Split cord malformation: Part I: A unified theory of embryogenesis for double spinal cord malformations

Much confusion still exists concerning the pathological definitions and clinical significance of double spinal cord malformations. Traditional terms used to describe the two main forms of these rare malformations, diastematomyelia and diplomyelia, add to the confusion by their inconsistent usage, ambiguities, and implications of their dissimilar embryogenesis. Based on the detailed radiographic and surgical findings of 39 cases of double cord malformations and the autopsy data on two other cases, this study endorses a new classification for double cord malformations and proposes a unified theory of embryogenesis for all their variant forms and features. The new classification recommends the term split cord malformation (SCM) for all double spinal cords. A Type I SCM consists of two hemicords, each contained within its own dural tube and separated by a dura-sheathed rigid osseocartilaginous median septum. A Type II SCM consists of two hemicords housed in a single dural tube separated by a nonrigid, fibrous median septum. These two essential features necessary for typing, the state of the dural tube and the nature of the median septum, do not ever overlap between the two main forms and can always be demonstrated by imaging studies so that accurate preoperative typing is always possible. All other associated structures in SCM such as paramedian nerve roots, myelomeningoceles manqué, and centromedian vascular structures frequently do overlap between types and are not reliable typing criteria. The unified theory of embryogenesis proposes that all variant types of SCMs have a common embryogenetic mechanism. Basic to this mechanism is the formation of adhesions between ecto- and endoderm, leading to an accessory neurenteric canal around which condenses an endomesenchymal tract that bisects the developing notochord and causes formation of two hemineural plates. The altered state of the emerging split neural tube and the subsequent ontogenetic fates of the constituent components of the endomesenchymal tract ultimately determine the configuration and orientation of the hemicords, the nature of the median septum, the coexistence of various vascular, lipomatous, neural, and fibrous oddities within the median cleft, the high association with open myelodysplastic and cutaneous lesions, and the seemingly unlikely relationship with fore and midgut anomalies. The multiple facets of this theory are presented in increasing complexity against the background of known embryological facts and theories; the validity of each facet is tested by comparing structures and phenomena predicted by the facet with actual radiographic, surgical, and histopathological findings of these 41 cases of SCM.

Spinal cord injury without radiographic abnormalities in children

Spinal cord injury in children often occurs without evidence of fracture or dislocation. The mechanisms of neural damage in this syndrome of spinal cord injury without radiographic abnormality (SCIWORA) include flexion, hyperextension, longitudinal distraction, and ischemia. Inherent elasticity of the vertebral column in infants and young children, among other age-related anatomical peculiarities, render the pediatric spine exceedingly vulnerable to deforming forces. The neurological lesions encountered in this syndrome include a high incidence of complete and severe partial cord lesions. Children younger than 8 years old sustain more serious neurological damage and suffer a larger number of upper cervical cord lesions than children aged over 8 years. Of the children with SCIWORA, 52% have delayed onset of paralysis up to 4 days after injury, and most of these children recall transient paresthesia, numbness, or subjective paralysis. Management includes tomography and flexion-extension films to rule out incipient instability, and immobilization with a cervical collar. Delayed dynamic films are essential to exclude late instability, which, if present, should be managed with Halo fixation or surgical fusion. The long-term prognosis in cases of SCIWORA is grim. Most children with complete and severe lesions do not recover; only those with initially mild neural injuries make satisfactory neurological recovery.

Tethered cord syndrome in adults

Patients with tethered cord syndrome (TCS) rarely have symptomatic onset in adulthood. Twenty-three adult patients with TCS were studied with respect to the clinical, radiological, and pathological features of this syndrome. Specific circumstances involving either additional tugging of the already tight conus, narrowing of the spinal canal, or direct trauma to the back or buttocks precipitated symptomatic onset in 60% of patients. Diffuse and non-dermatomal leg pain, often referred to the anorectal region, was the most common presenting symptom. Progressive sensorimotor deficits in the lower extremities as well as bladder and bowel dysfunction were also common findings; but, unlike TCS in children, progressive foot and spinal deformities were not seen. As in TCS with onset in childhood, the most common tethering lesions were thickened filum, intradural lipoma, and fibrous adhesions. The degree of cord traction, rather than the type or distribution of the tethering lesions, probably determines the age of symptom onset: less severe traction remains asymptomatic in childhood but results in neurological dysfunction in later life due to repeated tugging of the conus during natural head and neck flexion, or when abnormal tension is aggravated by trauma or spondylotic canal stenosis. Metrizamide myelography revealed the diagnosis of tethered conus in most cases, but the addition of computerized tomographic imaging provided valuable structural details concerning the tethering lesion. The surgical outcome was gratifying in relation to pain and motor weakness but disappointing in the resolution of bowel and bladder dysfunction. Early diagnosis and adequate release of the tethered conus are the keys to successful management.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Split cord malformation: Part II: Clinical syndrome

Thirty-nine patients with split cord malformations (SCM) were studied in detail with respect to their clinical, radiographic, and surgical findings as well as their outcome data. Eight patients were adults and 31 patients were children. According to the classification endorsed by Part I of the SCM study, 19 patients had Type I SCM (6 adults and 13 children), 18 patients had Type II SCM (2 adults and 16 children), and 2 patients had composite SCM with both lesion types situated in tandem. Six SCMs were cervical, 2 were thoracic, and 31 were in the lumbar region. All 8 adults had pain and progressive sensorimotor deficits at diagnosis. Only 16 of the 31 children had symptoms, and among these, 14 had progressive sensorimotor deficits, but only 6 had pain. The difference in the clinical picture between adults and children is similar to that described in the tethered cord syndrome, except for left-right functional discrepancy, which was prominent in 8 children with SCM but rarely seen in tethered cord syndrome due to other causes. Cutaneous manifestations of either occult or open dysraphic states were present in all but 3 patients; hypertrichosis was by far the best predictor of an underlying SCM, being found in 56% in the series. Neurological deterioration in SCM was independent of the lesion type: the Type I:Type II ratio for symptomatic progression was 13:11. It was also independent of the location of the lesion: 67% of patients with cervical SCMs had symptomatic progression versus 64% of patients with thoracolumbar lesions. High-resolution, thin cut, axial computed tomographic myelography using bone algorithms was more sensitive than magnetic resonance imaging in defining the anatomical details of the SCM. Radiographic classifications of the SCM, using the nature of the median septum and the number of dural tubes as criteria, was always possible without ambiguity. However, whereas every Type I bone septum was identified preoperatively, only 5 Type II fibrous septa were revealed by preoperative imaging, even though a fibrous septum and/or other fibroneurovascular bands were found tethering the hemicords in every Type II case at surgery. Complete imaging studies also showed that all lumbar SCMs had low-lying coni and at least one additional tethering lesion besides the split cords, whereas only 1 of 7 cervical and high thoracic SCMs had a low conus and a second tethering lesion. The surgical goal for SCM was release of the tethered hemicords by eliminating the bone spurs, dural sleeves, fibrous septa, or any fibroneurovascular bands (myelomeningoceles manqué) that might be transfixing the split cord. Type I cases were technically more difficult and had a slightly higher surgical morbidity than Type II cases, especially if an oblique bone septum had asymmetrically divided the cord into one larger hemicord and one smaller, hence, very delicate, hemicord.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of positive pressure airway support on mortality and the need for intubation in cardiogenic pulmonary edema: a systematic review

OBJECTIVE

To critically appraise and summarize the trials examining the addition of continuous positive airway pressure (CPAP) or noninvasive positive pressure ventilation (NPPV) to standard therapy on hospital mortality, need for endotracheal intubation, and predischarge left ventricular function in patients admitted to the hospital with cardiogenic pulmonary edema with gas exchange abnormalities.

DATA SOURCES

We searched MEDLINE (1983 to June 1997) and bibliographies of all selected articles and review articles. We also reviewed the abstracts from the proceedings of relevant meetings from 1985 to 1997.

STUDY SELECTION

(1) POPULATION: patients presenting to hospital with cardiogenic pulmonary edema; (2) intervention: one of the following three: (a) the use of CPAP and standard medical therapy vs standard medical therapy alone; (b) the use of NPPV and standard medical therapy vs standard medical therapy alone; and (c) the use of NPPV and standard therapy vs CPAP and standard therapy; (3) outcome: hospital survival, need for endotracheal intubation, or predischarge left ventricular dysfunction; and (4) study design: randomized controlled trial (RCT); if there were fewer than two RCTs, other study designs were included.

DATA EXTRACTION

Two authors independently extracted data and evaluated the methodologic quality of the studies.

DATA SYNTHESIS

CPAP was associated with a decrease in need for intubation (risk difference, -26%, 95% confidence intervals, -13 to -38%) and a trend to a decrease in hospital mortality (risk difference, -6.6%; +3 to -16%) compared with standard therapy alone. There was insufficient evidence to comment on the effectiveness of NPPV either compared with standard therapy or CPAP and standard therapy. Evidence was also lacking on the potential for either intervention to cause harm.

CONCLUSIONS

A modest amount of favorable experimental evidence exists to support the use of CPAP in patients with cardiogenic pulmonary edema. CPAP appears to decrease intubation rates and data suggest a trend toward a decrease in mortality, although the potential for harm has not been excluded. The role of NPPV in this setting requires further study before it can be widely recommended.

Spinal cord injury without radiographic abnormality in children--the SCIWORA syndrome

Spinal cord injury in children frequently occurs without fracture or dislocation. The clinical profiles of 55 children with spinal cord injury without radiographic abnormalities (SCIWORA) are reported in detail to illustrate features of this syndrome. No patient had vertebral fracture or dislocation on plain films and tomographies. There were ten upper cervical (C1-C4), 33 lower cervical (C5-C8), and 12 thoracic cord injuries; of these, 22 were complete or severe lesions and 33 were mild lesions. The mechanism of the neural injury probably relates to the inherent elasticity of the juvenile spine, which permits self-reducing but significant intersegmental displacements when subjected to flexion, extension, and distraction forces. The spinal cord is therefore vulnerable to injury even though the vertebral column is spared from disruption, and this vulnerability is most evident in children younger than 8 years. All but one of the 22 children with profound neurologic injuries were younger than 8 years (p less than 0.000001), whereas 24 of 33 children with mild injuries were older. Younger children were also more likely to have severe upper cervical lesions (p less than 0.05); lower cervical lesions were distributed evenly through the ages of 6 months to 16 years. Thoracic injuries most commonly resulted from distraction or crushing. Distraction invariably involved violent forces, and crush injuries were usually caused by children being run over while lying prone, when the spinal column was acutely bowed towards the spongy abdominal and thoracic cavities. Fifteen children had delayed onset of neurologic deficits; nine of these had transient warning symptoms of paresthesia, subjective paralysis, and Lhermitte's phenomenon 30 minutes to 4 days before the onset of deterioration. Eight other children suffered a second SCIWORA 3 days to 10 weeks after the initial SCIWORA. The spines in these children were presumably rendered incipiently unstable by the initial injury and thus were susceptible to additional, often more severe, neurologic trauma. The long-term neurologic outcome in children with SCIWORA is solely determined by their admission neurologic status. Realistically, the outcome can thus only be improved by: 1) ruling out occult fractures and subluxation which will require surgical fusion; 2) identifying patients likely to have delayed deterioration; and 3) preventing recurrent SCIWORA. Our experience and recommendations in these regards are discussed.

Sacral agenesis and caudal spinal cord malformations

Thirty-three children and one adult with sacral agenesis (SA) were studied by computed tomographic myelography and/or magnetic resonance imaging and were monitored for a mean period of 4.7 years. Four children had the OEIS (concurrent omphalocele, cloacal exstrophy, imperforate anus, and spinal deformities) complex, and three others had VATER (vertebral abnormality, anal imperforation, tracheoesophageal fistula, and renal-radial anomalies) syndrome. All patients shared some of the characteristic features of SA, namely, a short, intergluteal cleft, flattened buttocks, narrow hips, distal leg atrophy, and talipes deformities. Neurologically, lumbosacral sensation was much better preserved than the motor functions, and urinary and bowel symptoms were universal. The level of the vertebral aplasia was correlated with the motor but not with the sensory level. The important neuroimaging findings of SA were as follows: 1) 12 patients (35%) had nonstenotic, tapered narrowing of the caudal bony canal, and 2 patients had hyperostosis indenting the caudal thecal sac; 2) 16 patients (47%) had nonstenotic, tapered narrowing and shortening of the dural sac, but 3 patients (9%) had true, symptomatic dural stenosis, in which the cauda equina was severely constricted by a pencil-sized caudal dural sac; 3) the coni could be divided into those ending above the L1 vertebral body (Group 1, 14 patients) and those ending below L1 (Group 2, 20 patients). Thirteen of 14 Group 1 coni were club or wedge-shaped, terminating abruptly at T11 or T12, as if the normal tip was missing. All 20 Group 2 coni were tethered: 13 were tethered by a thick filum; 2 were extremely elongated and had a terminal hydromyelia; 3 were terminal myelocystoceles; and 2 were tethered by a transitional lipoma. High blunt coni were highly correlated with high (severe) sacral malformations (sacrum ending at S1), but low-lying tethered coni were highly correlated with low sacral malformations (S2 or lower pieces present).(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of dietary intake of omega-3 and omega-6 fatty acids on severity of asthma in children

We assessed the clinical and biochemical effects in asthmatic children of fish oil supplementation and a diet that increases omega-3 and reduces omega-6 fatty acids. Thirty nine asthmatic children aged 8-12 yrs participated in a double-blind, randomized, controlled trial for 6 months during which they received fish oil capsules plus canola oil and margarine (omega-3 group) or safflower oil capsules plus sunflower oil and margarine (omega-6 group). Plasma fatty acids, stimulated tumour necrosis factor alpha (TNFalpha) production, circulating eosinophil numbers and lung function were measured at baseline and after 3 and 6 months of dietary modification. Day and night symptoms, peak flow rates and medication use were recorded for 1 week prior to laboratory visits. Plasma phospholipid omega-3 fatty acids were significantly greater in the omega-3 group at 3 and 6 months compared to the omega-6 group (p<0.001). In the omega-3 group TNFalpha production fell significantly compared with baseline (p=0.026), but the magnitude of change between groups did not reach significance (p=0.075). There were no significant changes in clinical outcome measures. Dietary enrichment of omega-3 fatty acids over 6 months increased plasma levels of these fatty acids, reduced stimulated tumour necrosis factor alpha production, but had no effect on the clinical severity of asthma in these children.

Magnetic resonance imaging in the evaluation of spinal cord injury without radiographic abnormality in children

Seven children aged birth to 17 years with spinal cord injury without radiographic abnormality (SCIWORA) were studied with magnetic resonance imaging (MRI) between 3 hours and 16 days after the injury. There were six cervical cord injuries and one thoracic cord injury. The MRI findings were divided into two groups: extraneural and neural. The extraneural findings included one case of anterior longitudinal ligament disruption and anterior C6-C7 disc herniation associated with hyperextension; one case of posterior longitudinal ligament disruption and C2-C3 disc herniation associated with lateral flexion; and one case of C6-C7 disc abnormality consistent with increased water content occurring with hyperflexion. These ligament and disc injuries did not correlate with late instability. The neural MRI findings included one case of cord transection with rostral cord stump hemorrhage and one case of hemorrhage involving the majority of the cord's transverse diameter, both associated with permanent complete cord injuries; one case of hemorrhage involving a minor portion of the cord and of the brain stem's transverse diameter associated with a severe partial cord injury but subsequent incomplete improvement; one case of edema without hemorrhage associated with Brown-Séquard syndrome and subsequent incomplete improvement; and three cases of normal cord signal and outline. Two of the latter patients had mild cord injuries that recovered completely. In the third, a child with complete T12 sensorimotor paralysis at presentation, the normal MRI findings predicted the subsequent complete recovery. No extraaxial compressive lesion was demonstrated in these seven children.(ABSTRACT TRUNCATED AT 250 WORDS)

Lysis of intraventricular blood clot with urokinase in a canine model: Part 3. Effects of intraventricular urokinase on clot lysis and posthemorrhagic hydrocephalus

Nine millilitres of preclotted autologous blood was injected into the ventricles of 10 adult mongrel dogs (control dogs) to create subtotal ventricular casts with solid clots. The neurological status and systemic fibrinolytic profiles were closely monitored, and the changes in clot and ventricular volumes were measured by serial computed tomography (CT) for 3 months. The control animals showed severe neurological impairment for 7 to 9 days. No visible lysis of the intraventricular clots occurred for 5 to 7 days, after which slow clot lysis occurred at a constant rate. Complete lysis of the 10 clots took 38 to 65 days, indicating that canine cerebrospinal fluid normally possessed limited capacity for in situ fibrinolysis. Of the 10 control dogs, 8 developed progressive ventricular enlargement after a transient initial shrinkage parallel with initial clot lysis. Their final ventricular volume at 3 months was as much as 14 times the base line ventricular volume. Necropsy studies disclosed increased basal subarachnoid fibrosis and extensive ependymal and subependymal damage in the lateral ventricular walls of the hydrocephalic dogs. Ten other dogs (UK dogs) were given similar ventricular clot injections. Six hours later, each UK dog was begun on a regimen of 20,000 IU of intraventricular urokinase every 12 hours until solid clots were no longer seen in the ventricles on CT. In all 10 UK dogs, intraventricular urokinase induced complete lysis in 3 to 6 days without causing local or systemic hemorrhages. The neurological status of all 10 dogs also improved promptly. In 8 UK dogs, the ventricles that were initially distended by clots showed rapid shrinkage parallel with thrombolysis to a final volume at 3 months of less than four times the initial ventricular volume. Only 2 animals had persistently large or expanding ventricles. At necropsy, the ependymal and subarachnoid spaces of the UK dogs were remarkably free of damage and fibrosis. The possible mechanisms by which intraventricular urokinase may prevent posthemorrhagic hydrocephalus are discussed.

Parental smoking and childhood cancer: results from the United Kingdom Childhood Cancer Study

There are strong a priori reasons for considering parental smoking behaviour as a risk factor for childhood cancer but case - control studies have found relative risks of mostly only just above one. To investigate this further, self-reported smoking habits in parents of 3838 children with cancer and 7629 control children included in the United Kingdom Childhood Cancer Study (UKCCS) were analysed. Separate analyses were performed for four major groups (leukaemia, lymphoma, central nervous system tumours and other solid tumours) and more detailed diagnostic subgroups by logistic regression. In the four major groups, after adjustment for parental age and deprivation there were nonsignificant trends of increasing risk with number of cigarettes smoked for paternal preconception smoking and nonsignificant trends of decreasing risk for maternal preconception smoking (all P-values for trend >0.05). Among the diagnostic subgroups, a statistically significant increased risk of developing hepatoblastoma was found in children whose mothers smoked preconceptionally (OR=2.68, P=0.02) and strongest (relative to neither parent smoking) for both parents smoking (OR=4.74, P=0.003). This could be a chance result arising from multiple subgroup analysis. Statistically significant negative trends were found for maternal smoking during pregnancy for all diagnoses together (P<0.001) and for most individual groups, but there was evidence of under-reporting of smoking by case mothers. In conclusion, the UKCCS does not provide significant evidence that parental smoking is a risk factor for any of the major groups of childhood cancers.

The long-term outcome in children with late-onset aqueductal stenosis resulting from benign intrinsic tectal tumors

Benign intrinsic tumors arising in the dorsal midbrain have long been recognized as a potential cause of late-onset aqueductal stenosis. Where histopathological studies of such lesions have been performed, the majority have been reported to be low-grade gliomas. Because these tumors often present with a paucity of neurological findings and a characteristic radiographic appearance and because there has been substantial uncertainty regarding their potential for long-term progression, the authors have routinely deferred biopsy and/or radiotherapy for these lesions until there has been clear-cut evidence of disease progression. Herein, the authors report their experience with 16 children manifesting this syndrome who were treated between 1979 and 1992. The patients ranged in age from 6 months to 14 years at presentation (median 9.75 years). In general, symptoms of increased intracranial pressure developed insidiously; three of the older children had exhibited profound macrocephaly since infancy, which predated the onset of other symptoms of hydrocephalus by several years. Only one of the 16 children showed evidence of brain-stem dysfunction at presentation, a partial Parinaud's syndrome that resolved following placement of a ventriculoperitoneal shunt. In 12 patients, the tumor was detected by magnetic resonance (MR) imaging at initial evaluation as a bulbous enlargement of the tectal plate. In four patients who presented before the advent of MR imaging, initial computerized tomography (CT) scans failed to delineate the tectal lesion convincingly; however, subsequent MR studies clearly demonstrated the presence of an intrinsic tectal mass. All 16 patients underwent cerebrospinal fluid diversion initially, with conservative management of the tectal lesion and close long-term follow-up monitoring. Four children ultimately demonstrated clinical signs of progressive tumor growth with the insidious onset of partial or complete Parinaud's syndrome, despite the presence of a functioning shunt. The median interval to symptom progression was 7.8 years from the time of shunt insertion and 11.5 years from the onset of initial symptoms and signs of hydrocephalus. Follow-up CT and MR studies demonstrated obvious tumor enlargement in three of the four patients who then underwent stereotactic or open biopsy. The histological diagnosis in these three was benign mixed glioma, anaplastic astrocytoma, and low-grade astrocytoma. All four patients with clinical evidence of disease progression were treated with conventional radiotherapy; the patient with an anaplastic astrocytoma also received focal stereotactic radiosurgery. These patients subsequently remained clinically stable, with three showing tumor regression and one showing stable disease on serial MR studies (median follow-up period from tumor progression, 4.25 years).(ABSTRACT TRUNCATED AT 400 WORDS)

Dissemination of supratentorial malignant gliomas via the cerebrospinal fluid in children

Of 100 children with supratentorial gliomas (excluding gliomas of the anterior visual pathways) treated at the Children's Hospital of Pittsburgh from 1980 to 1990, 34 had malignant gliomas. Follow-up was adequate in 33 of these patients, and an antemortem diagnosis of dissemination of the malignant glioma via the cerebrospinal fluid (CSF) was made in 11. Of these 11, 8 were boys and 3 were girls; they ranged in age from 17 months to 16 years at the time of diagnosis of the primary glioma. The distribution of histological types was as follows: glioblastoma multiforme, 4; malignant oligodendroglioma, 3; anaplastic astrocytoma, 2; malignant mixed glioma, 1; and malignant ependymoma, 1. The interval between diagnosis and CSF dissemination ranged from 1 week to 59 months (median, 8 months). Survival after dissemination ranged from 3 weeks to 11 months (median, 4 months). Two patients were alive 5 and 3 months after diagnosis of dissemination, respectively. These 11 patients were compared with the other 22 patients who did not have CSF dissemination. The risk factors for dissemination suggested by our data were male sex, ventricular operative entry, multiple resections, and malignant oligodendroglioma. Because of the high incidence (33%) of CSF dissemination, postoperative evaluation of the craniospinal axis with gadolinium-enhanced magnetic resonance imaging should be performed on all children with supratentorial malignant gliomas. Moreover, since the mortality is extremely high once dissemination has occurred, craniospinal irradiation should be considered in children with one or more of the above risk factors, even before symptoms or definite radiological evidence of CSF dissemination emerge.

Low-pressure hydrocephalic state and viscoelastic alterations in the brain

Most shunt-dependent hydrocephalic patients present with predictable symptoms of headache and mental status changes when their cerebrospinal fluid shunts malfunction. Their intracranial pressure (ICP) is usually high, and they usually respond to routine shunt revision. This report describes 12 shunted patients who were admitted with the full-blown hydrocephalic syndrome but with low to low-normal ICP. All 12 patients had been maintained previously on medium-pressure shunts. Their symptoms included headache, lethargy, obtundation, and cranial neuropathies. At peak symptoms, their ventricular sizes were large (ventricular/biparietal ratio of 0.35 to 0.45) in six and massive (ventricular/biparietal ratio > 0.45) in six and their ICPs ranged from 2.2 to 6.6 mm Hg, with a mean of 4.4 +/- 1.3 mm Hg (+/- standard deviation), i.e., below or well within the pressure range of their shunts. The pressure volume index of three patients at peak symptoms ranged from 39.2 to 48.5 ml, with a mean of 43.9 +/- 4.6 ml, which represents a 190% increase from the predicted normal value. Seven patients failed to improve with multiple shunt revisions, including the use of low-pressure valves. In 11 patients, symptoms and ventriculomegaly were not reversed except with prolonged external ventricular drainage at subzero pressures (mean external ventricular drainage nadir pressure of -5.7 +/- 3.6 mm Hg, for a mean period of 22.2 days). During external ventricular drainage treatment, symptoms correlated only with ventricular size and not with ICP. All 11 were subsequently treated successfully with a new medium- or low-pressure shunt. One patient was treated successfully with prolonged shunt pumping. We postulate that: 1) the development of this low-pressure hydrocephalic state is related to alteration of the viscoelastic modulus of the brain, secondary to expulsion of extracellular water from the brain parenchyma, and to structural changes in brain tissues due to prolonged overstretching; 2) certain patients are susceptible to developing low-pressure hydrocephalic state because of an innate low brain elasticity due to bioatrophic changes; 3) low-pressure hydrocephalic state symptoms are due not to pressure changes but to brain tissue distortion and cortical ischemia secondary to severe ventricular distortion and elevated radial compressive stresses within the brain; and 4) treatment must be directed toward allowing the entry of water into the brain parenchyma and the restoration of baseline brain viscoelasticity.

Nonsurgical management of extradural hematomas in children

With the advent of computerized tomography (CT), an increasing number of patients with only minimal neurological symptoms and no signs of brain herniation are found to harbor subacute or chronic extradural hematomas (EH's). The authors present the cases of 11 symptomatic but neurologically normal children with medium to large EH's managed by close observation. These EH's were discovered 4 hours to 6 days after injury; three were in the posterior fossa, seven over the frontoparietal convexity, and one in the temporal fossa. These clots were followed by serial CT scans. Nine children recovered without surgery from 4 to 18 days after injury, and all had evidence on CT of spontaneous clot resorption. Of these nine EH's, five clots displayed volume expansion from 5 to 16 days after injury before final resorption occurred. Expansion correlated with persistence or increase in symptoms, whereas resorption correlated with improvement. Two patients showed gradual uncal herniation on Days 6 and 8, respectively, presumably during the "expansile phase" of their clots. Both had emergency craniotomy and recovered without morbidity. It is hypothesized that the resorption dynamics of the subacute or chronic EH are similar to that of the chronic subdural hematoma, with predictable volume changes, and the outcome of each lesion depends on the interplay between the patient's intracranial pressure buffering capacity and the rate of volume change. If subtle signs of brain dysfunction are adopted to signal the failure of conservative treatment and the need for craniotomy, these patients may be safely, and many successfully, managed without surgery. Factors that influence outcome of medical treatment include the size, location, configuration, and the rapidity of accumulation of the clot, the presence of associated intradural lesions, the extracranial decompression of blood through skull diastases, and the age of the patient. These factors, the criteria for patient selection, and the indications for immediate operative intervention are discussed.

Dissemination of low grade intracranial astrocytomas in children

The authors report three cases of histologically benign intracranial astrocytomas that developed in children and disseminated within the neuraxis. Multicentric disease was evident at the time of diagnosis in two of these patients, one of whom subsequently developed peritoneal seeding of tumor after placement of a ventriculoperitoneal shunt. To our knowledge, this latter represents the first documented case of extraneural seeding of a benign astrocytoma. All three children are currently alive and well 17-117 months after the diagnosis of tumor dissemination. We review the literature regarding this uncommon problem and discuss the pathophysiology and treatment options. Our results indicate that the presence of disseminated disease may not preclude long term survival, provided the lesions are truly benign histologically and that adjuvant therapy is instituted promptly.

Outcome following hindbrain decompression of symptomatic Chiari malformations in children previously treated with myelomeningocele closure and shunts

Between 1975 and 1989, 25 children treated with myelomeningocele closure and shunting for hydrocephalus at the Children's Hospital of Pittsburgh developed progressive lower brain-stem dysfunction from their Chiari malformation. Retrospective univariate and multivariate analyses of these cases were undertaken to assess the relationship between preoperative clinical factors and postoperative outcome. Since earlier reports have suggested that neonates with symptomatic Chiari malformations show a less favorable response than older children to craniocervical decompression, particular attention was directed at examining the effect of age on preoperative symptoms and postoperative outcome. Patients were subdivided by age into two groups, namely: 13 patients who became symptomatic before 2 months of age (neonatal group) and 12 older infants and children who developed initial symptoms between 6 months and 10 years of age. Once symptoms developed, patients in both groups deteriorated progressively until brain-stem decompression was performed. The mode of presentation and the rate and extent of neurological deterioration differed substantially in the two groups. Whereas the neonates typically showed rapid neurological deterioration and often manifested profound brain-stem dysfunction within a period of several days, the older patients experienced a more insidious symptom progression and rarely demonstrated the severe degree of impairment seen in the neonates. All patients underwent suboccipital craniectomy, cervical laminectomy, and dural decompression. A shunt from the fourth ventricle and/or syrinx to the subarachnoid space was placed in those with significant syringomyelia. Following surgery, 17 patients had complete or nearly complete resolution of all signs of brain-stem compression, three had mild to moderate residual deficits, and five showed no improvement. Outcome correlated closely with the preoperative neurological status. In particular, the presence of bilateral vocal cord paralysis was associated with a poor response to surgery (p < 0.001 on both univariate and multivariate analyses). Of the six patients (all neonates) who progressed to complete bilateral vocal cord paralysis before surgery, only one improved. In contrast, all patients with less profound but nonetheless severe deficits recovered function postoperatively. Although the neonates as a group had a poorer outcome than did the older patients (p = 0.02 on univariate analysis), this in large part reflected their more severe preoperative impairments; neonates who still had some preservation of vocal cord function before surgery subsequently did as well as the older patients. Accordingly, age did not prove to be an independent prognostic factor on multivariate analysis. Taken together, these results indicate that, in most patients with symptomatic Chiari II malformations (including neonates), neurological deficits are potentially reversible if hindbrain decompression is performed expeditiously.

Traumatic atlanto-occipital dislocation with survival: case report and review

Traumatic atlanto-occipital (A-O) dislocation is a rare injury that is associated with a high mortality rate. We are presenting the case of a 5-year-old child with this entity to illustrate the mechanism of injury, the often-confusing clinical picture, and the use of diaphragmatic fluoroscopy to localize the neurological lesion. We suggest using plain lateral roentgenograms, anteroposterior tomograms, and a cervical computed tomographic scan to confirm the diagnosis of A-O dislocation. We strongly favor using the halo apparatus for immediate immobilization and posterior occipitoatlantoaxial fusion for long term stability. The various diagnostic radiographic criteria for A-O dislocation are compared and discussed.

Monoamine oxidase: associations with alcohol dependence, smoking and other measures of psychopathology

BACKGROUND

Many reports have appeared on associations between platelet monoamine oxidase (MAO) activity and susceptibility to psychiatric conditions; principally alcohol dependence but also conduct disorder, other drug use and depression. Recently, it has become apparent that MAO activity is inhibited by some component of cigarette smoke, and smokers have low platelet MAO activity. Since the prevalence of smoking is higher in many of the conditions in which MAO has been implicated, the MAO susceptibility associations may be partly, or entirely, false.

METHODS

We have measured platelet MAO in 1551 subjects, recruited from the Australian NHMRC Twin Registry, who have provided information on alcohol use and dependence, smoking, conduct disorder, depression, attempted suicide, panic disorder and social phobia.

RESULTS

Current smoking reduced platelet MAO activity in a significant and dose-related manner, with no evidence of lower MAO in ex-smokers or in non-smoking subjects with co-twins who smoked. Alcohol use and lifetime DSM-III-R alcohol dependence history were not associated with MAO activity when smoking was taken into account. Depression, panic disorder and social phobia showed no significant associations with platelet MAO activity. Subjects with a history of serious attempts at suicide had low platelet MAO activity; but although the difference from controls was as great as the reduction associated with smoking it was not significant after correction for smoking effects.

CONCLUSIONS

Although synaptic MAO activity undoubtedly plays a role in psychopathology, the concept that platelet MAO activity is a direct genetic marker of vulnerability to alcohol dependence cannot be sustained.

Phosphoglycerate kinase-1 is a predictor of poor survival and a novel prognostic biomarker of chemoresistance to paclitaxel treatment in breast cancer

Background:

Phosphoglycerate kinase-1 (PGK1) has been recently documented in various malignancies; however, the molecular mechanisms of the variable PGK1 expression and its clinical significance in terms of survival status remain unclear.

Methods:

Real-time quantitative PCR (real-time qPCR) and western blotting were used to verify PGK1 expression in 46 fresh breast cancer tissues and matched normal tissues. A tissue microarray (TMA) comprising 401 breast cancer tissues and 123 matched normal tissues was investigated by immunohistochemistry for PGK1 expression. Then, the correlation between PGK1 expression and the clinicopathologic features was analysed.

Results:

PGK1 mRNA and protein expression were significantly increased in breast cancer tissues compared with that in normal breast tissues. High PGK1 expression was significantly associated with higher histologic grade (P=0.009) and positive status of ER (P=0.004), Her-2 (P=0.026) and P53 (P=0.012). High levels of PGK1 expression were associated with worse overall survival (OS, P=0.02). Furthermore, patients who underwent paclitaxel chemotherapy with high levels PGK1 expression had shorter OS than did those with low levels of PGK1 expression (P<0.001). Multivariate analysis indicated that PGK1 (P=0.001) was an independent predictor in the patients treated with paclitaxel.

Conclusions:

PGK1 is a prognostic biomarker of chemoresistance to paclitaxel treatment in breast cancer.

Cardiotonic agents. 1. Novel 8-aryl-substituted imidazo[1,2-a]- and -[1,5-a]pyridines and imidazo[1,5-a]pyridinones as potential positive inotropic agents

Several 8-arylimidazo[1,2-a]pyridines, 8-arylimidazo[1,5-a]pyridines, and 8-arylimidazo[1,5-a]pyridinones were prepared and tested in vitro for potential cardiac inotropic and electrophysiological activity. Selected analogues were further tested in vivo in canine hemodynamic and cardiac electrophysiology models. Compounds having an imidazole substituent consistently showed activity. A pharmacophoric relationship between heterocycle-phenyl-imidazole and positive inotropic activity was noted. The significance of this relationship is discussed.

A new surgical approach to closure of large lumbosacral meningomyelocele defects

A new method for the reconstruction of large thoracolumbar and lumbosacral meningomyelocele defects is described in which latissimus dorsi and gluteus maximus myocutaneous units are advanced medially and reapproximated in the midline, permitting primary closure of the defect in three layers. The flaps are based on the thoracodorsal and superior gluteal vessels and the intervening thoracolumbar fascia, providing tension-free, durable, and viable soft-tissue coverage over the dural repair. No lateral relaxing incisions, delays, or skin grafts are necessary. This technique has been used successfully in the repair of nine large meningomyelocele defects, and uncomplicated wound closure was achieved in all cases. The anatomic basis, technique, advantages, and functional implications of our approach are described. The flaps described do not alter the nerve supply of the muscles and merely redefine the muscle origins; therefore, no functional deficit from the reconstructive surgery is anticipated.

Lysis of intraventricular blood clot with urokinase in a canine model: Part 2. In vivo safety study of intraventricular urokinase

It was determined from in vitro experiments that the minimal dose of urokinase required to lyse 10 ml of clotted canine blood within a closed space must exceed 10,000 IU. We empirically doubled this minimum effective dose and tested the in vivo safety of injecting 20,000 IU of urokinase every 12 hours for 4 days into the ventricles of six adult mongrel dogs through an implanted catheter-reservoir system. The animals were monitored carefully for local and systemic bleeding by neurological and clinical examination, hematological tests reflecting systemic fibrinolytic status, serial computed tomography, and postmortem histological examinations of the brain, meninges, and peripheral organs. It was found that this intraventricular dose regimen of urokinase did not cause intracranial hemorrhage even though the dogs had recent brain wounds related to transcerebral ventricular catheterization. Mild activation of systemic fibrinolysis, implying passage of the enzyme from ventricle to blood, occurred 4 to 6 hours after each intraventricular injection, but no systemic hemorrhages were seen. This dose regimen also did not cause acute or chronic inflammatory changes in the brain or meninges and did not disturb cerebrospinal fluid circulation.

Lysis of intraventricular blood clot with urokinase in a canine model: Part 1. Canine intraventricular blood cast model

To test the safety and feasibility of using direct instillation of urokinase to induce rapid lysis of intraventricular clots, an animal model of intraventricular blood cast is required. Injections of 11 ml of fresh, unclotted autologous blood into the ventricles of adult mongrel dogs did not produce a solid blood cast in the ventricular system, suggesting that the adult dogs have an unusual ability to clear uncoagulated whole blood from the ventricles and subarachnoid space. Injection of 9 ml of preclotted blood resulted in a subtotal cast of the ventricles, leaving only portions of the occipital horns free of solid clots. This volume of injected clots incurred no mortality and minimal morbidity, whereas injection of 10 to 12 ml resulted in a mortality of 42% and formidable morbidity. The technique of producing this intraventricular blood cast model, as well as that of implanting an indwelling ventricular catheter-reservoir system useful in chronic urokinase administration, is described.