Diffusion-weighted magnetic resonance imaging of cerebrospinal fluid in patients with and without communicating hydrocephalus

BACKGROUND

Recent concepts about cerebrospinal fluid (CSF) circulation in communicating hydrocephalus (CoHy), which is also termed "restricted arterial pulsation hydrocephalus," suggest reduced arterial pulsations of subarachnoid vessels with a smaller amount of CSF shifted in subarachnoid spaces during the early systole. The postulated restriction of subarachnoid arterial pulsations in CoHy should induce a smaller motion artifact and reduced local stream effects in CSF in magnetic resonance (MR) diffusion-weighted imaging (DWI).

PURPOSE

To investigate the maximum diffusivity in CSF in patients with and without CoHy using DWI.

MATERIAL AND METHODS

12 patients without CSF circulation disturbances and six cases with proven CoHy were assessed. Diffusion was measured in six non-collinear directions without triggering the arterial pulse wave (scan time 6:45 min, voxel size 2x2x2 mm). Due to expected artifacts, the calculated maximum diffusivity was called apparent diffusivity. Regional high and low apparent diffusivity was assessed in CSF spaces on newly created 3D CSF motion maps.

RESULTS

Patients with regular CSF circulation exhibited high apparent diffusivity in CSF in basal subarachnoid spaces, whereas apparent diffusivity was low there in patients with CoHy.

CONCLUSION

DWI opens a feasible approach to study CSF motion in the neurocranium. Restricted arterial pulsations seem to be involved in CoHy.

A novel technique to measure position-dependent resistance changes in the vertebral arteries postmortem: new insights into the aetiology of SIDS?

AIM

A central respiratory regulation disturbance--triggered by impaired oxygen supply to the brainstem--is being discussed as an aetiological factor in sudden infant death syndrome. In this experimental study, further insight was sought into how far cervical spine movements may induce critical narrowing of the vertebral arteries.

METHODS

In 10 infant bodies, the vertebral arteries were cannulated close to their origin and perfused with a fluid bolus of 5 ml in 2 s. The intravascular peak pressure created was memorized. Individual resistance indices were computed for every vertebral artery by relating the average pressure maximum from 10 measurements each with maximal rotation of the neck to either side alone and then with additional hyperextension of the cervical spine to the average peak pressure in neutral head position.

RESULTS

Alterations of position-induced pressure changes occurred in the vertebral arteries of all children. Considering exclusively the combined movements of rotation plus extension, resistance increased ipsi- and contralaterally--no matter which side the head was turned--in three infants. A further three reacted with resistance surges only contralateral to the direction of rotation, and one only ipsilateral. Double contralateral associated with only one-directional ipsilateral rise was observed twice, and vice versa once.

CONCLUSION

The presented method enables crude quantification of postmortem dynamic resistance alterations in the vertebral arteries. How far such measurements reflect authentic circulatory conditions during life remains to be assessed.

Gamma knife radiosurgery of acoustic neurinomas

The authors report on their series of 40 patients with 41 acoustic neurinomas (ACNs), including one patient with bilateral acoustic neurinomas suffering from neurofibromatosis type 2 (NF II) who were treated with the gamma knife unit at their institution between August 1992 and October 1995. Of these 41 tumours, 21 ACNs had been operated on before (1 to 4 times), 20 ACNs were exclusively treated by gamma knife radiosurgery (GKRS). The maximal axial tumour diameter ranged from 6 to 33 mm (median: 25 mm), the maximal transverse tumour diameter ranged from 7 mm to 36 mm (median: 16 mm). The dose distributed to the tumour margin was 10 to 17 Gy (median: 12 Gy) by enclosing the tumour with the 40% to 95% isodose line (median: 50% isodose line) and using 1 to 12 isocenters (median: 5 isocenters). Central loss of contrast enhancement was observed in 78% of the patients within six to 12 months after radiosurgery. Thirty-two patients were observed over a minimum follow up period of at least 36 months, 9 patients were lost to follow up as they died of unrelated causes or refused further check-ups. Within the follow up period of up to seven years, magnetic resonance imaging (MRI) control scans revealed the tumour diameter stable or decreased in 29 cases and increased in three tumours. Of 14 patients with useful hearing before treatment, 9 patients were examined in addition to pure tone audiogramm by measurement of brainstem auditory evoked potentials (BAEPs) one to four years after radiosurgery. None of these patients showed a postoperative loss of the cochlea function. According to slight alterations of the cochlea function (cochlea summating action potential), pure tone audiometry of those patients revealed only slight changes of the hearing level (HL) within a maximum range of +/-15 Decibel (dB). The hearing threshold improved in two, was stable in four and deteriorated in three patients, respectively. We observed postradiosurgical aggravation of a pre-existing facial weakness in two out of 13 patients, a new occurrence of facial palsy was seen in two cases (four years after treatment), one of them was previously operated on and both suffered from cystic degeneration with mass effect. Tinnitus improved in six out of 13 patients, deteriorated in two and never appeared as a new permanent sequela. Trigeminal hypaesthesia did also not appear as a new permanent symptom, improved in three out of 9, and deteriorated in one out of 9 patients. Vertigo increased in six out of 23, was stable in 8 and decreased in nine out of 23 patients each. GKRS proves to be a safe and highly satisfactory therapeutical option or addition to open surgery, especially for radiologically verified regrowing residual ACNs, but also as primary treatment in selected patients. A high rate of tumour control can be achieved with an acceptable rate of neurological deficits.

An intramural macrocyst of an acoustic neurinoma rupturing after gamma knife radiosurgery: a case report

We want to describe the rare case when an intramural macrocyst within an acoustic neurinoma (ACN) treated by gamma knife radiosurgery (GKRS) ruptured, followed by an impressive decrease of tumor volume and improvement of neurological symptoms. In a 59-year-old female patient, a large ACN with a hugh intramural macrocyst was diagnosed. As she refused open surgery, we performed GKRS covering the tumor margin and the cyst with 11 Gy. Seven months after treatment symptoms worsened slightly. Magnetic resonance imaging (MRI) revealed no significant change of tumor volume. One year after GKRS she felt a sensation behind her treated ear, followed by an immediate improvement of all her symptoms. Trigeminal hypaesthesia and vertigo disappeared, tinnitus ameliorated. A control MRI showed the cystic compartment no longer, the solid part shrunk within the following six years. Within the whole follow-up period hearing was stable. To our knowledge this is the first report of a macrocyst within an ACN to rupture after GKRS.

Gamma knife radiosurgery of skull base meningiomas

BACKGROUND

The standard surgical treatment of meningiomas is total resection of the tumour. The complete removal of skull base meningiomas can be difficult because of the proximity of cranial nerves. Stereotactic radiosurgery (SRS) is an effective therapy, either for adjuvant treatment in case of subtotal or partial tumour resection, or as solitary treatment in asymptomatic meningiomas.

METHOD

Between September 1992 and October 1995. SRS using the Leksell Gamma Knife was performed on 46 patients (f:m 35:15), ranging in age from 35 to 81 years, with skull base meningiomas at the Neurosurgical Department of the University of Vienna. According to the indication of gamma knife radiosurgery (GKRS) the patients (n = 46) were divided into two subgroups. Group I (combined procedure: subtotal resection followed by GKRS as a planned procedure or because of a recurrent meningioma), group II (GKRS as the primary treatment). Histological examination of tumour tissue was available for 31 patients (67%) after surgery covering 25 benign (81%) and 6 malignant (19%) meningioma subtypes.

FINDINGS

The overall tumour control rate after a mean follow-up period of 48 months (ranging from 36 to 76 months) was 96% (97.5% in benign and 83% in malignant meningiomas). Group I displayed a 96.7% tumour control rate, followed by group II with 93.3% respectively. Neurological follow-up showed an improvement in 33% stable clinical course in 58%) and a persistent deterioration of clinical symptoms in 9%. Remarkable neurological improvement after GKRS was observed in group II (47%), whereas in group I (26%) the amelioration of symptoms was less pronounced.

INTERPRETATION

GKRS in meningiomas is a safe and effective treatment. A good tumour control and low morbidity rate was achieved in both groups (I, II) of our series, either as a primary or adjunctive therapeutic approach. The planned combination of microsurgery and GKRS extends the therapeutic spectrum in the treatment of meningiomas. Reduction of tumour volume, increasing the distance to the optical pathways and the knowledge of the actual growing tendency by histological evaluation of the tumour minimises the risk of morbidity and local regrowth. Small and sharply demarcated tumours are in general ideal candidates for single high dose-GKRS, even after failed surgery and radiation therapy, and in special cases also in larger tumour sizes with an adapted/reduced margin dose.

Ultrafast magnetic resonance imaging of the brain

The purpose of this study was to compare the diagnostic efficacy of single shot fast spin echo sequence (SSh-FSE), and single shot GRASE-sequence (SSh-GRASE) to the conventional T(2)-weighted fast spin echo-sequence (T(2)-FSE) in the imaging of brain disorders. Thirty three patients with high signal intensity lesions on T(2)-weighted images (n = 28), or intracerebral hemorrhage (n = 5), were examined on a 1.0 T MR scanner, with 23 mT/m gradient strength. The scan time for the conventional T(2)-FSE-sequence was 2 min 57 s, the scan time for the single shot-FSE-, and single shot-GRASE-sequences was 11 sec, and 17 sec, respectively. Twenty-one patients remained still during the examination, whereas 12 could not stay still with consecutive marked motion artifacts. Images were reviewed by three radiologists. Lesion conspicuity, image quality, and artifacts were scored on a subjective scale. Signal-to-noise ratios of lesions and normal tissue and contrast-to-noise ratios (CNR) were measured by region of interest (ROI). In the patient group without motion artifacts conspicuity for lesions > or =5 mm did not show a significant difference on conventional T(2)-FSE, single shot-FSE and single shot-GRASE. Detectability of the smaller lesions was significantly inferior on single shot-FSE-, and single shot-GRASE-sequences in artifact free images. For the patient group with motion artifacts SSh-FSE and SSh-GRASE were markedly superior to the conventional T(2)-FSE. Grey-white differentiation was better on conventional T(2)-FSE. Physiologic ferritin as well as pathologic hemosiderin depositions were slightly darker and therefore better visible on SSh-GRASE than on SSh-FSE. Conventional T(2)-FSE showed significantly more artifacts. In conclusion, SSh-FSE and SSh-GRASE imaging can be used for rapid imaging of the brain in those patients who are claustrophobic or in patients with involuntary movements due to extrapyramidal disorders, as well as in children in whom anesthesia is contraindicated or sedation is not possible.

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.

[Diagnostic imaging in intensive care medicine. Techniques, indications, diagnostic signs--I]

Die rasant fortschreitenden Entwicklungen auf dem Gebiet der Radiodiagnostik eröffnen auch der Intensivmedizin neue Aspekte: Mittels moderner Technik können heute ungleich rascher konklusive Diagnosen gestellt werden. Dies setzt jedoch die Kenntnis der Möglichkeiten und auch der Grenzen bildgebender Methoden in der Intensivmedizin voraus. Im vorliegenden Beitrag werden, ausgehend von relevanten klinischen Fragestellungen und Problemkomplexen, die Möglichkeiten bildgebender Verfahren vorgestellt und diskutiert. Es werden die wichtigsten diagnostischen Röntgenzeichen erläutert und ein diagnostisches Prozedere vorgezeichnet. Somit soll der vorliegende Beitrag eine kurze Zusammenfassung der für die Intensivmedizin wichtigen Aspekte der Bildgebung darstellen.

Image-guided neurosurgery comparing a pointer device system with a navigating microscope: a retrospective analysis of 208 cases

A retrospective analysis of neuronavigation procedures performed at the Vienna Neurosurgical Clinic was undertaken to elucidate the advantages of 2 technically different navigation systems in clinical use. In a 30-month period, 208 frameless stereotactic procedures were performed using a stereotactic microscope (MKM System, Zeiss; 92 procedures in 87 patients; 47 female, 40 male; mean age, 46 yrs) and a light emitting diode (LED) based pointer navigation device (Easy Guide Neuro (EGN), Philips; 116 procedures in 114 patients; 63 female, 51 male; mean age 46.4 yrs). The navigating microscope was exclusively used for cranial navigation, the pointer device system in 107 cases for cranial and in 9 cases for spinal navigation. Procedures were CCT-guided in 109 cases, MRI-guided in 95, and both CT/MRI guided in 4 cases. Skin fiducials were used in all these procedures. The MKM system provided coordinate-based navigation, similar to frame systems. This allowed surgical planning and performance using stereotactic coordinates for target calculation. Additionally, tumor volumes were defined by contours and projected into the ocular of the microscope, allowing guidance during targeting and resection of lesions. Both of these features proved beneficial in tumor surgery (60.8% MKM cases), cavernoma surgery (21.8% MKM cases), and epilepsy surgery (14.1% MKM cases). In contrast to the microscope, the pointer navigation system could be employed for intuitive correlation of image points with points of interest in the operating field by using a LED-equipped pointer device. This permitted image guidance during a wide spectrum of neurosurgical procedures, in tumor surgery (68.1% EGN cases), cavernoma surgery (5.1% EGN cases), epilepsy surgery (14.1% EGN cases), vascular surgery (3.4% EGN cases), spinal surgery (7.8% EGN cases), and guidance for burr holes and drainages (6.9% EGN cases), without calculating stereotactic coordinates. This analysis showed clear differences in the application of the two systems and may facilitate the decision as to which system best meets the individual demands of a neurosurgical department.

Subdural hygromas after bone marrow transplantation: results of a prospective study

BACKGROUND

Subdural hygromas after bone marrow transplantation (BMT) have been occasionally found in patients with persisting headache and vomiting. We assessed the incidence of subdural hygromas after BMT and tried to define possible risk factors associated with this complication.

METHODS

Fifty bone marrow graft recipients surviving more than 30 days were consecutively enrolled into a prospective study. Cranial CT scans were performed before and 30 days after BMT. Clinical data and symptoms were recorded daily during the first 30 days after BMT. In patients with subdural hygromas, a magnetic resonance imaging scan and monthly follow-up cranial computed tomography scans were performed until fluid collections had resolved completely.

RESULTS

In 9 of the 50 patients (18%) who survived 30 days after transplantation, newly acquired subdural hygromas were found. Patients with hygromas suffered significantly longer and more severely from headache and vomiting (P=0.01). Application of intrathecal methotrexate and arterial hypertension occurred significantly more often in patients with hygromas (P=0.01). In a stepwise logistic regression model, arterial hypertension and intrathecal methotrexate application were the only independent risk factors for the development of hygromas. Monthly follow-up cranial computed tomography scans showed that all hygromas resolved completely after a median of 60 days after diagnosis (range: 30-120 days).

CONCLUSIONS

Subdural hygromas are a frequent complication after BMT within the first 30 days after transplantation. They are reversible and disappear within 2-3 months. The need for routine application of intrathecal methotrexate in standard risk leukemia patients should be critically addressed. Furthermore, close monitoring of blood pressure and immediate antihypertensive therapy might contribute to avoid formation of subdural hygromas.

Imaging of the brain using the fast-spin-echo and gradient-spin-echo techniques

The aim of our study was to compare gradient-spin-echo (GRASE) to fast-spin-echo (FSE) sequences for fast T2-weighted MR imaging of the brain. Thirty-one patients with high-signal-intensity lesions on T2-weighted images were examined on a 1.5-T MR system. The FSE and GRASE sequences with identical sequence parameters were obtained and compared side by side. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, and image artifacts. In addition, signal-to-noise, contrast-to-noise, and contrast ratios and were determined. The FSE technique demonstrated more lesions than GRASE and with generally better conspicuity. Smaller lesions in particular were better demonstrated on FSE because of lower image noise and slightly weaker image artifacts. Gray-white differentiation was better on FSE. Ferritin and hemosiderin depositions appeared darker on GRASE, which resulted in better contrast. Fatty tissue was less bright on GRASE. With current standard hardware equipment, the FSE technique seems preferable to GRASE for fast T2-weighted routine MR imaging of the brain. For the assessment of hemosiderin or ferritin depositions, GRASE might be considered.

Tumour blood flow and partition coefficients: correlation with grade of cerebral gliomas using xenon-enhanced computed tomography

It is possible to underestimate the grade of nonenhancing cerebral tumours on conventional contrast-enhanced MRI or CT. Differentiation of high- and low-grade gliomas by measurement of the brain-blood partition coefficient lambda (T lambda) with Xe-enhanced CT (XeCT) has been reported. We assessed the practical applications of XeCT in suspected low-grade astrocytomas. We examined 15 patients with tumours which showed no contrast enhancement on conventional MRI and CT, using XeCT. Tumour blood flow (TBF) and T lambda were calculated. Fourteen patients underwent surgery, one patient had a biopsy. We recognized three histological groups. While T lambda differed significantly between them, TBF did not. Group 1 contained grade II-III astrocytomas and T lambda was 0.77; group 2 contained grade I-II astrocytomas with T lambda 1.14, and group 3 four oligodendrogliomas in which a T lambda of 1.50 was found.

Spiral CT angiography: study of stenoses and calcification at the origin of the vertebral artery

The origin of the vertebral artery may be difficult to show on sonography or conventional angiography. Our aim was to evaluate the accuracy of CT angiography (CTA) in detecting arteriosclerotic changes in the first segment (V1) of the vertebral artery. We performed CTA and intra-arterial digital subtraction angiography (DSA) on 24 patients with vertebrobasilar insufficiency. The ostium and the V1 segment were examined. Stenosis was assessed on a three-grade scale, and calcification and the degree of kinking were recorded. DSA and CTA results were compared. The ostium of the artery was seen in all cases on CTA and in 33 of 47 cases with DSA. All ostial stenoses diagnosed on DSA were seen with CTA. CTA revealed 4 stenoses in cases in which angiography proved inadequate, 11 zones of calcification and 5 cases of luminal reduction due to calcified plaques undetected on DSA. In the V1 segment DSA and CTA showed 3 stenoses, 9 cases of kinking, 1 of coiling and 4 stenoses due to kinking. CTA also demonstrated 4 additional stenoses, 2 cases of kinking and 3 stenoses due to kinking.

Stenoses of the first segment of the vertebral artery: difficulties in angiographic diagnosis

Pathology at the origin of the vertebral artery may be the cause of incapacitating vertebrobasilar insufficiency (VBI). Preoperative diagnosis is made primarily on angiographic criteria. We compared intraoperative and angiographic findings in 30 patients and found important diagnostic discrepancies in patients with a caudal, ventral or dorsal origin of the vertebral artery. In their angiograms, vessel superimposition led us to over look 3 ostial stenoses and 10 stenoses due to kinking. Angiographic assessment of patients with VBI can be difficult. Adequate visualisation of the origin of the vertebral artery is mandatory for accurate diagnosis.

Spiral CT angiography with digital subtraction of extra- and intracranial vessels

OBJECTIVE

A new imaging modality is presented in which a digital subtraction algorithm is applied to spiral CT angiography of extra- and intracranial vessels.

MATERIALS AND METHODS

Spiral CT angiography was carried out in 26 patients. When this was done for stereotactic purpose before radiosurgery, a Leksell stereotactic frame was used; in the other cases an atraumatic fixation system was applied. Spiral CT data were acquired twice--before and after contrast agent administration. Then, computerized subtraction of the density values of plain CT from the topographically corresponding enhanced CT was performed. Maximum intensity projection was used to visualize the vessels.

RESULTS

This method provided significant effacement of nonvascular structures and a considerably improved visualization of extracranial as well as intracranial vessels could be achieved. In some conditions, e.g., to exclude a suspected thrombotic occlusion of the basilar artery, conventional angiography could even be omitted.

CONCLUSION

Adequate visualization of extra- and intracranial vessels is possible with spiral CT angiography and digital subtraction. An important scope of this modality could be its contribution to radiosurgical planning and the follow-up after radiotherapy. In some conditions, CT subtraction angiography may possibly supersede conventional subtraction angiography.

Tension headache and the cervical spine--plain X-ray findings

The aim of the present study was to investigate if there is any causal connection between plain X-ray findings of the cervical spine and tension headache. We evaluated the X-rays of the cervical spine of 243 patients, in 91 of which the diagnosis was "tension headache", in 102 "headache not fulfilling the criteria of tension headache" and in 50 "spondylogenic complaints without headache". We compared these three groups with regard to frequency and severity of radiologically assessable changes of the cervical spine and found that patients with tension headache had normal findings significantly more often and significantly less often functional or organic changes or both than patients of the other two groups. The radiologically assessable changes of the cervical spine are unlikely to have an essential role in the cause or mechanism of tension headache.

Technetium-99m-d,1-hexamethylpropyleneamine oxime (HMPAO) uptake and glutathione content in brain tumors

Technetium-d, HMPAO SPECT was performed in 70 patients suffering from intracerebral tumors of various histologic types (glioma n = 30, meningioma n = 19, metastases n = 10, angioma n = 3, neuroma n = 2, lymphoma n = 2, neurocytoma n = 1, epidermoid n = 1, gliosis n = 1, cholesteatoma n = 1). Tumor classification was histologically verified in all subjects except in two cases with inoperable angiomas. SPECT was performed under resting state conditions with a dual-head rotating camera (SIEMENS ZLC 37) following intravenous injection of 18-25 mCi 99mTc-d, 1-HMPAO. Regional tracer deposit was expressed in terms of a cerebellar index (CBI). Significantly higher regional HMPAO uptake was found in meningiomas when compared with gliomas of different malignancy (ANOVA p less than 0.05). Within gliomas, regional uptake increased with malignancy (n.s.). In 23 patients, a total of 32 tumor specimens were obtained for histochemical analysis of glutathione (GSH) content using high-pressure liquid chromatography. A significant correlation (least square method, p less than 0.001) between CBIs and GSH values was found, supporting the hypothesis that GSH is the predominant factor for the conversion of the lipophilic complex to hydrophilic derivates.

[Transarterial EEG in superselective cerebral angiography]

Transarterial EEG-recording is a complementary method to surface and depth-techniques. In 8 patients having superselective angiography because of diagnosis or therapeutic manoeuvres transarterial EEG-recording was performed. There were only few artefacts and no clinical side effects. The value of this additional information is discussed.

Extra-CNS metastases of glioblastoma: CT and MR studies

The case of a 29-year-old man with glioblastoma and multiple metastases outside the CNS is presented. Cervical lymph node involvement was ascertained with CT and magnetic resonance (MR), and numerous bone metastases were detected with skeletal scintigraphy. The extent of the cervical tumor and its relationship to the carotid artery could be better assessed with MR than with CT. The patient died despite repeat operations, radiotherapy, and intraarterial systemic chemotherapy. The importance of radiological screening for detecting glioblastoma metastases in patients with long survival is discussed.

[Dust deposits in lung tumors--cause and significance]

In the diagnosis of a so-called scar carcinoma, one of the accepted morphological characteristics is the deposition of dust in tumours of the lung. In 50 bronchial carcinomas in former miners and patients not occupationally exposed to dust, the cause and significance of such lesions were investigated in autopsy and surgical material. Impregnation with dust must be considered to be a secondary phenomenon of the infiltrative tumour growth. Such depositions depend upon previously present dust depositions in the pulmonary parenchyma and on the localisation of the tumour, and reveal a clear correlation with the histological type and degree of differentiation of the tumour.

[Reversible opening of the blood-brain barrier in the chemotherapy of malignant gliomas]

The concept of a blood brain or blood tumour barrier blocking the passage of lipid insoluble cytoreductive drugs from blood into brain-tumor, leads to a protocol of intraarterial injection of high dose methotrexate (MTX) during reversible, osmotic blood brain barrier disruption (BBBD). Malignant Gliomas of grades III and IV in 9 patients and one primary CNS-lymphoma in one patient have been treated in 2 to 5 sessions per patient with BBBD plus polychemotherapy (MTX, cyclophosphamide, procarbazine). Median progression free intervals (PFI) which are still in continuation are 12.2 months. Median PFI which had been terminated by tumour recurrence are 7.75 months.

[Hemodynamic effects of an osmotic bolus for the reversible opening of the blood-brain barrier]

Reversible opening of the blood-brain barrier before administration of watersoluble cytoreductive agents constitutes a new tool in the treatment of central nervous malignancies. In this study a volume of 172 ml mannitol 25% has been injected into one of the cerebral arteries within 30 seconds. 5 minutes later the osmolality had augmented from 286 to 303 mosmol/kg and the plasma volume by 15%. The hemodynamic measurements--cardiac index (+47%), heart rate (+7%), LVSWI (+50%), systemic vascular resistance (-20%) and blood volume (+15%)--indicate a biphasic response with early fall in SVR followed by a rise in cardiac performance which is independent of the preload.

[Digital subtraction myelography--a preliminary report on the use of the digital subtraction technic in myelography]

Preliminary examinations with digital subtraction myelography revealed the possibility of saving up to 70% of water soluble contrast medium compared with usual myelographic procedures, thereby reducing the risk of neurotoxic adverse reactions.

Spinal cavernous haemangioma (intradural-extramedullary) underlying repeated subarachnoid haemorrhage

Within a period of 13 months a 24-year-old male student experienced four attacks of subarachnoid haemorrhage. An intradural-extramedullary haemangioma at the level of the second thoracic segment was found to be the cause of the repeated bleeding.