Paragangliomas of the temporal bone: results of different treatment modalities in 53 patients.

BACKGROUND: The authors retrospectively compared the results of three different treatment modalities (surgery, conventional radiotherapy and gamma knife radiosurgery) in patients with paragangliomas of the temporal bone, in order to determine the optimal current treatment concept. METHOD: Between 1978 and August 2001, 53 patients (12 men and 41 women; mean age, 58.3 years; range, 17 to 84 years) with paragangliomas of the temporal bone were treated at the neurosurgery and ENT departments of the University of Vienna. According to the Fisch classification, 6 patients had class B tumours, 20 had class C, and 27 patients had class D tumours. Thirty-two patients (mean age, 57.0 years; 6 B, 14 C, 12 D) underwent surgery. In 17 cases the tumour was embolised prior to surgery. Nine patients (mean age, 73.9 years; 6 C, 3 D) received primary radiotherapy (median total dose, 46.8 Gy). Six patients (mean age, 73.5 years; 6 D) underwent primary radiosurgery (median centre dose 24, Gy) and 6 patients (6 D) admitted from other departments with recurrent tumours adjuvant radiosurgery (median centre dose, 25.5 Gy). FINDINGS: In 20 of the surgical cases (62.5%) complete tumour resection was achieved and the patients required no further treatment over a mean follow-up period of 9.1 years. Of the 12 patients with incomplete tumour resection, 9 (5 C, 4 D) received postoperative adjuvant radiotherapy and three patients (3 D) adjuvant radiosurgery. In 15 (83.4%) of the 18 patients who underwent radiotherapy the tumours showed no signs of progression and the patients remained clinically unchanged over a mean period of 9.4 years. Three patients (16,6%) experienced progression of their tumour within an average period of 2.8 years. In the 15 patients who underwent primary radiosurgery, an objective 100% tumour control rate with no evidence of progression of disease was observed. INTERPRETATION: The results indicate that the most effective current treatment option for patients with paragangliomas of the temporal bone is a single-stage radical tumour resection, performed in advanced tumours as an interdisciplinary neuro-otosurgical procedure. For subtotally resected or non-resectable tumours, gamma knife radiosurgery has proved to be a safe and effective treatment modality.

Cranioplasty with individual carbon fibre reinforced polymere (CFRP) medical grade implants based on CAD/CAM technique.

BACKGROUND: The authors present a new method for the reconstruction of large or complex-formed cranial bone defects using prefabricated, computer-generated, individual CFRP (carbon fibre reinforced plastics) medical grade implants. METHOD: CFRP is a composite material containing carbon fibres embedded in an epoxy resin matrix. It is radiolucent, heat-resistant, extremely strong and light (its weight is 20% that of steel), has a modulus of elasticity close to that of bone, and an established biocompatibility. The utilisation of a CAD/CAM (computer aided design/computer aided manufacture) technique based on digitised computed tomography (CT) data, with stereolithographic modelling as intermediate step, enabled the production of individual, prefabricated CFRP medical grade implants with an arithmetical maximum aberration in extension of less than +/-0.25 mm. Between 1995 and February 2002, 29 patients (15 men and 14 women; mean age, 39.9 years; range, 16 to 67 years) underwent cranioplasty with CFRP medical grade implants at the neurosurgical department of the University of Vienna. Twenty-four patients were repaired secondarily (delayed cranioplasty) while 5 were repaired immediately following craniectomy (single stage cranioplasty). All cases were assessed for the accuracy of the intra-operative fit of the implant, restoration of the natural skull contour and aesthetics and adverse symptoms. FINDINGS: The intra-operative fit was excellent in 93.1% and good in 6.9% of the implants. In two cases minor adjustments of the bony margin of the defect were required. The operating time for insertion ranged from 16 to 38 minutes, median 21 minutes. Postoperatively, 86.2% of the patients graded the restoration of their natural skull shape and symmetry as excellent while 13.8% termed it good. In one patient a non-space occupying subdural hygroma was found at the follow-up, but required no intervention. Two patients experienced atrophy of the frontal portion of the temporal muscle while one patient had a transient palsy of the frontal branch of the facial nerve. Over the mean follow-up period of 3.3 years (range, 0.08 to 6.8 years), there were no adverse reactions and no plate had to be removed. INTERPRETATION: Individual, prefabricated CFRP medical grade implants may be considered as an alternative to conventionally utilised materials for cranioplasty, in particular in the challenging group of patients with extensive cranial defects or more complex-formed defects of the fronto-orbital or temporo-zygomatic region, guaranteeing short operating times and excellent functional and aesthetic results, which justifies the expense of their production.

Outcome after chronic sciatica as the only reason for lumbar microdiscectomy.

There are only a few long-term studies on microsurgical disc operations, and none concentrated on long-term follow-up of therapy-resistant sciatica. A total of 258 patients whose only neurologic symptoms were sciatica were included in this study. Patients were operated on between 1990 and 1997. All outcome results have been performed by an independent reviewer. The mean follow-up period was 7.3 years (range 4-11 years). At follow-up 25% of the patients were free of pain, 66% demonstrated marked improvement, and 9% had either no improvement or worsening of pain. At follow-up 65% of the patients reported returning to their original occupation or being able to go into retirement without hindrance. A total of 15% required changing of profession following discectomy (75% of these patients applying for early retirement were rejected), 6% were incapacitated and unable to work, and 14% were forced into early retirement. Patients with a history of sciatica longer than 3 months acquired failed back surgery syndrome considerably more often than those <3 months (p = 0.005).

Microsurgical anterior cervical foraminotomy (uncoforaminotomy) for unilateral radiculopathy: clinical results of a new technique.

BACKGROUND: The authors report the clinical application of a new microsurgical technique. The cervical anterior foraminotomy (uncoforaminotomy), which is used for the surgical treatment of unilateral cervical radiculopathy secondary to posterolateral disc herniations or spondylotic foraminal stenoses. METHOD: Between June 2000 and May 2001, 34 patients (16 men and 18 women with a mean age of 43.8 years, range 29 to 80 years) underwent anterior cervical foraminotomy (uncoforaminotomy) for the treatment of cervical radiculopathy at one or two adjacent levels in the Neurosurgical Department of the University of Vienna. This surgical technique was devised to accomplish direct anterior decompression of the affected nerve root by removing an offending posterolateral sponylotic spur or disc fragment. The nerve root is decompressed from its origin in the spinal cord to the point were it passes behind the vertebral artery laterally. The intervertebral disc of the affected level is maintained in its form and function. Thus, the functioning motion segment is preserved and fusion related sequelae, including graft related complications, graft site complications and the adjacent level disease, are avoided. Prior to its clinical application, anatomical features of the anterior cervical spine were reviewed, and an anatomical morphometric analysis and work-up of the technique was performed in 4 cervical specimens. FINDINGS: The follow-up period varied from two to 17 months with a mean of 8.2 months. The large majority (97%) of patients were pleased with the results of their operation. The relief of neck pain and redicular pain in the affected dermatome was immediate in all patients. Motor-weakness and sensory deficit improved dramatically immediately postoperatively, and improved to normalisation in the majority of patients within 3 to 6 months. Two of the patients sustained an incomplete transient recurrent laryngeal nerve palsy, which fully resolved within two to 4 weeks. One of the patients had a repeat herniation on the second postoperative day, but recovered completely after re-operation and continued to do well at the 6-month follow-up. No permanent surgery related morbidity or associated complications were encountered. INTERPRETATION: The results indicate that this new microsurgical technique is an attractive treatment option for adequate anterior decompression of the cervical nerve root via a minimized approach. It was associated with excellent clinical outcome and a less painful postoperative course, allowing patients an almost immediate return to unrestricted full activity.

The complexity of trauma to the cranio-cervical junction: correlation of clinical presentation with Doppler flow velocities in the V3-segment of the vertebral arteries.

BACKGROUND: Trauma to the craniocervical junction (CCJ) encompasses a wide and complex spectrum of injury with an even broader range of clinical presentation, and since trauma to this area borderlines neurosurgical main areas of interest, these relatively rare injuries can be overlooked. In fact, there has been an abundance of documentation in the literature since Sir Charles Bell first reported on a case of occipital condyle fracture in 1817 in which a patient suddenly dropped dead as he turned his head to thank physicians and nurses while leaving the hospital. The death was attributed to compression of the medulla oblongata by a fractured occipital condyle. METHOD: At our department, we have been applying specialized diagnostic procedures in our clinical work-up in the acute and chronic situation of isolated injury to the CCJ as well as polytrauma with CCJ involvement in a total of 33 patients throughout a 3-year period (1997 to 2000). In this article, we present some of our experiences with these diagnostic procedures, introducing the application of V3-segment Doppler of the vertebral artery (VA), which we consider to be an effective supplementary method in a precise work-up in CCJ injury. The V3-segment of the vertebral artery, especially where it courses through its' groove behind the superior facet of the atlas is particularly vulnerable to injury. The authors measured flow velocity of the V3-segment from a point just below and roughly 2 to 3 centimeters dorsal to the mastoid process. FINDINGS: All patients were investigated for the occurrence of changes in the blood flow in the V3-segment of the VA after suffering a CCJ injury. There was an increase or decrease in the flow velocity in trauma patients with whiplash injuries as well as in patients with occipital condyle fractures and associated ligament injury. In severe injuries, some with fatal outcome, a dissection or thrombosis of the VA was found with a loss of the V3-doppler flow signal, or rather flow void. CONCLUSION: CCJ injuries in the polytrauma patient as well as in patients presenting with delayed onset of symptoms often remain unrecognised, despite the advances in medicine. CCJ injuries are potentially lethal and can be treated if detected early. The V3 method enables rapid, effective, feasible and inexpensive diagnosis in the initial work-up of CCJ-injury.

A clinical study of a fibrinogen-based collagen fleece for dural repair in neurosurgery.

BACKGROUND: There is frequently a need for dural grafts to cover defects resulting from retraction, shrinkage, or excision following neurosurgical procedures. Many substances have been tried as possible dural substitution, and different tissues and materials have been evaluated for use in dural repair. METHOD: The authors performed a retrospective review of 288 consecutive neurosurgical procedures using a fibrinogen based collagen fleece (TachoComb), a resorbable mesh of collagen from horse tendons, coated with human fibrinogen, bovine thrombin, bovine aprotinin and riboflavin (for marking the coated side), for dural substitution. The fibrinogen and thrombin imitate the last step of the coagulation cascade. On contact with bleeding wounds or other body fluids the coagulation factors dissolve and a link is formed between the collagen carrier and the wound surface. Thrombin converts fibrinogen into fibrin by splitting off peptides. Aprotinin prevents premature lysis of the fibrin clot by plasmin. FINDINGS: Neither superficial or deep wound infections nor aseptic meningitis were noted. We found good fibrous incorporation of TachoComb into the surrounding normal dura. Postoperative cerebrospinal-fluid (CSF) leaks developed in only five cases, who had to be re-operated, upon as well as one patient with a rebleeding. In another four cases, there was notable subcutaneous cerebrospinal-fluid accumulation without CSF-leak. They required a lumbar cerebrospinal-fluid drainage. INTERPRETATION: We conclude that TachoComb is a valuable alternative to the patients fibrous tissues for dural repair in cases in which autogenous tissues are either unavailable or insufficient for proper reconstruction.

Efficiency of gamma knife radiosurgery in the treatment of glomus jugulare tumors.

This study was performed to assess the impact of gamma knife radiosurgery (RS) in the treatment of glomus jugulare tumors. Between February 1993 and February 1999, thirteen patients (9 women, 4 men; mean age 63.5 years, range 29 to 79 years) underwent stereotactic radiosurgery for glomus jugulare tumors with the Leksell Gamma Knife at the Neurosurgical Department of the University of Vienna. Four patients, mean age 74.5 years, range 67 to 79 years, underwent radiosurgery as the only treatment. Nine patients received radiosurgery as adjuvant therapy after previous treatment had failed: surgical resection in 9 patients and additional fractionated external beam radiation in two of these patients. Pretreatment evaluation included the staging of all tumors according to the Fisch Classification: De1 (7), De2 (1), Di1 (4) and Di2 (1). The mean follow-up period was 4.2 years, range 0.7 to 6.7 years. Ten patients, 77 %, were treated prior to 1997, the mean follow-up period being 5 years. Six patients showed no clinical changes, while six experienced an improvement of their clinical symptoms and neurological deficits. One patient was lost to follow-up. Radiation-induced transient cranial nerve neuropathies were observed in two patients. Serial MRI scans revealed tumor control in all patients, with unaltered tumor size in 10 and shrinkage in three patients. The results indicate that RS is an attractive treatment option for glomus jugulare tumors and will occupy an increasingly important role in the management of these tumors in selected patients.

Extraforaminal, thoracic, epidural cavernous haemangioma: case report with analysis of magnetic resonance imaging characteristics and review of the literature.

BACKGROUND: A case of a solitary, thoracic, extradural, extraforaminal cavernous haemangioma causing a chronic neuralgia syndrome is presented. In the spectrum of spinal axis cavernous malformations, extradural lesions are exceedingly rare. A purely extraforaminal, paraspinal cavernous haemangioma has never been previously reported. METHOD: A 56-year-old woman suffered from a chronic neuralgia syndrome at the right D3 dermatome. Conservative treatment was ineffective. MRI revealed an extraforaminal mass at T3-4 which homogeneously enhanced after Gadolinium administration mimicking a schwannoma. The lesion was completely removed via an extraforaminal approach. FINDINGS: Histopathological investigation revealed a cavernous haemangioma. The patient recovered completely within 4 weeks after surgery. INTERPRETATION: Cavernous haemangiomas are developmental vascular hamartomas representing a single entity regardless of their location. As purely epidural lesions are rare, their clinical and radiological presentation could be confusing if located foraminally or extraforaminally. Thus, their signal characteristics providing valuable information will facilitate diagnosis and treatment.

Quality assurance for the Leksell gamma unit: considering magnetic resonance image-distortion and delineation failure in the targeting of the internal auditory canal.

Our aim in this study was to distinguish quantitatively between the localization accuracy of a commercially available stereotactic fixation device as claimed by the manufacturer and the target accuracy as measured by a user, applying neuroradiologic imaging in Gamma Knife planning and phantom irradiation. Missing the target is the most serious possible failure in Gamma Knife and Linac therapy. To reduce this risk, we developed a quality control algorithm and designed a phantom. To evaluate the accuracy of the targeting procedure with a Leksell Gamma unit, and to experience the possible errors in all procedural steps, irradiations of phantoms were performed, using the so-called "unknown" targeting method. Accuracy is defined by the extent of spatial deviation of the irradiated target from the calculated target. Digital imaging was used for therapy planning. GafChromic films, which had been irradiated while affixed to a specially developed phantom, were used for measuring the precision of the radiation unit. A series of MR images (in two plains: transverse and coronal) was acquired sequentially to image the three-dimensional (3-D) volume of the phantom. The results obtained for isocentric accuracy of the Leksell Gamma unit, model B, were in good agreement to the calculated position. The observed spatial deviations between calculated and irradiated targets is less than 1 mm. The newly designed phantom and quality control algorithm are useful in quality assurance measurements of stereotactic radiation therapy.

An unusual management of an open compound depressed skull fracture with venous sinus involvement. A case report.

A neurosurgical management of an open compound depressed fracture perforating the superior sagittal sinus is reported. Undue bleeding from the fracture did not allow a conservative management. The patient had been operated primarily at an outside emergency surgery unit. Profuse uncontrollable bleeding made a tamponade of the sinus necessary for transportation to our neurosurgical department. After reconstruction of the sinus he survived without evidence of a neurological deficit.

Experimental bifurcation aneurysm: a model for in vivo evaluation of endovascular techniques.

An experimental aneurysm model for in vivo testing of endovascular techniques is described. The aneurysm is produced surgically in the neck of the rabbit by partial anastomosis of the left to the right common carotid artery, thus creating an arterial bifurcation. Subsequently, a venous pouch is sutured into the artificial bifurcation. The size of the arteries, coagulation profile and hemodynamic features in this aneurysm model closely mimic human conditions. Surgical technique and our preliminary experience with this model are discussed.

Gamma-knife radiosurgery for brain metastases of renal cell carcinoma: results in 23 patients.

From Jan. 1993 to Sept. 1995 23 patients suffering from brain metastases from renal cell carcinoma were treated with the Leksell Gamma Knife at the University of Vienna. At the time of diagnosis 13 patients had single and 10 patients presented with multiple metastatic lesions with a total of 44 metastases in MRI scans. Median tumour volume was 5500 cmm (range 100-24000 cmm). Predominant neurological symptoms and signs were different forms of hemiparesis, focal and generalized seizures, cognitive deficit, headache, dizziness, ataxia and CN XII paresis. Fourteen patients received Gamma Knife Radiosurgery (GKRS) with a median dose of 22 Gy (range 8-30 Gy) at the tumour margin. Nine patients underwent a combined treatment of a radiosurgical boost with a median dose of 18 Gy (range 10-22 Gy) at the tumour margin followed by Whole Brain Radiotherapy (total dose 30 Gy/2 weeks). In 20 patients tumour volume reduction up to 30% of the primary tumour volume was found after 4 weeks, evaluated on CT or MRI. A total remission was seen in 4 cases 3 months after GKRS. We achieved a local tumour control of 96%. Rapid neurological improvement after GKRS was seen in 17 patients. The median survival time was 11 months; the one-year actual survival in this unselected group was 48%. Five long term survivors were still alive, 18 patients had subsequently died, 15 of them of general tumour progression. GKRS induces a significant tumour remission accompanied by rapid neurological improvement and therefore provides the opportunity for extended high quality survival. Neither local tumour control was improved nor CNS relapse free survival was prolonged significantly by additional WBRT.

Clinical, radiological and histological presentations of dysembryoplastic neuroepithelial tumors (DNT). Report of two cases.

Dysembryoplastic neuroepithelial tumor (DNT) is a recently described rare brain neoplasm with characteristic clinical and morphological features and favorable prognosis. We report here two cases of DNT. The first concerned a 12 years old girl who presented complex seizures preceded by acoustic aura (melodies). Computed tomography revealed a hypodense tumor measuring 2 x 2.5 cm in diameter, located paracortically in the left temporal lobe. The second tumor was removed from a 21-year-old man with partial complex seizures. Nine years earlier patient underwent neurosurgery with partial removal of the tumor The tumor's histopathologic diagnosis is unfortunately lacking. Computed and magnetic resonance imaging showed a mass occupying the cortex and paracortical areas of the anterior pole of the temporal lobe. Histologically, both tumors consisted of small, S-100 protein immunopositive oligodendrocyte-like cells (OLCs) arranged between synaptophysin- and, to a lesser degree, NFP-immunopositive axons (glioneuronal element). In the second case, an area of pilocytic astrocytoma-like appearance was also found, these cells were immunopositive for GFAP. The present study provides clinical, radiological and histological data, which may be helpful in differential diagnosis of this newly recognised brain tumor.

Microsurgical anterior decompression and internal fixation with iliac bone graft and titanium plates for treatment of cervical intervertebral disc herniation.

42 cervical interbody fusions with iliac bone graft and titanium plate fixation were performed between October 1991 and March 1994. The mean follow up period in this study was 10.7 months. In 32 cases fusion was done for 1 and in 10 cases for 2 segments. 2 different types of plates were used. In 25 cases micro-osteosynthesis plates and screws with 2.7 mm diameter were used, and in 17 cases cervical H-plates and screws with 3.5 mm diameter. A favourable outcome was achieved in 31 of 42 cases (74%). Satisfactory pain relief was achieved in 90%. For radicular motor deficit good results were obtained in 84% and for cervical myelopathy in 54%. The 2 different types of plates showed a remarkable difference in the clinical outcome. The results were regarded favourable in 15 of 25 microplate fusions (60%) and in 16 of 17 H-plate fusions (94%). Compression of the bone graft was seen in 5 patients of the micro plate group, however, radiological signs for fusion were present in all 42 cases at follow up. Major surgical complications, damage to neural structures or neurological deterioration did not occur in this study. Plate fixation in cervical interbody fusions seems to be a safe procedure and may reduce graft related complications at the fusion site if the plates and screws are sufficiently well proportioned. A favourable impact upon the results for cervical interbody fusion might be expected and should be further investigated in a long term follow up study.