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Object: Traditionally, access to the posterior fossa involved a suboccipital craniectomy. More recently, posterior fossa craniotomies have been described, although the long-term benefits of this procedure are not clear. The authors compared the postoperative complications of craniectomies and craniotomies in children with posterior fossa tumors., Methods: From a total of 110 children undergoing surgery for posterior fossa tumors, 56 underwent craniectomy and 54 had a craniotomy. The mean duration of the hospital stay was longer in the craniectomy group (17.5 compared with 14 days). At operation, similar numbers of patients in both groups had total macroscopic clearance of the tumor, complete dural closure, and duraplasty. Postoperatively, more patients in the craniectomy group were noted to have cerebrospinal fluid (CSF) leakage (27 compared with 4%; p < 0.01) and pseudomeningoceles (23 compared with 9%; p < 0.05). There was no significant difference between the two groups in the numbers of patients with CSF infections, wound infections, or hydrocephalus requiring permanent CSF drainage. Patients with CSF leaks had a longer duration of hospital stay (20.7 compared with 14.9 days; p < 0.01), and were more likely to have CSF infections (35 compared with 12%; p < 0.01) and wound infections (24 compared with 1%; p < 0.01) than patients without CSF leaks. Postoperatively, wound exploration and reclosures for CSF leakage were more likely in the craniectomy group (11 compared with 0%; p < 0.01). Multivariate analysis revealed that the only predictor of CSF leakage postoperatively was the type of surgery (that is, craniotomy compared with craniectomy; odds ratio 10.8; p = 0.03)., Conclusions: Craniectomy was associated with postoperative CSF leaks, pseudomeningocele, increased wound reclosures, and thus prolonged hospital stays. In turn, CSF leakage was associated with infections of the CSF and wound. The authors propose mechanisms that may explain why CSF leakage is less likely if the bone flap is replaced.

SPECT can be used to image regional cerebral blood flow (rCBF) and has been shown to help localize the seizure focus in partial epilepsies as part of the presurgical evaluation. Few studies have explored the possible relation between preoperative SPECT and underlying pathology, or any relation to postsurgical outcome. In this study preoperative ictal and interictal rCBF in relation to the histopathological diagnosis and outcome in a series of 35 children (24 females, 11 males; mean age 9.6 years, age range 11 months to 18 years) who had undergone resective surgery for epilepsy were retrospectively evaluated. A correlation between ictal hyperperfusion and the underlying responsible pathology was shown, with a consistent ictal increase in perfusion in developmental pathologies and Rasmussen's encephalitis, and consistent interictal hypoperfusion in hippocampal sclerosis (HS). No rCBF study parameter appeared to relate to outcome but in the group with HS the best outcome was seen in those with localizing ictal rCBF. The varied group of pathologies from hemispherectomy had excellent outcome but the SPECT findings had little to contribute over the abnormalities detected on MRI. In conclusion, rCBF studies remain a useful presurgical investigation in children with partial epilepsy, especially where HS, cortical dysplasia, or inflammatory disease are the underlying pathology. However, rCBF studies add little to the investigation of children with seizures secondary to benign tumours or cerebral infarcts, or where hemispherectomy is the likely preferred surgical option.

Hippocampal sclerosis (HS) is the most common pathological substrate for temporal lobe epilepsy with a characteristic pattern of loss of principle neurons primarily in CA1 and hilar subfields. Other cytoarchitectural abnormalities have been identified in human HS specimens, including dispersion of dentate granule cells and cytoskeletal abnormalities in residual hilar cells. The incidence of these features, their relationship to the severity of HS and potential indication of underlying hippocampal maldevelopment is unverified. In a series of 183 hippocampectomies we identified classical HS (grades 3 and 4) in 90% of specimens, granule cell disorganization or severe dispersion in 40% of cases with a bilaminar pattern in 10%, and cytoskeletal abnormalities in hilar cells in 55% of cases. The severity of granule cell disorganization correlated closely with the degree of hippocampal neuronal loss but not with the age at first seizure or a history of a precipitating event for epilepsy such as prolonged febrile seizures. These findings suggest that granule cell disorganization is closely linked with the progression of HS rather than a hallmark of impaired hippocampal maturation. Furthermore, stereological quantitation of granule cells showed evidence of cell loss but greater numbers in regions of maximal dispersion, which may indicate enhanced neurogenesis of these cells. Quantitation of reelin-and calretinin-positive Cajal-Retzius cells in the dentate gyrus molecular layer in 26 cases showed no correlation between the number of these cells and the severity of granule cell dispersion, but increased numbers of these cells were present in HS with respect to control groups. Although a role for Cajal-Retzius cells is therefore not implicated in the mechanism of granule cell disorganization, their excess number may be indicative of underlying hippocampal maldevelopment in HS.

Diffusion tensor imaging is an imaging method that is sensitive to the molecular movement of water, which indicates cellular integrity and pathology. A patient with refractory epilepsy and normal conventional MRI was examined with diffusion tensor imaging. An area of abnormal diffusion in the right frontal lobe was identified and surgically resected. The patient had a good clinical outcome. Histopathological examination of the resected tissue showed gliosis. Our findings may affect the investigation of similar patients, and provide histopathological confirmation of diffusion abnormalities.

The objective of this case report is to demonstrate that a benign tumour arising solely from the olfactory bulb can act as a primary epileptic focus and to illustrate the difficulty in making a preoperative diagnosis of pathological lesions in this area. The case of a 29-year-old male with intractable epilepsy is presented. Radiological imaging demonstrated a conspicuous, calcified lesion in the mesial inferior frontal lobe. Electroclinical findings confirmed this to be the epileptogenic zone. Surgery and subsequent histology surprisingly revealed this focal lesion to be a benign hamartoma arising solely from the olfactory bulb. Resection resulted in seizure resolution. Tumours of the olfactory apparatus are extremely rare, but can present with epilepsy., (Copyright 2002 S. Karger AG, Basel)

Microdysgenesis is a microscopic cortical malformation considered to act as a substrate for seizures in some patients with generalized epilepsy. It is also recognized to involve the temporal lobe in a proportion of patients with intractable temporal lobe epilepsy, but the incidence of this abnormality, its relationship to mesial temporal lobe sclerosis and relevance to epileptogenesis remain unknown. This is partly due to a lack of well-defined quantitative pathological diagnostic criteria. To begin to address these issues, we have carried out a rigorous quantitative analysis, using three-dimensional cell counting methods, of several components of microdysgenesis in temporal lobectomy specimens. White matter, cortical and layer I neuronal densities (NDs) were measured using immunohistochemistry for the neuronal markers neuronal nuclear antigen and calbindin D-28-K. Patients with a seizure-free outcome (Class I) showed significantly more microdysgenetic features including higher white matter ND (P < 0.05), particularly of small (<10 microm diameter) neurones (P < 0.01), higher layer I ND (P < 0.05) and increased numbers of Cajal-Retzius-like calbindin-positive neurones (P < 0.05). We also demonstrated that white matter ND was independent of the degree of temporal lobe gliosis as assessed by quantitation of glial fibrillary acidic protein-immunoreactive cells. These findings suggest that microdysgenesis may be a significant lesion in temporal lobe epilepsy in terms of post-surgical prognosis.

Ependymomas are the third most common brain tumour in the paediatric population. Although cytogenetic and molecular analyses have pinpointed deletions of chromosomes 6q, 17, and 22 in a subset of tumours, definitive patterns of genetic aberrations have not been determined. In the present study, we analysed 40 ependymomas from paediatric patients for genomic loss or gain using comparative genomic hybridisation (CGH). Eighteen of the tumours (45%) had no detectable regions of imbalance. In the remaining cases, the most common copy number aberrations were loss of 22 (25% of tumours) and gain of 1q (20%). Three regions of high copy number amplification were noted at 1q24-31 (three cases), 8q21-23 (two cases), and 9p (one case). Although there was no association with the loss or gain of any chromosome arm or with benign versus anaplastic histologic characteristics, the incidence of gain of 7q and 9p and loss of 17 and 22 was significantly higher in recurrent versus primary tumours. This study has identified a number of chromosomal regions that may contain candidate genes involved in the development of different subgroups of ependymoma., (Copyright 2001 Wiley-Liss, Inc.)

Although astrocytomas are the most common central nervous system tumours in all age groups, there is substantial evidence that tumours arising in young patients (< 25 years of age) do not have the same genetic abnormalities that are characteristic of tumours in older patients. Furthermore, novel, consistent changes have not been identified in astrocytomas in children and young adults. We analysed 13 malignant astrocytomas from young patients using comparative genomic hybridisation. Regions of genomic imbalance were identified in 10 cases. The most common recurrent copy number aberrations were loss of 16p (54% of cases), 17p (38%), 19p (38%), and 22 (38%) and gain on 2q (38%), 12q (38%), 13 (38%), 4q (31%), 5q (31%), and 8q (31%). Seven regions of high copy number amplification were observed at 8q21-22 (three cases), 7q22-23 (two cases), and 1p21-22, 2q22, 12q13-pter, 12q15-21, and 13q11-14 (one case each). This study provides evidence of new characteristic chromosomal imbalances from which potential candidate genes involved in the development of malignant astrocytoma in children and young adults may be identified., (Copyright 2001 Wiley-Liss, Inc.)

The introduction of parasitic honey bee mites, the tracheal mite, Acarapis woodi (Rennie) in 1984 and the Varroa mite, Varroa jacobsoni, in 1987, has dramatically increased the winter mortality of honey bee, Apis mellifera L., colonies in many areas of the United States. Some beekeepers have minimized their losses by routinely treating their colonies with menthol, currently the only Environmental Protection Agency-approved and available chemical for tracheal mite control. Menthol is also expensive and can interfere with honey harvesting. Because of inadequate sampling techniques and a lack of information concerning treatment, this routine treatment strategy has increased the possibility that tracheal mites will develop resistance to menthol. It is important to establish economic thresholds and treat colonies with menthol only when treatment is warranted rather than treating all colonies regardless of infestation level. The use of sequential sampling may reduce the amount of time and effort expended in examining individual colonies and determining if treatment is necessary. Sequential sampling also allows statistically based estimates of the percentage of bees in standard Langstroth hives infested with mites while controlling for the possibility of incorrectly assessing the amount of infestation. On the average, sequential sampling plans require fewer observations (bees) to reach a decision for specified probabilities of type I and type II errors than are required for fixed sampling plans, especially when the proportion of infested bees is either very low or very high. We developed a sequential sampling decision plan to allow the user to choose specific economic injury levels and the probability of making type I and type II errors which can result inconsiderable savings in time, labor and expense.

Objective: Tumours of the choroid plexus are rare tumours of neuro-ectodermal origin, accounting for less than 1% of all intracranial tumours. Most cases present in children less than 2 years of age. While choroid plexus carcinomas (CPC) are reported to have an extremely poor prognosis, choroid plexus papillomas (CPP) are generally regarded as benign tumours with a very favourable long-term outcome. Management dilemmas are associated with the choice of surgical procedure, tumour vascularity, the treatment of hydrocephalus and the value of adjuvant therapy. The objective of this study was to review our experience with this rare tumour over a 20-year period., Methods: Patients were identified from the Great Ormond Street Neurosurgical Brain Tumour Database. Over a 20-year period (1979-1999), 34 children were identified with a choroid plexus tumour. There were 25 cases of CPP and 9 cases of CPC. A retrospective review of case notes, radiological imaging, operation reports and pathology was performed., Results: The median age at presentation was 17 months (1-138) for CPP and 13 months (2-102) for CPC. There was no sex difference for CPP. However, 8 of the 9 CPCs were male (89%). A complete surgical resection was achieved in all 25 cases of CPP and in 3 cases of CPC (33%). The median survival for CPPs was 75.5 months (2-228), with a median follow-up of 73.5 months (2-228). The median survival for CPCs was 6 months (1-90), with a median follow-up of 6 months (1-90)., Conclusion: With modern neurosurgical practise, a cure should be the aim for all children with CPP. There is no evidence that adjuvant therapy has any role in the primary management of these children. However, CPC still has an extremely poor prognosis, and the efficacy of adjuvant therapy remains to be established., (Copyright 2000 S. Karger AG, Basel)

Five patients with dysembryoplastic neuroepithelial tumour (DNT) showing extensive secondary haemorrhage, a finding not previously associated with these neoplasms, are described. The clinical presentations, neuroimaging findings, and histopathological features of these patients are reviewed. One patient, a previously asymptomatic 12 year old girl, presented with an acute intracerebral haemorrhage into a DNT. A further four young adults with histories of intractable partial and generalised seizures dating from childhood showed significant chronic haemorrhages within DNT, the MRI appearances in one patient giving a false impression of a cavernoma. Histopathology disclosed vascular abnormalities within these tumours which, together with other factors discussed, may have predisposed these tumours to haemorrhage.

High-resolution MRI can detect dual pathology (an extrahippocampal lesion plus hippocampal atrophy) in about 5-20% of patients with refractory partial epilepsy referred for surgical evaluation. We report the results of 41 surgical interventions in 38 adults (mean age 31 years, range 14-63 years) with dual pathology. Three patients had two operations. The mean postoperative follow-up was 37 months (range 12-180 months). The extrahippocampal lesions were cortical dysgenesis in 15, tumour in 10, contusion/infarct in eight and vascular malformation in five patients. The surgical approach aimed to remove what was considered to be the most epileptogenic lesion, and the 41 operations were classified into lesionectomy (removal of an extrahippocampal lesion); mesial temporal resection (removal of an atrophic hippocampus); and lesionectomy plus mesial temporal resection (removal of both the lesion and the atrophic hippocampus). Lesionectomy plus mesial temporal resection resulted in complete freedom from seizures in 11/15 (73%) patients, while only 2/10 (20%) patients who had mesial temporal resection alone and 2/16 (12.5%) who had a lesionectomy alone were seizure-free (P < 0.001). When classes I and II were considered together results improved to 86, 30 and 31%, respectively. Our findings indicate that in patients with dual pathology removal of both the lesion and the atrophic hippocampus is the best surgical approach and should be considered whenever possible.

The rate of seizure relief following hemispherectomy varies between 50 and more than 80%. There has been particular debate concerning the significance of bilateral electroencephalography (EEG) abnormalities in influencing prognosis. This study was set out to determine the frequency of bilateral EEG abnormalities and their relationship to underlying pathology and outcome. We investigated 28 children with unilateral hemisphere lesions, who underwent hemispherectomy. Interictal and ictal EEGs before and after hemispherectomy were reviewed. Post-operative outcome with respect to seizures was noted. Bilateral EEG abnormalities were seen in 75%, but were more common in children with malformations of cortical development than in patients with acquired cerebral lesions, and were found more often in interictal than in ictal records. Post-operative EEG abnormalities were variable and did not consistently predict outcome. Short-term outcome was similar, irrespective of aetiology. With longer term follow-up, only 47% of children with developmental abnormalities were still seizure-free in contrast to 77% of children with acquired abnormalities. Although the incidence of bilateral EEG abnormalities in patients with major unilateral hemisphere lesions is high, these findings alone should not preclude further consideration for hemispherectomy. Our findings emphasise that the aetiology of the lesion plays a major role in determining outcome.

More data are needed providing strong evidence that nutrition services are cost-effective. Economic evaluations, such as cost-effectiveness analyses, are excellent practice-based research projects. We conducted a cost-effectiveness analysis in a clinical setting to compare the cost-effectiveness of lipid-lowering medications plus diet therapy (medication + diet) with diet therapy alone (diet alone) for treating patients with hypercholesterolemia. Twenty-five adults with hypercholesterolemia (13 receiving medication + diet, 12 receiving diet alone) either participated in an 8-week, home-based, step 1 intervention or were counseled about diet and lifestyle by their care provider. Diet, cost, and laboratory data were collected at baseline, at 9 months, and at 19 months after participation in the intervention (follow-up). Cost per unit change in outcome was evaluated for each group. The diet-alone group made only small changes in dietary intake, changes that were smaller in magnitude than those made by the medication + diet group. Nevertheless, at 9 months, costs per unit change in total serum cholesterol level and low-density lipoprotein cholesterol (LDL-C) level were approximately $24 and $83 less, respectively, for the diet-alone group. At follow-up, however, the cost per unit change in LDL-C level was approximately $17 less for the medication + diet group, which can be explained by the medication + diet group's greater decrease in LDL-C level. The following elements should be considered when conducting a cost-effectiveness analysis of medical nutrition therapy: effectiveness of the nutrition intervention, adequate sample size, confounding variables, compliance with diet and drug therapy, direct and indirect costs of care, and follow-up evaluation.

There is still no consensus on the natural history and optimal management of optic pathway gliomas (OPG) in children. In order to tackle optimal management issues, we need to clearly understand the prognostic and confounding factors affecting relapse of OPG. We propose the use of the Cox proportional hazards (PH) model in a retrospective study of childhood OPG of 69 children seen from 1977 to 1994. We have developed a comprehensive model capable of multivariate analyses and handling time-dependencies. Our studies showed that relapse-free survival improves with increasing age, the presence of neurofibromatosis 1 (NF1), and chemotherapy and radiotherapy (p < 0.0005). Sex, tumor position and surgery do not significantly affect survival. Older children with NF1 have extremely good prognosis. We noted behavior that departs from the strictly proportional hazards model, but results were inconclusive.

Objective: To assess the quantity and nature of the proteins that adsorb to hydrocephalus shunt catheters after implantation, and to determine whether sufficient could accumulate to obstruct the catheter., Design: Elution of proteins from 102 explanted shunt catheters, with protein assay and electrophoresis of the eluate, and scanning electron microscopy (SEM) of the catheters., Results: The amount of protein elutable was extremely low, and significant protein, apart from a thin film, was not found on SEM. Qualitative analysis disclosed that most of the adsorbed protein was albumin., Conclusions: Protein deposition on hydrocephalus catheters does not occur in sufficient quantities to cause catheter obstruction.

Remodelling the cranial vault in an attempt to increase the intracranial volume and thus control intracranial hypertension, whilst at the same time improving the patient's appearance, has been the mainstay of surgery for syndromic craniosynostosis. We report a case of craniosynostosis in whom cranial vault expansion was followed by the development of hind-brain herniation and hydrocephalus. This prompted a review of our other cases of craniosynostosis who had been evaluated by magnetic resonance imaging following surgery in order to assess the frequency of hind-brain herniation and hydrocephalus in these children. Magnetic resonance imaging had been performed in the postoperative evaluation of 34 cases of craniosynostosis who had undergone procedures intended to increase the intracranial volume. The position of the cerebellar tonsils and the presence or otherwise of hydrocephalus was recorded for all cases. The effectiveness of surgery in treating raised intracranial pressure (ICP) was evaluated by means of postoperative ICP monitoring and had been performed in 22 cases. Herniation of the hind-brain below the level of the foramen magnum was observed in 18 cases (53%). Hydrocephalus, requiring the insertion of a ventriculoperitoneal shunt, was present in 14 cases (41%) and had developed after the cranial vault procedure in 9. The mean sleeping ICP measured postoperatively was normal (<10 mm Hg) in 5, borderline (10-15) in 7, and raised (>15 mm Hg) in 10 cases. Cranial vault expansion in complex craniosynostosis may fail to address the underlying aetiology of intracranial hypertension. Furthermore, both hydrocephalus and hind-brain herniation may develop following such surgery. Neither the increase in intracranial volume afforded by cranial vault expansion nor the shunting of hydrocephalus precludes the persistence of abnormal ICP. These findings are discussed in the light of possible mechanisms, in addition to cephalocranial disproportion responsible for intracranial hypertension in complex craniosynostosis. The implications for the surgical management of complex craniosynostosis are reviewed.

The occurrence and extent of herniation of the hindbrain has been evaluated in a population of children with craniosynostosis by means of magnetic resonance imaging of the craniocervical junction. The role of intracranial pressure (ICP), posterior fossa size and hydrocephalus in the development of this deformity has also been assessed. Magnetic resonance imaging (Siemens Magnetom 1.5T) was reviewed in 27 cases of craniosynostosis in whom there had been no previous cranial vault surgery. The position of the cerebellar tonsils in relation to the plane of the foramen magnum was measured and an index of the size of the posterior fossa relative to the rest of the cranial vault was also calculated for each case. The presence of hydrocephalus (requiring a cerebrospinal fluid diversion procedure) was documented. In 22 of these cases overnight, subdural ICP monitoring using the Camino fibre optic device had also been performed. Herniation of the hindbrain below the plane of the foramen magnum occurred in 10 of 27 cases (37%). The level of ICP showed a significant correlation with the extent of hindbrain herniation (p < 0.001) as did small posterior fossa size (p = 0.0035). Hydrocephalus was present in 4 patients, all of whom had hindbrain herniation. The extent of hindbrain herniation did not correlate with age (p = 0.48). We propose that herniation of the hindbrain in craniosynostosis is a consequence of brain deformation occurring in response to the physical forces imposed by a combination of the anatomical deformity at the skull base and intracranial hypertension rather than a primary malformation of brain development as commonly supposed.

We describe 5 women and 5 men with periventricular nodular heterotopia and electroclinical features suggestive of temporal lobe epilepsy, who were surgically treated for control of medically refractory seizures. Magnetic resonance imaging revealed bilateral periventricular nodular heterotopia in 7 of the 10 patients. Because of the lack of clear localization, 6 patients were studied with intracranial depth electrode recordings. Seizures were of hippocampal onset (3 patients), regional temporal lobe onset (2 patients), or occipital-temporal onset (1 patient). Anterior temporal lobectomy was performed in 6 patients; selective amygdalohippocampectomy, in 1; and anterior temporal lobectomy plus resection of the heterotopic tissue, in 3. None of the 9 patients followed for more than 12 months postoperatively were seizure free. Two patients were initially seizure free for approximately 18 months, but then seizures recurred. One patient had a major reduction in seizure frequency at a 39-month follow-up after most of the unilateral heterotopic tissue was included in the temporal resection. Temporal resection did not lead to a long-term favorable outcome in this group of patients with periventricular nodular heterotopia and epileptogenic discharges involving the temporal lobe. This suggests a more widespread disorder with epileptogenic activity possibly originating in or near the heterotopic tissue. The clinical and electrographic features of periventricular nodular heterotopia pointing to temporal lobe origin are misleading and temporal resection does not result in long-term cessation of seizures.

Modern neuroimaging can disclose epileptogenic lesions in many patients with partial epilepsy and, at times, display the coexistence of hippocampal atrophy in addition to an extrahippocampal lesion (dual pathology). We studied the postoperative seizure outcome of 64 patients with lesional epilepsy (median follow-up, 30 months) and considered separately the surgical results in the 51 patients with a single lesion and in the 13 who had dual pathology. In patients with a single lesion, 85% were seizure free or significantly improved (Engel's class I-II) when the lesion was totally removed compared with only 40% when there was incomplete resection (p < 0.007). All three patients with dual pathology who had both the lesion and the atrophic hippocampus removed became seizure free. In contrast, only 2 of the 10 patients with dual pathology undergoing surgery aimed at the lesion or at the hippocampus alone became seizure free (p < 0.05), although 4 of them showed significant improvement (Engel's class II). We conclude that the outcome in patients with single epileptogenic lesions is usually dependent upon the completeness of lesion resection. In patients with dual pathology, surgery should, if possible, include resection of both the lesion and the atrophic hippocampus.

The authors reviewed 175 paediatric patients with posterior fossa tumours treated at the Hospital for Sick Children at Great Ormond Street, London, between 1983 and 1993, in an attempt to determine the requirement for shunt procedures in these children. The age of the patient population ranged from 4 months to 14 years 6 months. The factors evaluated included age at diagnosis, tumour type, extent of surgical resection, and the presence of CSF leak and/or infection. Shunt placement was required postoperatively in 18.9% of patients. Age of the patient was felt to be a significant factor in the need for shunt placement. Tumour type and completeness of tumour excision were also felt to be significant factors affecting the need for post-operative shunt insertion.

A 7-year-old boy with severe acquired epileptic aphasia (Landau-Kleffner syndrome) was treated by multiple subpial transections to the left temporal lobe. In the course of electrocorticography, event-related potentials (ERP) were recorded to the phonemes /ba/ and /ga/; /ba/ occurred 72.5% of the time and /ga/ 27.5%, in a pseudo-random sequence. The ERPs were distributed over the middle and inferior temporal gyri and there was a marked overlap with the area of maximal spiking detected on the electrocorticogram. Repetition of the frequent syllable /ba/ was associated with diminution of the prominent negative component of the ERP culminating around 550 ms suggesting habituation. Presentation of the novel syllable /ga/ restored the amplitude of this negative component, showing that discrimination was preserved despite the apparent global aphasia. This finding supports clinical evidence that some children with epileptic aphasia can still process auditory speech input. Intraoperative ERP recording may help improve our understanding of the relationship between epileptiform activity and aspects of language processing in Landau-Kleffner syndrome where lack of cooperation precludes detailed clinical testing.

Studies of cervical spine anomalies in patients with Crouzon's and Apert's syndromes have shown an increased incidence of fusions in comparison with that in the normal population. Currently, only small series of patients with Pfeiffer's syndrome who exhibit abnormalities have been published. The objective was to assess the incidence and pattern of radiological cervical spine abnormalities in patients with Pfeiffer's syndrome. All cervical spine radiographs of 22 patients with a confirmed diagnosis of Pfeiffer's syndrome treated at Great Ormond Street Hospital during the last 10 years were studied. All of the radiographs were reviewed by the craniofacial team along with a pediatric radiologist with experience in the assessment of skeletal dysplasias. Radiological abnormalities included hypoplasia of the neural arches, hemivertebrae, and a "butterfly" vertebra as well as vertebral fusion. Evidence of vertebral fusion was present in 16 (73%) of cases. Fusion of both the vertebral bodies and the posterior elements were noted. C2-C3 was the level most commonly involved, although fusion was noted at all levels within the cervical spine. Block fusions involving multiple vertebrae were noted. Analysis of sequential radiographs in 11 patients revealed evidence of progression in eight patients. These results reveal an incidence of anomalies that is higher than previously reported. The older age of the patients in our study demonstrates the progressive nature of the cervical fusions in Pfeiffer's syndrome.

Background: Prosthetic infections are a major problem, requiring complex and lengthy management. The role of blood proteins in the pathogenesis of implant infection has been investigated, but research into the role of CSF protein in shunt infections has not been undertaken, even though a high CSF protein has been assumed to increase the risk of such infections., Methods: New shunt catheters were exposed to either CSF or individual protein solutions, and the numbers of radiolabelled staphylococci that adhered to them were compared with controls that had been exposed to saline only., Results: A significant reduction in bacteria adhering to the test catheter was found in each instance. Furthermore, the CSF with the highest protein content, from a patient with intraventricular haemorrhage, had the greatest inhibitory effect on bacterial adhesion. The effect of the solutions on the hydrophobicity of the silicone rubber was also investigated. The silicone rubber was more hydrophilic, and bacterial adhesion was less, with solutions containing a higher protein content, and these findings were in keeping with the current theories on the mechanism of bacterial adhesion to polymers., Conclusions: A high CSF protein content does not predispose to the development of shunt infections.

Most removed shunt valves are discarded with no investigation into why they had to be replaced or whether they still performed to specification. However, improvements in valve design will only occur if valves that have needed removal are examined and the reasons that they failed are determined. An in-depth study of 43 valves that were removed in this unit over a 15-month period was performed. They were submitted to a four-part study, comprising flow-pressure testing, opening and closing pressure measurement, assessment of the susceptibility to syphoning, and dismantling with internal inspection of the valve components. Overall, 81% of valves failed to meet the manufacturers' specified performance data, even though the peroperative cause of shunt failure was thought to lie outside the valve. Over 80% of valves with metallic parts were found to have accumulated debris internally, and this was thought to have impaired their performance. In contrast, only 25% of non-metallic valves contained debris, a significant difference (0.01 > p > 0.001). All of the valves had a high tendency to overdrainage. Attention is drawn to the high number of malfunctioning valves. It is recommended that a change of valve should be considered in all shunt revisions, and that future valve designs should avoid metal components.

A prospective study was performed to determine whether the popular opinion that a high CSF protein concentration increases the risk of shunt complications is true. Ninety-five patients were enrolled into the study and they had 116 shunt operations over 15 months. It was considered that the CSF protein content might influence the development of complications that occurred within 2 months of surgery. Shunt complications occurred following 24.6% of operations within this period. This included 12 infections, 13 obstructions and three cases of overdrainage. The distribution of complications, compared to CSF protein content, was non-significant on a chi 2-test (p > 0.5). The total protein content of each of the complication groups was also analysed using the Mann-Whitney U-test and the differences were non-significant for the infection (0.1 > p > 0.05) and obstruction groups (0.5 > p > 0.1). It is concluded that an elevated CSF protein content does not increase the risk of shunt complications, and that there is no reason why shunting should be delayed in patients with a high CSF protein content.

It has long been assumed that a high cerebrospinal fluid protein concentration adversely affects the performance of shunts. There is little experimental evidence to support this viewpoint, however, and the few reports that have been published can be criticized for poor experimental design or presentation of results. A flow-dependent shunt perfusion model was constructed. PS Medical Flow Control valves (PS Medical Corporation, Goleta, CA) and Cordis-Hakim valves (Cordis Corporates, Miami, FL) were perfused with saline-plasma solutions in concentrations from 0 to 9 g/L of protein. Blood suspensions in dilutions from 0.25 to 1% were also studied. The opening and closing pressures of the valves were measured with a simple manometer, and the physical properties of the solutions were studied. The results indicated that the valves performed within the ranges specified by their manufacturers, even with markedly increased protein concentrations in the perfusate. Furthermore, the valve opening and closing pressures were lower with the protein-containing solutions than with the control solutions. Thus, the protein did not impair shunt function and we conclude that shunts can be inserted into patients who have elevated cerebrospinal fluid protein contents. However, blood cells did adversely affect performance and, therefore, patients with hemorrhagic cerebrospinal fluid should not receive shunts.

Near infrared spectroscopy (NIRS) can be used to quantify cerebral haemodynamic states non-invasively and to estimate cerebral blood flow (CBF). In the first part of this study we have compared CBF measurements in conscious and anaesthetized subjects. In the second part we have compared paired measurements made during anaesthesia, first on the scalp and then the dura after craniotomy. Mean CBF was 17 (SD 7) ml 100 g-1 min-1 in the conscious subjects compared with 21 (8) ml 100 g-1 min-1 on the scalp during anaesthesia (P > 0.1). Mean CBF on the dura was 68 (21) ml 100 g-1 min-1 (P < 0.0001). Computer modelling suggests that the difference in magnitude between scalp and dura measurements of CBF is likely to be caused by the optical effect of extracerebral tissue which powerfully scatters light passing through it but does not contribute significantly to the measured CBF because it has only a small blood content itself. The results lend support to this method of estimating CBF although formal validation by comparison with an established technique is needed.

In the management of craniosynostosis subdural intracranial pressure (ICP) monitoring has proved a useful and safe means of identifying those children with raised ICP who are at risk from its long-term sequelae and who would benefit from early surgical intervention. Overnight subdural ICP recordings have been obtained in 136 unoperated cases of craniosynostosis. Fifteen patients were studied both before and after cranial vault remodelling procedures. ICP was raised (> 15 mmHg) in 35%, borderline (10-15 mmHg) in 37% and normal (< 10 mmHg) in 27% of cases. Raised ICP was present in 28/53 of the syndromic craniofacial dysostosis cases and in 20/83 non-syndromic craniosynostosis cases investigated (P < 0.001). Raised mean ICP and periodic plateaux of sustained ICP during sleep were particularly associated with the syndromic cases. Of the 15 patients studied following cranial vault surgery, 9 showed a reduction in ICP, 3 were unchanged and 3 had higher ICP postoperatively. The results of ICP monitoring can contribute significantly to formulating a rational and staged surgical management plan incorporating the need to normalise ICP and correct the frequently severe functional and cosmetic consequences of these disorders.

CSF surface tension has received little study, and yet it will effect the pressure at which shunt valves operate, and by influencing the degree of hydrophobicity (contact angle) will alter the attraction between bacteria and neurosurgical prostheses. A study is therefore presented of the effect of protein content upon the surface tension of CSF and its contact angle to silicone rubber. Both of these quantities fell throughout the normal range of CSF protein, but above 1 g/l, additional protein had little effect, and the results obtained were similar to that reported for plasma. The effect of surface tension on the opening and closing pressures of hydrocephalus shunt valves and of contact angle in the adhesion of bacteria to neurosurgical implants is discussed.

Viscosity is the resistance to flow of a fluid and it is the only property of a fluid that will affect its flow through a system of valveless tubing (surface tension will affect the opening and closing of valves that are included in the system). The effect that an elevated protein concentration has upon CSF viscosity has received little study, yet many neurosurgeons believe that CSF with an elevated protein content is too viscous to flow satisfactorily through shunts. The total protein content and viscosity of 126 specimens of CSF from hydrocephalic patients were measured and analysed with reference to the aetiology of the hydrocephalus. The results indicate that high protein concentrations do not greatly affect the viscosity of CSF, and that the aetiology is also of little consequence. These findings were highly significant on linear regression analysis (p < 0.001). The flow of the most viscous CSF that is likely to be encountered would be reduced by only 7% through a given catheter, compared with that of the least viscous CSF.

Butylated hydroxytoluene is an antioxidant that has antiviral properties and sustains sperm viability during freezing and thawing. A field trial involving 11 bulls and 19,000 AI was conducted to determine whether addition of .5 mM butylated hydroxytoluene to whole milk extender during seminal processing affected bull fertility as estimated by nonreturn rates generated by cows bred to the bulls. Effects of bull, batch of semen nested within bull, treatment, and month of AI were studied. Nonreturn rates were recorded for each month for every bull, batch of semen (ejaculates pooled on a given day), and treatment combination. Because some bulls had < 6 batches of semen, the original experimental design was reduced to two smaller designs. Categorical data analysis with maximum likelihood estimation was used for analysis of nonreturn rates. The results from three models were used to interpret the data. The nonreturn rates were approximately 73.9% for the butylated hydroxytoluene treatment and 74.1% for the control. In all models, bull effect was significant, but batch, month of AI, and treatment had no effect on bull fertility. Addition of .5 mM butylated hydroxytoluene to whole milk extender during semen processing did not affect bull nonreturn rates.

Craniosynostosis poses a challenge to a multiplicity of paediatric specialties. In addition to the obvious cosmetic considerations there are often severe functional connotations. The spectrum of these disorders is outlined, and their investigation and the options for surgical correction are discussed.

A prospective study was undertaken of all children referred to the Hospital for Sick Children with a provisional diagnosis of shunt blockage over a 5-month period. Fifty-two admissions were recorded, relating to 45 children, 5 of whom had multiple admissions. Only 19 of the 52 admissions led to a final diagnosis of shunt malfunction. No source of referral, whether by the child's general practitioner or from another hospital, was found to be more accurate than direct referral by the parents to the neurosurgical ward. Headache, vomiting and irritability were not significant indicators as to whether the child's shunt was actually blocked, and nor was the duration of the symptoms. Drowsiness was a significant, but not definite, indicator of shunt blockage, while pyrexia made it more likely that the patient had an alternative diagnosis. In 35 of the admissions a computed tomographic scan was performed: a normal scan, unchanged from previous scans, did not reliably exclude the diagnosis of shunt blockage. Percutaneous manometry via the reservoir of the shunt system was performed during 26 admissions: this investigation produced no false positives nor false negatives, but was equivocal in 5 cases, all of which were found at surgery to have a definite shunt blockage. The accuracy of the diagnosis of shunt blockage made prior to referral to a neurosurgical unit is discussed, together with the implications for resource use.

Patients with damage to the striate cortex have a subjectively blind region of the visual field, but may still be able to detect and localize targets within this region. But the relative roles in this 'blindsight' of subcortical neural systems, and of pathways to extra-striate visual areas, have been uncertain. Here we report results on two infants in whom one cerebral hemisphere, including both striate and extra-striate visual cortex, needed surgical removal in their first year. Single conspicuous targets in the half-field contralateral to the lesion could elicit fixations, implying detection and orienting by a subcortical system. In contrast, binocular optokinetic nystagmus (OKN), for which a subcortical pathway has often been thought adequate, showed a marked asymmetry. In normal neonates, fixation shifts and OKN have both been taken to reflect subcortical control; our results are consistent with subcortical control for fixation but not for OKN.

Tumours of mixed glial and sarcomatous elements occurring in intracranial neoplasms are well recognised and have been termed gliosarcomas. These tumours account for up to 8% of all glioblastomas. The sarcomatous elements are thought to derive from the neoplastic transformation of mesenchymal cells in or adjacent to the tumour. This transformation usually has the appearance of a fibrosarcoma or angiosarcoma. Alternative mesenchymal neoplastic differentiation may occur, however, giving rise to the appearances of chondrosarcoma and osteosarcoma. In 1969 Goldman described a case in which the sarcomatous elements of a mixed gliosarcoma appeared, on the basis of light microscopy alone, to differentiate towards skeletal muscle having the features of a rhabdomyosarcoma. He coined the term gliomyosarcoma. In 1986 Barnard et al reported a second case and demonstrated the features of rhabdomyosarcoma using the electron microscope. A further case characterised with both light microscopic and immunohistochemical techniques is reported.

Modern interest in craniosynostosis began when clinicians, regardless of their individual specialty but united in their interest in the problems raised by patients with this condition, first realised that if treatment was confined simply to opening up the fused sutures of the skull vault, success in terms of both function and the restoration of a more normal appearance was likely to be limited. Indeed, the grouping together of such specialists into formal craniofacial units was tacit recognition of this, as was the acceptance that many affected children had evidence of clinical problems that could not be explained on simple mechanical grounds alone. It is not surprising, therefore, that the advent of any new method of investigation has been welcomed by craniofacial surgeons eager to learn anything that might lead to an improvement in management, particularly of the more complex syndromes.

CT-guided stereotactic biopsy is now an accepted method of tissue sampling in intracranial mass lesions but many surgeons still practise freehand burrhole biopsy. This study compares two groups of patients who had either stereotactically guided (n = 153) or freehand (n = 217) biopsy. Stereotactic biopsy has a lower incidence of both mortality (2.6%) and morbidity (1.3%) than freehand (7.8 and 7.8%) while diagnostic accuracy is 92.1 and 64.9%, respectively. The success rate for stereotactic biopsy is independent of the size and depth of the lesion while freehand biopsy is most successful for large, superficial lesions but its success never exceeds 88%. The stereotactic technique is superior to the freehand for all intracranial biopsies regardless of size or site.

Serological evidence of infection of swine in Great Britain with an influenza A virus closely related to the human A/Hong Kong/68 (H3N2) variant was detected by a variety of serological tests. The Hong Kong/68 virus was first detected in man in Great Britain in August 1968 and was prevalent in the winters of 1968-69 and 1969-70. There was no evidence that swine had been infected with a Hong Kong/68-like virus before the appearance of the virus in man. The detection of virus-neutralizing antibody and high titres of neuraminidase-inhibiting antibody for Hong Kong/68 virus, and the production of precipitin lines corresponding to influenza A ribonucleoprotein and haemagglutinin and neuraminidase antigens of Hong Kong virus in immunodiffusion tests indicated that the swine sera contained antibody specific for the Hong Kong/68 virus. Evidence suggested that the infection of swine occurred in the early months of 1970. Clinical influenza among swine in Great Britain was not reported during the study period and there was no serological evidence of infection with "classical" swine influenzavirus strains.