Unclassified white matter disorders: A diagnostic journey requiring close collaboration between clinical and laboratory services

BACKGROUND

Next generation sequencing studies have revealed an ever-increasing number of causes for genetic disorders of central nervous system white matter. A substantial number of disorders are identifiable from their specific pattern of biochemical and/or imaging findings for which single gene testing may be indicated. Beyond this group, the causes of genetic white matter disorders are unclear and a broader approach to genomic testing is recommended.

AIM

This study aimed to identify the genetic causes for a group of individuals with unclassified white matter disorders with suspected genetic aetiology and highlight the investigations required when the initial testing is non-diagnostic.

METHODS

Twenty-six individuals from 22 families with unclassified white matter disorders underwent deep phenotyping and genome sequencing performed on trio, or larger, family groups. Functional studies and transcriptomics were used to resolve variants of uncertain significance with potential clinical relevance.

RESULTS

Causative or candidate variants were identified in 15/22 (68.2%) families. Six of the 15 implicated genes had been previously associated with white matter disease (COL4A1, NDUFV1, SLC17A5, TUBB4A, BOLA3, DARS2). Patients with variants in the latter two presented with an atypical phenotype. The other nine genes had not been specifically associated with white matter disease at the time of diagnosis and included genes associated with monogenic syndromes, developmental disorders, and developmental and epileptic encephalopathies (STAG2, LSS, FIG4, GLS, PMPCA, SPTBN1, AGO2, SCN2A, SCN8A). Consequently, only 46% of the diagnoses would have been made via a current leukodystrophy gene panel test.

DISCUSSION

These results confirm the importance of broad genomic testing for patients with white matter disorders. The high diagnostic yield reflects the integration of deep phenotyping, whole genome sequencing, trio analysis, functional studies, and transcriptomic analyses.

CONCLUSIONS

Genetic white matter disorders are genetically and phenotypically heterogeneous. Deep phenotyping together with a range of genomic technologies underpin the identification of causes of unclassified white matter disease. A molecular diagnosis is essential for prognostication, appropriate management, and accurate reproductive counseling.

OP0289 LLDAS (LOW LUPUS DISEASE ACTIVITY STATE), LOW DISEASE ACTIVITY (LDA) AND REMISSION (ON- OR OFF-TREATMENT) PREVENT DAMAGE ACCRUAL IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) PATIENTS IN A MULTINATIONAL MULTICENTER COHORT

Background:

Remission, LDA and LDAS have been proposed as treatment goals for SLE. However, the independent impact of these states on damage accrual has not been fully evaluated.

Objectives:

To determine the independent impact of remission (both off & on treatment), LDA, and LLDAS on damage accrual.

Methods:

We studied a long-term longitudinal multinational SLE cohort, including patients completing at least two annual assessments. Remission off-treatment was defined as a SLEDAI (excluding serology) =0, without prednisone and immunosuppressive (IS) drugs. Remission on-treatment was defined as a SLEDAI (excluding serology) =0, prednisone daily dose<=5 mg/d and maintenance IS drugs. LDA was defined as a SLEDAI (excluding serology) <=2, without prednisone or IS drugs. LLDAS was defined as a SLEDAI <=4 with no activity in major organ systems, with no new features of lupus disease activity compared to the previous assessment, prednisone daily dose<=7.5 mg/d and maintenance IS drugs. Antimalarials were allowed in all groups. Damage accrual was ascertained with the SLICC/ACR damage index (SDI). Univariable and multivariable generalized estimated equation (GEE) negative binomial regression models were used. To create mutually exclusive groups, disease activity was divided into five states: remission off-treatment, remission on-treatment (minus remission off treatment), LDA (minus remission), LLDAS (minus remission and LDA) and not-optimally controlled. The proportion of the time that patients were in the specific state at each visit since cohort entry was determined. Possible effect modifiers and confounders adjusted for included sex, age at diagnosis, race/ethnicity, education, baseline disease duration, follow-up time, the highest-ever glucocorticoid dose prior to cohort entry, antimalarials and SDI. Time-dependent covariates were determined at the same annual visit as disease activity state; the outcome was the increase in the SDI and it was assessed at the subsequent visit.

Results:

There were 1,652 patients, 1464 (88.6%) were female, mean age at diagnosis was 34.6 (SD 13.4) years and mean baseline disease duration was 5.5 (SD 4.1) months. Patients had a mean follow-up of 6.5 (SD 4.3) years, 11686 visits were included. 763 patients (46.2%) had an increase in SDI score ≥1 during follow-up. 2483 (21.2%) of the visits were classified as remission off-treatment, 2276 (19.5%) as remission on-treatment, 544 (4.7%) as LDA, 657 (5.6%) as LLDAS and 5726 (49.0%) as not-optimally controlled. Being in remission off-treatment, remission on-treatment, LDA and LLDAS were predictive of a lower probability of damage accrual [remission off-treatment IRR=0.403, 95% CI 0.301-0.541); remission on-treatment IRR=0.313 (95% CI 0.218-0.451) LDA: IRR=0.469 (CI 95% CI 0.272-0.809); LLDAS IRR=0.440 (95% CI 0.241-0.803)]. The multivariable model is summarized in Table 1.

Table 1.

Multivariable GEE model of the impact of disease activity states on damage accrual.

Incidence Rate Ratio95% CIDisease activity stateRemission off treatment0.4030.301-0.541Remission on treatment0.3130.218-0.451LDA0.4690.272-0.809LLDAS0.4400.241-0.803Gender, male1.2741.086-1.495Age at diagnosis1.0241.020-1.029EthnicityCaucasian USRef.Caucasian other1.0170.849-1.217African1.4671.211-1.776Asian0.8630.693-1.075Hispanic1.2661.034-1.550Other1.1210.759-1.656Educational level, years0.9770.957-0.996Disease duration at baseline0.9600.801-1.150Follow-up time0.9420.923-0.960Antimalarial use0.7860.681-0.908Highest prednisone dose before baseline1.0021.001-1.007SDI before1.1001.050-1.1152

LLDAS: Low lupus disease activity state LDA: Low disease activity SDI: SLICC/ACR Damage Index

Conclusion:

Remission on- and off-treatment, LDA and LLDAS were associated with less damage accrual, even adjusting for possible confounders and effect modifiers. This highlights the importance of treating to target in SLE.

Disclosure of Interests:

Manuel F. Ugarte-Gil Grant/research support from: Pfizer, Janssen, John Hanly: None declared, Murray B Urowitz: None declared, Caroline Gordon Speakers bureau: UCB, Consultant of: Center for Disease Control, Astra-Zeneca, MFP, Sanofi, UCB, Sang-Cheol Bae: None declared, Juanita Romero-Diaz: None declared, Jorge Sanchez-Guerrero: None declared, Sasha Bernatsky: None declared, Ann E Clarke Consultant of: AstraZeneca, BristolMyersSquibb, GlaxoSmithKline, and Exagen Diagnostics, Daniel J Wallace Grant/research support from: Exagen, David Isenberg: None declared, Anisur Rahman: None declared, Joan T Merrill: None declared, Paul Fortin: None declared, Dafna D Gladman Consultant of: Abbvie, Janssen, Pfizer, Novartis, Amgen, Grant/research support from: Abbvie, Janssen, Pfizer, Novartis, Amgen, Ian N. Bruce: None declared, Michelle A Petri: None declared, Ellen M Ginzler Grant/research support from: Aurinia pharmaceutical, M.A. Dooley: None declared, Rosalind Ramsey-Goldman: None declared, Susan Manzi: None declared, Andreas Jonsen: None declared, Ronald van Vollenhoven Speakers bureau: AbbVie, Galapagos, GSK, Janssen, Pfizer, UCB, Consultant of: Abbvie, AstraZeneca, Biogen, Biotest, Celgen, Galapagos, Gilead, Janssen, Pfizer, Sanofie, Servier, UCB, Vielabo, Grant/research support from: BMS, GSK, Lilly, UCB, Cynthia Aranow: None declared, Meggan Mackay: None declared, Guillermo Ruiz-Irastorza: None declared, S. Sam Lim: None declared, Murat Inanc: None declared, Kenneth C Kalunian Consultant of: Roche, Biogen, Janssen, AstraZeneca, Eli Lilly, Genetech, Gilead, ILTOO, Nektar, Viela, Equillium, Bristol-Meyers Squibb, Soren Jacobsen Grant/research support from: BMS, Christine Peschken: None declared, Diane L Kamen: None declared, Anca Askanase Consultant of: Abbvie, Grant/research support from: Glaxo Smith Kline, Astra Zeneca, Janssen, Eli Lilly and Company, Mallinckrodt, Pfizer, Bernardo Pons-Estel Consultant of: GSK, Janssen, Graciela S Alarcon: None declared.

Australian clinical consensus guideline for the subacute rehabilitation of childhood stroke

Childhood stroke results in long-term, multifaceted difficulties, affecting motor, cognitive, communication, and behavioral domains of function which impact on participation and quality of life. The Childhood Stroke Consensus Rehabilitation Guideline was developed to improve the care of children with stroke by providing health professionals with recommendations to assist in their rehabilitative treatment. Clinical questions were formulated to inform systematic database searches from 2001 to 2016, limited to English and pediatric studies. SIGN methodology and the National Health and Medical Research Council system were used to screen and classify the evidence. The Grade of Recommendation, Assessment, Development and Evaluation system was used to grade evidence as strong or weak. Where evidence was inadequate or absent, a modified Delphi consensus process was used to develop consensus-based recommendations. The guideline provides 56 recommendations (1 evidence-based recommendation and 55 consensus recommendations). These relate to the framework of rehabilitation service delivery as well as domain-specific rehabilitation treatment strategies for each domain of function. It is anticipated that this guideline will provide health professions with recommendations to improve the subacute care of children with stroke both in Australia and internationally.

Arterial Ischemic Stroke Secondary to Cardiac Disease in Neonates and Children

OBJECTIVE

We describe the risk factors for peri-procedural and spontaneous arterial ischemic stroke (AIS) in children with cardiac disease.

METHODS

We identified children with cardiac causes of AIS enrolled in the International Pediatric Stroke Study registry from January 2003 to July 2014. Isolated patent foramen ovale was excluded. Peri-procedural AIS (those occurring during or within 72 hours of cardiac surgery, cardiac catheterization, or mechanical circulatory support) and spontaneous AIS that occurred outside of these time periods were compared.

RESULTS

We identified 672 patients with congenital or acquired cardiac disease as the primary risk factor for AIS. Among these, 177 patients (26%) had peri-procedural AIS and 495 patients (74%) had spontaneous AIS. Among non-neonates, spontaneous AIS occurred at older ages (median 4.2 years, interquartile range 0.97 to 12.4) compared with peri-procedural AIS (median 2.4 years, interquartile range 0.35 to 6.1, P < 0.001). About a third of patients in both groups had a systemic illness at the time of AIS. Patients who had spontaneous AIS were more likely to have a preceding thrombotic event (16 % versus 9 %, P = 0.02) and to have a moderate or severe neurological deficit at discharge (67% versus 33%, P = 0.01) compared to those with peri-procedural AIS.

CONCLUSIONS

Children with cardiac disease are at risk for AIS at the time of cardiac procedures but also outside of the immediate 72 hours after procedures. Many have acute systemic illness or thrombotic event preceding AIS, suggesting that inflammatory or prothrombotic conditions could act as a stroke trigger in this susceptible population.

Alterations in Blood-Brain Barrier Permeability in Patients with Systemic Lupus Erythematosus

BACKGROUND AND PURPOSE

Neuropsychiatric systemic lupus erythematosus refers to central and peripheral nervous system involvement, which may occur secondary to antineuronal antibodies crossing the blood-brain barrier that preferentially target cells in the hippocampus leading to abnormal hypermetabolism and atrophy. Thus, we hypothesized that alterations in BBB permeability, detected on dynamic contrast-enhanced MR imaging, occur in the hippocampus in patients with systemic lupus erythematosus before development of neuropsychiatric systemic lupus erythematosus.

MATERIALS AND METHODS

Six patients with systemic lupus erythematosus without neuropsychiatric systemic lupus erythematosus and 5 healthy controls underwent dynamic contrast-enhanced MR imaging with postprocessing into BBB permeability parameters (K ^trans and Ve) and CBF. Standardized methods selected ROI sampling of the abnormal brain regions detected on FDG-PET. The mean and SD of K ^trans, Ve, and CBF were calculated. Linear regression and nonparametric Spearman rank correlation analyses of K ^trans and Ve with CBF were performed. Dynamic contrast-enhanced curves and the area under the curve were generated for each brain region. Student t test comparisons were performed.

RESULTS

Quantitative data revealed that patients with systemic lupus erythematosus have statistically increased K ^trans (P < .001) and Ve (P < .001) compared with controls. In patients with systemic lupus erythematosus, statistically significant positive correlations were seen between K ^trans (P < .001) and Ve (P < .001) with CBF. Furthermore, the mean area under the curve revealed statistically increased BBB permeability in the hippocampus (P = .02) compared with other brain regions in patients with systemic lupus erythematosus compared with controls.

CONCLUSIONS

These initial findings are proof-of-concept to support the hypothesis that patients with systemic lupus erythematosus have increased BBB permeability, specifically in the hippocampus, compared with other brain regions. These findings may advance our understanding of the underlying pathophysiology affecting the brain in autoimmune diseases.

Dynamic Contrast-Enhanced MRI Reveals Unique Blood-Brain Barrier Permeability Characteristics in the Hippocampus in the Normal Brain

We report a prospective dynamic contrast-enhanced MR imaging analysis of region-specific blood-brain barrier permeability in 5 healthy subjects. By means of standardized postprocessing and ROI sampling methods, the hippocampi revealed significantly elevated area under the dynamic contrast-enhanced curve and significantly increased blood-brain barrier permeability metrics (volume transfer constant and volume in the extravascular extracellular space) from model-based quantitation. These findings suggest unique blood-brain barrier permeability characteristics in the hippocampus, which are concordant with previous animal studies, potentially laying the groundwork for future studies assessing patient populations in which hippocampal pathology plays a role.

Clinical and Imaging Characteristics of Arteriopathy Subtypes in Children with Arterial Ischemic Stroke: Results of the VIPS Study

BACKGROUND AND PURPOSE

Childhood arteriopathies are rare but heterogenous, and difficult to diagnose and classify, especially by nonexperts. We quantified clinical and imaging characteristics associated with childhood arteriopathy subtypes to facilitate their diagnosis and classification in research and clinical settings.

MATERIALS AND METHODS

The Vascular Effects of Infection in Pediatric Stroke (VIPS) study prospectively enrolled 355 children with arterial ischemic stroke (2010-2014). A central team of experts reviewed all data to diagnose childhood arteriopathy and classify subtypes, including arterial dissection and focal cerebral arteriopathy-inflammatory type, which includes transient cerebral arteriopathy, Moyamoya disease, and diffuse/multifocal vasculitis. Only children whose stroke etiology could be conclusively diagnosed were included in these analyses. We constructed logistic regression models to identify characteristics associated with each arteriopathy subtype.

RESULTS

Among 127 children with definite arteriopathy, the arteriopathy subtype could not be classified in 18 (14%). Moyamoya disease (n = 34) occurred mostly in children younger than 8 years of age; focal cerebral arteriopathy-inflammatory type (n = 25), in children 8-15 years of age; and dissection (n = 26), at all ages. Vertigo at stroke presentation was common in dissection. Dissection affected the cervical arteries, while Moyamoya disease involved the supraclinoid internal carotid arteries. A banded appearance of the M1 segment of the middle cerebral artery was pathognomonic of focal cerebral arteriopathy-inflammatory type but was present in <25% of patients with focal cerebral arteriopathy-inflammatory type; a small lenticulostriate distribution infarct was a more common predictor of focal cerebral arteriopathy-inflammatory type, present in 76%. It remained difficult to distinguish focal cerebral arteriopathy-inflammatory type from intracranial dissection of the anterior circulation. We observed only secondary forms of diffuse/multifocal vasculitis, mostly due to meningitis.

CONCLUSIONS

Childhood arteriopathy subtypes have some typical features that aid diagnosis. Better imaging methods, including vessel wall imaging, are needed for improved classification of focal cerebral arteriopathy of childhood.

Evidence-based guideline update: medical treatment of infantile spasms. Report of the Guideline Development Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society

OBJECTIVE

To update the 2004 American Academy of Neurology/Child Neurology Society practice parameter on treatment of infantile spasms in children.

METHODS

MEDLINE and EMBASE were searched from 2002 to 2011 and searches of reference lists of retrieved articles were performed. Sixty-eight articles were selected for detailed review; 26 were included in the analysis. RECOMMENDATIONS were based on a 4-tiered classification scheme combining pre-2002 evidence and more recent evidence.

RESULTS

There is insufficient evidence to determine whether other forms of corticosteroids are as effective as adrenocorticotropic hormone (ACTH) for short-term treatment of infantile spasms. However, low-dose ACTH is probably as effective as high-dose ACTH. ACTH is more effective than vigabatrin (VGB) for short-term treatment of children with infantile spasms (excluding those with tuberous sclerosis complex). There is insufficient evidence to show that other agents and combination therapy are effective for short-term treatment of infantile spasms. Short lag time to treatment leads to better long-term developmental outcome. Successful short-term treatment of cryptogenic infantile spasms with ACTH or prednisolone leads to better long-term developmental outcome than treatment with VGB.

RECOMMENDATIONS

Low-dose ACTH should be considered for treatment of infantile spasms. ACTH or VGB may be useful for short-term treatment of infantile spasms, with ACTH considered preferentially over VGB. Hormonal therapy (ACTH or prednisolone) may be considered for use in preference to VGB in infants with cryptogenic infantile spasms, to possibly improve developmental outcome. A shorter lag time to treatment of infantile spasms with either hormonal therapy or VGB possibly improves long-term developmental outcomes.

Autoantibodies as biomarkers for the prediction of neuropsychiatric events in systemic lupus erythematosus

OBJECTIVE

Neuropsychiatric events occur unpredictably in systemic lupus erythematosus (SLE) and most biomarker associations remain to be prospectively validated. This study examined a disease inception cohort of 1047 SLE patients to determine which autoantibodies at enrolment predicted subsequent neuropsychiatric events.

METHODS

Patients with a recent SLE diagnosis were assessed prospectively for up to 10 years for neuropsychiatric events using the American College of Rheumatology case definitions. Decision rules of graded stringency determined whether neuropsychiatric events were attributable to SLE. Associations between the first neuropsychiatric event and baseline autoantibodies (lupus anticoagulant (LA), anticardiolipin, anti-β(2) glycoprotein-I, anti-ribosomal P and anti-NR2 glutamate receptor) were tested by Cox proportional hazards regression.

RESULTS

Disease duration at enrolment was 5.4 ± 4.2 months, follow-up was 3.6 ± 2.6 years. Patients were 89.1% female with mean (±SD) age 35.2 ± 13.7 years. 495/1047 (47.3%) developed one or more neuropsychiatric event (total 917 events). Neuropsychiatric events attributed to SLE were 15.4% (model A) and 28.2% (model B). At enrolment 21.9% of patients had LA, 13.4% anticardiolipin, 15.1% anti-β(2) glycoprotein-I, 9.2% anti-ribosomal P and 13.7% anti-NR2 antibodies. LA at baseline was associated with subsequent intracranial thrombosis (total n=22) attributed to SLE (model B) (HR 2.54, 95% CI 1.08 to 5.94). Anti-ribosomal P antibody was associated with subsequent psychosis (total n=14) attributed to SLE (model B) (HR 3.92, 95% CI 1.23 to 12.5, p=0.02). Other autoantibodies did not predict neuropsychiatric events.

CONCLUSION

In a prospective study of 1047 recently diagnosed SLE patients, LA and anti-ribosomal P antibodies are associated with an increased future risk of intracranial thrombosis and lupus psychosis, respectively.

De novo SCN1A mutations in migrating partial seizures of infancy

OBJECTIVE

To determine the genetic etiology of the severe early infantile onset syndrome of malignant migrating partial seizures of infancy (MPSI).

METHODS

Fifteen unrelated children with MPSI were screened for mutations in genes associated with infantile epileptic encephalopathies: SCN1A, CDKL5, STXBP1, PCDH19, and POLG. Microarray studies were performed to identify copy number variations.

RESULTS

One patient had a de novo SCN1A missense mutation p.R862G that affects the voltage sensor segment of SCN1A. A second patient had a de novo 11.06 Mb deletion of chromosome 2q24.2q31.1 encompassing more than 40 genes that included SCN1A. Screening of CDKL5 (13/15 patients), STXBP1 (13/15), PCDH19 (9/11 females), and the 3 common European mutations of POLG (11/15) was negative. Pathogenic copy number variations were not detected in 11/12 cases.

CONCLUSION

Epilepsies associated with SCN1A mutations range in severity from febrile seizures to severe epileptic encephalopathies including Dravet syndrome and severe infantile multifocal epilepsy. MPSI is now the most severe SCN1A phenotype described to date. While not a common cause of MPSI, SCN1A screening should now be considered in patients with this devastating epileptic encephalopathy.

AFLP and SSR analysis of genetic diversity among landraces of bread wheat (Triticum aestivum L. em. Thell) from different geographic regions

A set of 44 bread wheat landraces was used to determine the efficacy of 16 amplifed fragment length polymorphism (AFLP) primers and 63 wheat simple sequence repeat (SSR) markers in identifying polymorphisms between accessions. The SSR markers detected approximately 10 alleles per locus with a mean gene diversity (Hz) of 0.63, whereas AFLP primers identified approximately 147 fragments per primer with a mean gene diversity of 0.25. A set of 54 SSR markers and 11 AFLP primers was identified as highly polymorphic (polymorphic information content (PIC) ≥ 0.5 and 0.3 for SSR and AFLP, respectively), and suitable for molecular characterisation of germplasm. Principle coordinate analysis suggested that the AFLP and SSR loci could be used to discriminate among accessions collected from North Africa and southern Europe from those collected from the Middle East. Both marker types indicate that accessions from North Africa and southern Europe, the Middle East, and southern and eastern Asia are genetically diverse. The results indicate the usefulness of the molecular markers to assess genetic diversity present within germplasm collections.

Practice parameter: medical treatment of infantile spasms: report of the American Academy of Neurology and the Child Neurology Society

OBJECTIVE

To determine the current best practice for treatment of infantile spasms in children.

METHODS

Database searches of MEDLINE from 1966 and EMBASE from 1980 and searches of reference lists of retrieved articles were performed. Inclusion criteria were the documented presence of infantile spasms and hypsarrhythmia. Outcome measures included complete cessation of spasms, resolution of hypsarrhythmia, relapse rate, developmental outcome, and presence or absence of epilepsy or an epileptiform EEG. One hundred fifty-nine articles were selected for detailed review. Recommendations were based on a four-tiered classification scheme.

RESULTS

Adrenocorticotropic hormone (ACTH) is probably effective for the short-term treatment of infantile spasms, but there is insufficient evidence to recommend the optimum dosage and duration of treatment. There is insufficient evidence to determine whether oral corticosteroids are effective. Vigabatrin is possibly effective for the short-term treatment of infantile spasm and is possibly also effective for children with tuberous sclerosis. Concerns about retinal toxicity suggest that serial ophthalmologic screening is required in patients on vigabatrin; however, the data are insufficient to make recommendations regarding the frequency or type of screening. There is insufficient evidence to recommend any other treatment of infantile spasms. There is insufficient evidence to conclude that successful treatment of infantile spasms improves the long-term prognosis.

CONCLUSIONS

ACTH is probably an effective agent in the short-term treatment of infantile spasms. Vigabatrin is possibly effective.

Arterial ischaemic stroke in children

OBJECTIVE

Arterial ischaemic stroke (AIS) in childhood is a serious disorder about which little is published. The aim of this study is to determine the epidemiology and outcome of AIS in Australian children.

METHODS

Cases of childhood AIS occurring at the Royal Children's Hospital, Melbourne 1993-2001, were identified by medical record search using International Classification of Disease Codes. Information was collected on demographics, risk factors, arterial distribution, results of thrombophilic testing, management and outcome.

RESULTS

During the 8 years of review 95 patients presented with 98 cases of AIS calculating an incidence of 1.8 per 100000 children per year. Children less than 12 months of age represented greater than one third of all cases. Identifiable risk factors were present in 64% of cases with congenital heart disease the major risk factor. Thrombophilic testing was incomplete with initial abnormalities present in 18% of cases tested. The estimated stroke-related mortality was 8.4%. Of the patients who survived and who had follow-up details available, 78% had a neurological deficit. Twenty-six patients (26%) received anticoagulation. There was no statistically significant association between treatment with anticoagulation and normal neurological outcome.

CONCLUSION

AIS is over-represented in children under 12 months of age and results in death or residual neurological impairment in the majority of cases. Further prospective studies are needed to identify risk factors for poor outcome. The recently established Australian and New Zealand Stroke and Thrombophilia Registry should provide important information on clinical and laboratory based risk factors and create a basis for international clinical trials to improve the outcome of childhood AIS.

Cerebral sinus venous thrombosis in children

OBJECTIVE

Cerebral sinus venous thrombosis (cerebral SVT) is rare in children. Information on clinical characteristics, radiological findings and outcome is emerging.

METHODS

Cases of cerebral SVT diagnosed between 1995 and 2001 were identified by a computer-assisted search using International Classification of Disease codes. Medical records were reviewed to collect information on clinical presentation, investigations, treatment and outcome.

RESULTS

Sixteen cases of cerebral SVT were identified. All cases presented in association with head and neck pathology. The majority of cases presented with symptoms of raised intracranial pressure and focal neurological signs. Magnetic resonance imaging identified all cases of cerebral SVT whilst CT scanning failed to demonstrate the diagnosis in two cases. Management with anticoagulation was associated with radiological resolution of the thrombosis and normal neurological outcome. Long-term follow up demonstrated neurological deficits in greater than 40% of patients.

CONCLUSION

Cerebral SVT in children is associated with significant residual neurological morbidity. Prospective studies to identify predictors of outcome and effective management interventions are required.

Malformations of cortical development with balloon cells: clinical and radiologic correlates

BACKGROUND

Balloon cells are a key feature of tuberous sclerosis (TS) but are also seen in focal cortical dysplasia (FCD). The authors compare the clinical and MRI characteristics in children with medically refractory localization-related epilepsy who were found to have balloon cells on histology after cortical resections.

METHODS

A retrospective review of clinical and MRI data in cases ascertained from a search of pathology records from 1990 until 2000 for those with a diagnosis of FCD or TS. Seventeen patients were identified with malformations of cortical development with balloon cells on histology. Seven had clinical diagnosis of TS and the remaining 10, FCD with balloon cells (FCDBC).

RESULTS

Seventy percent of patients with FCDBC (mean follow-up 3.3 years) and 33% of patients with TS (mean follow-up 5.1 years) are seizure free after surgery. There was agreement between the diagnosis based on preoperative MR imaging and on histology in 60% of patients with FCDBC and 71% of patients with TS. Myelin depletion and calcification were noted more frequently in patients with TS.

CONCLUSIONS

No significant differences were noted between patients with refractory epilepsy caused by TS or FCDBC. There was a trend toward better postoperative seizure control in the FCDBC group. These two conditions are difficult to distinguish on the basis of MR and histologic appearances. The authors conclude that FCDBC likely represents a phenotypic variation of TS, and as such, all patients with balloon cell dysplasias should be carefully screened for other features of TS to enable appropriate genetic counseling.

Reliability of cancer registration data in Scotland, 1997

The aim of this study was to assess the reliability of cancer registration data in Scotland following a major re-organisation of the Scottish Cancer Registry. From a random sample of 3500 primary cancers (excluding non-melanoma skin cancers and death certificate only (DCO) registrations) diagnosed between April and September 1997, 3175 (90.7%) had medical records available for scrutiny. Data were re-abstracted by a team of trained medical coders and compared with information registered originally. Reliability was generally high for demographic, diagnostic, and fact of treatment details, but less reliable for grade of differentiation, staging variables and dates of treatment. Some discrepancies probably arose because of differing availability of information at the time of registration compared with the time of re-abstraction. Although data quality is high overall, further improvements might be achieved through continued training, structured recording of information by clinicians in medical records, and continued exploitation of the data.

Molybdopterin synthase mutations in a mild case of molybdenum cofactor deficiency

Molybdenum cofactor deficiency is a rare inborn error of metabolism with generally severe symptoms, most often including neonatal seizures and severe developmental delay. We describe a patient with an unusually mild form of the disease. Two mutations in MOCS2A (molybdenum cofactor synthesis enzyme 2A) were identified: a single base change, 16C > T, that predicts a Q6X substitution on one allele and a 19G > T transversion that predicts a valine to phenylalanine substitution, V7F, on the second. It is postulated that the milder clinical symptoms result from a low level of residual molybdopterin synthase activity derived from the 19G > T allele.

Pharmacokinetics of oral cyclosporin A when co-administered to enhance the absorption of orally administered docetaxel

OBJECTIVE

To evaluate the pharmacokinetics of oral cyclosporin A (CsA) when co-administered to enhance the absorption of orally administered docetaxel.

METHODS

Patients (n = 9) with histological proof of solid cancer received oral docetaxel 75 mg/m2 in combination with oral CsA 15 mg/kg.

RESULTS

The area under the blood concentration-time curve (AUC) of CsA when combined with docetaxel 75 mg/m2 was 31.0+/-9.3 mg/l h (mean +/- SD). Compared with literature data of the same dose of CsA, AUC values in our study appear to be substantially higher. In addition, compared with the AUC values of CsA in combination with oral paclitaxel (previously published data), AUC values in this study are approximately 1.5-fold higher.

CONCLUSIONS

The higher AUC values of CsA obtained in this study compared with literature data may be explained by competitive inhibition of cytochrome P450 (CYP) 3A4-mediated metabolism of CsA by docetaxel. In addition, the higher levels of CsA with docetaxel than with paclitaxel co-administration may be explained by the fact that docetaxel is almost exclusively metabolised by CYP 3A4, whereas paclitaxel is predominantly metabolised by CYP 2C8 and to a lesser extent by CYP 3A4.

Effect of creatine supplementation on metabolism and performance in humans during intermittent sprint cycling

This double blind study investigated the effect of oral creatine supplementation (CrS) on 4 x 20 s of maximal sprinting on an air-braked cycle ergometer. Each sprint was separated by 20 s of recovery. A group of 16 triathletes [mean age 26.6 (SD 5.1) years. mean body mass 77.0 (SD 5.8) kg, mean body fat 12.9 (SD 4.6)%, maximal oxygen uptake 4.86 (SD 0.7) l.min-1] performed an initial 4 x 20 s trial after a muscle biopsy sample had been taken at rest. The subjects were then matched on their total intramuscular creatine content (TCr) before being randomly assigned to groups to take by mouth either a creatine supplement (CRE) or a placebo (CON) before a second 4 x 20 s trial. A muscle biopsy sample was also taken immediately before this second trial. The CrS of 100 g comprised 4 x 5 g for 5 days. The initial mean TCr were 112.5 (SD 8.7) and 112.5 (SD 10.7) mmol.kg-1 dry mass for CRE and CON, respectively. After creatine loading and placebo ingestion respectively, CRE [128.7 (SD 11.8) mmol.kg-1 dry mass] had a greater (P = 0.01) TCr than CON [112.0 (SD 10.0) mmol.kg-1 dry mass]. While the increase in free creatine for CRE was statistically significant (P = 0.034), this was not so for the changes in phosphocreatine content [trial 1: 75.7 (SD 6.9), trial 2: 84.7 (SD 11.0) mmol.kg-1 dry mass, P = 0.091]. There were no significant differences between CRE and CON for citrate synthase activity (P = 0.163). There was a tendency towards improved performance in terms of 1 s peak power (in watts P = 0.07; in watts per kilogram P = 0.05), 5 s peak power (in watts P = 0.08) and fatigue index (P = 0.08) after CrS for sprint 1 of the second trial. However, there was no improvement for mean power (in watts P = 0.15; in watts per kilogram P = 0.1) in sprint 1 or for any performance values in subsequent sprints. Our results suggest that, while CrS elevates the intramuscular stores of free creatine, this does not have an ergogenic effect on 4 x 20 s all-out cycle sprints with intervening 20-s rest periods.

Practical experience with bed occupancy management and planning systems: an Australian view

Pressure is increasing on hospitals to do more with fewer resources. The appropriate management of hospital beds is crucial. The author's practical experience of applying the Harrison and Millard Flow Model (BOMPS) and Sorensen's multi-phased bed model to aspects of the public hospital system in South Australia are detailed. These techniques can provide decision makers with improved bed management information. Modelling enables the effects of decisions to be analyzed before implementation. Further development of these tools, together with other modelling approaches, cannot be ignored as a means of improving the strategic management of hospital beds.

Peripheral nerve repair and grafting techniques: a review

In this review, various conventional nerve repair techniques including direct epineurial repair, grouped fascicular repair, fascicular repair, and nerve grafting are described. The indications for use, as well as the relative advantage and disadvantage, of each technique are discussed. The experimental and clinical evidence from a review of the pertinent literature does not demonstrate a significant difference in outcome of one method over the others. Surgical decisions should be made by a thorough evaluation of all aspects of the nerve injury and surgical methods. All nerve injuries cannot be repaired using only one type of nerve repair method. The surgeon should be familiar with all the techniques described and be prepared to use them under appropriate circumstances.

Docetaxel in 253 previously treated patients with progressive locally advanced or metastatic breast cancer: results of a compassionate use program in The Netherlands

The aims of this study were to evaluate the efficacy and safety of docetaxel (Taxotere) in patients with progressive locally advanced or metastatic breast cancer, previously treated with at least one chemotherapy regimen, and the effect of the number of previous chemotherapy lines on response rate, progression-free survival and overall survival. Two-hundred and fifty-three patients from 10 hospitals in The Netherlands received docetaxel as part of a compassionate use program. The majority had received prior anthracycline-containing chemotherapy (84.2%). The recommended starting dose was 100 mg/m2 i.v. every 3 weeks. All patients received corticosteroid premedication. Two-hundred and thirty patients were evaluable for response. The overall response rates (ORR) to docetaxel when used as second-, third- or fourth-line treatment were, respectively, 40.2, 26.0 and 34.6% (p value 0.30). The median progression-free survival for this population was 4.9 months and the median overall survival of the whole group was 8.5 months, and both were not related to the number of previous chemotherapy regimens (p value, respectively, 0.71 and 0.16). The toxicity of docetaxel was manageable and neutropenia was the most frequently noted toxicity. This study confirms that docetaxel is an active cytotoxic agent in pretreated patients with progressive locally advanced or metastatic breast cancer and is still active when used as third- or fourth-line treatment.

Prescribed drugs: a major cause of ill health

Harm caused by ill-effects of prescribed drugs is largely unrecognised, but when looked for has been found to be an important cause of ill health. Perhaps 6% of all hospital admissions and some 800 deaths a year are caused by prescribed medication in Australia. The elderly, especially those in institutions, are particularly prone to injury by drugs. Attempts to use visiting pharmacists to influence the prescribing habits of doctors have resulted in unspectacular success. It is suggested that prescribing habits may more effectively be changed by visiting from specially trained practising doctors.

Measuring and modelling surgical bed usage

Surgical departments treat two groups of inpatients--the simple and the complex--consequently a single average fails to describe the use being made of the occupied beds. Using decision support techniques, we show why indicators such as the average length, the average occupancy and the average admissions mislead. Furthermore, by analysing the fluctuating pattern of weekly admissions we show how weekends and the Christmas holiday periods impact on bed usage. Next, we demonstrate that flow process models can be used to describe how the in-patient workload concerns two groups of patients. On an average day, 71.4% of the beds contained patients who will have an average (exponential) stay of 4.8 days, and the other beds, 28.6%, contain patients who will have an average (exponential) stay of 22.8 days. The article concludes by demonstrating the short and long-term impact on daily admissions of a 10% change in four different parameters of the model. The data used come from a surgical department in Adelaide, as UK data sets report finished consultant episodes rather than completed in-patient spells.

Application and comparison of two modelling techniques for hospital bed management

The use of the bed occupancy management and planning system (BOMPS) and the Sorensen multi-phased bed model were used to assess the implications of a hospital expanding its emergency facility. BOMPS flow modelling generates resource utilisation data dependent on the best visual and statistical fit between mixed exponential equations and time of bed occupancy; the Sorensen model creates models based on probabilities and length of stay distributions. Both models identified the presence of two streams of flow. However, there were differences in the number of beds identified as being short and longer stay. The advantage of flow modelling is that it enables decision-makers to pre-test their decisions.