Aetiological factors and development in subjects with obstructive sleep apnoea

OBJECTIVE

To examine whether maternal pregnancy complications, adverse birth events, respiratory illnesses, or developmental difficulty were increased in neurologically normal children with obstructive sleep apnoea (OSA) and whether severity of OSA adversely affects the child's development and temperament.

METHODOLOGY

Maternal report of perinatal events, respiratory illness and developmental difficulty in 37 children with OSA was contrasted with a comparison group (n = 67). Children with OSA were assessed developmentally (Griffiths Scales), had a parental rating of temperament (Australian Temperament Scale) and attended an overnight polysomnographic sleep study.

RESULTS

Children with OSA had an increased prevalence of adverse maternal pregnancy and perinatal events, respiratory disease and developmental concerns. Limited associations were found between the severity of OSA and development or temperament difficulty.

CONCLUSIONS

This study suggests a relationship between OSA, though not its severity, and pre/perinatal adversity and child development. Polysomnographic and detailed developmental assessment of community-based samples of children with OSA and control children are necessary to confirm these findings.

Six-month follow-up of children with obstructive sleep apnoea

OBJECTIVES

This study examined prospectively changes in development, temperament and sleep related behaviour in children referred for obstructive sleep apnoea (OSA) and polysomnographic sleep study, some of whom had surgical intervention.

METHODOLOGY

Using a prospective cohort study design, parents of 56 children referred for OSA completed sleep and temperament questionnaires and their child was assessed developmentally at the time of the polysomnographic sleep study. Forty (72%) of the children were neurologically normal. At 6 months, 42 children were reassessed using sleep and temperament questionnaires and a developmental assessment. After excluding the primary snorers, subjects were categorised as having had intervention (n = 24) or not (n = 15), and differences over the 6-month period in Griffiths scores, temperament and sleep related behaviour were examined.

RESULTS

Regardless of intervention status, there was an improvement in night-time and day-time sleep behaviour for the total group, though the extent of improvement was more marked in the intervention group. For the neurologically normal children, improvement in the sleep behaviour was only significant for the intervention group (P < 0.05). Intervention did not result in any significant changes in Griffiths developmental score or temperament.

CONCLUSION

Surgical intervention improves sleep behaviour in children though not temperament or development.

The influence of growth on development outcome in extremely low birthweight infants at 2 years of age

OBJECTIVE

To determine if weight < 3rd and < 10th centile at 2 years in extremely low birthweight (ELBW) infants is associated with problems of development and motor skills, and whether this association is explained by perinatal risk status.

METHODOLOGY

One hundred and ninety-eight of 226 (88%) surviving ELBW infants born between January 1987 and December 1992 were assessed at 2 years corrected age. Children were classified as being at low perinatal risk (n = 128) or high perinatal risk (n = 70) for adverse developmental outcome based on perinatal risk factors. Weight at 2 years was classified as < 3rd, 3rd-9th or > or = 10th centile for age and gender. Development was assessed using the Griffiths Mental Developmental Scales and motor skills using the Neurosensory Motor Developmental Assessment (NSMDA).

RESULTS

For the total study group weight centile was strongly related to General Quotient (GQ) and motor abilities. For children < 3rd percentile (n = 48) mean (GQ) was 90.4 (SD, 15.9), for children between the 3rd-9th percentile (n = 49) 91.5 (SD, 17.9), and for children > or = 10th percentile (n = 99) mean GQ was 99.8 (SD, 8.6). The association with mean GQ and NSMDA category occurred for the high-risk subgroup and became non-significant in the low-risk subgroup if neurologically abnormal children were excluded. Other perinatal risk factors, exposure to breast milk, level of maternal education, marital status and history of feeding problems or infections over the 2 years did not confound this association.

CONCLUSION

Low weight percentile at 2 years was related to adverse developmental outcome in ELBW infants at high perinatal risk or with neurological impairment, though minimal association was present for neurologically normal infants at low perinatal risk.

Clinical versus polysomnographic profiles in children with obstructive sleep apnoea

OBJECTIVE

To examine the clinical and polysomnographic (PSG) profiles of neurologically normal and abnormal children with obstructive sleep apnoea (OSA) and explore the relationship between these profiles.

METHODOLOGY

We enrolled 56 children with persistent snoring and OSA for the study, 16 of whom were neurologically abnormal. All children were examined clinically and attended an overnight PSG study. Total clinical scores, PSG scores, and mild/moderate or severe ratings were derived for each child.

RESULTS

Comparison of individual PSG parameters with neurological status demonstrated that the abnormal children had significantly increased obstructive apnoea indices, increased desaturation events and lower mean arousal indices compared to their neurologically normal OSA peers. For the neurologically abnormal children, there was a significant correlation between severity ratings of disease according to clinical and PSG profiles (r = 0.56, P = 0.03, sensitivity 82%) using the clinical summary as the gold standard, although the association was less marked in the neurologically normal children (r = -0.08, P = NS, sensitivity 69%).

CONCLUSION

Neurologically abnormal children are likely to have more severe abnormalities in selected polysomnographic indices and overall scores. However, the clinical assessment is only likely to reflect this at the severe end of the spectrum. These relationships are not seen in the neurologically normal child, where little or no reliance can be placed upon predicting the severity of the polysomnographic findings from the clinical data. Decisions regarding the severity of disease and treatment should be based on the combined findings of the clinical and PSG data rather than overall clinical and polysomnographic scores or selected clinical and polysomnographic parameters.

Placental pathology and neurodevelopment of the infant with intrauterine growth restriction

The placentas of 68 infants with intrauterine growth restriction (IUGR) were examined for evidence of impaired uteroplacental circulation and compared with those of 65 appropriately grown infants. Infarcts and/or accelerated villous maturation were present in the placentas in 27 (40%) of the infants with IUGR compared with seven (11%) of the infants without IUGR (P<0.001). The infants were followed-up at 4 and 12 months of age and growth parameters recorded. Medical and developmental assessments and neuromotor developmental examinations were also performed. The 23 infants in the IUGR group with placentas with evidence of impaired uteroplacental circulation were compared with the 31 infants with IUGR with normal placentas. There was no difference between the groups in growth, cognitive development, or neuromotor abnormality. It was concluded that IUGR is strongly associated with placental markers of impaired uteroplacental blood flow while it would appear that there is no association between placental pathology and growth or neurodevelopment in the first year.

Maternal hypertension and neurodevelopmental outcome in very preterm infants

AIM

To determine the outcome of preterm infants born to mothers with hypertension during pregnancy, and preterm controls.

METHODS

107 infants of 24-32 weeks gestation, born to hypertensive mothers, and 107 controls matched for gestational age, sex, and multiple pregnancy, born to normotensive mothers, were prospectively enrolled over 2 years. Information on maternal complications and medication was obtained and neonatal mortality and morbidities recorded. Survivors were followed up to at least 2 years, corrected for prematurity.

RESULTS

One third of the hypertensive mothers were treated with antihypertensive drugs, while 18% received convulsion prophylaxis with phenytoin. Magnesium sulphate was not prescribed. Both groups had a mean gestational age of 29.9 weeks, with the study infants having a significantly lower birthweight than the controls. Four study and three control infants died in the neonatal period. Cerebral palsy was not diagnosed in any infant of a hypertensive mother compared with five of the controls. The mean general quotient for the two groups was very similar and no difference in the incidence of minor neuromotor developmental problems was shown.

CONCLUSIONS

Maternal hypertension seems to protect against cerebral palsy in preterm infants without increasing the risk of cognitive impairment. This was independent of the use of maternally administered magnesium sulphate.

Obstetric and perinatal factors as predictors of child behaviour at 5 years

OBJECTIVE

To identify whether obstetric and perinatal factors are independent predictors of child behaviour at 5 years.

METHODOLOGY

The Mater University Study of Pregnancy (MUSP) is a prospective cohort study of 8556 mothers enrolled in early pregnancy. The relationship of obstetric and perinatal factors, maternal lifestyle, age and gender of the child, and social disadvantage were examined as predictors of child behaviour in 5005 children completing a modified child behaviour checklist at 5 years. This checklist contained three independent groups of behaviour: externalizng, internalizing and SAT (social, attentional and thought problems).

RESULTS

In the initial analysis a limited number of associations were present. After adjusting for measures of social disadvantage, only number of antenatal admissions was associated with child behaviour in all three scales, while maternal cigarette smoking in pregnancy and male gender were associated with externalising and SAT behaviours.

CONCLUSIONS

Most common epidemiologic obstetric and perinatal risk factors were not independent predictors of behaviour problems in children at 5 years.

Biological predictors and co-morbidity of attention deficit and hyperactivity disorder in extremely low birthweight infants at school

OBJECTIVE

To examine biological predictors and co-morbidity of Attention Deficit Hyperactivity Disorder (ADHD) and associated academic and social impairment in a cohort of extremely low birthweight of (ELBW) children attending school.

METHODOLOGY

Eight seven (70%) of 125 ELBW children born between 1977 and 1986 were followed prospectively. Neonatal and biological data including cranial ultrasound for 62% of children, formal developmental assessment at 4 or 6 years of age, teacher and parent ADHD questionnaire, parental rating of health status and social impairment and school teacher rating of academic performance was recorded.

RESULTS

Apart from grades 3 or 4 intraventricular haemorrhage in a minority of children, there was no evidence to suggest an association between ADHD and perinatal adversity in ELBW children. Social impairment, academic difficulty and atopic symptoms were significantly related to ADHD.

CONCLUSIONS

Extremely low birthweight children presenting with symptoms of ADHD are likely to suffer social and learning impairment and these, rather than perinatal risk factors, should be the focus of clinical attention.

Characteristics at four months follow-up of infants born small for gestational age: a controlled study

This prospective study compared 65 small-for-gestational-age (SGA) (birth weight < 3rd centile) and 71 control infants at a corrected age of 4 months. It was hypothesised that differences would exist in growth, development, temperament and minor neurological signs and that these would be predicted by type (proportional/disproportional) of growth restriction at birth and maternal mood disturbance at birth or at 4 months. Infants had a Griffith's developmental test and neuromotor assessment. Maternal mood and infant temperament were surveyed. Few differences were found between SGA and control infants. SGA infants showed catch-up growth with 63% being above the third percentile and 43% being above the tenth percentile for weight. SGA infants had lower Griffith's GQ scores (97 vs. 102, P = 0.02) and they were rated in temperament as more manageable than controls. There were no differences in subtle neuromotor signs. Neither type of SGA nor maternal mood disturbance at birth had prognostic significance for infant catch up growth, neuromotor scores, or temperament though level of maternal stress and anxiety at 4 months were related to lower GQ scores in SGA infants.

Prediction of obesity in children at 5 years: a cohort study

OBJECTIVE

To examine determinants of moderate and severe obesity in children at 5 years of age.

METHODOLOGY

A prospective cohort of mothers were enrolled at first antenatal visit, and interviewed shortly after delivery, at 6 months and 5 years. Detailed health, psychological and social questionnaires were completed at each phase by mothers, and child health questionnaires at 6 months and 5 years. At 5 years 4062 children were assessed physically, the Peabody Picture Vocabulary Test administered and mothers completed a modified Child Behaviour Checklist. Moderate obesity was defined as BMI between 85th and 94th percentiles inclusively, and severe obesity as a BMI greater than the 94th percentile.

RESULTS

Independent predictors of severe obesity at 5 years were birthweight, female gender, maternal BMI and paternal BMI. Moderate obesity at 5 years was predicted by birthweight, paternal BMI and sleeplessness at 6 months, while small for gestational age (SGA) status and feeding problems at 6 months were protective factors for moderate obesity. Obesity was not associated with problems of language comprehension or behaviour.

CONCLUSIONS

Findings of this study suggest that biological rather than psychosocial factors are the major determinants of obesity at 5 years.

Aetiology and classification of small for gestational age infants

OBJECTIVE

To determine important aetiological factors in small gestational age (SGA) infants and the effectiveness of anthropometric indexes in identifying patterns of growth retardation.

METHODOLOGY

Eighty-four SGA infants and 81 controls were enrolled. Maternal biological, lifestyle and psychosocial factors were compared for the total group and the term Caucasian subset. Anthropometric indexes were also examined in relation to growth patterns.

RESULTS

Decreased maternal size, poor weight gain, previous SGA infant and smoking were significantly associated with SGA status. Poor parental education and unemployment was increased in the study group. Mothers of SGA infants, especially the term Caucasian group, had a greater prevalence of hypertension and depressive and stress symptomatology. Ponderal index failed to identify discreet patterns of disproportionate/proportionate growth retardation.

CONCLUSION

Biological, lifestyle and psychosocial differences remain important aetiological factors of intrauterine growth retardation. Identification of specific patterns of growth retardation by ponderal index remains controversial.

Survival and neonatal and neurodevelopmental outcome of 24-29 week gestation infants according to primary cause of preterm delivery

A total of 189 infants of 24-29 weeks' gestation were born in a regional perinatal centre during a 2-year period. They were divided into groups according to the primary cause of preterm delivery: antepartum haemorrhage (n = 37, 20%), preeclampsia (n = 27), 14%), preterm premature rupture of membranes (n = 64, 34%), preterm labour (n = 27, 14%), chorioamnionitis (n = 16, 8%), other complications (n = 18, 10%). The perinatal mortality rate (PMR) was 286/1,000 of whom 44% were stillbirths. The 'other complication' group had the highest PMR due to a large number of intrauterine deaths, with no differences in neonatal mortality between the groups. Preeclampsia was associated with an increased risk of necrotizing enterocolitis and chorioamnionitis was associated with an increased risk of periventricular haemorrhage. Follow-up to at least 2 years was performed in 122 (97%) of survivors. Cerebral palsy occurred in 7%, while 18% had neurodevelopmental disability. No relationship was found between primary cause of preterm delivery and outcome. This information should be of value in counselling parents when preterm delivery is imminent.

Prevalence of maternal depression and its relationship to ADL skills in children with developmental delay

OBJECTIVE

To determine the prevalence of maternal affective symptoms in children with developmental problems compared to a control group, and to examine their relationship to the child's Activities of Daily Living (ADL), socialization skills and behaviour.

METHODOLOGY

This study examined prospectively the prevalence of symptoms of maternal depression, maternal anxiety, stress and adverse life events in 65 mothers whose children were attending a Child Development Clinic. ADL and socialization skills were measured using the Vinelands Adaptive Behaviour Scales, and behaviour using a checklist.

RESULTS

Symptoms of maternal depression (P = 0.04), maternal anxiety (P = 0.01) and number of adverse life events (P = 0.03) were increased in the study compared to control mothers. Presence of maternal symptoms was unrelated to ADL or socialization skills though was associated with increased behavioural symptoms in the child.

CONCLUSION

Affective disturbance in mothers of children with developmental problems are common and should be addressed as part of a comprehensive assessment of such children.

School performance of ELBW children: a controlled study

This paper examines the prevalence of learning difficulty in reading, spelling, mathematics and writing and the prevalence of attention deficit disorder (ADD) in extremely low-birthweight (ELBW) children at school compared to their peers. Parents of 87 eligible ELBW children completed an educational questionnaire and questionnaire for ADD. Teachers of the ELBW children completed a detailed educational and ADD questionnaire for the study child and two control children in the same class, matched for age and nearest in birth date to the study child. Parents reported that 4% of the ELBW children born between 1977 and 1986 were in a special education unit, 46% received remedial help and 21% repeated a grade. Teacher assessment of six aspects of reading and spelling and five aspects of mathematics and writing skills indicated that the ELBW children experienced marked problems in all areas compared to control children and were approximately 3 times more likely to be delayed by more than a year in all areas. Prevalence of ADD was not increased in the ELBW children compared to the control group, though males in both groups had a higher prevalence of symptoms. Early intervention and special education resources must be available for ELBW children attending school.

Prevalence and aetiology of neurological impairment in extremely low birthweight infants

OBJECTIVE

To determine the prevalence and perinatal predictors of cerebral palsy, intellectual impairment, visual impairment and deafness in a cohort of extremely low birthweight (ELBW) infants at two years of age.

METHODOLOGY

The study population comprised 199 of the 224 (89%) ELBW infants managed at the Mater's Mothers Hospital, Brisbane, between July 1977 and February 1990 and who survived to two years. The prevalence of cerebral palsy, intellectual impairment, blindness and deafness was measured by clinical,psychometric and audiological assessment and the association with 24 risk factors examined.

RESULTS

Cerebral palsy occurred in 20 children (10%). Risk of cerebral palsy was associated with ventricular dilatation, intraventricular haemorrhage, necrotizing enterocolitis and multiple birth, though only ventricular dilatation (OR 4.41; 95% CI 1.32-14.8) remained significant in the adjusted analysis. Intellectual impairment occurred in 20 children (10%) and was independently associated with ventricular dilatation (OR 15.0; 95% CI 2.2-102.8), ventilation F(i)(2) > 80% (OR 3.4; 95% CI 1.01-11.5), vaginal delivery (OR 3.5; 95% Cl 1.09-11.4) and male sex (OR 6.1; 95% Cl 1.67-22.3). No perinatal predictor was statistically associated with risk of deafness. Retinopathy of prematurity (OR 36.9; 95% Cl 2.8-495.5) was associated with risk of later visual impairment.

CONCLUSIONS

Intellectual impairment was associated with a broad range of perinatal variables. Cerebral palsy was associated with fewer variables, all of which were also associated with intellectual impairment. Neurologic injury was associated with male sex and multiple birth, which are not biological insults themselves, but may be markers of susceptibility to injury.

Neurodevelopmental outcome of preterm infants with bronchopulmonary dysplasia

The neurodevelopmental outcome of 78 infants with bronchopulmonary dysplasia (BPD) was compared with that of 78 control infants matched for birthweight. To determine the effect of the severity of BPD, 62 infants requiring oxygen at 36 weeks' postmenstrual age (sBPD) were compared with their matched controls. Infants were followed up to 2 years of age, corrected for prematurity, and were classified for neurological impairment, developmental delay, and neurodevelopmental disability. Seventy six (98%) BPD infants and 71 (91%) controls had follow up data available to two years. Neurological impairment, developmental delay, and neurodevelopmental disability occurred more frequently in infants with BPD than in controls but this was not significant. For infants with sBPD, the increased incidence of neurological impairment and definite developmental delay was not significant when compared with the controls, though neurodevelopmental disability occurred more frequently (odds ratio (OR) 3.6: 95% confidence intervals (CI) 1.1-11.8). Predictors of disability in infants with sBPD included periventricular haemorrhage (OR 19.4: 95% CI 4.3-86.6), ventricular dilatation (OR 12.8: 95% CI 2.9-57.3), and sepsis (OR 5.0: 95% CI 1.3-19.4). Adjusting for the presence of these factors, the association between BPD and disability was no longer apparent (OR 0.9: 95% CI 0.2-3.6). The findings suggest that BPD is not independently associated with adverse neurodevelopmental outcome.

Changing patterns of survival and outcome at 4 years of children who weighted 500-999 g at birth

OBJECTIVE

To evaluate the impact of changing perinatal practices on survival rates and 4 year neurodevelopmental outcome for infants of birthweight 500-999 g.

METHODOLOGY

The study was a tertiary hospital-based prospective cohort study that compared survival, impairment and handicap rates between two eras, July 1977 to December 1982 (era 1) and January 1983 to June 1988 (era 2). All 348 live, inborn infants and 49 outborn infants of birthweight 500-999 g were prospectively enrolled in a study of survival and outcome. Rates of survival, neurodevelopmental impairment and functional handicap at 4 years were compared between eras. Perinatal risk factors for handicap were also compared between eras.

RESULTS

Four year survival rates for inborn infants 500-999 g improved from 32.6% in era 1 to 49.2% in era 2 (OR 2.1, 95% CI 1.26-3.48) but for outborn infants the improvement between 31.8% and 53.6% was not significant. There were significant improvements in survival for inborn infants in birthweights 800-899 g and 900-999 g between study periods. The rates of functional handicap between the first and second eras (mild 10 vs 7%; severe or multiply severe 14 vs 16%) were not significantly different. Although the rate of cerebral palsy increased from 0 to 12% (P < 0.01) other rates of impairment such as blindness 0 vs 3%, deafness 2 vs 2% and developmental delay 12 vs 11% did not change. The chance of a survivor being free of handicap remained unchanged at 78% and 76% for the two eras, respectively. Although the absolute number of intact survivors more than doubled (41 vs 83) so too did the number of severe or multiply severe handicapped survivors (7 vs 17). Multivariate logistic regression analysis for the entire study cohort revealed male gender, multiple birth, prolonged mechanical ventilation and cerebral ventricular dilatation but not birthweight or gestational age to be independently associated with severe or multiply severe handicap.

CONCLUSIONS

The advances in neonatal intensive care for extremely low birthweight infants between July 1977 and December 1982 and January 1983-June 1988 resulted in an increased number of non-disabled survivors but had no impact on incidence of severe disability. The application of prediction of mortality or severe handicap to clinical practice has the potential to reduce the proportion and absolute number of severely handicapped survivors.

Improvement of spatial light modulator optical input/output performance using microlens arrays

Advanced spatial light modulators both detect incident light and modulate reflected light. Each pixel may contain multiple photodetectors, a modulator, control circuitry, and signal-processing circuitry. Because each detector and modulator occupies only a fraction of the area of a pixel the optical efficiency of these devices suffers. We have experimented with improving optical input/output performance by integrating a microlens array with a ferroelectric liquid-crystal VLSI spatial light modulator. We have studied the microlens VLSI spacing accuracy that must be achieved to yield minimum distortion of ref lected wave fronts and the best optical efficiency for Fourier-transform applications.

Extremely low birth weight and control infants at 2 years corrected age: a comparison of intellectual abilities, motor performance, growth and health

A 2-year cohort of 63 surviving extremely low birth weight (ELBW) infants was prospectively studied and 60 of these infants, together with 44 normal birth weight control infants, were assessed at 2 years of age for intellectual abilities, motor skills, growth and health. The total ELBW group differed significantly from controls on overall Griffiths developmental quotient (99.3 vs. 103.8 P = 0.02) and in the personal/social subscale (100.7 vs. 106.7 P = 0.01). A subset of 43 of the ELBW infants was identified as low risk at discharge. No statistically significant differences were present between the low risk ELBW subset and controls in intellectual abilities though both the total ELBW group and the low risk ELBW subset differed from controls in fine and gross motor abilities, and in weight at 2 years. The total ELBW group also experienced more frequent ill health and hospital readmission.

Prognostic factors and long-term outcomes for children who have nearly drowned

OBJECTIVE

To find predictors of outcome and to describe the long term outcome for children who require mechanical ventilation after nearly drowning.

PATIENTS AND SETTING

From 1981 to 1989, all children who underwent ventilation in the Intensive Care Unit of the Master Children's Hospital, Brisbane, after an immersion. Children who died within 24 hours were excluded. Of 57 children eligible for entry, 18 died after 24 hours.

DESIGN

Retrospective study of hospital records and prospective assessment of neurodevelopmental outcome. Thirty-eight families of survivors were contacted by questionnaire and 25 children of these families were examined. Follow-up was between 0.8 and 9.6 years after immersion.

RESULTS

All children who had a motor response to pain in the hospital's emergency department survived without sequelae. Thirty-one children were in cardiac arrest and, of these, 17 died, six survived with severe spastic quadriplegia and eight are ambulant. Of those ambulant, four have motor coordination difficulties and three have learning difficulties. Children in cardiac arrest who had a delay of more than 20 minutes between rescue and arrival at hospital were more likely to die or sustain severe spastic quadriplegia. No child survived if more than 25 minutes of advanced resuscitation was required after they had been warmed.

CONCLUSIONS

Children with a motor response to pain seem to have a good prognosis. However, we could not predict which children in cardiac arrest would die or survive either severely impaired or ambulant. All children in cardiac arrest should receive aggressive resuscitation for at least 25 minutes after being warmed; they have a better prognosis if advanced resuscitation is started less than 20 minutes after rescue. Children who survive a cardiac arrest without spastic quadriplegia warrant long term surveillance as they may have coordination and learning difficulties.

Handedness in extremely low birth weight infants: aetiology and relationship to intellectual abilities, motor performance and behaviour at four and six years

Hand preference was measured in a total group of 71 ELBW children to determine patterns of hand preference at 4 and 6 years, possible aetiological factors leading to handedness, and whether left or non right hand preference were markers for intellectual, motor, temperament or behavioural differences. At both 4 and 6 years the prevalence of left handedness was increased, though this prevalence changed over the period of the study. Results supported brain injury as one mechanism leading to increased left hand preference, though this process did not adequately explain this increase. Possible reasons for this and the apparent change in prevalence with time are examined. Mixed handedness at 4 years was associated with lower intellectual abilities though otherwise children were similar in motor skills, temperament and behaviour independent of hand preference category.

The prevalence and origins of left hand preference in high risk infants, and its implications for intellectual, motor and behavioural performance at four and six years

This study investigates the origins of hand preference at 4 years in a cohort of 115 high risk and premature infants; the relationship between patterns of hand preference and intellectual, motor, temperament and behavioural status at 4 and 6 years; and evidence for brain injury in mediating the relationship between hand preference and development disorder. Increased left hand preference was independently associated with extreme prematurity, high neonatal risk, increased numbers of minor physical anomalies, lowered intellectual and motor abilities, and more difficult temperament. These findings supported the presence of intrauterine and neonatal pathological mechanisms leading to left hand preference in a small number of children. Neither poor function of the non dominant hand nor absence of a family history of left handedness could further define this pathological subgroup. Support for pathological mechanisms producing left handedness was found predominatly in the infants of high birth weight, whereas prevalence of left handedness was increased mainly among the extremely low birth weight infants. In this latter group the prevalence of left handedness was also increased among children of normal intelligence, suggesting that mechanisms other than brain damage lead to left hand preference in very premature infants.

Perinatal hypoxic-ischaemic brain injury: prediction of outcome

Twenty-six term babies with hypoxic-ischaemic brain injury were studied during the neonatal period to evaluate the prediction of outcome to at least one year of age by means of ultrasonography, CT scanning and Doppler ultrasound assessment of cerebral palsy blood flow velocity (CBFV). Adverse outcome was defined as the occurrence of cerebral palsy, developmental delay or death. At follow-up, 17 infants had an adverse outcome (seven died, 10 had disability); the remainder had no detectable impairment. Abnormalities on cranial ultrasound were not, but generalised decreased tissue density on CT scan was, associated with adverse outcome. Abnormal mean CBFV in the middle cerebral artery had no association with outcome, but abnormal mean CBFV in the anterior cerebral artery and a low resistance index in both arteries were significantly associated with adverse outcome. Such information may be used for appropriate counselling of parents of asphyxiated infants.

Single daily dose ceftriaxone therapy in epiglottitis

Ceftriaxone as a single daily intravenous dose for 5 days was used to treat seven patients with proven Haemophilus influenzae epiglottitis. All children responded favourably. The serum levels achieved exceeded the MIC by up to 1500 times at the trough level during and for up to 24 h after the completion of the treatment. Side effects were mild and transient and did not disrupt the continuity of the treatment. Ceftriaxone potentially offers a number of clinical and economic advantages in the management of epiglottitis.

Diffractive ferroelectric liquid-crystal shutters for unpolarized light

Electro-optic modulators using ferroelectric liquid-crystal technology have generally been limited to use with polarized light. It is possible, however, to construct a diffractive array of ferroelectric liquid-crystal phase modulators that can act as a shutter for unpolarized light. We have built two types of polarization-independent diffractive shutter based on this principle. We describe their principles of operation and performance.