Search

Background: Chondrosarcoma is a rare differential diagnosis of malignant tumours of the skull base. The prognosis was rated as unfavourable in articles for many years. It has, however, improved considerably in recent years. The objective of this study was to evaluate and current, new optimised treatment strategies., Patients and Methods: We retrospectively analysed the case histories and course of four patients whom we treated for chondrosarcoma of the skull base over the past 5 years at the Freiburg Skull Base Centre., Results: Because of initially mild symptoms, the patients first came for examination at an advanced stage of the tumour. All patients underwent surgery, whereby an R0-resection was barely or only questionably present. Three patients underwent radiation therapy postoperatively. All patients are currently tumour free., Conclusions: Surgical treatment with curative intent is basically the therapy of choice. Due to the usually large size of the tumour and its close relationship to relevant structures, complete resection is, however, not always possible despite advances in surgical procedures. Taking the possibility of modern adjuvant radiotherapeutic procedures into account, an incomplete, function-preserving resection is preferred to a radical and mutilating resection.

Background and Objective: The rare bone disease craniofacial fibrous dysplasia is only treated in cases of visible deformities of the splanchnocranium and neurocranium, compression syndromes, and delocation of nasal and paranasal drainage., Methods and Patients: In a retrospective quality assessment analysis of six patients with craniofacial monostotic fibrous dysplasia, the indications were analysed for situations in which computer-assisted surgery (CAS) might be helpful., Results and Conclusions: CAS serves as an intraoperative basis for the assessment of cosmetic-aesthetic corrections of visible bone deformities of the splanchnocranium and neurocranium, and allows the controlled removal of pathologically affected bone in contralateral symmetry. This seems to be important, especially at the anterior skull base, as deformities of the human face produce strong psychological suffering. Furthermore, CAS allows the configuration of implants for defect reconstruction after focal restorations with bony radical surgery. Implants of various material can be prefabricated from these data, which can then be exactly fitted to cover the defect.

Solitary aneurysms of spinal arteries lacking associated vascular malformations are rare. We report three patients with spinal subarachnoid hemorrhage (SAH) due to rupture of such aneurysms, which regressed spontaneously, as confirmed on conventional angiography. One patient had spinal SAH with presumed spontaneous dissection of a segmental artery. In the other two, SAH resulted from ruptured fusiform aneurysms of the artery of Adamkiewicz immediately proximal to the anterior spinal artery. Solitary aneurysms of the spinal arteries appear to be etiopathologic entities completely different from intracranial aneurysms. Spontaneous occlusion seems to be common, justifying a wait-and-see strategy rather than urgent treatment.

Background: Endolymphatic sac tumours (ELST) have only been known as own tumour entities since 1984. ELST might occur solitarily and sporadically as well as hereditary connected to von Hippel-Lindau disease (VHL). This connection has been observed in 1992 for the first time and confirmed by molecular genetic analyses of the VHL gen. There is no agreement yet concerning diagnostics and therapy., Methods: Our attempt of classifying this type of tumour is the first one. According to our own experience and to literature, we suggest the following classification: ELST type A is locally confined without erosions of the temporal bone nor infiltration of the subarachnoidal area; ELST type B with bony infiltration of the labyrinth block and clinical hearing loss, and ELST type C with additional infiltration of the sigmoid sinus and the vein of jugular bulb. Preoperative diagnostics are performed according to defined radiological criteria in CT and MRI scans including MR-angiography., Results: In 6 patients, including two with a VHL syndrome, ELST was completely sanitized by stage-compatible surgery, using translabyrintine to infratemporal approaches, according to the tumour classification that we developed. The VII (th) nerve could be saved in all tumour stages, and in stage ELST type A the VIII (th) nerve as well. All patients remained without local recurrence in MRI check during the observation period of 4 to 38 months., Conclusion: Our stage-compatible surgery of ELST allows total tumor removal with minor morbidity. In contrast to the antero-, retrosigmoidal and suboccipital approaches, the tumour matrix can be safely removed via transmastoidal approach to exclude local recurrences.

Interventional neuroradiological techniques are described, which are used for revascularisation of the intra-extracranial vessels in acute stroke. The results are based on our experience gained during the endovascular treatment of more than 300 patients suffering from acute stroke during the last years. Indication, procedures and results of intraarterial thrombolysis, thrombo-aspiration, percutaneous transluminal angioplasty, and implantation of stents in cases of occlusion or pseudoocclusion of brain supplying vessels are discussed. Furthermore first experiences with new techniques from other centers are presented, e.g., thrombolysis by ultrasound (sonothrombolysis), by angiojet aspiration, and laser evaporation of the thromboembolic occlusion of intra- and extracranial blood vessels.

We report the case of a 57-year-old man with a known history of antineutrophil cytoplasmic antibody-positive Wegener granulomatosis with initial involvement of the upper and lower respiratory tract. MR imaging of the brain was performed because of new onset CNS symptoms (nausea, altered mental status). The images revealed a mass in the fourth ventricle. The mass diminished in size after systemic steroid treatment, as shown by follow-up MR imaging. The patient died in acute respiratory distress secondary to pneumonia. Histopathologic findings confirmed a Wegener granuloma of the fourth ventricle.

We report the case of a 74-year-old woman with a complex indirect (Barrow D) carotid cavernous sinus fistula. The patient was treated incrementally and finally cured by a rarely reported bilateral retrograde direct transvenous approach via the superior ophthalmic vein. The treatment of the complex carotid cavernous fistula with multiple bilateral fistula points showed additional complexity due to a partially thrombosed left superior ophthalmic vein, which required a combined microsurgical and endovascular treatment, showing that treatment can be achieved, if necessary, by catheterization of a thrombosed orbital vein.

Purpose: To evaluate the effect of anticoagulation control by bedside ACT during interventional neuroradiological procedures with intraarterial heparin application., Materials and Methods: The study included 168 patients with intraarterial anticoagulation. Depending on the expected duration of the intervention and the body weight, a heparin dose of 5000 i.u. (70 patients) or 7500 i.u. (98 patients) was given through the catheter. The clotting time was measured with the Hemochrom 401 (Fa. Fresenius)., Results: The effect of anticoagulation with heparin was measurable a few minutes after administration. Within the first 20 minutes the ACT increased about two times above the normal ACT from 156.1 +/- 26.1 (5000 i.u. heparin) to 296 +/- 58.0 and from 146.5 +/- 26.3 (7500 i.u. heparin) to 317.2 +/- 72.0. Additional administration of 2500 i.u. heparin was necessary in 16 patients. An ACT monitored neutralisation with protamine hydrochloride took place in 15 patients with high ACT values at the end of the intervention. Three thromboembolic events and one bleeding complication occurred during the interventions., Conclusions: (1) The ACT is a useful and readily available parameter to monitor the anticoagulation status of patients in the interventional suits. (2) ACT detects heparin nonresponders. (3) Exact monitoring of heparin administration and neutralisation with protamine hydrochloride is helpful in preventing thromboembolic events and bleeding complications.

Epilepsy is the leading symptom in low grade gliomas. In order to evaluate the effect of interstitial radiosurgery on seizure incidence the authors retrospectively analysed the outcome of 80 patients with temporal grade-II astrocytomas and a history of epilepsy. Patients were treated by 125-iodine temporary implants using 60 Gy as reference dose. The dose rate was 9.6 +/- 1.6 cGy/h. Median follow-up was 4.1 years. In 20 patients benzodiazepine receptor imaging was performed using single photon emission computed tomography and iomazenil. Treatment with carbamazepine alone led to a significant reduction in seizure incidence with 28% of patients being seizure-free (p < 0.05). Interstitial radiosurgery led to a further reduction of seizures rendering 40% of patients seizure-free after 3 months. After 6 months only 21% of patients still had seizures that were refractory to medical treatment (p < 0.01). SPECT imaging revealed that all tumours had a significant reduction of benzodiazepine receptors which also applied to the surrounding brain. After interstitial radiosurgery of tumours, receptor density increased in brain adjacent to the tumour (0.68 to 0.94 ratio ipsi to contralateral brain, p < 0.01) coincident with significant tumour shrinkage. Thus, in epileptogenic temporal low grade gliomas, interstitial radiosurgery not only reduced the tumour burden but also effectively treated the concomitant epilepsy, resulting in 79% of patients being seizure-free after combined treatment by radiosurgery and anticonvulsive medication. These results compare favourably to the outcome after resection in lesional epilepsy raising the issue of radiosurgery as a less invasive alternative to open epilepsy surgery.

Stereotactic radiosurgery is an elegant alternative to microsurgery in both skull base meningiomas and solitary brain metastasis. Though efficacy for both entities has been established prognostic variables pertaining to individual tumour biology have not yet been identified. Therefore the authors measured regional glucose utilisation, thallium-uptake and blood flow in 20 patients (10 meningiomas, 10 metastasis) before and after LINAC radiosurgery. Measurements were performed using SPECT and stable xenon-CT. The mean tumour dose given was 16.3 and 19.5 Gy in meningiomas and metastasis respectively. Metastatic tumours were hypermetabolic in comparison to contralateral normal brain and responders to radiosurgery showed a lower tumour/brain ratio than non-responders (1.43 vs 0.91 respectively, p < 0.01). Meningiomas did not exhibit hypermetabolism and therapeutic outcome was not related to glucose utilisation. Thallium-uptake, however, was closely related to therapeutic response in meningiomas (1.37 vs 2.2 in responders vs non-responders, p < 0.01). This relationship could not be established in metastatic lesions. Blood flow was widely distributed in both meningiomas and metastasis (26-72.8 and 30.2-70.8 ml/100 g/min). rCBF did not correlate with therapeutic outcome. Using FDG-SPECT and thallium-201-SPECT the authors were able to distinguish between tumours likely to respond to stereotactic radiosurgery and those not prone to respond. Furthermore the methodology can be used to monitor therapeutic response in treated tumours before morphologic changes occur.

Radiographic imaging of the intratemporal portion of the fallopian canal is important in cases of traumatic facial nerve palsy to visualize the site of involvement. Even if high-resolution computed tomography is used, several images in various planes are necessary to obtain satisfactory diagnostic information. By using a classic axial scan and a wide window (bone algorithm), a 2D reconstruction can be performed "off-line" to visualize the mastoid portion of the fallopian canal. A reconstruction plane 45 degrees to the median-sagittal plane and through the lateral genu of the facial nerve provides the best imaging of the mastoid portion down to the stylomastoid foramen. In cases of temporal bone fractures with facial paralysis, an excellent demonstration of fracture line without further radiation exposure can be obtained in cases considered for surgical decompression.

This investigation of the optic canal is based on measurements of 60 macerated adult European skulls from the Alexander-Ecker Collection at the Anatomy Department of the University of Freiburg. An indian skull is also described, in which the cranial end of the left optic canal is closed by a bony plate. Computer tomographical and anatomical measurements were compared in order to assess the correlation of the two methods of investigation and the accuracy of the CT representation of osseous structures. The coronal projection of the optic canal proved to be optimal for CT examination--the sections meet the optic canal at an angle of 85.5 degrees. The measurements of transverse diameters correlate poorly, whereas vertical diameters and distances correlate well. The extent to which anatomical variations can be assessed by CT was also investigated. All anatomical variants could be observed in coronal sections, except the bony lamina in the Indian skull, which could not be seen until a contrast medium was used. The so-called "keyhole anomaly" appeared in 3.3% in our material, the "figure-of-eight" variant in 2.5%, and a carotid clinoid canal in 13.3%.