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OBJECTIVE: To determine the efficacy and safety of early intervention with nimodipine treatment in diffuse axonal injury. METHODS: Based on the characteristic radiological signs and criteria for diffuse axonal injury (DAI), 89 patients with the diagnosis of DAI were enrolled in this randomized, double-blind, placebo-controlled trial. RESULTS: Nimodipine proved to be safe and well tolerated. With TCD sonography we found that there was a higher incidence of cerebral vasospasm in this series (38.2%). Overall, Nimodipine produced a better clinical result than placebo, but there was no statistically significant difference in favorable outcome at 3 months after injury (P=0.11) between the two groups. A trend toward a favorable effect was suggested by the analyses in two small subgroups, either in the patients suffering from clinical Grade III DAI (P=0.04), or in those with the TCD-evidence of cerebral vasospasm during clinical observation (P=0.049). CONCLUSIONS: We postulate that a clinically valuable benefit is possible with nimodipine treatment in DAI patients. However, the effects on outcome should be verified by further controlled study.

This rare case of brain stem tethering presented with chronic and progressive geniculate neuralgia. In view of the fact that an occipital subcutaneous lipoma had been resected in childhood, it probably concerned a primary tethering, fitting in with an occult occipital dysraphism. Magnetic resonance imaging (MRI) clearly demonstrated an underlying tethering, causing a distortion of the brain stem. Consequently, this led to the hypothesis that the geniculate neuralgia could be explained by traction on the lower cranial nerves secondary to the brain stem displacement. Untethering resulted in a considerable decrease of the neuralgia. MRI proved to be essential in the diagnosis and treatment of this unusual case.

We retrospectively reviewed 32 patients operated on for lipoma of the conus and lipomyeloschisis, the two main anatomical subtypes of congenital lumbosacral lipomas associated with tethered cord syndrome. Surgery was proposed to patients when they were symptomatic, and in most cases for progressive symptoms. The evolution of the different symptoms was studied separately. In most patients, symptoms improved or stabilized after surgery; in some, however, postoperative worsening, at least of some of the symptoms, was seen. This postoperative worsening became apparent either early or late after the operation, and was not associated with surgical trauma or postoperative complications. We suggest it was caused mainly by the natural course of the disease (especially in the case of the orthopedic deformities), and in some cases by retethering. Our series is not large enough to detect statistical significance for the different symptoms or for the anatomical subgroups. Importantly, according to our analysis by the different symptoms, the operation did not seem to protect the patients from later development of new deficits. This can be interpreted as an argument against prophylactic surgery in asymptomatic patients.

We describe the first observation of a child with a posterior fossa subdural effusion with secondary hydrocephalus and tonsillar herniation. We diagnosed this entity in a 14-month-old girl with no history of trauma or coagulation disorder. The patient presented in our emergency department with opisthotonus and raised intracranial pressure resulting from supratentorial hydrocephalus. An emergency ventriculo-peritoneal shunt was placed, which resolved the symptoms only temporarily. Eventually external drainage of the subdural fluid was performed. The collection gradually disappeared, and both the external subdural shunt and the ventriculo-peritoneal shunt were removed. The patient made a complete neurological recovery. We review the physiopathology and treatment of subdural effusions in general, and propose some guidelines for the management of symptomatic effusions occurring in the posterior fossa in particular.

The development of secondary tumours is a rare but well known late effect of radiation therapy of lesions in the central nervous system. Most radiation-induced tumours are of mesenchymal origin, but on rare occasions gliomas can occur. We describe a patient in whom a supratentorial anaplastic astrocytoma developed 15 years after surgery and radiotherapy for a childhood posterior fossa medulloblastoma. A concise review of the pertinent literature is given.

Three patients with a spontaneous spinal epidural hematoma are presented, one of which is exceptional because it could be attributed to thrombolysis with alteplase. The other two were correlated with oral anticoagulant therapy. Our second case suggests that Morbus Kahler may be an underlying pathology in spinal extradural hematoma. In the third patient neither an obvious 'locus minoris resistentiae' nor a pathological coagulation test could be held responsible for the spontaneous bleeding. All three patients underwent laminectomy and evacuation of the hematoma. Although two of our cases are examples of complete recuperation after late operative intervention, early surgery is preferable. Permanent clinical attention together with a low threshold to perform magnetic resonance imaging (MRI) leads to a quicker diagnosis of spinal epidural hematoma. We show that administration of gadolinium may facilitate correct preoperative localization of the hematoma because there may be contrast enhancement of the hematoma. Finally, the postoperative policy concerning thromboembolic prophylaxis is discussed.

This article reviews the clinical presentation, pathophysiology, diagnostic strategies, and therapeutic management of closed spinal dysraphism in infancy. Four groups of symptoms are distinguished: (1) cutaneous abnormalities, (2) lower motor neuron dysfunction due to congenital spinal and nerve root abnormalities, (3) upper motor neuron dysfunction due to tethering of the spinal cord, and (4) symptoms caused by associated malformations. Guidelines are proposed concerning timing and type of diagnostic investigations in infancy. This essentially encompasses a neurological assessment, including spinal ultrasonography and nuclear magnetic resonance imaging of the spine and the brain, and a urological assessment, including ultrasonography of kidneys and bladder, cystourethrography and a urodynamic study. As to the tethered cord syndrome it is concluded that first, already in infancy, a progressive neurological dysfunction can be detected; second, surgical untethering should be performed only upon appearance of upper motor neuron signs or upon progression of lower motor neuron signs. Despite its frequently asymptomatic course, the diagnosis of a congenital lumbosacral lipoma, and in the more general sense, of a closed spinal dysraphism, implies a periodic, multidisciplinary follow-up for life.

Two cases of aggressive pituitary macroadenoma (prolactinoma) with diffuse invasion of the skull base are described. Clinical signs usually appear late. CT shows the bone destruction, whereas MRI accurately delineates the extension of the tumor and involvement of the surrounding neurovascular structures. Histopathology and immunohistochemical staining are necessary for a definitive diagnosis differentiating prolactimonas from a wide range of skull base tumours and for deciding on additional therapy and prognosis. Aggressive pituitary macroadenoma is a large and diffuse tumor which is difficult to treat; therapy usually consists of extensive surgery, radiotherapy and pharmacotherapy with dopaminergic agents.

Prognostic factors for the outcome of patients with a chronic subdural haematoma were analysed in a consecutive study of 260 patients, regardless of the method of neurosurgical treatment. CT findings such as haematoma volume, midline shift and residual subdural collections had no influence on the outcome. The only statistically significant factor of importance for the outcome of patients with chronic subdural haematoma was the neurological condition at the time of treatment. Early diagnosis is therefore of major importance.

We present our experience with the use of ventriculosubgaleal shunting (VSGS) for the management of hydrocephalus associated with posterior fossa tumors in a consecutive series of 63 children. In 42 children, a temporary VSGS was inserted. There were no complications associated with the procedure, and it gave a period of several days in which to improve the general condition of the child, and to perform the necessary imaging studies, without an encumbering external drainage device. In most cases the VSGS could be removed after the posterior fossa surgery, without new general anesthesia. Other advantages and drawbacks of this technique are discussed.

A case of juvenile fibrosarcoma arising from the head and neck region is described. This type of tumour should be considered as a separate entity different from the fibrosarcoma in adults because of the different clinical behaviour. The symptomatology, the radiographic features and the literature data are reviewed.

We present a retrospective analysis of a consecutive series of 50 patients, over 60 years of age, with spontaneous cerebellar hematomas. Treatment was chosen on an individual basis : conservative treatment in 8 "benign" cases, craniotomy and/or ventricular drainage in the majority of cases (37), depending on the clinical presentation and the degree of hydrocephalus on CT scan, and surgical abstention in 5 moribund patients. The outcome at one month was studied and compared for different possible prognostic factors. Seventeen patients (34%) died, and three were in a vegetative state; they later died as a direct result of their initial cerebellar hemorrhage. At the latest follow-up, five other patients had also died, one due to cancer, and the others from cardiac causes. The obliteration of the basal cisterns, the volume of the hematoma, the absence of brain stem reflexes and the presence of coma were highly significant factors determining early mortality. The age of the patients, their estimated premorbid health and the degree of hydrocephalus were not significantly associated with fatal outcome. Intensive treatment for cerebellar hematomas, including suboccipital craniotomy, may be justified even in aged patients after careful selection.

This study presents the 5-9-year follow-up after anterior cervical fusion and osteosynthetic stabilization anterior plating for fractures and/or dislocations of the cervical spine in 25 patients. Adequate bony fusion was obtained in all patients within 1 year postoperatively. There were no problems of late screw loosening. Fracture of the osteosynthetic plate occurred in one patient. Late degenerative changes of the cervical spine at the disc levels adjacent to the fusion area were radiologically detected in 15 of the 25 patients (60%) and were related to the following situations: fusion on more than one disc level, fusion on a lower cervical segment, Frankel class A-C at admission, and hyperflexion injuries. However, these late degenerative changes had no subjective or clinical repercussions, at least until now. From a neurological point of view all patients remained stable postoperatively and no patients had late deterioration.

Cerebellar mutism has been reported after surgery for posterior fossa tumors in children and, rarely, in adults. The pathogenesis of this syndrome remains unclear, and controversy exists regarding whether it is a purely psychogenic disorder or an organic syndrome. The anatomical substrate for the mutism also remains unknown. We encountered five cases of postoperative transient cerebellar mutism in a consecutive series of 63 children with posterior fossa tumors. These cases were analyzed and compared with the patients without mutism to find predictive factors for the occurrence of mutism, with the hope of elucidating further the pathophysiological mechanism. The most significant finding was the presence in all cases of a period of cerebellar dysarthria after resolution of the muteness. We, therefore, believe that cerebellar mutism is an extreme form of dysarthria, rather than a real cognitive deficit or a psychological disturbance.

A 22-year-old male patient of Indian origin presented with generalized seizures. Brain magnetic resonance imaging (MRI) showed two cystic lesions. Extensive screening only revealed positive skin tests for tuberculosis. Immunoassays for cysticerosis were negative in serum and cerebrospinal fluid. Biopsy of the temporal lesion revealed a cysticercus. Although neurocysticercosis is a common cause of seizures in patients from countries where cysticercosis is endemic, the diagnosis can be difficult in a patient with evidence of multiple infections or in whom serological evidence is lacking, as is illustrated by the present case. Furthermore, because the pathogenic factors determining the activity of the disease are poorly understood, its management represents a similar problem as it depends upon the activity of the disease as estimated by clinical, radiological and laboratory tests. The present case report illustrates these difficulties.

We present a case of spinal epidermoid tumour that was probably caused by lumbar punctures. The tumour was detected on MRI in a child with tuberous sclerosis complaining of atypical low back pain. Preoperatively the tumour was considered to be a cystic astrocytoma of ependymoma of the conus terminalis. The association of tuberous sclerosis with a spinal tumour is rare but has been recorded in the literature. The diagnosis was an epidermoid tumour (E.T.). The MRI appearances were unusual for a spinal ET: the signal intensity changes were different from those reported in the literature and the presence of calcification and cavitation has not yet been reported. This case represents a diagnostic pitfall, since both entities were unrelated.

Purpose: To study the clinical and radiologic findings in 15 patients presenting with both developmental venous anomalies and cavernous angiomas and to determine which lesions caused the acute clinical symptoms., Methods: Lesions were infratentorial in 7 patients and supratentorial in 7 other patients. In one patient the developmental venous anomaly was infratentorial and the cavernous angioma supratentorial. In all 15 patients clinical examination and CT were performed. In 10 patients MR was performed at the time of the initial CT scan. In 5 patients only late MR is available., Results: Acute clinical signs were present in 9 patients (epilepsy, hemiplegia, meningeal signs, cranial nerve deficit). On CT the cavernous angioma was missed in 9 patients, in 6 patients because of acute hemorrhage. On MR the cavernous angioma was missed in 1 of 2 cases with acute hemorrhage but seen in all other patients. On repeat MR all cavernous angiomas were correctly identified. On CT, 11 developmental venous anomalies were seen. On MR all developmental venous anomalies were seen., Conclusions: The frequent association of developmental venous anomalies and cavernous angiomas is confirmed. MR is superior to CT in the detection of both cavernous angiomas and developmental venous anomalies. Furthermore our data support the hypothesis that cavernous angiomas and not the developmental venous anomalies cause the acute clinical symptoms because of hemorrhage.

A case is reported of recurrent intracerebral abscesses occurring in a patient with isolated drainage of a persistent left superior vena cava to the left atrium without causing cardiac symptoms or arterial desaturation. The diagnosis and therapy are discussed.

To determine the catecholamine response to progressive intracranial hypertension, intracranial pressure (ICP) was raised gradually by continuous expansion of an epidural balloon in seven dogs. Hemodynamic parameters, ICP, and cerebral perfusion pressure (CPP) were monitored continuously and serum catecholamine levels began to rise when CPP was in the low-positive range (20 to 30 mm Hg), reaching a peak just after brain death (CPP < or = o mm Hg). There was no correlation between ICP and the catecholamine peak. Compared to control values, the mean increase was 286-fold for epinephrine and 78-fold for norepinephrine. Temporally, the catecholamine peak corresponded well with the observed hemodynamic changes. These results suggest that ischemia in certain parts of the brain stem is responsible for the hemodynamic changes observed in intracranial hypertension (such as the Cushing response), and they show that catecholamines play an important role in these hemodynamic changes.

Transcatheter embolization was performed in 8 young patients (mean age 24.5 years) with intracerebral arteriovenous malformations. In total 12 arteries were embolized in 10 sessions. Clinical complaints of the patients included epilepsy in 4, sudden coma in 3 and severe sudden neurological deficit in 1. Intracerebral hemorrhage was documented in 4 patients and subarachnoid hemorrhage in 1. In all patients, prior to embolization a superselective Wada-test was performed under wake-up anesthesia. Embolization was performed with a mixture of acrylic glue and lipiodol. In one patient a detachable balloon was added. In 6 patients embolization of all the feeding arteries was possible, with total obliteration of the arteriovenous malformations in 4 and subtotal embolization (> 90%) in 2. In 2 patients reduction of the size of the arteriovenous malformation by one third was followed by total surgical removal of the lesion. In 1 patient reflux of the embolization material in the anterior choroidal artery caused severe neurological deficit with good clinical recuperation.

A case of intracerebral primitive neuro-ectodermal tumor (PNET) is presented. PNETs are rare, undifferentiated neoplasms occurring primarily in children and young adults. These tumors exhibit a highly malignant behaviour with a tendency to disseminate along the cerebrospinal fluid (CSF) pathways. Preoperative diagnosis is difficult, owing to the non-specific CT and MR appearances and to the rarity of this tumor. Our patient was 33 years old, which is uncommon. CT findings initially suggested an intracerebral hematoma. Later on, CT and MR findings were specific for a brain tumor and showed a solid, non-calcified invasive mass, with poor perilesional edema.

Purpose: To compare CT and MR in the differentiation of benign enlargement of the subarachnoid spaces and subdural collections in infants with macrocephaly., Methods: MR was performed in 19 infants with macrocephaly, showing bifrontal enlargement of the subarachnoid spaces on CT., Results: In 11 patients, a single fluid layer could be distinguished on MR of the pericerebral collections, suggesting benign enlargement of the subarachnoid spaces. In eight patients, two separate layers were clearly differentiated, an outer layer that was hyperintense on all sequences and an inner layer with the same intensity as the cerebrospinal fluid. This indicated the presence of subdural collections. These collections were mainly frontal in six and extended over the entire hemisphere in two patients. On CT, these separate lesions were seen only in three patients and missed in three others. In two final patients, CT findings were equivocal with evidence of membrane formation within the hypodense collections. In seven patients with a subdural collection, subdural-external drainage was performed. In three patients, the collection was hemorrhagic. The protein content of the fluid showed a mean of 1381.7 +/- 785.6 mg/dL. The MR and surgical findings of a subdural collection correlated with the absence of a family history of macrocrania, an age under 5 months, and acute clinical signs of vomiting, somnolence, and hypotonia., Conclusion: MR appears essential in the differential diagnosis between benign enlargement of the subarachnoid spaces and subdural collections in infants.

Two cases of dermoid cysts of the posterior fossa in association with a dermal fistula and with different clinical presentations are reported. The patient in case 1 is a 14-month-old girl with a history of recurrent bacterial meningitis. Case 2, a 7-year-old girl, presented with a skin "granuloma" at the inion. Both cases, and a review of the literature, demonstrate the need for a thorough exploration of the cranial and spinal midline skin areas in every newborn and argue for widespread use of nuclear magnetic resonance imaging whenever a suspected midline lesion is found.

We have reviewed our experience with a series of 49 consecutive patients with spontaneous cerebellar haematoma, treated according to a standardized management protocol. Seventeen patients were managed conservatively, 30 underwent ventricular drainage, and in six patients the haematoma was evacuated. The indications for the different modes of treatment are discussed. The most significant prognostic factors determining the outcome at one month were the grade of quadrigeminal cistern obliteration on the initial CT scan and the Glasgow Coma Scale on admission. Patients with normal cisterns had a good outcome, and only needed (temporary) ventricular drainage in case of hydrocephalus. Patients with totally obliterated cisterns had a bad outcome irrespective of treatment. In the patients with compressed cisterns, it is suggested that evacuation of the haematoma might improve outcome; treatment of hydrocephalus alone is insufficient in many cases in this group.

The contribution of MR in 10 patients with surgically proven intracranial hemangioblastomas was retrospectively evaluated and correlated with the computed tomographic findings. Angiography was obtained in eight cases. Multiple lesions were shown in only two patients, but none proved to have von Hippel-Lindau disease. In six patients the tumor typically appeared as a cystic lesion with an intensely enhancing mural nodule at the pial surface of the cyst; three patients presented with a solid lesion with a central cyst and one with a solid lesion only. Thirteen tumors were located in the posterior fossa, with one in the brain stem extending towards the spinal cord. A supratentorial localization was found in two patients. Abnormal serpiginous vessels supplying or draining the mural nodule or solid lesion were not visualized on contrast-enhanced computed tomography, but were easily identified as flow voids on MR in five patients. Calcification or hemorrhage were not seen in the entire series. Because of the multiplanar imaging capability and the lack of streak artifacts from the petrous bone, MR provides better localization than CT. MR is more accurate in predicting the number, extension and vascularity of hemangioblastomas, and provides a sound basis for further diagnostic and therapeutic procedures.

Intraspinal synovial or ganglion cysts of the cervical spine are rare. We present the third reported case of a degenerative articular cyst of the upper cervical spine, involving the quadrate ligament of the odontoid process. Magnetic resonance examination reveals typical images. A new, more general terminology is proposed.

A patient with right hearing loss, in whom computed tomographic scanning demonstrated a mass in the right cerebellopontine angle with widening of and extension into the internal auditory canal, but with important posterior extension and broad implantation on the surface of the petrous bone, is reported. On both T2-weighted and gadolinium-enhanced T1-weighted magnetic resonance images, there were clearly two separate tumoral lesions: an acoustic neurinoma extending into the internal auditory canal and a meningioma with broad implantation on the petrous apex. These findings were confirmed at surgery.

Juxta-facet cysts are relatively uncommon intraspinal lesions, causing radiculopathy, neurogenic claudication or myelopathy. To the best of our knowledge, only 4 cases of bilateral synovial or ganglioncysts were described. We report the 5th case of bilateral ganglioncysts of the lumbar spine. Generally, juxta-facet cysts should be differentiated from other intraspinal lesions, such as herniated discs, meningiomas and neurinomas. Correct preoperative diagnosis is necessary for adequate treatment, namely the (microscopic) resection of the cyst. After adequate treatment, complete recovery may be expected.

Two cases of tuberous sclerosis are presented. Extensive superficial occipital calcifications were found as classically described in Sturge-Weber syndrome. Other radiologic signs of tuberous sclerosis, such as subependymal calcifications in both patients and surgically proved giant cell astrocytoma in one patient, were present. At pathologic examination, the calcifications appeared to be located in extensive cortical tubers.

MRI findings are described in two patients with subdural haematomas isodense on CT. In one patient, admitted 6 weeks after trauma, a chronic subdural haematoma showed extreme hypointensity on T2-weighted images, suggesting acute trauma, and therefore acute rebleeding. In the second patient with severe anaemia, an acute subdural haematoma was hyperintense on T2-weighted images, suggesting chronic trauma; this may be explained by the low haematocrit and a possible mixture of blood with cerebrospinal fluid. The MRI features of subdural haematomas and hygromas have to be kept in mind, in order not to misjudge the age of the haematoma.

Prominent dural enhancement was noted in 10 (16%) of 61 superficial malignant intracranial tumors studied with contrast-enhanced MR imaging during a 2-year period. Included were six glioblastomas, three parenchymal metastases, and one case of dural metastasis. Seven patients had surgery. In four, there was extensive leptomeningeal invasion in the center of the lesion. In two of these lesions there was firm attachment of the center of the tumor to the dura, but without dural invasion despite extensive external carotid artery supply to the tumor in one case. In two cases the overlying dura was normal, and there was no leptomeningeal tumoral invasion. In the case of dural metastasis, huge nodular lesions were present along the inner aspect of the dura. In none of the cases did prominent dural enhancement adjacent to the tumor correspond with tumoral invasion or extension to the dura. Prominent dural enhancement on contrast-enhanced MR images appears to be much less frequent in malignant tumor than in meningioma, where it is seen in up to 60% of the cases. We believe this finding is more likely to represent reactive changes of the dura than tumoral invasion.

Gadolinium-enhanced MR was performed in 28 patients with 17 supratentorial and 11 cerebellar venous angiomas. The use of gadolinium allowed detection of 9 of 28 venous angiomas (32%) that were not visible before gadolinium or which were only recognized in retrospect. Before gadolinium the peripheral medullary veins that are typical for these venous malformations were only visualized in 4 of 17 (23%) supratentorial and in 5 of 11 (45%) cerebellar lesions, for a total of 9 of 28 (32%) venous angiomas. After intravenous administration of gadolinium these veins were seen in 27 of 28 (96%) venous angiomas. Extension of the lesions to the wall of the ventricles was seen in 24 of the 28, 16 of 17 supratentorial and 8 of 11 cerebellar, lesions after gadolinium. This information was missed on plain MR in 6 of these lesions. The type of venous drainage, either superficial or deep, could be determined by gadolinium-enhanced MR in all cases where angiography was available for comparison. Before gadolinium this information was not available in eight patients. The intravenous administration of gadolinium adds significant information in the MR study of venous angioma.

The radiologic findings in a case of an extradural diploic epidermoid tumor (ET) of the frontal bone, examined with plain X rays, CT and MRI, are reported. A head injury with traumatic inclusion of epidermis could have been the origin of the tumor. This report stresses the importance of the plain skull X ray in the diagnosis of extradural ET.

Two patients with ruptured intracranial dermoids, examined with both CT and MRI are reported. Clinical presentation was transient cerebral ischemia in one patient and acute meningeal signs in the other. CT scan showed typical fat density of the tumor and the subarachnoid space. On MRI both the tumor and the subarachnoid fat, were strongly hyperintense on T1-weighted images.

The magnetic resonance (MR) findings in 50 surgically verified intracranial meningiomas were reviewed. An attempt was made to correlate their signal intensity on spin echo (SE) T1-weighted, proton density [N(H)], and T2-weighted images with the different histologic subtypes. The T1-weighted images were nonspecific in differentiating the subtypes of meningiomas. On proton density and T2-weighted images, more information was available, but there remained large group (46%) of meningiomas that were not classifiable. The average signal intensity scores on T1-weighted, proton density, and T2-weighted images in the different histologic subtypes were correlated with each other using the Student t test. Only one significant correlation (psammomatous-anaplastic) and three almost significant correlations (syncytial-transitional or psammomatous and transitional-psammomatous) were found. Different histologic subtypes may have a different MR appearance, but this does not suffice to reach a histologic diagnosis by MR imaging.

This study presents a series of 10 patients with anterior skull base tumours, treated by a team of neurosurgeons and head- and neck surgeons. The series included 7 malignant tumours of the nose and paranasal sinuses and 1 retinoblastoma, all with intracranial extension through the lamina cribrosa. There were also 2 patients with an anterior base meningioma, growing into the ethmoid sinus and the nasal cavity. 8 tumours were resected by a combined bifrontal craniotomy and uni- or bilateral rhinotomy. In 2 cases a bifrontal craniotomy alone without facial incision sufficed. The skull base was closed with a pediculated pericranial flap and a split-thickness free skin graft underneath. There were no postoperative problems of wound infection, CSF-leakage or meningitis. Recurrent tumour growth or systemic metastasis occurred in 5 out of 7 patients with malignant tumours, 6 months to 2 years postoperatively. The related literature and especially questions of operative indications and technique, including different possibilities of closure and reconstruction of the skull base, are discussed.

Fifty patients with newly diagnosed, untreated intracranial tumors were examined with 1H nuclear magnetic resonance single-volume spectroscopy (MRS) using a 1.5 T whole-body MR system. Prior to the MRS, contrast enhanced MR and/or CT imaging studies were carried out. Histological verification was obtained in all patients except one. All tumor spectra revealed distinct abnormalities as compared with the normal brain spectra. Although most meningiomas showed a rather characteristic spectral pattern, generally features specific for the various tumor types were not observed. For instance, though a strong lactic acid signal was seen in most malignant tumors, this signal was also evident in five benign neoplasms.

The purpose of this study was to investigate the effect of propofol on cerebral blood flow, cerebral metabolism, and cerebrovascular autoregulatory capability. Seven anesthetized baboons were given propofol at three different infusion rates. An infusion of 3 mg.kg-1.h-1 caused minimal changes, but infusion rates of 6 and 12 mg.kg-1.h-1 decreased cerebral blood flow by 28% and 39%, respectively. The changes in cerebral metabolic rate of oxygen were not statistically significant. However, with the two higher infusion rates, there was a trend toward decrease, by 5% and 22%, respectively, for the cerebral metabolic rate of oxygen, and by 18% and 36% for the cerebral metabolic rate of glucose. A 25-30 mm Hg increase in arterial blood pressure had no influence on cerebral blood flow. Replacement of nitrous oxide by nitrogen had no significant influence on cerebral blood flow or metabolism. It is concluded that propofol causes a dose-dependent decrease in cerebral blood flow. However, the study does not prove that this decrease in cerebral blood flow is accompanied by the same degree of decrease in cerebral metabolism. Further studies are clearly needed to clarify propofol's influence on the coupling between cerebral metabolism and blood flow. The physiologic responsiveness of the cerebral circulation to alterations in arterial pressure is well preserved. Propofol appears to prevent the metabolic stimulation and increased cerebral blood flow that has been associated with the administration of nitrous oxide.

Magnetic resonance was performed in five patients with obstructive hydrocephalus due to surgically proven colloid cyst of the third ventricle. On T1-weighted images two lesions were homogeneously hyperintense and another homogeneously isointense with the surrounding brain parenchyma. On T2-weighted images these three lesions were strongly hypointense except for a hyperintense rim at the periphery. At surgery in these patients the cyst was thin walled and filled with viscous colloidal material. In two patients the content of the lesion was composed of two layers. The outer layer was hyperintense and the inner layer hypointense in one patient. In the other patient the periphery of the lesion was isointense with central hypointensity. On T2-weighted images the content of both lesions was hyperintense at the periphery with central hypointensity. In these last two patients at surgery the cyst was thin walled too. However, two clearly different components could be found in the cyst content: an outer component composed of amorphous material and cellular debris and an inner component consisting of viscous material.

A case of hemangioblastoma of the right lateral ventricle is presented. Only five other cases of intraventricular hemangioblastoma have been reported. The literature on supratentorial intraventricular hemangioblastoma is reviewed.

The authors present a review of their experience with posterior fossa tumours in adults during a period of 20 years. Symptoms, physical findings, tumour histology, operative treatment and results are reviewed in 109 cases. The value of preoperative normalization of intracranial pressure by insertion of a ventriculo-subcutaneous drainage is discussed.

Retrospectively we assessed the value of routine postoperative CT scans in 113 children shunted for hydrocephalus. Of the 165 routine CT scans 13 showed fortuitous findings (= 8%) with a change in treatment accompanied by questionable benefits in only 2 (= 1.3%). Therefore we suggest that post-operative CT should not be performed as a routine examination but only on clinical grounds.

In 7 patients with a brain tumor and intracranial hypertension treated by ventriculosubcutaneous drainage, intracranial pressure and cerebral perfusion pressure were continuously monitored during induction of anesthesia with fentanyl 1.5 micrograms/kg, propofol 2.5 mg/kg and vecuronium 0.1 mg/kg. End-tidal pCO2 was kept constant by manual ventilation and arterial pCO2 was verified before induction and before and after intubation. Five minutes after induction the patients were intubated and measurements continued for five more minutes. Mean arterial pressure decreased from 102 (+/- 9.8) mmHg to 57 (+/- 11.6) mmHg (p less than 0.01). Intracranial pressure did not change significantly before intubation. However in two patients intracranial pressure increased before intubation due to a significant rise in arterial pCO2. In 4 of the 7 patients an important increase to 25 (+/- 4.6) mmHg in intracranial pressure was observed during intubation. Cerebral perfusion pressure decreased from 88 (+/- 4.6) to 45 (+/- 9.8) mmHg (p less than 0.01) before intubation, but did not differ from the baseline during and after intubation. It is concluded that propofol 2.5 mg/kg in a bolus injection does not increase ICP but can produce a significant decrease of the cerebral perfusion pressure due to a marked decrease in mean arterial pressure in patients with a brain tumor.

Pseudoangiomatous dilatation of retromedullary veins at myelography was noted in three cases of intramedullary spinal cord tumours. This concerned two haemangioblastomas at levels Th8 and L1, respectively, and an ependymoma of the conus terminalis. MRI accurately demonstrated the tumoural mass, together with the enlarged and tortuous draining perimedullary veins. In patients with dilated vascular shadows on myelography, MRI should be performed before medullary angiography to differentiate between spinal vascular malformations and intramedullary tumours with enlarged draining veins.