as high-risk groups for early progression if the tumor shows a high ²⁰¹Tl uptake, even if the tumor demonstrates low proliferative activity on histopathologic examination.     

Vestibular schwannoma microsurgery with special reference to facial nerve preservation

Objective

To retrospectively study the outcomes of vestibular schwannoma (VS) resection.

Methods

Between January 2003 and December 2006, 103 consecutive patients who had undergone VS resection were included in this study. Medical records, operation summaries, follow-up data, and neuroradiological findings were analyzed. The relationship between tumor size, location, and topography relative to the facial nerve bundles was studied for a mean duration of 16 months (range: 3–39 months).

Results

Complete tumor resection in combination with anatomic preservation of the facial nerve was achieved in 101 (98.1%) cases. The facial nerve was fully preserved in 100% of cases with small or medium tumors and in 37/39 patients with large tumors. Overall, 83.5% of patients had normal or near-normal facial nerve function 3–12 months post-surgically. The mortality rate was 0%.

Conclusions

Even in large VS, preservation of facial nerve function (H-B Grade I or II) should be prioritized over total resection. For tumors >3 cm, the goal of low morbidity and maintenance of normal facial nerve function can be attained with the retrosigmoid transmeatal approach, refined microsurgical technique, and intraoperative facial nerve monitoring.     

Low field intraoperative MRI-guided surgery of gliomas: A single center experience

Introduction

The aim of this article is to report on our experience in using a low field intraoperative MRI (iMRI) system in glioma surgery and to summarize the hitherto use and benefits of iMRI in glioma surgery.

Patients and methods

Between July 2004 and May 2009, a total of 103 patients harboring gliomas underwent tumor resection with the use of a mobile low field iMRI in our institution. Surgeries were performed as standard micro-neurosurgical procedures using regular instrumentarium. All patients underwent early postoperative high field MRI to determine the extent of resection. Adjuvant treatment was conducted according to histopathological grading and standard of care.

Results

All tumors could be reliably visualized on intraoperative imaging. Intraoperative imaging revealed residual tumor tissue in 51 patients (49.5%), leading to further tumor resection in 31 patients (30.1%). Extended resection did not translate into a higher rate of neurological deficits. When analyzing survival of patients with glioblastoma, patients undergoing complete tumor resection did significantly better than patients with residual tumor (50% survival rate at 57.8 weeks vs. 33.8 weeks, log rank test p = 0.003), while younger age did not influence survival (p = 0.12).

Conclusion

Low field iMRI is a helpful tool in modern neurosurgery and facilitates brain tumor resection to a maximum safe extent. Its use translates into a better prognosis for these patients with devastating tumors. Future studies covering the use of iMRI will need to be conducted in a prospective, randomized fashion to prove the true benefit of iMRI in glioma surgery.     

Stereotactic brain biopsy: Single center retrospective analysis of complications

Objective

Stereotactic biopsy is a widely used surgical technique for the histological diagnosis of intracranial lesions. Potential risks of this procedure, such as hemorrhage, seizure, and infection have been established, and different risk factors have been characterized. However, these risks have been addressed by only few studies conducted in Asian countries.

Materials and methods

The study group is comprised of 299 consecutive stereotactic biopsy procedures by 11 neurosurgeons between 2004 and 2007. The pre-operative medical conditions, methods of biopsy and postoperative complications were analyzed.

Result

The overall diagnostic yield was 90.64%. Complications were observed in 7.36% of the cases, with symptomatic hemorrhages occurring in 4.35% of the cases, and the overall mortality rate in this study population was 1.34%. Patients with liver cirrhosis were at a higher risk of hemorrhage. Other clinical, radiological, or histological variables were not associated with an increased risk of complications.

Conclusion

Stereotactic brain biopsy is a safe and reliable way to obtain a histological diagnosis. Based on our recent clinical experiences, the data suggests that more attention should be paid to liver cirrhotic patients, since the chance on hemorrhage is significantly larger.     

Surgical resection of osteolytic calvarial lesions: Clinicopathological features

Objective

Osteolytic calvarial lesions are infrequent findings. Some cases are found incidentally during cancer staging or subsequent to unspecific symptoms. There are no standardized algorithms for the treatment of such lesions. Thus, the aim of this study was to describe the clinicopathological features and surgical outcome in various osteolytic calvarial lesions.

Material and methods

The clinical presentation, radiological imaging findings, surgical treatment and histopathological findings of 36 patients who underwent surgery for an osteolytic calvarial lesion at our institution between 1998 and 2008 were reviewed.

Results

Thirty-six osteolytic calvarial lesions were identified in 20 men and 16 women. Mean age at diagnosis was 37 years. Ten patients were children younger than 15 years. Five lesions were detected during cancer staging. Complete removal of the calvarial lesions was achieved in all patients without complications. The most common histopathological diagnosis was metastasis (n = 9), Langerhans-cell histiocytosis (n = 9), and intraosseous hemangioma (n = 5). In two asymptomatic patients, histopathological findings revealed metastases of a previously unknown tumor. In two other patients known to suffer from cancer, histopathological findings indicated intraosseous hemangioma and intraosseous meningioma, respectively. Reconstruction of the calvarial defect was performed in 24 cases with poly-methyl-methacrylate and with titanium mesh in 1 case.

Conclusions

Osteolytic calvarial lesions can be found in any age group. The histopathological examination reveals various entities, and in some instances it was not concurrent with a primary malignancy. Because surgical morbidity is low, we recommend complete resection of osteolytic calvarial lesions with reconstruction when feasible.     

Early clinical and neuroradiological worsening after radiotherapy and concomitant temozolomide in patients with glioblastoma: Tumour progression or radionecrosis?

Objectives

This study investigates the diagnosis and management of patients with resected brain glioblastomas who presented early clinical and neuroradiological worsening after the completion of the Stupp protocol. Its aim is to discuss the occurrence of early radionecrosis.

Methods

Fifty patients with brain glioblastoma treated by surgical resection and Stupp protocol were reviewed; 15 among them (30%) had early clinical and neuroradiological worsening at the 6-month follow-up. The MR spectroscopy and surgical findings of these patients are reviewed.

Results

MR spectroscopy was in favour of tumour recurrence in 14 among 15 patients and showed radionecrosis in one. Among 10 patients who were reoperated on, 7 had histologically verified tumour recurrence or regrowth, whereas in 3 histopathology showed necrosis without evidence of tumour. The 7 patients with tumour progression had prevalence of focal neuroradiological signs (6/7) and a survival of 7.5–12 months (median survival 10 months). The 4 patients with early radionecrosis (including one patient who was not reoperated on) had clinical worsening with mental deterioration, confusion and ataxia, and MR spectroscopy positive for tumour recurrence in 3. Three were alive 24–30 months after the end of the radiotherapy, whereas one died at 40 months.

Conclusion

Early radionecrosis after the Stupp protocol is not a rare event due to the radiosensitization effect of temozolomide. This phenomenon may predict a durable response to radiotherapy. MR spectroscopy may simulate tumour recurrence. A correct diagnosis is necessary to avoid useless reoperations and incorrect withdrawal of temozolomide.     

Fractionated radiosurgical management of intramedullary spinal cord metastasis: A case report and review of the literature

Objective and importance

Intramedullary spinal cord metastasis (ISCM) comprises 8.5% of central nervous system metastases and confers significant morbidity. Radioresistant histologies such renal cell carcinoma and melanoma are not generally amenable to long-term palliation with conventional radiotherapy while surgery has often been found to be technically challenging and frequently morbid. In this report, we present a patient with a C5 ISCM from renal cell carcinoma treated with fractionated stereotactic radiosurgery.

Clinical presentation

A 50-year-old gentleman with metastatic renal cell carcinoma presented with profound bilateral shoulder pain and upper extremity paresthesias. Magnetic resonance imaging revealed an intramedullary lesion at the level of fifth cervical vertebra (C5). Medical management and chiropractic manipulation proved to be ineffective. The patient was then treated with external beam radiation therapy, but continued to experience severe pain, paresthesias, and progressive, profound neurologic symptoms.

Intervention

The patient was referred to radiation oncology and neurosurgery for evaluation. Consideration was given to cordotomy and resection but the location and procedure was deemed to be high-risk and therefore was deferred. The decision was made to treat with fractionated stereotactic radiosurgery. A dose of 15 Gy was successfully delivered in 3 fractions to the 80% isodose line without complication or adverse effects. Twenty-six months following treatment, the patient was still alive, fully functional, and reported no pain and rare of paresthesias.

Conclusion

Fractionated stereotactic radiosurgery is a feasible, safe, and effective modality for the treatment of ICSM and should be carefully considered in the management of this difficult to treat condition.     

Gamma Knife radiosurgery in the management of brainstem metastases

Background

Metastases to the brainstem portend a poor prognosis and present a challenge in clinical management. Surgical resection is rarely a viable option.

Methods

Post-treatment MRI scans of patients with brainstem metastases treated with radiosurgery were used to determine local control and disease progression. Median survival was calculated using Kaplan–Meier analysis. Univariate and multivariate analyses were performed using log-rank test and Cox proportional hazards model, respectively.

Results

Thirty-two consecutive patients with brainstem metastasis underwent Gamma Knife radiosurgery. Median age was 50 years. Median tumor volume was 0.71 cm³ and median tumor margin dose was 13 Gy. Seventeen of 32 patients received WBRT prior to stereotactic radiosurgery. Median survival was 5.2 months. There was a statistically significant difference in survival based on RTOG recursive partition analysis (RPA) class. Median survival of patients categorized as RPA class I was 19.2 months, RPA class II was 8.4 months, and RPA class III was 1.9 months. The overall local tumor control rate was 87.5%. There were no acute complications following stereotactic radiosurgery and no evidence of radiation necrosis noted on post-treatment MRI scans.

Conclusion

Stereotactic radiosurgery is an effective treatment for brainstem metastases and should be considered especially for patients with good performance status.     

Evaluation of brain biopsy in the diagnosis of severe neurologic disease of unknown etiology

Objective

To determine the value of non-stereotactic brain biopsies in patients with severe neurologic disease of unknown etiology and indeterminate brain imaging.

Methods

We reviewed 42 consecutive patients who underwent non-stereotactic brain biopsy at a single institution for evaluation of severe neurologic disease of unknown etiology. All patients had indeterminate or normal imaging results. Seventy-nine percent had been symptomatic for less than a year. Exclusion criteria were immunocompromise or a preoperative diagnosis of intracranial neoplasm. Diagnostic yield and surgical complication rate were calculated. We performed exploratory univariate analysis aimed at identifying clinical features possibly predictive of diagnostic biopsies.

Results

A histologic diagnosis was achieved in 12 of 42 biopsies (29%). Three patients experienced minor transient complications from the procedure (7%). There were no permanent deficits or deaths. Treatment was altered based on biopsy result in five patients (12%). A more precise prognosis was obtained in eight patients (19%). In total, 11 different patients (26%) benefited from biopsy. Exploratory univariate analysis showed a possible inverse relationship between age and the likelihood of a diagnostic biopsy (OR = 0.929; 95% CI = 0.864–0.998).

Conclusions

Our data suggest that the value of non-stereotactic brain biopsy is sufficiently high and the morbidity sufficiently low to justify its use in carefully selected patients with severe neurologic disease that remains undiagnosed despite thorough less invasive evaluation.     

Fibrinolytic therapy versus craniotomy for anticoagulant-associated intracerebral hemorrhage

Object

Anticoagulant-associated intracerebral hemorrhages (AAICH) have a high morbidity and mortality, necessitating urgent treatment. We examined outcomes after conventional craniotomy and stereotactic fibrinolytic therapy in a series of patients with anticoagulant-associated hemorrhages.

Methods

Among 129 consecutive surgically treated patients with supratentorial intracerebral hemorrhage, 27 patients with AAICH were identified (mean age 62; range 36–79). Thirteen patients underwent craniotomy for surgical hematoma evacuation, and 14 patients hematoma puncture and catheter placement for clot lysis. The groups had comparable major prognostic factors such as hematoma volume, age, and Glasgow coma scale (GCS) score at admission.

Results

Nine patients died despite treatment (mortality = 33%). Mortality in the craniotomy group was comparable to that of the lysis group (46% versus 21%; p = 0.13). Good outcomes (Glasgow outcome score of 4 or 5) were seen in 3 craniotomy patients (23%) and 2 fibrinolysis patients (14%). Half the patients survived with major neurological deficits (GOS 2 or 3) (n = 13; 48%). One rebleed was observed two days after uneventful craniotomy and hematoma removal, while no patient who underwent fibrinolysis had rebleeding.

Conclusions

Approximately one-fifth of patients with AAICH managed surgically may have good outcomes. Mortality and favourable outcome rates are comparable between craniotomy and fibrinolytic therapy. Fibrinolytic therapy appears to be a reasonable less invasive alternative treatment modality for intracerebral hemorrhage in the anticoagulated patient.     

Endoscopy in the management of intra-ventricular lesions: Preliminary experience in the Middle East

Objectives

The study is aimed at evaluating neuroendoscopic procedures in the management of various intra-cranial intra-ventricular lesions.

Methods

We retrospectively review 24 consecutive patients harboring various intra-ventricular lesions with or without associated hydrocephalus, operated and managed by the authors between December 2002 and December 2007. Depending on the preoperative imaging and working diagnosis, endoscopic biopsy or endoscopic resection/debulking, along with concomitant treatment of hydrocephalus via third ventriculostomy or fenestration of the septum pellucidum and ventriculo-peritoneal shunting, were done.

Results

The single endoscopic procedure was successful in most of the patients (22/24), where the goals of surgery in attaining a diagnostic biopsy or resection, and simultaneous treatment of hydrocephalus, were attained helping guide further therapy. The endoscopic procedure was the only procedure needed in most of the patients.

Conclusions

The endoscopic procedures carried a high success rate in the management of intra-ventricular lesions, and were especially valuable in patients harboring chemo and/or radiosensitive deep seated tumors.     

Linfomas primarios del sistema nervioso central

Introduction

Primary central nervous system lymphoma is a rare subtype of extranodal non-Hodgkin lymphoma that accounts for 4% of central nervous system tumours.

Patients and methods

Retrospective review of 24 patients diagnosed with primary central nervous system lymphoma between 1990 and 2010. All patients were diagnosed using magnetic resonance imaging and the diagnosis was confirmed surgically.

Results

Of the 24 patients analysed, all except 4 were immunocompetent. Median age at diagnosis was 59.3 years (range 13-79) and the sex ratio (male to female) was 1:1.1. Cognitive decline (in 33.4%) and headache (in 25%) were the most common complaints. Diagnosis was performed In 13 cases (54%) following craniotomy and in the other 11 cases (46%) after stereotactic biopsy. Breakdown by pathology was as follows: 22 cases of B-cell lymphoma (91.6%), 1 case of anaplastic large-cell lymphoma, and 1 case of T-cell lymphoma. Mean survival time was 12.8 months with an overall 1-year survival rate of 37.5%.

Conclusions

Primary central nervous system lymphoma often presents in the sixth decade with cognitive decline, headache, and focal neurological deficits. A single intracranial lesion was present in 75% of the patients (18 cases), and the remaining 25% (6 cases) had between 2 and 4 lesions. Preoperative clinical status was the most important factor determining prognosis.     

Accuracy of frameless and frame-based image-guided stereotactic brain biopsy in the diagnosis of glioma: comparison of biopsy and open resection specimen

OBJECTIVES: Tissue heterogeneity and rapid tumor progression may decrease the accuracy a prognostic value of stereotactic brain biopsy in the diagnosis of gliomas. Correct tumor grading is therefore dependent on the accuracy of biopsy needle placement. There has been a dramatic increase in the utilization of frameless image-guided stereotactic brain biopsy; however, its accuracy in the diagnosis of glioma remains unstudied. METHODS: The diagnoses of 21 astrocytic brain tumors were derived using image-guided stereotactic biopsy (12 frame-based, nine frameless) and followed by open resection of the lesion 1.5 (0.5-4) months later. The histologic diagnoses yielded by the biopsy were compared with subsequent histologic diagnosis from open tumor resection. RESULTS: Histology of 21 stereotactic biopsies accurately represented the greater lesion at open resection a median of 45 days later in 16 (76%) cases and correctly guided therapy in 19 (91%) cases. Biopsy accuracy of frameless versus frame-based stereotaxis was similar (89 versus 66%, p=0.21). In three (14%) cases, biopsy specimens were adequate to diagnose glioma; however, histology was insufficient for definitive tumor grading. Anaplastic oligodendroglioma (ODG) was under-graded as low-grade ODG in one (5%) case. Biopsy of new onset glioblastoma multiforme (GBM) yielded necrosis/gliosis and was termed non-diagnostic in one patient. Tumors <50 cm(3) were 8-fold less likely to accurately represent the grade of the entire lesion at resection compared with lesions <50 cm(3) (OR, 8.8; 95% CI, 0.9-100, p=0.05). DISCUSSION: Both frameless and frame-based MRI-guided stereotactic brain biopsy are safe and accurately represent the larger glioma mass sufficiently to guide subsequent therapy. Large tumor volume had a higher incidence of non-concordance. Increasing the number of specimens taken through the long dimension of large tumors may improve diagnostic accuracy.     

Bevacizumab as salvage therapy for progressive brain stem gliomas

Objective

There is no standard of care for patients with progredient brain stem gliomas. Therefore, we report about clinical, radiological and metabolic response to anti-angiogenic treatment with bevacizumab in a series of 3 patients with gliomas involving the brain stem.

Patients and methods

Three patients with histologically confirmed gliomas involving the brain stem were treated with bevacizumab for tumor progression. The clinical data, histopathological findings as well as MRI and PET follow up examinations during bevacizumab therapy were retrospectively analyzed.

Results

The histopathological diagnosis revealed an anaplastic astrocytoma WHO grade III in two patients and an astrocytoma WHO grade II in 1 patients with clinical and neuroradiological signs of malignization. One patient is still progression-free 97 weeks after initiation of bevacizumab therapy. Mean progression-free survival and overall survival for the other two patients after initiation of bevacizumab therapy was 34.5 weeks and 43.5 weeks. During bevacizumab therapy mean KPS improved from 60 to 80 and mean dosage of daily dexamathasone was reduced from 7.3 mg to 1.3 mg. MRI showed a decrease of T2 weighted hyperintense lesions in all patients and a decrease of contrast enhancement in two patients. ¹⁸F-FET-PET showed a decrease of tracer uptake in all cases (mean maximum decrease: 25%).

Conclusion

In this series treatment of progressive gliomas involving the brain stem with bevacizumab resulted in an improved clinical condition of the patients as well as a reduction of the T2 weighted lesions and reduced amino acid uptake in the tumor area. It therefore may represent a therapeutic salvage option for this type of tumor.     

Glioblastoma with the appearance of arteriovenous malformation: Pitfalls in diagnosis

Objectives

Very few cases of arteriovenous malformations (AVMs) associated with gliomas were reported so far in the literature.

Methods

Here, we report a rare case of a glioblastoma with an AVM-like lesion and review the existing literature.

Results

We report an unusual case of a 72-year old woman, who presented with a progressive history of aphasia, memory deficit, and headache. Initial MRI imaging was suggestive of a high-grade glioma for which a pterional craniotomy was performed. Intraoperatively, the lesion resembled a vascular malformation. Total extirpation of the lesion was verified by intraoperative MR imaging. Initial histopathological analysis revealed an AVM. Due to the discrepancy between the radiologic and histopathologic findings, the patient was monitored at close intervals. Two month later, multiple lesions were visible on MRI imaging, thus, supporting the diagnosis of malignant glioma. Therefore, after reinvestigating the histopathological sections and cutting the paraffin block in additional serial sections, in only 5% of the section a glioblastoma was discerned which was surrounded by an AVM-like lesion.

Conclusion

Gliomas are rarely found in association with AVMs and require accurate diagnostic evaluation and interpretation for adequate therapeutic interventions.     

Muscle and nerve biopsies: Techniques for the neurologist and neurosurgeon

Objective

Muscle and nerve biopsies are commonly performed procedures for the diagnosis of neuromuscular disorders. Neurologists and neurosurgeons are often consulted to perform these procedures in clinical practice. We provide guidelines in the performance of muscle and nerve biopsies.

Methods

We describe the technique for performance of muscle and nerve biopsy, and review the relevant literature.

Results

The quadriceps muscle is the most typical biopsy site for most myopathies, whereas the sural nerve is the most common nerve biopsy site for most peripheral neuropathies. Other sites may be utilized depending upon the pattern of symptoms or the differential diagnosis. Motor nerves may be sampled in the setting of motor neuron disease, for example. We advocate the use of conduit repair to allow for sensory or motor recovery to occur following nerve biopsy.

Conclusion

The muscle biopsy and nerve biopsy may be performed with high yield, low morbidity, and rare complications.     

The microsurgical treatment of cranio-orbital tumors assisted by intraoperative electrophysiologic monitoring and neuronavigation

Objective

Total resection of cranio-orbital tumors without any major complications is still a challenge for neurosurgeons. Intraoperative electrophysiologic monitoring and neuronavigational system have been widely used in microneurosurgery, but their effects during microsurgical treatment of cranio-orbital tumors warrant further investigation.

Methods

Thirty-eight patients with cranio-orbital tumors admitted to our hospital underwent microsurgery assisted by intraoperative electrophysiologic monitoring. We also simultaneously performed intraoperative neuronavigation in 20 patients. A retrospective review of clinical notes, operation records and prognoses of all patients was performed.

Results

Gross total resection was achieved in 29 patients (76%), near total resection in 5 (13%), subtotal resection in 3 (8%) and partial resection in 1 (3%). With the helps of electromyogram (EMG) monitoring of levator palpebrae superioris (LPS) muscle and navigation system, no surgical damages to the oculomotor nerve and other important structures occurred. A follow-up study showed that 31 patients (82%) resumed normal lives (Glasgow Outcome Scale (GOS) score 5), 5 patients (13%) had independent lives (GOS score 4), and 2 patients (5%) were unable to live independently (GOS score 3).

Conclusion

Microsurgical treatment assisted by intraoperative electrophysiologic monitoring and neuronavigation might be a useful method for resection of cranio-orbital tumors, especially better for protection of the important cranial nerve and structure in the kull base.     

Methodology and prognostic reliability of stereotaxic biopsy in tumors of glial origin

Between 1978 and 1984, 227 patients affected from glial tumors underwent serial stereotactic biopsy. Correct prognostic indications have been obtained in 85% of the entire series. In 10.5%, the stereotactic procedure provided only the diagnosis of the nature of the tumor, while the histological grading and prognosis remained unknown. The operative mortality was 2.6% and the permanent morbidity included 3.9% of patients who complained about worsening of the preoperative neurological conditions. The methodology of stereotactic biopsy is described in detail. The results are discussed with particular reference to the prognostic value of serial stereotactic biopsies.