Image registration of MR and CT images using a frameless fiducial marker system.

A new system of fiducial stereotactic markers that can easily be adapted to various imaging modalities without losing image registration was developed and tested. Utilizing MR and CT imaging the accuracy of the new system was evaluated with phantom studies and preliminary patient studies. The markers are clearly visible without artifacts on both imaging modalities. The clear delineation of the marker dots on the images enables an accurate automated marker detection. Using the marker system, image registration was found to yield an accuracy of up to 1 mm, depending on the imaging modality and the employed marker arrangement. The presented marker system shall improve patient comfort in comparison to conventional fixed stereotactic frames if repeated, highly accurate registrations are necessary over longer periods.

Effect of amiloride and emopamil on intracranial pressure.

The authors sought to determine whether amiloride or emopamil could reduce intracranial pressure in experimental brain edema of the rat. For this purpose the rats functionally nephrectomized and brain edema of the cytotoxic type induced by infusion of 100 ml aqua bidest/kg body weight. After the end of the infusion 10 or 20 ml mM amiloride/kg body weight or 50 microliters mM (s)-emopamil/kg body weight in 10 ml 150 mM NaCl/kg body weight or 10 ml isotonic saline/kg body weight were injected followed by continued recording of intracranial pressure (ICP) and systemic arterial pressure for at least 3 hours. The values of the ICP for the amiloride and s-emopamil treated animals are significantly (p < 0.05, Student's t-test for unpaired data) lower at any point after the injection of amiloride or (s)-emopamil. Amiloride and (s)-emopamil prevent the rise in ICP seen after the saline injection in the control group.

Effect of torasemide on intracranial pressure, mean systemic arterial pressure, and cerebral perfusion pressure in experimental brain edema of the rat.

Torasemide, a puridine-3-sulfonylurea derivative, is a lipophilic diuretic compound. It interacts with the Na+2Cl-K+ carrier and at higher concentrations with the chloride channels. The lipophilic nature of torasemide may determine its access to glial and neuronal cells across the blood brain barrier. The present study was performed to establish whether torasemide could modify intracranial pressure and cytotoxic brain edema in functionally nephrectomized Wistar rats (150-240 g). Brain edema of the cytotoxic type was induced by infusion of 100 ml aqua bidest/kg body weight. After the end of the infusion 100 mg torasemide/kg body weight or a corresponding volume of isotonic saline were injected followed by continuous continued recording of ICP and systemic arterial pressure for at least 3 hours. Torasemide prevented the rise in intracranial pressure seen in control animals. The ICP values for the torasemide-treated animals were lower at all points. Following intravenous injection of 100 mg torasemide/kg body weight at 50, 60, 70, 90 and 120 minutes a significant decrease of intracranial pressure compared to that in controls was observed. Torasemide may be a useful adjunct in the therapy of brain edema and increased intracranial pressure.

Effect of torasemide on intracranial pressure, mean systemic arterial pressure and cerebral perfusion pressure in experimental brain edema of the rat.

The study was performed to establish whether a lipophilic loop diuretic, torasemide could modify intracranial pressure and cytotoxic brain edema. Brain edema was induced by water intoxication in nephrectomized rats. Following intravenous injection of 100 mg torasemide/kg body weight at 50, 60, 70, 90 and 120 min, a significant decrease of intracranial pressure was observed.

[Problems in diagnosis and therapy of extensive intramedullary tumors (illustrated by a case report)]. / Problem der Diagnostik und Therapie ausgedehnter intramedullärer Tumoren (demonstriert anhand eines Falles).

The case is presented of a patient with intramedullary ependymoma extending from C 1 to D 5, treated by a three-stage surgical procedure. A historical review is provided, followed by a discussion of the difficulties of diagnosis, especially at an early stage, and of the surgical management.

Photodynamic treatment of malignant brain tumors.

30 patients with primary or recurrent malignant brain tumors (9 primary, 18 recurrent malignant gliomas, 1 malignant meningioma, 2 melanomas) were treated altogether 37 times by photodynamic therapy (PDT) whether after intravenous, intraarterial or direct intratumoral sensitisation by hematoporphyrin (HPD) after conventional surgical removal of the tumor mass. The light was produced by an Argon pumped dye laser at doses varying from 40-220 J/cm2. A single dose of radiation of 4 Gy was administered to 18 patients immediately after PDT. The 9 patients with primary glioblastomas received in addition a full course of radiation therapy. The histological specimens taken during PDT demonstrated tumor necrosis, with oedema of normal brain tissue adjacent to the tumorbed. The median survival of patients with multiple recurrences and various radio- and chemotherapeutic modalities was 6 months (range 4-13 months). 9 patients with primary manifestation of a glioblastoma had a median survival of 19 months (0.5-29 months). Increased phototoxicity of the skin was the only side effect of PDT and did not reduce the quality of life of the patients.

[Neurosurgical therapy of epilepsy]. / Zur neurochirurgischen Therapie der Epilepsien.

We are witnessing a renaissance of the surgical treatment of epilepsy, with renewed interest in the classic procedures and development of new ones such as selective amygdalohippocampectomy. Surgery is being increasingly used in the treatment of medically intractable seizures. Exact presurgical evaluation, with definition of the focus, is of the utmost importance and good results are largely dependent on case selection for surgical therapy. The various therapeutic options such as temporal lobectomy, selective amygdalohippocampectomy, extratemporal cortical resections, hemispherectomy and corpus callosotomy are described and the risks and benefits of surgery discussed. Selective amygdalohippocampectomy, anterior temporal lobectomy and hemispherectomy yield very rewarding results as regards seizure control, while corpus callosotomies frequently reduce the number and severity of generalized seizures.

[Tractotomy and partial nucleotomy as a form of therapy in refractory pain of the trigeminal nerve and cancer pain in the head and neck area]. / Die Traktotomie und partielle Nukleotomie als Therapieform bei therapieresistenten Schmerzen des Nervus trigeminus und Karzinomschmerzen im Hals-Kopf-Bereich.

Persistent trigeminal neuralgia, herpes zoster neuralgia of the first division of the trigeminal nerve and pain caused by cancer situated in the head and neck pose frustrating problems for patients and physicians. Tractotomy and/or partial vertical nucleotomy of the subnucleus caudalis nervi trigemini offers a logical approach to the treatment of such pain, since these structures contain fibres of the Vth nerve, as well as the somatosensory fibres of the VIIth, IXth and Xth nerve. Tactile and some thermal sensitivity of the face is preserved and anaesthesia dolorosa and keratitis neuroparalytica is avoided. Over the past 30 years 370 patients with therapy-refractory trigeminal pain, pain due to cancer of the head and neck and herpes zoster trigeminal pain were treated by means of tractotomy (personal series of V. Grunert), including 30 patients who underwent partial vertical nucleotomy. The mean age of the patients was 68 years (range 54-84 years). The mortality in this series was 0.9% (4 patients; one operative mortality due to air embolism, one postoperative cardiac failure following myocardial infarction and two intracerebral haematomas). 60% of the patients with persistent trigeminal neuralgia were pain-free and 28% improved, whereas 12% were unchanged or suffered from recurrent pain. Of the patients with cancer who complained of pain derived from the Vth, VIIth, IXth and Xth nerve, 40% demonstrated marked pain relief and 60% showed no improvement. Tractotomy and partial vertical nucleotomy offer a valuable method in experienced hands for relieving pain where other methods have failed.

Effect of gammahydroxybutyrate on intracranial pressure, mean systemic arterial pressure and cerebral perfusion pressure in experimentally induced brain oedema of the rat.

In the treatment of raised intracranial pressure (ICP) an agent is needed which can similarly reduce ICP and protect the brain without reducing systematic arterial pressure and cerebral perfusion pressure. Gammahydroxybutyrate (GHB) decreases cerebral metabolic requirement of oxygen (CMRO2) and glucose utilization rate. The effect of GHB on ICP, systemic arterial pressure and cerebral perfusion pressure in the experimentally induced brain oedema of the rat was examined. 400 mg/kg GHB reduced significantly ICP (11.74 +/- 1.20 mmHg; control: 16.20 +/- 8.89 mmHg; p less than 0.01) while increasing mean systemic arterial pressure (109.89 +/- 6.35 mmHg; control: 89.65 +/- 4.22 mmHg; p less than 0.05) and cerebral perfusion pressure (98.11 +/- 6.79 mmHg; control: 73.84 +/- 5.25 mmHg; p less than 0.02). In the dose-effect curve 200 mg/kg GHB show an increase in mean systemic arterial pressure from 89.60 +/- 9.35 mmHg to 98.60 +/- 3.48 mmHg (p less than 0.02) and 400 mg/kg GHB to 108.00 +/- 5.20 mmHg (p less than 0.001) mean systemic arterial pressure. The decrease in intracranial pressure is not due to a reduction in the mean systemic arterial pressure, but GHB does reduce the ICP while increasing mean systemic arterial pressure and cerebral perfusion pressure. GHB may be a useful adjunct to neurosurgical therapy in controlling elevated ICP.

[Depressed fracture of the calvaria]. / Die Impressionsfraktur am Schädeldach.

This study is based on 147 depressed fractures of the calvaria. 60% of the diagnosed and treated cases were compound depressed fractures. Of the 147 patients 12 developed intracerebral, epidural and subdural hematomas. 3 persons developed infections. Of course the decision to institute prophylactic anticonvulsive therapy we only found 7 cases of posttraumatic epilepsy. Because of our experience in treatment of the depressed fracture we divide a consequent and rapid diagnosis by X-rays in combination with modern computer-tomography.

Effect of gammahydroxybutyrate on intracranial pressure, mean systemic arterial pressure and cerebral perfusion pressure in experimentally induced brain oedema of the rat.

The effect of gammahydroxybutyrate (GHB) on ICP, systemic arterial pressure and cerebral perfusion pressure in the experimentally induced brain oedema of the rat was examined. 400 mg/kg GHB reduced significantly ICP (11.74 +/- 1.20 mm Hg; control: 16.20 +/- 8.89 mm Hg; p less than 0.01) while increasing mean systemic arterial pressure (109.89 +/- 6.35 mm Hg; control: 89.65 +/- 4.22 mm Hg; p less than 0.05) and cerebral perfusion pressure (98.11 +/- 6.79 mm Hg; control: 73.84 +/- 5.25 mm Hg; p less than 0.02). In the dose-effect curve 200 mg/kg GHB show an increase in mean systemic arterial pressure from 89.60 +/- 9.35 mm Hg to 97.60 +/- 3.48 mm Hg (p less than 0.02) and 400 mg/kg GHB to 108.00 +/- 5.20 mm Hg (p less than 0.001) mean systemic arterial pressure. Thus, the decrease in intracranial pressure is not due to a reduction in the mean systemic arterial pressure, but GHB does reduce the ICP while increasing mean systemic arterial pressure and cerebral perfusion pressure. GHB may be a useful adjunct to neurosurgical therapy in controlling elevated ICP.

Effect of furosemide, bumetanide and mannitol on intracranial pressure in experimental brain edema of the rat.

Loop diuretics interfere with NaCl-KCl cotransport, which operates not only in the kidney but as well in a variety of nonepithelial cells including neuronal and glial cells. In these cells loop diuretics are able to reduce cellular volume. The present study has been performed to establish, whether furosemide or bumetanide directly modify intracranial pressure in cytotoxic brain edema. To this end, water intoxication was induced in animals acutely nephrectomized, to exclude any consequences of renal effects. Neither furosemide nor bumetanide proved effective in reducing intracranial pressure. In contrast, infusion of hypertonic mannitol solution leads to a marked, rapid reduction of intracranial pressure. The observations rule out a direct action of loop diuretics on intracranial cells to reduce intracranial pressure in water intoxicated animals.

Steroid-induced complete remission in a case of primary cerebral non-Hodgkin's lymphoma.

A case of a primary non-Hodgkin's lymphoma of the CNS is reported in which a complete and stable disappearance of an enhancing mass lesion on the CT scan after treatment with dexamethasone was followed by the occurrence of a high-grade malignant lymphoma in the opposite hemisphere 18 months later. The long-lasting and stable remission suggests a direct oncolytic effect of corticosteroids on lymphoma cells. Furthermore, this case illustrates the usefulness of repeated CT examinations in patients with CNS lymphoma and steroid treatment.

[Lumbar disk hernia in children and adolescents]. / Die lumbale Diskushernie im Kindes- und Jugendalter.

Of 3,946 patients with lumbar disc herniation, who were operated on from 1980 to 1987 at the Clinic of Neurosurgery of the University of Innsbruck, 11 consecutive patients (0.27%) were younger than 19 years. In 9 patients (82%) there was radicular pain; in 90% the straight-leg raising test was positive, in 36% there was clear relation trauma to the onset of symptoms. Water-soluble contrast myelography or computerized tomography were used to confirm the diagnosis, in 36% both investigations. In 91% the surgical procedure was unilateral partial hemilaminectomy and in one case a laminectomy. In all cases a good or excellent result could be achieved.

Rupture of a giant aneurysm of the inferior wall of the internal carotid artery after saphenous vein interposition graft to the middle cerebral artery.

A patient with a giant aneurysm of the inferior wall of internal carotid artery presented with progressive vision failure with optic nerve atrophy on the left eye. She underwent exploration of the aneurysm, which was found impossible to clip. Clamping of the common carotid artery was not tolerated there being inadequate collateral circulation. A saphenous vein graft was interposed between the occipital artery and a branch of the middle cerebral artery. The previously unruptured aneurysm bled fatally 4 hours after surgery, just before intended clipping of the aneurysm or ligation of the internal carotid artery.

[Space-occupying, traumatically-induced hemorrhage of the posterior cranial fossa]. / Raumfordernde, traumatisch bedingte Blutungen in der hinteren Schädelgrube.

A total of 4,408 patients were treated for head injuries from 1980 to 1986 at the University Hospital of Innsbruck in Austria. Nine of them (0.2%) showed a traumatic, space-occupying hematoma in the posterior fossa. Clinical signs are often elusive, but tentorial or foraminal herniation with apnea may suddenly arise. Heightened awareness of these lesions and closely monitoring these patients are both necessary, especially when there is a fracture over the transverse sinus or the foramen magnum. Computed tomography helps to establish the diagnosis and leads to appropriate neurosurgical treatment. The overall mortality of patients with these lesions was 22% in our patients.

[Hydrocephalus following spontaneous subarachnoid hemorrhage]. / Hydrozephalus nach spontaner Subarachnoidalblutung.

In the period 1980-1985 221 patients presenting with subarachnoid haemorrhage were operated on at the Department of Neurosurgery of the University of Innsbruck. 26 patients (11.7%) of them required a ventriculoatrial or ventriculoperitoneal shunt. The relationship between the incidence of this complication and the various clinical features of subarachnoid haemorrhage is discussed. Computed tomography is the most important investigative tool for diagnosis and follow-up of hydrocephalus. The results after shunt operation are correlated with the site of the aneurysm and the pre-operative grade of the patient.