New professionalism in the 21st century.
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Biomedical subjects
Publications and source records attributed to Richard Hayward.
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OBJECTIVE: To compare visual acuity, optic disc appearance, and transient pattern reversal visual evoked potentials as markers of possible visual dysfunction in children with syndromic craniosynostosis. METHODS: Serial visual acuity, optic disc appearance, and pattern reversal visual evoked potential data were recorded in 8 patients with syndromic craniosynostosis before and after cranial vault expansion. The pattern reversal visual evoked potentials were analyzed using linear regression modeling, applied to the N80 to P100 amplitude. RESULTS: Serial optic disc appearances were available for all 8 patients and visual acuities for 7 patients. The visual acuity deteriorated in only 1 patient, improved in 4, and fluctuated in 2, before surgery. Of the 8 patients, 3 showed no papilledema in either eye at any time, 3 showed progressive bilateral swelling before surgery, and 2 exhibited only unilateral disc swelling. In all 8 patients, there was a trend for the N80 to P100 amplitude to decrease before surgery and to increase, in all but 2 patients, after surgery. CONCLUSIONS: This study suggests that neither optic disc appearance nor visual acuity assessment alone is a reliable marker of potential visual dysfunction in children with syndromic craniosynostosis. It also suggests that the pattern reversal visual evoked potential can provide early evidence of visual dysfunction before vault expansion surgery in these children; this dysfunction may recover postoperatively.
Nothing in clinical medicine is one hundred per cent certain. Part of a doctor's education involves learning how to cope with the anxiety that uncertainty in decisions affecting life and death inevitably produces. This paper examines: (1) the role of anxiety -- both rational and irrational -- in the provision of health care; (2) the effects of uncertainty upon the doctor-patient relationship; (3) the threat uncertainty poses to medical authority (and the assumption of infallibility that props it up); (4) the contribution of clinical uncertainty to the rising popularity of alternative therapies; and (5) the clash between the medical and the legal understanding of how certainty should be defined, particularly as it affects the paediatric community. It concludes by suggesting some strategies that might facilitate successful navigation between the opposing and ever-present forces of certainty and uncertainty.
OBJECTIVES: In 1996 we published our results for treatment of childhood craniopharyngioma. That study did not only reveal that there was a significant morbidity associated with our then policy of attempted radical removal followed by post-operative radiotherapy in those cases with residual disease, but also that risk factors for poor outcome could be identified based on the clinical and radiological findings at presentation. As result of that study, we redefined the role of radical surgery in the treatment of craniopharyngioma and developed a new treatment strategy in an attempt to improve the quality of outcome without compromising tumour control. Our aims in this paper were to compare the results of our current treatment strategy with that reported in the 1996 paper to assess whether we have achieved this goal. METHODS: A detailed assessment of the treatment pathway and outcome was undertaken for children treated for craniopharyngioma in our unit from 1996 to 2004. This included a morbidity score based on visual, motor, cognitive, hypothalamic and endocrinological data obtained from our neuro-oncology database and review of clinical records. Where possible we have attempted to record data in the same manner as for our previous study allowing for meaningful comparison. RESULTS: Forty-eight children with craniopharyngioma presented in the study period. On the basis of clinical presentation and radiological findings, 25 were deemed suitable for attempted radical surgery and 23 were treated with various subtotal surgical procedures. Radiotherapy was used in patients over the age of 5 years where residual tumour was present or progressed after the initial surgical intervention(s). Morbidity scores, particularly in relation to visual and cognitive outcome, are improved and there was no surgical mortality in the current series. CONCLUSIONS: A treatment paradigm for childhood craniopharyngioma is presented which improves the quality of outcome without compromising tumour control.
BACKGROUND: Blockage of the ventricular catheter is the most common reason for shunt malfunction and is usually due to ingrowth of choroid plexus into the catheter lumen. The authors describe a simple technique to unblock the ventricular catheter in situ. METHODS: In children with symptoms and radiological evidence of shunt malfunction, the Rickham reservoir was tapped under a general anesthetic. Manometry with saline was performed to confirm isolated proximal blockage of shunt. A guide wire, insulated to the scalp, was passed into the ventricular catheter using the Seldinger technique. Bursts of monopolar diathermy were applied to the guide wire to coagulate choroids plexus and manometry was repeated. In this preliminary study, all ventricular catheters were subsequently revised. RESULTS: This percutaneous technique was undertaken in 7 children with confirmed proximal shunt malfunction. Successful unblocking of the ventricular catheter was established by increased flow of cerebrospinal fluid around the guide wire. The mean +/- SEM manometry reading post-diathermy (21.9 +/- 5 cm) was higher than the pre-diathermy value (0.6 +/- 0.6 cm; P < .01). CONCLUSIONS: Percutaneous coagulation of the choroids plexus using the Seldinger technique is a simple, inexpensive, minimally invasive method to unblock ventricular catheters and it may be suitable as a stand-alone technique in selected patients.
Ependymomas are glial cell-derived tumors characterized by varying degrees of chromosomal abnormalities and variability in clinical behavior. Cytogenetic analysis of pediatric ependymoma has failed to identify consistent patterns of abnormalities, with the exception of monosomy of 22 or structural abnormalities of 22q. In this study, a total of 19 pediatric ependymoma samples were used in a series of expression profiling, quantitative real-time PCR (Q-PCR), and loss of heterozygosity experiments to identify candidate genes involved in the development of this type of pediatric malignancy. Of the 12,627 genes analyzed, a subset of 112 genes emerged as being abnormally expressed when compared to three normal brain controls. Genes with increased expression included the oncogene WNT5A; the p53 homologue p63; and several cell cycle, cell adhesion, and proliferation genes. Underexpressed genes comprised the NF2 interacting gene SCHIP-1 and the adenomatous polyposis coli (APC)-associated gene EB1 among others. We validated the abnormal expression of six of these genes by Q-PCR. The subset of differentially expressed genes also included four underexpressed transcripts mapping to 22q12.313.3. By Q-PCR we show that one of these genes, 7 CBX7(22q13.1), was deleted in 55% of cases. Other genes mapping to cytogenetic hot spots included two overexpressed and three underexpressed genes mapping to 1q31-41 and 6q21-q24.3, respectively. These genes represent candidate genes involved in ependymoma tumorigenesis. To the authors' knowledge, this is the first time microarray analysis and Q-PCR have been linked to identify heterozygous/homozygous deletions.
OBJECT: Elevated intracranial pressure (ICP) is a well-recognized complication affecting children suffering from complex forms of craniosynostosis. The effects of ICP, including those on vision, and the underlying mechanisms involved remain uncertain. The aim of this study was to examine the relationships among ICP, cerebral perfusion pressure (CPP), and the episodic alterations in respiratory obstruction that are common in children with craniosynostosis. METHODS: Eleven children with complex craniosynostosis underwent monitoring overnight, including simultaneous recording of subdural ICP, arterial blood pressure (ABP), and a variety of respiratory parameters. Sleep status was also analyzed. Mean values were calculated for all variables, including ICP, CPP, and ABP, during both quiet and active sleep. Mean ICP during quiet sleep was elevated in five patients, borderline in three, and normal in three children. During active sleep, plateaus of high mean ICP were observed in all patients. Marked decreases in CPP were demonstrated during active sleep with absolute values as low as 14 mm Hg. During quiet sleep, the mean baseline CPP was 53.3 mm Hg (range 34-70 mm Hg). During active sleep, CPP fell to a mean of 32.6 mm Hg (range 23-52 mm Hg). All patients experienced obstructive breathing problems, including 10 with obstructive sleep apnea, the effects of which demonstrated a temporal relationship to the alterations in sleep status, ICP, and CPP. Elevations of ABP appeared modest and remained within the normal limits for age. CONCLUSIONS: The findings of this study indicate that ICP, CPP, and respiratory obstruction interact in a vicious cycle, an observation that helps explain the pattern of plateau waves of elevated ICP characteristic among children with complex forms of craniosynostosis. The data gathered in this series revealed levels of CPP considerably lower than those described previously in clinical reports. Such reductions in CPP most likely contribute to the neurological, cognitive, and ophthalmological morbidity from which these children suffer frequently; therefore, the results of this study have important implications for the management of children with complex forms of craniosynostosis as well as for our understanding of the control of cerebral blood flow in general.
OBJECT: The aim of this study was to audit the treatment of symptomatic atlantoaxial instability in Down syndrome and to assess factors associated with fusion failure in this group of patients. METHODS: The authors reviewed the cases of 12 children with Down syndrome presenting with symptomatic atlantoaxial instability who underwent surgery for internal fixation and fusion. A review of clinical histories, radiological investigations, and details of operative interventions was also performed. The mode of presentation was acute spinal cord injury (five cases), progressive myelopathy (four cases), and neck pain or stiffness (three cases). The atlantodental interval ranged from 5 to 13 mm. The posterior atlantodental interval at the C-1 level was 9.5 mm (range 6-11 mm). In 10 patients an os odontoideum was present. Translocation of the odontoid process occurred in one patient, and occipitoatlantal instability was also identified in two cases. Twenty-four operations were performed in the 12 patients. A transoral odontoidectomy was required in four children. Successful fusion was demonstrated in seven patients at the first operation. Three of the five patients with acute cord injury made significant functional recovery and were left with no or mild disability. CONCLUSIONS: Additional bone abnormalities at the CVJ are common in the Down syndrome population. Young age at the time of fusion and multiple osseous anomalies pose a higher risk factor in fusion failure. The authors recommend an aggressive surgical approach for management of symptomatic cases of CVJ instability.
BACKGROUND AND PURPOSE: There has been limited description of hydromyelia after surgery for spinal dysraphism. The opportunity to compare pre- and post-operative hydromyelia in patients with spinal dysraphism has been possible in two groups of patients using MRI. Post-operative assessment and possible relationship of hydromyelia to clinical findings has been made during a 7- to 14-year period. METHODS: A total of 38 patients with congenital lumbar or sacral lipomas and 20 with diastematomyelia were studied pre-operatively with a 1.5-T MRI. Most patients in each group were examined with surveillance MRI (1.5 T) post-operatively. Clinical correlations were carried out with each examination. RESULTS: Of the 38 dorsal or terminal lipoma post-operative patients, hydromyelia increased in 3 and was a new finding in 4. One symptomatic patient in the latter group had extensive septated lumbar hydromyelia. In 8 of 20 diastematomyelia patients, pre-operative hydromyelia was unchanged post-operatively. Hemicord hydromyelia developed in 1. CONCLUSION: Hydromyelia of varying degree was found in almost one-third of post-operative dorsal or terminal lipoma patients and nearly one-half of diastematomyelia patients. In five post-operative lipoma and two diastematomyelia patients, significant neurological findings remained. One of the six post-operative lipomas had new extensive lumbar hydromyelia that may have been responsible for the patient's symptoms. In the remaining symptomatic patients, hydromyelia was absent or modest.
OBJECT: Atlantoaxial rotatory fixation (AARF) is an uncommon disorder of childhood in which resolution usually occurs spontaneously or after traction therapy. In a minority of children irreducible or chronic fixation develop, and the natural history then usually involves restriction of head on neck movement, abnormal head position, and progressive facial asymmetry. The conventional management in these cases has been a posterior fusion. METHODS: The authors performed an open reduction via the extreme-lateral approach without adjunctive fixation surgery in 13 children who ranged in age from 4 to 11 years. Postoperatively, halo jacket therapy was undertaken for 8 to 12 weeks. There were no neurological complications despite damage to one vertebral artery and one wound infection. Functional outcome was assessed after a minimum of 24 months (range 29-72 months). Facial asymmetry markedly improved. Sagittal movements were similar to those observed in control individuals. Axial rotation, although reduced compared with that in controls, was present but usually asymmetrical. CONCLUSIONS: In the authors' opinion, open reduction provides the best possibility of normal facial development and return of axial movement in cases of AARF.
Craniosynostosis, the premature fusion of cranial sutures, may be associated with raised intracranial pressure (ICP) with or without a reduced intracranial volume. Regardless of the aetiology, raised ICP may result in optic neuropathy, the timely detection of which can prevent further visual deterioration. Raised ICP is usually treated with craniofacial surgery such as cranial vault expansion. In this case study, we recorded serial pattern reversal visual evoked potentials (pVEPs) and obtained digital optic disc images before and after cranial vault expansion surgery. The amplitude of the pVEPs continued to decrease after cranial vault expansion surgery, prompting further neuroimaging that implicated a blocked ventriculo-peritoneal shunt. Only after shunt revision did the pVEP amplitude increase. Throughout the monitoring period, there was no change in the appearance of either the right or left optic disk, nor a consistent change in visual acuity.
OBJECTIVE: Posterior fossa tumours in children predispose to hydrocephalus, although the natural history is unclear and the need for drainage of the ventricles is controversial. We report on the natural history of ventriculomegaly and tonsillar herniation, as seen on serial MRI scans in children with posterior fossa tumours. RESULTS: Eighty-nine children with posterior fossa tumours were reviewed retrospectively. Overall, 18 (20%) patients required permanent cerebrospinal fluid (CSF) drainage in the form of a ventriculoperitoneal shunt (n = 15) or third ventriculostomy (n = 3). On pre-operative MRI scan, the ventricular size was assessed by measurement of the ventricular index (VI) and 59 patients (66%) had a VI greater than 0.4. There was a progressive decrease in the mean VI from pre-operative to post-operative MRI scans and beyond 3-9 months after surgery, the mean VI was less than 0.4 (p = 0.0001). Patients requiring permanent CSF drainage had a greater VI pre-operatively and at 3-9 months post-operatively (p < 0.05). On pre-operative MRI scan, 75 patients (84%) had greater than 5 mm herniation of the cerebellar tonsils below the level of the foramen magnum. There was a progressive decrease in the mean tonsillar herniation from pre-operative to post-operative MRI scans, with time (p = 0.0001), although this did not relate to the need for CSF drainage. On multivariate analysis, the need for permanent CSF drainage was associated with pre- and intra-operative CSF drainage (odds ratio = 23.3; p = 0.0001) and incomplete surgical excision of tumour (odds ratio = 7.7; p = 0.006). CONCLUSIONS: Hydrocephalus and tonsillar herniation are common in children with posterior fossa tumours, although post-operatively there is a natural tendency for it to resolve and only a fifth of the patients needed permanent CSF drainage. We recommend selective drainage of CSF in children with posterior fossa tumours. Patients at risk are those with severe symptoms at presentation, needing peri-operative CSF drainage and those with subtotal resection of tumour.
This study investigated the occurrence, nature, and severity of speech, language, and cognitive impairment in 76 children (61 males, 15 females) with isolated sagittal synostosis (ISS) aged 9 months to 15 years 7 months. There was no increased prevalence of global cognitive impairment in the group but there was a high prevalence rate of speech and/or language impairment with 28 (37%) displaying impairment of whom 20 (71%) had moderate or severe impairments that fulfilled the criteria for specific impairments. Prevalence rates were only increased for children over two years of age. Expressive language impairment occurred most frequently. Raised intracranial pressure, peri-neonatal risk factors, otitis media, or being operated were not associated with impairment. Surgery at a later age and a family history of speech and language impairment were both associated with impairments but numbers were small. The findings suggest that children with ISS are at an increased risk of developing speech and language impairment.
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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.