Abducens (sixth) nerve palsy presenting as a rare case of isolated brainstem metastasis from a primary breast carcinoma

Most isolated abducens (sixth) nerve palsies are ischaemic in nature. However, there are other causes that can mimic an abducens nerve palsy, which requires aggressive diagnostic management. A 56-year-old hypertensive woman presented with a right abduction deficit. Her past history revealed that she had undergone a mastectomy and completed a course of chemo- and radiation therapy for breast carcinoma. She was well until she develped binocular diplopia five months later. Magnetic resonance imaging showed a right pontine mass. Stereotactic biopsy was performed, and histopathology revealed a metastatic carcinoma that was compatible with an origin from the breast primary. We conclude that identifying and managing patients with metastatic lesions involves a multidisciplinary approach. Thorough history-taking and neuro-ophthalmologic evaluation would help physicians in establishing the primary differentials, which could not only be sight-saving but life-saving as well.

Breast and ovarian recurrence of acute lymphoblastic leukaemia after allogeneic peripheral blood haematopoietic stem cell transplantation

Breast recurrence of acute lymphoblastic leukaemia (ALL) after stem cell transplant is uncommon, with less than 20 reported cases in the literature. In the majority of cases, the lesions developed without simultaneous involvement of other sites or graft-versus-host disease (GvHD). We describe the first case of simultaneous bilateral breast and ovarian relapses after allografting in ALL, occurring in an 18-year-old female Chinese patient while she was having oral and hepatic chronic GvHD, persistent haematological remission and donor haematopoiesis. She received radiotherapy and chemotherapy, which resulted in resolution of the breast and ovarian lesions, and remained disease free ten months after the onset of the relapse. This case suggests that there may be different mechanisms for bone marrow vs. extramedullary relapses and a complex relationship between GvHD and graft-versus-leukaemia.

Optic neuritis in Singapore

INTRODUCTION

Optic neuritis (ON) is the commonest optic neuropathy encountered in the younger group of patients from the Singapore Neuro-Ophthalmology Study Group. Previous surveys in Asia and our study suggest that ON in Singapore differs from that in Western populations where the majority of cases are associated with multiple sclerosis (MS).

METHODS

Patients satisfying our entry criteria for ON seen between September 2002 and June 2004 were enrolled in the study. The data collected was recorded in a central database and analysed two years later.

RESULTS

The majority (60 percent) of our patients had anterior ON with optic disc swelling (papillitis), were idiopathic in 49.1 percent, and associated with MS in only 25.5 percent. Bilateral cases comprised 16.4 percent of our series and were usually of the anterior variety and mostly idiopathic, although it is still essential to rule out secondary causes. Recurrent ON is indicative of an underlying disease process.

CONCLUSION

The pattern of ON as seen in Singapore differs from that reported in Caucasian studies and from the seminal Optic Neuritis Treatment Trial. We found a higher incidence of optic disc swelling, i.e. anterior ON (papillitis), and a lesser association with MS; visual recovery is similarly good but our recurrence rate is lower.

Isolation of purified autologous peripheral blood CD34+ cells with low T cell content using CliniMACS device--a local experience

INTRODUCTION

Peripheral blood stem cells (PBSC) mobilised with growth factor with or without chemotherapeutic regimens, are used increasingly in both autologous and allogeneic transplantation. Previously, many PBSC harvests are used directly without ex vivo manipulation, and these PBSC have been shown to be contaminated with tumour cells, which may contribute to subsequent relapses post transplantation. Therefore, requirement for purging of malignant cells from the harvest has initiated the use of various methods to reduce tumour cell contamination of the graft by the positive selection of CD34+ progenitor cells or negative selection of tumour cells using other cell-specific antigens. We report here our local experience with the CliniMACS (magnetic-activated cell separation system) in eight adult patients with haematologic malignancies.

OBJECTIVE

To evaluate the purity, recovery and viability of CD34+ cells selected from harvested peripheral blood stem cells using the CliniMACS device, as well as to evaluate the T and B cell contents of these products.

METHOD

Eight adult patients with malignant haematological diseases (5 non-Hodgkin's lymphomas in 2nd complete remission (CR) and 3 acute myeloid leukaemias in 1st CR) were mobilised with granulocyte colony-stimulating factor (G-CSF) with or without chemotherapeutic regimens. A total of nine leukaphereses for peripheral blood stem cell harvest using the Cobe Spectra cell separator (Cobe BCT Lakewood, CO) were performed. The harvested PBSC were then positively selected for CD34+ cells using the CliniMACS device (Milteny Biotech, Germany).

RESULTS

A total of nine leukapheresis products from eight adults with a median pre-selection total CD34+ cell count of 282.2 x 10(6) (range 103.7 - 738.2 x 10(6)) were positively selected with CliniMACS. The median post-selection total CD34+ cell count was 99.5 x 10(6) (range 7.7 - 443.9 x 10(6)) with the median recovery was 66.0% (range 2 - 94%) and median purity of products of 79% (range 18 - 86%). The median total T cell count was reduced dramatically from 3.1 x 10(9) pre-selection to 7.9 x 10(6) post-selection. The selection did not affect the viability of selected cells that was tested with trypan blue exclusion method with a median pre and post selection viabilities of 98% (range 95 - 98%).

CONCLUSION

We conclude that positive selection of CD34+ cells using magnetic separation technology by CliniMACS device results in low T-cell content stem cell with acceptable purity and recovery for autologous peripheral blood stem cell transplantation.

Incidence of upper limb venous thrombosis associated with peripherally inserted central catheters (PICC)

The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).

The use of mycophenolate mofetil in treating patients with non responding aplastic anemia

Aplastic anemia is a relatively uncommon disease and conventional management options include immunosuppressive drugs and/or haematopoeitic stem cell transplantation. It is now known that the pathogenesis of aplastic anemia is immune mediated. Mycophenolate mofetil is a common immunosuppressive drug now used mainly in prophylaxis of graft rejection in organ transplant and also for prevention/treatment for graft versus host disease in haemtopoeitic stem cell transplantation. It is thought that mycophenolate mofetil may be useful in this group of patients. In this short report, mycophenolate mofetil was tried in 6 patients who had severe aplastic anemia with variable doses for a minimum duration of 9 months. The result has however not been encouraging.

A case of T-cell acute lymphoblastic leukemia after treatment of acute promyelocytic leukemia

We diagnosed T-cell acute lymphoblastic leukemia (T-ALL) with multiple cytogenetic abnormalities in a 17-year-old girl a year after she had received a diagnosis of acute promyelocytic leukemia (APML). After the diagnosis of APML in June 2001, the patient was treated with idarubicin and all-trans-retinoic acid. In September 1999, her younger sister also received a diagnosis of APML and to date has remained well. T-ALL after remission of APML is very rare, and only 1 such case has been reported. Possible causes include therapy-related reasons, genetic susceptibility to leukemia, and environmental exposure.

Successful peripheral blood stem cell mobilisation with filgrastim in patients with chronic myeloid leukaemia achieving complete cytogenetic response with imatinib, without increasing disease burden as measured by quantitative real-time PCR

Imatinib mesylate (Glivec) is a selective inhibitor of bcr-abl tyrosine kinase, the product of the Philadelphia chromosome, which is the hallmark of chronic myeloid leukaemia (CML). With imatinib, complete cytogenetic response (CCR) can be achieved in over 70% of newly diagnosed patients with CML. However, the optimal long-term management of patients who achieve CCR after imatinib is unknown. With longer follow-up, it is anticipated that some patients are likely to progress and become candidates for autologous transplantation. We studied filgrastim (r-metHuG-CSF) mobilisation of peripheral blood stem cells (PBSC) in 32 patients who have achieved CCR with imatinib. Our data demonstrate that (1) the target CD34(+) cell yields of >/=2.0 x 10(6)/kg were attained with filgrastim 10 microg/kg/day, in 9/18 (50%) of patients during uninterrupted imatinib therapy, and in 10/14 (70%) when imatinib was temporarily withheld. The median CD34(+) cell yield per aphaeresis was 0.70 x 10(6)/kg (range 0.14-2.18) and 2.90 x 10(6)/kg (range 0.15-8.71) in the two groups, respectively (P&<0.005). (2) The cell yields did not correlate with the duration of imatinib administration. (3) There was no impact of the mobilisation procedure on the level of leukaemia as measured by serial blood bcr-abl levels using real-time quantitative PCR with either protocol. (4) bcr-abl remained detectable at low levels in the harvests in most but not all patients. In conclusion, filgrastim can safely be used to mobilise PBSC in patients who have achieved CCR with imatinib, but CD34(+) cell yields are significantly improved when imatinib is temporarily withheld.

Non-sporulating Chrysosporium: an opportunistic fungal infection in a neutropenic patient

We report a case of an invasive infection with non-sporulating Chrysosporium species in a patient who was treated with chemotherapy for relapsed acute lymphoblastic leukemia. This patient presented with a persistent lobar pneumonia, skin lesions, and possible involvement of the central nervous system. The patient responded to treatment with amphotericin B and oral itraconazole.

The role of early tracheostomy in critically ill neurosurgical patients

OBJECTIVE

To determine the value of early tracheostomy (within 7 days) in ventilated neurosurgical patients.

METHODS

Retrospective review of intubated patients in the neurosurgical intensive care unit (NICU) who underwent elective open tracheostomies for prolonged ventilation.

RESULTS

Thirty patients over a 2-year period were analysed. There were 19 males and 11 females, mean age 53.9 +/- 18.1 years (range 14 to 89), and mean Glasgow Coma Scale (GCS) score on admission 7.1 +/- 3.8 (range 3 to 15). The underlying disease aetiology was cerebrovascular disease in 53% of patients, head trauma in 33% and tumour or infection in 13%. Tracheostomy was performed after a mean period of 8.5 +/- 3.5 days (range 2 to 18), with patients requiring ventilation for a mean duration of 13.5 +/- 6.3 days (range 3 to 31). Complications were minimal; 1 wound infection (3.3%) and 4 tube obstructions (13.3%). Patients who underwent elective early tracheostomy (Group 1 = within 7 days) had poorer GCS on admission (6.3 +/- 2.9 versus 7.7 +/- 4.3 in Group 2, P = 0.271). Tracheostomy was performed after a mean of 5.3 +/- 1.7 days in Group I vs. 10.6 +/- 2.7 days in Group 2. Group 1 patients had faster recovery from nosocomial pneumonia (12.3 +/- 6.2 versus 17.9 +/- 12.5 days, P = 0.168), shorter duration of ventilation (9.8 +/- 5.9 versus 16.0 +/- 5.4 days, P = 0.007), and reduced incidence of multibacterial tracheobronchial colonisation (42% versus 72%, P = 0.098). The most prevalent organisms were Acinetobacter baumanii (43.3%), Pseudomonas (40%), methicillin-resistant Staphylococcus aureus (MRSA) (33%), Klebsiella (30%) and Staphylococcus aureus (26.7%).

CONCLUSION

Early tracheostomy in selected neurosurgical patients with poor GCS scores was associated with reduced incidence of tracheobronchial colonisation by multiple pathogens, improvement in chest infections, and rapid weaning from ventilatory support.

An unusual case of traumatic intracranial hemorrhage caused by wakeboarding

Wakeboarding is a relatively new and exciting sporting activity which is similar to water-skiing. While there have been several reports of water-skiing-related injuries, there has been nothing reported in the literature so far concerning injuries in wakeboarding. We present the case of a 14-year-old male who sustained an unusual intracranial subdural hemorrhage while wakeboarding and postulate on the mechanisms which could have resulted in the injury.

Is decompressive craniectomy for acute cerebral infarction of any benefit?

BACKGROUND

Acute occlusion of the major cerebral arteries results in ischaemic changes to the brain, without time for reperfusion by the collateral circulation. The subsequent cellular events lead to a breakdown of the blood-brain barrier, causing malignant cerebral edema manifested clinically by a rapid neurological deterioration. The aim of this study was to determine the value of surgical decompression in patients who present with acute cerebral infarction.

METHODS

Retrospective review of patients with deteriorating consciousness level from massive cerebral ischemia and secondary edema, treated by decompressive craniectomy. RESULTSThere were 10 patients over a 2-year period from 1997-99, consisting of seven male and three female patients (mean age 47.56 years) with a mean preoperative Glasgow Coma Scale (GCS) score of 6/15. Three patients had dominant middle cerebral artery (MCA) infarction, four had nondominant MCA infarction, one had posterior cerebral artery infarction, and the remaining two had cerebellar infarction. At a mean follow-up period of 7 months, two patients had died (20% mortality), four patients (40%) were vegetative or severely disabled, and the remaining four patients (40%) had mild disability or good outcome. Favorable prognostic factors were younger age (less than 50 years) and good initial GCS score (14 or better).

CONCLUSION

Decompressive craniectomy in the setting of acute brain swelling from cerebral infarction is a life-saving procedure and should be considered in younger patients who have a rapidly deteriorating neurologic status.

Giant cell arteritis causing bilateral sequential anterior ischaemic optic neuropathy--a case report

Giant cell arteritis is a chronic granulomatous inflammation of unknown aetiology involving large and medium size arteries in the elderly. It causes acute visual loss from ischaemia to the optic nerves or central retinal artery occlusion. This is a rare cause of anterior ischaemic optic neuropathy in our local population. We present a patient who had bilateral loss of vision from sequential arteritic ischaemic optic neuropathy. She was treated with intravenous steroids immediately. Diagnosis was based on histopathological studies of temporal artery biopsies.

Sympathetic storms in a child with a midbrain glioma: a variant of diencephalic seizures

The authors report the unusual case of a 7-year-old child, one of the youngest reported to date, who developed repeated episodes of sympathetic hyperactivity after surgical resection of a midbrain glioma. These paroxysmal events were similar to previously described diencephalic seizures. However, there was no evidence of epileptogenic activity on electroencephalography, and radiologic imaging did not reveal hydrocephalus or intraparenchymal hemorrhage. In this report, clinical features are described of this patient, along with the novel use of clonidine--a sympathetic blocking agent--in his treatment, published reports are reviewed on diencephalic seizures, and steps are recommended in the treatment of a patient who presents in this manner. The authors believe that diencephalic seizures can present with a spectrum of autonomic features, and treatment should be tailored with the appropriate pharmacologic blockade.

Recombinant tissue plasminogen activator for the treatment of spontaneous adult intraventricular hemorrhage

BACKGROUND

Intraventricular hemorrhage (IVH) has a poor prognosis with mortality rates of between 80 and 100% when all four ventricles are involved. Fibrinolytic therapy has been reported to improve overall outcome.

METHODS

Patients with severe primary IVH were treated by direct intraventricular injection of recombinant tissue plasminogen activator (rt-PA) into the lateral ventricles, followed by cerebrospinal fluid (CSF) drainage if the intracranial pressure rose above 20 mm Hg.

RESULTS

Over a 15-month period from 1995 through 1996, 10 patients were treated, (4 male and 6 female, mean age 35 years; range, 21-55 years). The mean Glasgow Coma Scale score on admission was 6 (range, 4-8) and the mean Graeb score for severity of IVH on the first CT scan was 10 (range, 8-12). Angiography was negative in five cases but identified arteriovenous malformations in three, a post-traumatic pseudoaneurysm in one, and Moya-moya disease in one. The mean total dose requirement of rt-PA was 8.25 mg (range, 6-12 mg) with a significant reduction in the mean Graeb score after 7 days to 3.9 (range, 2-7, p<0.0001). Outcome at 3 months was death in one case (mortality 10%), severe disability in two (20%), moderate disability in three (30%), and good result in four (40%). Four patients (40%) required subsequent CSF shunting. No complications of rehemorrhage, infection, or catheter obstruction were encountered.

CONCLUSION

Intraventricular fibrinolysis with rt-PA seems to be safe and effective for the treatment of severe IVH.

Intramedullary spinal cord ependymomas in children: treatment, results and follow-up

A retrospective review of 20 pediatric patients with intramedullary spinal cord ependymomas, all of whom underwent operative resection between 1985 and 1996, was undertaken to determine surgical results, long-term follow-up and tumor recurrence. Twelve children operated on in the same period with filum or cauda equina ependymomas were not included in this study. Nine children had had previous treatment before referral. Gross total resection was achieved in 14 patients and subtotal in 6. None of these had a post-operative radiation therapy. The median follow-up period was 67 months (range 25-177 months). All children were clinically evaluated before and after operation and at the last follow-up. The clinical grade at the last follow-up showed improvement in 8 patients (40%), was unchanged in 10 (50%) and deteriorated in 2 (10%). Three patients had a recurrence, 2 at the primary site (2 and 3 years after our surgery) and 1 at a distant site (3 years after). The actuarial 5- and 10-year survival rates were both 90%; 5- and 10-year progression-free survival rates were 93 and 70%, respectively. We conclude that a complete removal can be achieved in almost all cases of intramedullary spinal cord ependymomas in children, and that the long survival rates justify avoiding post-operative radiation therapy.

Intraparenchymal clear cell meningioma of the brainstem in a 2-year-old child. Case report and literature review

We report an unusual case of an intraparenchymal clear cell meningioma of the brainstem, occurring in a 22-month-old girl. She presented with bulbar dysfunction and a right hemiparesis due to an intrinsic tumor of the medulla, which was confirmed by radiologic imaging to be focal and with an exophytic component. At surgery, a partial resection was achieved and no dural attachment was found. Pathologic examination revealed a clear cell meningioma. In reviewing the literature, there have been fewer than 20 reported cases of clear cell meningioma, none of which were intraparenchymal, involved the brainstem or occurred in such a young patient. The pathologic findings, treatment options and present understanding of this tumor are discussed.

Haemostatic changes during surgery for primary brain tumours

OBJECTIVE

Primary brain tumours may be associated with coagulation disorders which can pose intraoperative and postoperative management difficulties. The aim was to evaluate the coagulation profile of patients with brain tumours undergoing surgery using thromboelastography (TEG) in combination with simple laboratory tests.

METHODS

Fifty adult patients with primary brain tumours larger than 4 cm in maximum diameter and no history of coagulation disorders were studied in a prospective, observational manner over a one year period. Preoperative, intraoperative, and postoperative measurements included haemoglobin concentration, platelet count, prothrombin and partial thromboplastin times, fibrin(ogen) degradation product concentration, D-dimer concentration, and TEG.

RESULTS

Eleven patients (22%) had abnormal intraoperative TEGs, of whom six (12%) subsequently developed haematomas requiring surgical evacuation. The coagulopathy seemed to be hyperfibrinolysis in two cases (4%) and disseminated intravascular coagulation in four (8%). There was no preoperative difference in reaction time (R time) for clot formation between the non-haematoma and haematoma groups(mean 11.44 (SD 3.42) v 12.33 (2.50) min, P=0.46). However, when other preoperative indices were compared, in the non-haematoma group, K time (time to reach a clot amplitude of 20 mm) was shorter (6.72 (2.15) v 10.56 (3.50) min, P=0.001), rate of clot growth (å) was faster (43.67 degrees (7.53) v 27.11 degrees (5.42), P<0.0001) and maximum amplitude of clot strength (MA) was greater (52.64 (7.85) v 40.33 (6.59) mm, P<0.001). Intraoperatively, R time was significantly shortened in the non-haematoma group, (7.67 (1.78) min, P<0.0001) unlike the haematoma group (10.67 (1.58) minutes, P=0.11).

CONCLUSIONS

Although these results indicate a general hypercoagulability during brain tumour surgery, in certain cases, a predisposition towards hypocoagulability may exist even before surgery, detectable only when the physical characteristics of clot formation are studied by TEG. Judicious replacement of clotting factors, platelets, and antifibrinolytic agents should be considered intraoperatively if the TEG is abnormal, without waiting for laboratory test results.

Does teleradiology improve inter-hospital management of head-injury?

OBJECTIVE

In many countries, neurosurgical care is concentrated in regional centres, which often necessitates the inter-hospital transfer of patients with head injury for optimal treatment. The aim of this study was to evaluate the role of teleradiology in the management of head-injured patients when-referred from a district general hospital to a tertiary neurosurgical centre.

METHODS

Prospective data were collected over a fifteen month period from March '95 to May '96. Head-injured patients referred without the facility of teleradiology (Group 1), were compared to similar patients referred with teleradiologic images (Group 2), with particular regard to therapeutic intervention before transfer and adverse events during transfer.

RESULTS

There were 28 patients in Group 1 and 35 in Group 2, of which 31 were transferred. Both groups were comparable with respect to age, admission Glasgow Coma Scale score, and intracranial pathology. For patients transferred with teleradiology consultation (Group 2), therapeutic interventions were more (32.1% vs. 10.7%, p = 0.06), adverse events during transfer were significantly lower (6.4% vs. 32.1%, p = 0.01), and transfer time was reduced (72 vs. 80 minutes, p = 0.38). Four patients in Group 2 were treated by a mobile neurosurgical team at the referring hospital because of rapid clinical deterioration.

CONCLUSION

Our findings indicate that teleradiology has an important role in improving inter-hospital management of head-injured patients.

Pediatric intramedullary spinal cord tumors: is surgery alone enough?

Pediatric intramedullary spinal cord tumors occur infrequently with limited data on treatment strategies and outcome. Over an 11-year period, 44 patients with such tumors who were primarily managed by radical surgery were retrospectively reviewed. The majority of tumors (42/44, 95%) were in the cervical or thoracic spine and were histologically low grade. Gross total resection was achieved in 73% (32/44). At a median follow-up of 45 months, 11% (5/44) had severe weakness (modified McCormick scale IV-V), 66% (29/44) had mild-moderate deficits (I-III), and 16% (7/44) had sphincter dysfunction. Tumor recurrence rate was 18% (8/44) after a mean period of 54 months. Age, number of involved spinal cord segments and extent of surgical resection did not significantly impact on tumor recurrence rates (p = 0.28, 0.44 and 0.13, respectively). The only significant prognostic factor was histological type; mixed or higher grade tumors having a higher recurrence rate (p = 0.04). Radical surgery for intraspinal tumors can achieve long tumor-free survival without requiring adjuvant therapy.

Is routine computed tomographic (CT) scanning necessary in suspected basal skull fractures?

The aim of this prospective observational study was to assess the yield of routine fine-cut computed tomographic (CT) scans in patients with suspected basal skull injuries. Over an 8 month period in 1994, 500 consecutive head-injured patients were examined for clinical signs of basal skull fracture and underwent fine-cut (5 mm) CT scans through the skull base in addition to standard (10 mm) cuts through the vault. Clinical signs were present in 144 patients (144/500, 28.8 per cent) of which 75 (75/144, 52 per cent) had corresponding CT evidence of fracture. A further 22 patients (22/500, 4.4 per cent) had no clinical signs but fractures were seen on CT. The presence of cranial nerve injury, cerebrospinal fluid leak, epistaxis, periorbital bruising, and two or more signs, were more likely to be associated with positive CT scans (P < 0.001, chi 2 tests). The incidence of associated mass lesions was 50.5 per cent, of which 55.1 per cent required craniotomy. This was significantly higher than in patients without evidence of skull base fracture (16.6 per cent) (P < 0.001, chi 2 27.165). Six patients, two of whom had meningitis, required surgical repair of the dural defects seen on CT. The diagnostic yield of routine fine-cut CT scans in this sub-type of head injury is 52 per cent, and is of value in detecting associated mass lesions or significant dural defects which may require surgical intervention.

Optic nerve sheath fenestration for pseudotumor cerebri

The objective of the study was to determine the efficacy of optic nerve sheath fenestration (ONSF) in eyes with progressive visual or field loss in pseudotumor cerebri in spite of medical therapy with oral Diamox. Visual data on 29 eyes of patients with pseudotumor cerebri who underwent ONSF at Bascom Palmer Eye Institute from 1987 to 1995 were studied retrospectively. These patients had progressive visual loss despite medical therapy. Visual acuity and fields were compared before and after surgery (within 1 and 6 months). During a mean follow-up of 15.7 months (range, 1-50 months), visual acuity improved in four eyes (14%), was unchanged in 22 (76%) eyes, and worsened in three (10%) eyes. Visual fields improved in 10 (48%) eyes, remained unchanged in eight (38%) eyes, and worsened in three (14%) eyes (six were lost in long-term follow-up). There were four repeat surgeries in which vision was lost in one eye. Data from these patients indicate that ONSF improves or protects visual function in patients with pseudotumor cerebri who experience deteriorating visual acuity and fields in spite of medical therapy.

Cloverleaf skull--when should one operate?

Cloverleaf skull or kleeblattschadel usually occurs as a result of premature closure of the cranial sutures, with accompanying hydrocephalus, proptosis, cranial base and midface hypoplasia. The incidence of this abnormality is rare, with less than 130 reported cases in the literature, and is associated with various congenital syndromes. Conventional surgical management advocates shunting prior to definitive craniotomy and bone remodeling. We report an unusual case of Pfeiffer syndrome with associated cloverleaf skull deformity, in which early surgery was vital for decompression of raised intracranial pressure and shunt independence for the first six months. A secondary craniofacial procedure was performed at nine months of age to improve cosmesis. In such cases, good outcome can be achieved if aggressive surgery is combined with good paediatric anaesthesia and intensive care.

Intracranial vascular calcifications, glioblastoma multiforme, and lead poisoning

A 72-year-man with previous lead poisoning presented with raised intracranial pressure and localizing neurologic signs. CT scans showed a high-grade glioma and extensive intracranial calcifications, which proved to be vascular in distribution on postmortem examination. The latter findings support the concept of dystrophic calcification following lead-induced cerebrovascular injury. Lead poisoning should be considered in the differential diagnosis of unexplained intracranial calcifications. There is also evidence from previous studies to suggest a causative relationship between lead poisoning and development of glioma.

Pseudomyopia in a patient with blocked ventriculo-peritoneal shunt--a case report

Accommodative spasm usually encompasses a classical triad of pseudomyopia, esodeviation and pupillary constriction. Accommodative spasm is most often psychogenic in nature; however, it may be associated with other organic diseases of which a rare cause is that of intracranial catheter complications. We report a case of dorsal midbrain syndrome with pseudomyopia in a patient with a blocked ventriculo-peritoneal shunt inserted for aqueductal stenosis. Clinical presentation was unusual in this patient as pseudomyopia occurred with exodeviation and without pupillary constriction.

Orbital color Doppler imaging in nonischemic optic atrophy

PURPOSE

The authors studied the orbital hemodynamics of patients with nonvascular and nonglaucomatous optic neuropathy.

METHODS

The authors performed orbital color Doppler imaging on 19 eyes of 10 patients with compressive, inflammatory, toxic, or hereditary optic neuropathy. The peak systolic velocity (PSV), end diastolic velocity (EDV), and Pourcelot's resistivity (PR) index of the central retinal, temporal short posterior ciliary, nasal short posterior ciliary, and ophthalmic arteries were assessed. Statistical comparison of these values was performed against ten normal controls of similar age and gender using the two-sample Student's t test.

RESULTS

No statistical significance was found in the PSV, EDV, and PR of the central retinal, temporal short posterior ciliary, nasal short posterior ciliary, and ophthalmic arteries between the optic atrophy and control groups and analysis of 95% confidence intervals for these variables suggested that the tru differences between these groups were small.

CONCLUSIONS

This study suggests that optic atrophy in and of itself does not appear to alter orbital hemodynamics to the extent previously demonstrated for glaucoma patients.

The impact of teleradiology on the inter-hospital transfer of neurosurgical patients

The aim of this study was to examine the role of teleradiology in the management of inter-hospital transfer of neurosurgical patients, especially in terms of safety and early therapeutic interventions. Data were collected prospectively, comparing events during the inter-hospital transfer of patients from a district general hospital to a tertiary neurosurgical centre, before and after teleradiology became available. From March to December 1995, 50 referrals made without teleradiology were compared with 66 referrals after teleradiology installation. Our results showed that for patients referred with teleradiologic images, unnecessary transfers were reduced (21%), more therapeutic measures before transfer were implemented (27% vs 20%, p = 0.41), adverse events occurring during transfer were significantly reduced (8% vs 32%, p = 0.002), and transfer time was shortened (72 min vs 80 min, p = 0.38). The potential advantages of this system in facilitating safer transfers and faster management of neurosurgical emergencies therefore merit further attention.

Features of pediatric head injury in Hong Kong

Head injury in children causes special concern in most communities. From 1989 to 1994, 2,785 children younger than 16 years old were admitted to our neurosurgical service because of head injury. Fall from a height was the major cause of head injury leading to admission in infants and children in preschool age groups, whereas traffic-related or bicycle-related accidents were more likely to be the cause of head injury for those aged 11-15 years. In all age groups there was a male preponderance. The overall mortality was 0.6%. Traffic-related accidents caused more severe injury and accounted for 67% of all fatalities. For patients under 6 years old, about 40% of head injuries occurred at home. Preventive measures for pediatric head injury in Hong Kong are suggested.

Water and sodium disorders following surgical excision of pituitary region tumours

A prospective observational study of the pathophysiology of sodium and water disorders in patients with pituitary region tumours after surgical excision was carried out in 20 patients. Serial pre-operative and post-operative fluid and sodium balance, plasma and urine elctrolyte biochemistry and their derived parameters, and circulating hormones associated with fluid balance, atrial natriureic peptide (ANP) and antidiuretic hormone (ADH) were documented to correlate with the patients' clinical conditions. Ten out of these twenty cases developed diabetes insipidus (DI) requiring ADH replacement therapy, although in the majority (6 cases), this way only a transient event. Of the nine patients who developed hyponatraemia, six had symptoms such as impaired consciousness and convulsions. Four patients developed alternating hypoatraemia and hypernatraemia, which constituted a difficult group, where appropriate sodium and fluid management, and ADH replacement therapy were based upon twice daily plasma and urine biochemistry and their derived parameters. Whilst DI in this group of patients was the result of a low circulating ADH level, hyponatraemia was not associated with an exaggerated ADH activity (6.0 +/- 2.3 vs 7.4 +/- 2.3 pmol/ml, mean +/- SEM). Rather, hyponatraemia was strongly associated with an elevated circulating ANP concentration (82.4 +/- 10.5 vs 30.0 +/- 3.1 pmol/ml, mean +/- SEM, p < 0.001), resulting in salt wasting and hypovolaemia.

Traumatic chiasmal syndrome: a feature photograph

Traumatic chiasmal neuropathy results from injury to the face, sphenoid and clivus. Its pathogenesis remains enigmatic. Because of its close relationship to the pituitary gland, hypothalamus and internal carotid artery, a neuro-ophthalmic evaluation and imaging is needed in such cases. We present a patient who developed traumatic chiasmal syndrome after an automobile accident. Computed tomographic scan showed fracture of the sella turcica. A carotid angiography showed a traumatic pseudoaneurysm of the internal carotid at the base of the skull.

Head injuries in Vietnamese refugees in Hong Kong

The Vietnamese refugee camps in Hong Kong represent a unique social situation, where as many as 55 000 people have at one time lived. The Neurosurgical Division of the Prince of Wales Hospital receives all head injured patients from two of the largest camps for management. A retrospective analysis was undertaken of all Vietnamese patients hospitalised with head injuries over a four year period from January 1990 to December 1993. Our results showed that there was a higher incidence of head injuries as compared to epidemiological studies in the USA (Marshall, 1981) and Britain (Jennett, 1981), with the highest risk group being children aged 12 years and below. The majority of head injuries were minor, with the most common cause being a fall from bed. With these findings, appropriate preventive measures were advised and steps were taken to reduce the incidence of head injuries amongst the Vietnamese children.

A hospital based audit of tuberculosis deaths

An audit was done on 54 tuberculosis patients presenting to Penang Hospital who died during 1993. Active tuberculosis was the cause of death in 29 (53.7%) and 48.3% were aged under 50 years. Tuberculosis was a contributory cause of death in 8 patients and in 17 patients tuberculosis was irrelevant to the cause of death. The diagnosis of tuberculosis was made after death in 17 patients (31.5%). Late diagnosis was the most important factor resulting in death. Only 41.4% of the deaths from active tuberculosis were correctly certified in government hospitals. Medically inspected and certified deaths from tuberculosis is an unreliable indicator of tuberculosis mortality because of inaccuracies in death certification, tuberculosis deaths occurring outside hospital and tuberculosis patients undiagnosed until after death.

Children's head injuries in the Vietnamese refugee population in Hong Kong

All Vietnamese patients with head injuries from two of the largest refugee camps in Hong Kong are routinely referred to the Neurosurgical Unit of the Prince of Wales Hospital for management. In order to determine the epidemiology of head injuries in this population group, we have retrospectively reviewed all hospitalized cases over a 4 year period from January 1990 to December 1993. We have found a unique social situation in this population group, with an unusually high proportion of paediatric cases (2253 per 100,000 children aged 5 years or less), compared with other epidemiological studies. The most common mechanism of injury in between 57 and 75 per cent of cases was a fall from bed. Based on this information, appropriate preventive measures have been recommended and have successfully decreased the incidence of head injuries. This study demonstrates the value and effectiveness of epidemiological studies in identifying a previously unrecognized health risk in a specified population group.

Does thrombolysis affect the prognostic value of the post-infarct exercise test?

There has been some debate on usefulness of the exercise test in risk stratification after myocardial infarction in the thrombolytic era. This was assessed in 295 patients of whom 184 were treated with thrombolysis. Each had an exercise test using a modified Naughton protocol within 14 days of acute myocardial infarction. The tests were graded as high risk positive (112), low risk positive (83), or negative (100). These gradings predicted use of multiple drug therapy (p = 0.05), severity of coronary artery disease (p < 0.01), and coronary artery bypass grafting (p < 0.01). There was no influence on heart failure, recurrent myocardial infarction or death. This was independent of the use of thrombolytic therapy. The whole group had a good prognosis with a mortality of 2.4% after 56 weeks' follow-up. The exercise test is still a useful screening test after myocardial infarction. In this study, there was a high negative predictive accuracy of 91% for any event. Its use is not altered by thrombolysis. The finding of a lack of influence of the exercise test on major events may be a reflection of the current good prognosis after myocardial infarction and the prompt use of revascularisation.

Optic nerve sheath meningioma--report of three cases

Meningiomas involving the optic nerve and the anterior visual pathways have intrigued neurosurgeons, neurologists and ophthalmologists for more than a century. They may present with the classical triad of progressive painless visual loss, optic atrophy and opto-ciliary bypass vessels. Optic nerve sheath meningiomas are most frequently diagnosed radiologically and lately, magnetic resonance imaging has greatly improved their visualisation. Surgical removal to preserve vision has met with dismal results. We present three patients with optic nerve sheath meningiomas which were diagnosed based on radiological findings. One had improvement in her visual acuity after external beam irradiation. Another had the tumour excised by a neurosurgeon. The last patient absconded follow-up and returned with no deterioration in her visual acuity after three years.