Aspergillus infection originating in the nasal cavity or paranasal sinuses is a rare cause of benign, locally invasive disease affecting the skull base. We describe a case in which extensive disease led to bilateral proptosis and invasion of the anterior cranial fossa.

Aneurysms of the vertebrobasilar system carry relatively high operative mortality and morbidity due to their anatomical location. A variety of skull base techniques is described to improve access to these lesions and to reduce or abolish the need for retration on neurovascular structures. Surgical results are generally favorable and should encourage a more widespread application of these techniques in appropriate circumstances.

Until very recently the skull base and adjacent stuctures were only accessible as a result of severe and sustained brain retraction, which inevitably lead to increased postoperative neurovascular complications, often of a serious and permanent nature. It is a measure of the success of skull base surgery that many of these obstacles to a better outcome have been overcome by means of novel applications of operative techniques, some new, but, more often than not, extant already in the repertoire of disciplines not overtly concerned in transclivai penetration. The major spur to progress has been the evolution of team-work, without which much of this work would never have come to fruition. The conjunction of multiple disciplines to form teams, each bringing complementary expertise to bear on the tasks in hand, has created a tremendous impetus to the development of the complex techniques that are often necessary to achieve optimal exposure of the conditions involving the skull base. It is true to say that there are no areas of the brain's surface that are denied surgical access, thanks to these recent innovations. The revolution in radiological imaging techniques has been an enormous boon to students of this region. The combination of computerised transverse axial scanning (CT), and magnetic resonance imaging (MRI) has transformed our perceptions of tumour pathology and its consequences. Improved diagnosis has resulted in better patient management, and the imaging techniques are invaluable in charting postoperative progress, both in the immediate phase, and in the long term. The new angiographic MRI sequences have largely supplanted invasive angiography in studying the vascular relationships of skull base tumours, except where fine detail is still required, or embolisation is being considered, and, of course, in those cases where ballon occlusion may be necessary.

This is a review of 21 patients with meningiomas involving the region of the cavernous sinus. All underwent surgery, and the fronto-zygomatic (F-Z) approach, first described by Fujitsu and Kubawara, was employed in every case. The mean age at presentation was 47 years; seven patients were male and 14 female. The mean duration of symptoms before surgery was 4 years. In 10 patients, resection was considered to be complete. Peri-operatively there were two deaths, but the majority of deficits in the survivors were temporary and quickly resolved. The mean follow-up period was 48 months. In that time, five patients experienced recurrence or progression of tumour, of whom three required repeat operation (followed by radiotherapy); and two patients were referred for radiotherapy alone. These five patients appear to be disease-free 2-5 years after their additional treatment. Of the 19 patients who left hospital, 17 were able to live independent lives. It would appear from this review that: (1) F-Z craniotomy usually gives excellent exposure to the region of the cavernous sinus; (2) selected patients should undergo angiography with balloon occlusion to evaluate the collateral vascular supply; (3) regular review should include annual MRI. Evaluation over a much longer time of both surgery and radiotherapy, individually and in combination, is needed before it will be possible to furnish a treatment protocol for individual cases at initial presentation or recurrence.

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.

A small number of haemangiopericytomas (HPCs) are compared with a group of cases labelled as atypical meningiomas (AMs) extracted from our records over a 10-year period. There was close convergence between the two groups in terms of clinical presentation. Radiologically, they were quite different. HPCs subjected to angiography demonstrated a major vascular supply from branches of the internal carotid or vertebral arteries, whereas this was not a feature of the meningioma group. Half the HPCs arose from the lateral petrosal attachment of the tentorium; all the meningiomas were parasagittal. The HPCs did not prove to be more formidable technical challenges than the meningiomas: the operative blood loss was much the same in both. The same number of recurrences and deaths occurred in the two groups at approximately the same interval during the follow-up period, making both conditions equally grave in terms of prognosis.

One of the standard treatments for herniation of lumbosacral disc material has become the microdiscectomy. Although multiple studies have assessed the outcome of microdiscectomy, only a few studies have evaluated the outcome of those patients who have undergone a second microdiscectomy at the same location as the original one. The purpose of this study was to review 55 patients who, over a 4-year period, underwent a second microdiscectomy at the same location as their original operation and to evaluate those factors associated with improved outcomes. The results showed the overall outcome to include 86% with complete or partial relief of all pain symptoms; 88% with complete or partial relief of sciatica; 85% with complete or partial relief of back pain; 100% returning to work in an average of 7 weeks; and 89% were glad they had the second operation. Those factors without predictive value included age, sex, weight, height, level of operation, side of operation, surgeon at the first or second operation (e.g. consultant or junior staff), length of the first operation ( < or = 60 min or > 60 min) and duration of symptoms before the first operation. The key features centred on preoperative job status, the interval between recurrence of symptoms and the second operation, and the duration of the second operation ( < or = 90 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adults who have had repair of an open myelomeningocoele at birth are susceptible to a variant of adult onset tethered cord syndrome (ATCS). Precipitous and profound loss of lower extremity motor function occurred in two postrepair adult patients, but was not seen in any of our 12 cases of adult tethered cord with any other aetiologies. Both postrepair ATCS patients made a good recovery after surgical release of the tether. For the patients with other aetiologies, surgery yielded improvement or recovery of urinary continence in 57%, relief from pain in 78% and improved strength in 80%. Evidence of retethering was observed in 25% of the operated patients at intervals ranging from 1 to 9 years postoperatively. We conclude that surgical release of tether can reverse incontinence in ATCS of any aetiology and that in the post-myelomeningocoele repair patient, both dexamethasone and surgical intervention are helpful in reversing acute neurological deterioration.

The management of syringomyelia is often difficult because of its uncertain pathogenesis and the many therapeutic options available. Many procedures, including foramen magnum decompression, plugging the obex, and various shunting procedures are used with varying success rates. In order to assess both the symptomatic and anatomic responses to the placement of a shunt prior to more invasive placement of syringoperitoneal or syringopleural shunts, we have placed a shunt catheter via a Touhy needle into the syrinx cavity. This was done under local anaesthetic via percutaneous puncture with the patient in the prone position under screening in the X-ray suite. We have performed this procedure in four patients, in one twice. In all patients the symptoms improved. In one of these patients, after two temporary shunt placements, a permanent shunt was placed in situ percutaneously and tunnelled to the pleura. In a second of these patients a standard surgical syringopleural shunt was placed. In a third patient there was some improvement in symptoms but the patient did not wish a permanent shunt. In the fourth patient there was only a transient improvement in symptoms and his permanent shunt was found to be patent.

The surgical treatment of anteriorly placed aneurysms of the posterior circulation crries a high morbidity which is mainly due to their inaccessibility. This is partly due to the need to retract the brainstem and cranial nerves. An anterior approach theoretically avoids this and we have used a Le Fort 1 maxillotomy to approach ten of these aneurysms.

A long-term prospective study was carried out of 100 consecutive patients undergoing microlumbar discectomy (MLD) and fulfilling stringent selection criteria. A 95% long-term follow-up result was obtained at a mean duration of 8.6 years. At the 7-11-year assessment, 88% of patients had an excellent result, 5% a good result and 7% had either a poor result or new symptoms. Ten patients (10.5%) underwent repeat MLD during the course of the study; nine of the ten reoperations were performed at the same level as the original surgery. The percentage with an excellent result remained relatively constant (88-89%) throughout the study. No reliable predictors of long-term outcome were identified. The results suggest that microlumbar discectomy compares favourably with other surgical techniques with regard to long-term outcome.

Fungal infections including those due to aspergillus are rare in neurosurgical practice despite their possible inclusion in many differential diagnoses. Recently, these diseases have been diagnosed with increasing frequency, principally as opportunistic infections in patients undergoing treatment for diseases resulting in immune compromise. The epidemiology is poorly understood as mycoses are not notifiable diseases. We have recently been involved in the care of seven patients with aspergillosis between 1988 and 1991. Its presentation, with abscess formation, granulomas, the rhinocerebral form, meningitis, hydrocephalus and vascular involvement, is varied. The majority of cases were seen in immunocompromised patients following haematogenous dissemination from a pulmonary or gastro-intestinal focus. Direct spread from sinus infection has also been seen. The prognosis is poor despite modern antifungal treatment, which in part reflects the primary underlying condition.

Four giant prolactin-secreting tumours invading the skull base are described. All of them occurred in men. The presenting features were sufficiently diverse to be clinically misleading. We advocate the estimation of prolactin levels before embarking on complicated skull base surgery in men where doubt remains regarding the diagnosis after clinical and radiological study.

Malignant schwannomas are uncommon primary tumours of nerve sheath origin. They are rarely found within the spine and spinal canal, and little is known about their management in this unusual location. We describe the presentation of three patients with primary spinal malignant schwannomas and discuss the surgical management.

Titanium cranioplasty has been used in our unit for reconstruction of cranial defects following trauma, tumour resection and bone loss due to postcraniotomy infection. It has previously been assumed that imaging to assess recurrence of disease progression after cranioplasty would be severely compromised in the presence of metallic material. Titanium is a non-ferrous metal of low atomic number, which is relatively radiolucent and allows exceptionally clear images to be obtained without significant degradation of image quality, on CT and magnetic resonance (MR) imaging. Cases are presented that demonstrate the use of CT contrast cisternography and MR imaging after titanium cranioplasty. On the basis of its strength, biocompatibility and excellent handling characteristics, allied to its suitability for all post-operative imaging techniques, we conclude that titanium plate is the material of choice for cranioplasty.

Despite a reduction in the mortality of patients with brain abscess since the introduction of the computed tomography (CT) scanner, controversy persists as to the prefered method of treatment for this condition. Eleven patients were treated by CT guided stereotactic aspiration of pus and appropriate antibiotic therapy. A total of 14 aspirations were performed. Ten abscesses were supratentorial and one was in the posterior fossa.