Bilateral spastic cerebral palsy--a comparative study between southwest Germany and western Sweden. II: Epidemiology

Trends in Prevalence and Severity of Pre/Perinatal Cerebral Palsy Among Children Born Preterm From 2004 to 2010: A SCPE Collaboration Study

Aim: To report on prevalence of cerebral palsy (CP), severity rates, and types of brain lesions in children born preterm 2004 to 2010 by gestational age groups.

Methods: Data from 12 population-based registries of the Surveillance of Cerebral Palsy in Europe network were used. Children with CP were eligible if they were born preterm (<37 weeks of gestational age) between 2004 and 2010, and were at least 4 years at time of registration. Severity was assessed using the impairment index. The findings of postnatal brain imaging were classified according to the predominant pathogenic pattern. Prevalences were estimated per 1,000 live births with exact 95% confidence intervals within each stratum of gestational age: ≤27, 28–31, 32–36 weeks. Time trends of both overall prevalence and prevalence of severe CP were investigated using multilevel negative binomial regression models.

Results: The sample comprised 2,273 children. 25.8% were born from multiple pregnancies. About 2-thirds had a bilateral spastic CP. 43.5% of children born ≤27 weeks had a high impairment index compared to 37.0 and 38.5% in the two other groups. Overall prevalence significantly decreased (incidence rate ratio per year: 0.96 [0.92–1.00[) in children born 32–36 weeks. We showed a decrease until 2009 for children born 28–31 weeks but an increase in 2010 again, and a steady prevalence (incidence rate ratio per year = 0.97 [0.92–1.02] for those born ≤27 weeks. The prevalence of the most severely affected children with CP revealed a similar but not significant trend to the overall prevalence in the corresponding GA groups. Predominant white matter injuries were more frequent in children born <32 weeks: 81.5% (≤27 weeks) and 86.4% (28–31 weeks), compared to 63.6% for children born 32–36 weeks.

Conclusion: Prevalence of CP in preterm born children continues to decrease in Europe excepting the extremely immature children, with the most severely affected children showing a similar trend.

Quantitative sensory testing profiles in children, adolescents and young adults (6-20 years) with cerebral palsy: Hints for a neuropathic genesis of pain syndromes

INTRODUCTION

Many patients with cerebral palsy (CP) suffer chronic pain as one of the most limiting factors in their quality of life. In CP patients, pain mechanisms are not well understood, and pain therapy remains a challenge. Quantitative sensory testing (QST) might provide unique information about the functional status of the somatosensory system and therefore better guide pain treatment.

OBJECTIVES

To understand better the underlying pain mechanisms in pediatric CP patients, we aimed to assess clinical and pain parameters, as well as QST profiles, which were matched to the patients' cerebral imaging pathology.

PATIENTS AND METHODS

Thirty CP patients aged 6-20 years old (mean age 12 years) without intellectual impairment underwent standardized assessments of QST. Cerebral imaging was reassessed. QST results were compared to age- and sex-matched controls (multiple linear regression; Fisher's exact test; linear correlation analysis).

RESULTS

CP patients were less sensitive to all mechanical and thermal stimuli than healthy controls but more sensitive to all mechanical pain stimuli (each p < 0.001). Fifty percent of CP patients showed a combination of mechanical hypoesthesia, thermal hypoesthesia and mechanical hyperalgesia; 67% of CP patients had periventricular leukomalacia (PVL), which was correlated with mechanic (r = 0.661; p < 0.001) and thermal (r = 0.624; p = 0.001) hypoesthesia.

CONCLUSION

The combination of mechanical hypoesthesia, thermal hypoesthesia and mechanical hyperalgesia in our CP patients implicates lemniscal and extralemniscal neuron dysfunction in the thalamus region, likely due to PVL. We suspect that extralemniscal tracts are involved in the original of pain in our CP patients, as in adults.

The Prevalence of Cerebral Palsy in British Columbia, 1991-1995

Objective:

To quantify the prevalence of cerebral palsy (CP) in British Columbia within a four-year birth cohort.

Methods:

The study was a population-based record linkage study of a birth cohort of British Columbian children born between April 1, 1991 and March 31, 1995. Cases were identified by the presence of International Classification of Diseases, Version 9 (ICD-9) diagnostic code “343” recorded at three years of age or older or by having the ICD-9 diagnostic code “343” recorded prior to the third birthday with two confirmatory diagnoses within the first three years of life through a record search of the BC Medical Services Plan billing files for the fiscal years 1991 to 1995.

Results/Conclusion:

This research has provided an estimate of the prevalence of CP in the four-year birth cohort 1991 to 1995 in British Columbia. An aggregate prevalence rate of CP was measured as 2.68 per 1000 live births, and a congenital rate was measured at 2.57 for the same population. Birth weight and gestational age demonstrated a significant relationship with the development of CP. This study should lend credence to the establishment of a CP register in British Columbia.

Does verbal and gestural expression ability predict comprehension ability in cerebral palsy?

Some people with cerebral palsy have motor and associated impairments that may hinder verbal and gestural expression to various extents. This study explores whether the ability to produce verbal or gestural expressions may be related to the comprehension of verbal communications and gestures. The influence of severity of motor impairment, general cognitive performance, and age on comprehension ability was also explored. Forty people with cerebral palsy were assigned to different groups according to their verbal and gestural expression abilities. A neuropsychological assessment of comprehension abilities and general cognitive performance was carried out. Multiple linear regression analysis was applied to identify the possible influence of expression abilities on comprehension abilities and also to detect the possible contribution of severity of motor impairment, general cognitive performance, and age. Results indicate that verbal and gestural comprehension was mainly predicted by general cognitive performance. Severity of motor impairment and age did not contribute to predicting comprehension abilities. Only verbal grammar comprehension was significantly predicted by verbal expression ability. Verbal expression ability may be an important marker for cerebral palsy therapies. In non-ambulant patients with bilateral cerebral palsy, impaired gestural expression should not be taken as an indicator of impaired gestural comprehension.

Using the manual ability classification system in young adults with cerebral palsy and normal intelligence

PURPOSE

The study aimed to establish whether the manual ability classification system (MACS), a valid classification system for manual ability in children with cerebral palsy (CP), is applicable in young adults with CP and normal intelligence.

SUBJECTS

The participants (n = 83) were young adults with CP and normal intelligence and had a mean age of 19.9 years.

METHOD

In this study, inter observer reliability of the MACS was determined. We investigated relationships between the MACS level and patient characteristics (such as the gross motor function classification system (GMFCS) level, limb distribution of the spastic paresis and educational level) and with functional activities of the upper extremity (assessed with the Melbourne assessment, the Abilhand questionnaire and the domain self-care of the functional independence measure (FIM)). Furthermore, with a linear regression analysis it was determined whether the MACS is a significant determinant of activity limitations and participation restrictions.

RESULTS

The reliability was good (intraclass correlation coefficient 0.83). The Spearman correlation coefficients with GMFCS level, limb distribution of the spastic paresis and educational level were 0.53, 0.46, and 0.26, respectively. MACS level correlated moderately with outcome measures of functional activities (correlations ranging from -0.38 to -0.55). MACS level is, in addition to the GMFCS level, an important determinant for limitations in activities and restrictions in participation.

CONCLUSION

We conclude that the MACS is a feasible method to classify manual ability in young adults with CP and normal intelligence with a good manual ability.

The updated European Consensus 2009 on the use of Botulinum toxin for children with cerebral palsy

An interdisciplinary European group of clinical experts in the field of movement disorders and experienced Botulinum toxin users has updated the consensus for the use of Botulinum toxin in the treatment of children with cerebral palsy (CP). A problem-orientated approach was used focussing on both published and practice-based evidence. In part I of the consensus the authors have tabulated the supporting evidence to produce a concise but comprehensive information base, pooling data and experience from 36 institutions in 9 European countries which involves more than 10,000 patients and over 45,000 treatment sessions during a period of more than 280 treatment years. In part II of the consensus the Gross Motor Function Measure (GMFM) and Gross Motor Function Classification System (GMFCS) based Motor Development Curves have been expanded to provide a graphical framework on how to treat the motor disorders in children with CP. This graph is named "CP(Graph) Treatment Modalities - Gross Motor Function" and is intended to facilitate communication between parents, therapists and medical doctors concerning (1) achievable motor function, (2) realistic goal-setting and (3) treatment perspectives for children with CP. The updated European consensus 2009 summarises the current understanding regarding an integrated, multidisciplinary treatment approach using Botulinum toxin for the treatment of children with CP.

Cerebral palsy update

A common language on CP has been developed for the European registers by the SCPE (Surveillance of Cerebral Palsy in Europe) working group and the common database allows prevalence analyses on a larger basis. CP prevalence increases with lower birthweight and higher immaturity. Increase of survival after preterm birth has first also increased CP rates. But already in the 80s this trend was reversed for LBW infants, and in the 90 s also for VLBW or very immature infants. The outcome with respect to CP in the group of extremely LBW or immature infants remains a matter of specific concern, as prevalence seems to be rather stable on a high level. CP is caused in more than 80% by brain lesions or maldevelopments which can be attributed to different timing periods of the developing brain. Extent and topography determine the clinical subtype of CP and are related also to the presence and severity of associated disabilities. CP, thus, offers a model to study plasticity of the developing brain. Reorganisation following unilateral lesions is mainly interhemispheric and homotopic. In the motor system, it involves the recruitment of ipsilateral tracts; functionality seems to be limited and decreases already towards the end of gestation. There is no clear evidence for substantial reorganisation in the sensory system. The best compensatory potential is described concerning language function following left hemispheric lesions. Language function reorganized to the right hemisphere eventually seems not to be impaired, this occurs, however, on the expense of primary right hemispheric functions.

Clinical presentation, associated disorders and aetiological moments in Cerebral Palsy: A Dutch population-based study

PURPOSE

Cerebral Palsy (CP) contains varying clinical presentations, associated disorders and aetiological moments. Quantitative data and trends on these aspects were lacking in The Netherlands.

METHOD

Within a population-based study on prevalence, presentation and functioning of Dutch children with CP born in the years 1977-1988, individual history taking, examination and medical file checking was done by experienced clinicians. Clinical subtypes, motor disability, important co-morbidity (mental retardation, visual disability and epilepsy) were recorded, aetiological moments identified if possible. By comparing the four most recent years with the earlier years possible trends were studied.

RESULTS

A quarter of children beforehand recorded as CP did not meet inclusion criteria after individual examination. Spastic subtypes accounted for over 90% of all CP cases: bilateral spastic cerebral palsy as a group are the majority although spastic hemiplegia is percentage-wise the largest individual clinical subtype. Epilepsy and mental retardation are common. Clinical patterns and associated disorders remained rather constant comparing earlier to more recent birth years.

CONCLUSIONS

An early diagnosis of CP may be challenged. General clinical patterns remained rather constant in following years, as did most studied items. Even if this study revealed a prevalence rise, no aspect stood out as a possible explanation for this prevalence rise. Comparable studies performed elsewhere showed similar findings.

Functional activities of the upper extremity of young adults with cerebral palsy: a limiting factor for participation?

PURPOSE

To assess functional activities of the upper extremity of young adults with cerebral palsy (CP) and to determine their relations with participant characteristics and participation.

METHOD

Assessment of functional activities of the upper extremity was performed on 103 participants (aged 16-20 years) with the Melbourne assessment and the Abilhand Questionnaire. Participation was measured with the Life Habits Questionnaire. Participant characteristics included age, gender, limb distribution of the spastic paresis, educational level and gross and fine motor function. Relations among these variables were studied by means of correlation coefficients and linear regression analysis.

RESULTS

Limitations in functional activities of the upper extremity were related to the limb distribution of the spastic paresis and were especially present in quadriplegic participants. Significant correlations between participant characteristics and measures of functional activities were present. Limitations in functional activities of the upper extremity, measured with the Abilhand Questionnaire, were an important determinant for participation, in addition to the gross motor function and educational level.

CONCLUSION

Limitations in functional activities of the upper extremity are an important determinant for restrictions in participation in young adults with CP. It is recommended to include assessment of functional activities of the upper extremity in patients with CP.

Raven's Coloured Progressive Matrices as a measure of cognitive functioning in Cerebral Palsy

BACKGROUND

Cognitive dysfunction is frequent in Cerebral Palsy (CP). CP motor impairment and associated speech deficits often hinder cognitive assessment, with the result being that not all CP studies consider cognitive dysfunction. Raven's Coloured Progressive Matrices is a simple, rapid test which can be used in persons with severe motor impairment and speech limitations. We studied whether this test can offer a reliable measure of cognitive functioning in CP.

METHOD

Visuoperceptual, language, memory and frontal lobe functions were evaluated in 30 participants with severe motor impaired CP and a variety of speech difficulties. The relationship between Raven's Coloured Progressive Matrices and a variety of tests was analysed.

RESULTS

Raven's Coloured Progressive Matrices performance was associated with visuoperceptual, language, visual and verbal memory but not with frontal functions. Receptive vocabulary and visuospatial measures were the best predictors of Raven's Coloured Progressive Matrices raw scores.

CONCLUSIONS

Raven's Coloured Progressive Matrices is a fast, easy-to-administer test able to obtain a measure related with linguistic, visuoperceptual, and memory cognitive functioning in persons with CP despite their motor and speech disorders.

Bilateral spastic cerebral palsy--prevalence through four decades, motor function and growth

The aim was to depict changes in the prevalence and severity of bilateral spastic cerebral palsy (CP) over a 40-year period. Another objective was to characterise the group born in 1991-1998 with respect to gross motor function, spasticity and growth. Data were obtained from the CP register of western Sweden and rehabilitation records.

RESULTS

After a rise to 1.27 per 1000 live births in 1983-1986, the prevalence decreased significantly, in children born both preterm and at term, to 0.69 in 1995-1998. After 1975, more children were born preterm than at term. There was a significant decrease in severe bilateral spastic CP during the same period, mainly in children born at term. In all, 46% of the children born at term and 33% of those born preterm had a severe motor impairment, i.e. no walking ability. In the 167 children born in 1991-1998, the gross motor function classification system (GMFCS) level was I in 14%, II in 34%, III in 10%, IV in 25% and V in 17%. The GMFCS level correlated with the gross motor function measure (GMFM) and the Ashworth spasticity scores, as well as with the deviation in postnatal weight and height. We conclude that the prevalence of bilateral spastic CP has decreased since the mid-1980s, parallel to a reduction in the severity of the motor impairment. Children born preterm have predominated since the mid-1970s. The severity of the motor impairment correlated with the degree of spasticity, GMFM and growth. The percentage of children who were underweight was substantial.

Trends in cerebral palsy among infants of very low birthweight (<1500 g) or born prematurely (<32 weeks) in 16 European centres: a database study

BACKGROUND

The risk of cerebral palsy, the commonest physical disability of children in western Europe, is higher in infants of very low birthweight (VLBW)--those born weighing less than 1500 g--and those from multiple pregnancies than in infants of normal birthweight. An increasing proportion of infants from both of these groups survive into childhood. This paper describes changes in the frequency and distribution of cerebral palsy by sex and neurological subtype in infants with a birthweight below 1000 g and 1000-1499 g in the period 1980-96.

METHODS

A group of 16 European centres, Surveillance of Cerebral Palsy in Europe, agreed a standard definition of cerebral palsy and inclusion and exclusion criteria. Data for children with cerebral palsy born in the years 1980-96 were pooled. The data were analysed to describe the distribution and prevalence of cerebral palsy in VLBW infants. Prevalence trends were expressed as both per 1000 livebirths and per 1000 neonatal survivors.

FINDINGS

There were 1575 VLBW infants born with cerebral palsy; 414 (26%) were of birthweight less than 1000 g and 317 (20%) were from multiple pregnancies. 1426 (94%) had spastic cerebral palsy, which was unilateral (hemiplegic) in 336 (24%). The birth prevalence fell from 60.6 (99%CI 37.8-91.4) per 1000 liveborn VLBW infants in 1980 to 39.5 (28.6-53.0) per 1000 VLBW infants in 1996. This decline was related to a reduction in the frequency of bilateral spastic cerebral palsy among infants of birthweight 1000-1499 g. The frequency of cerebral palsy was higher in male than female babies in the group of birthweight 1000-1499 g (61.0 [53.8-68..2] vs 49.5 [42.8-56.2] per 1000 livebirths; p=0.0025) but not in the group of birthweight below 1000 g.

INTERPRETATION

These data from a large population base provide evidence that the prevalence of cerebral palsy in children of birthweight less than 1500 g has fallen, which has important implications for parents, health services, and society.

Antenatal and delivery risk factors and prevalence of cerebral palsy in Duzce (Turkey)

This cross-sectional study aimed at investigating the prevalence and the etiological factors of cerebral palsy (CP) and comparing them with normal population within the rural and urban areas of Duzce province. Of the 102 children with cerebral palsy, 98 were associated with antenatal and delivery risk factors. The mean crude prevalence of cerebral palsy was 1.1 per 1000 live births. The children with CP were compared with 530 control subjects. The mothers of the children with cerebral palsy were significantly younger than the mothers of children in control group, and they had less parity and abortion. Preeclampsia, premature rupture of membranes, home births, prolonged labor, and twin pregnancies were significantly more common in the mothers of children with cerebral palsy, where no significant differences were found between the groups in terms of breech delivery, rate of cesarean births, gestational diabetes, and hemorrhage in late pregnancy. Birth asphyxia, liqueur with meconium stained, prolonged jaundice and neonatal seizure were also significantly more common in the group with cerebral palsy. Of the children with cerebral palsy, 78% were born at term, 20% were born with gestational ages of 32-36 weeks, 2% were born with gestational ages of 30-31 weeks. Nine percent of those children had a birth weight of >or= 3000 g, 12.2% had a birth weight of 2500-2999 g, 33.7% had a birth weight of 1500-2499 g, and 5.1% had a birth weight of <or= 1500 g. The causes of low prevalence of cerebral palsy were due to insufficient neonatal care, resulting in low survival in preterm and low birth weight children, and poor postnatal care of children with cerebral palsy.

European consensus table 2006 on botulinum toxin for children with cerebral palsy

An interdisciplinary group of experienced botulinum toxin users and experts in the field of movement disorders was assembled, to develop a consensus on best practice for the treatment of cerebral palsy using a problem-orientated approach to integrate theories and methods. The authors tabulated the supporting evidence to produce a condensed but comprehensive information base, pooling data and experience from nine European countries, 13 institutions and more than 5500 patients. The consensus table summarises the current understanding regarding botulinum toxin treatment options in children with CP.

Visual impairment in children born at full term from 1972 through 1989 in Finland

OBJECTIVE

To investigate the incidence, prevalence, and causes of visual impairment in children born at full term and to determine conditions and factors associated with visual impairment.

DESIGN

Retrospective, cross-sectional, population-based study.

PARTICIPANTS

All visually impaired individuals from 0 to 17 years of age who were born at full term from 1972 through 1989 in Finland and recorded in the Finnish Register of Visual Impairment (n = 556) were eligible for this study.

METHODS

Data in the Finnish Register of Visual Impairment relating to 556 subjects were supplemented with data from hospital records and other national registers (Register of Births, Register of Congenital Malformations, Finnish Care Register, and Finnish Cancer Register). Data relating to the children born at full term were compared with Finnish perinatal and vital statistics and with data concerning children born prematurely. The chi-square test (Mantel-Haenszel) and stepwise logistic regression analysis were used in statistical analysis of the data.

MAIN OUTCOME MEASURES

Visual acuity, time of onset of visual impairment, ophthalmic diagnosis of visual impairment, systemic disease, multiple handicap, 5-minute Apgar score, prenatal disorders, perinatal disorders, disorders arising during infancy and childhood, and treatment.

RESULTS

Four hundred thirty-one of the 556 individuals with visual impairment (78%) had been born at full term. Visual impairment was predominantly associated with genetic (53%) and prenatal (34%) factors. Ocular malformations (34%), retinal diseases (31%), and neuro-ophthalmologic disorders (26%) were the main ophthalmic diagnoses. Optic nerve atrophy (20%) and congenital cataract (13%) were the most common single diagnoses. The occurrence of blindness, systemic disease, and multiple handicap was 40%, 43%, and 45%, respectively.

CONCLUSIONS

The incidence of visual impairment in children born at full term did not decline during the 2 decades covered by this study. The findings reflected the lack of treatment for genetic eye diseases. The results also confirmed an obvious need for further understanding of mechanisms underlying congenital anomalies of the human visual system.

Macropremies: underprivileged newborns

The focus of neonatal intensive care has been on very low birthweight infants, who comprise only 1.4% of neonates. Too little attention is paid to moderately preterm infants that we call macropremies or moderately low birthweight infants (MLBW, with birthweights 1500-2500 grams). Admitting over half MLBW infants to normal nurseries presumes that they have few needs and an excellent prognosis similar to fullterm newborns. It does not take into account the macropremie's vulnerability to complications of prematurity due to immature organ systems. Obstetricians are increasingly willing to deliver these infants prematurely for signs of fetal distress. As many as 25% of children with cerebral palsy referred to a disability clinic in Paris were MLBW, with hypoxic-ischemic-inflammatory associated disorders in one-third. The majority of MLBW infants who required neonatal intensive care at a tertiary care center in Baltimore had complications of prematurity: 47% had respiratory problems, 20% had feeding intolerance and 9% had hypoglycemia. MLBW infants comprise 5-7% of the neonatal population but account for 14% of neonatal deaths, 18-37% of children with cerebral palsy and 7-12% of children with mental retardation. Increasing the level of neonatal care for the macropremie's transition to extrauterine life would be economically feasible if it prevented as few as 30% of cases of major disability. A change in attitude towards this low risk (but not risk free) group of MLBW infants will both reduce morbidity and improve their health and neurodevelopmental outcome. It includes: 1) Providing an intermediate level of neonatal care for a short duration, with close monitoring and prompt intervention as needed, and 2) Neonatal neurodevelopmental screening to allow focused neurodevelopmental followup of MLBW infants with abnormalities.

Prevalence of cerebral palsy in The Netherlands (1977-1988)

Children with cerebral palsy (CP) and their families often make strong demands on diagnostic, therapeutic, technical and social facilities. Prevalence estimates are needed to improve treatment and services. As recent Dutch data are not available, the present study aimed to assess the population prevalence of CP in the Netherlands. A representative Dutch area with 1.2 million inhabitants of which 172,000 were born between 1977 and 1988 was studied. To ascertain the children with CP from these birth years, medical practices (such as rehabilitation centres, paediatric and child neurological departments) were consecutively asked to contact their (supposed) CP cases. Next, a parents' organisation and finally regional news media assisted in the ascertainment. In total, 170 'supposed' CP cases underwent an expert examination. Of these 170, 127 children proved to be definite CP-cases, yielding a 'crude' average prevalence of 0.74 per 1,000 inhabitants (95% CI: 0.61-0.87). Under-ascertainment was recognised and quantified. Accordingly, the population prevalence of CP over the birth year period 1977-1988 was calculated as 1.51 per 1,000 inhabitants (average over the 12 birth years). The calculated CP prevalence rose significantly over time: from 0.77 (1977-1979) to 2.44 (1986-1988). This trend is in accordance with other studies.

Cerebral palsy in Northern Ireland: 1981--93

This paper describes the method of compilation of the Northern Ireland Cerebral Palsy Register (NICPR) and outlines the epidemiology of cerebral palsy (CP) in Northern Ireland in 1981--93 based on an analysis of 784 cases. Multiple and overlapping sources of notification were used to compile the NICPR. Each case was followed up with a standardised assessment completed at age 5 years and validated by a paediatrician. Over 70% of cases were multiply notified, and paediatricians were the most important source of notification. Cases of CP most likely to be under-ascertained included those very mildly affected, cases who died before the register began (death certificates were searched but found to be unreliable) and cases who moved out of the area before their diagnosis was confirmed. The prevalence of CP for the birth period 1981--93 was 2.24 per 1000 livebirths [95% CI 2.08, 2.40]. There were no statistically significant temporal or geographic variations in the rate of CP. Almost half the cases of CP were of low birthweight (<2500 g), and this proportion increased during 1987--89, but decreased (P < 0.01) more recently (1990--93). The proportion of cases weighing <1000 g trebled from 3% in 1981--83 to 10% in 1990--93 (P < 0.01). The most common CP subtype was bilateral spastic cerebral palsy (55%). Just over a quarter (29%) of cases were unable to walk (with/without aids), and one-fifth (22%) had no useful hand/arm function. Almost half (49%) the cases had at least one other impairment (intellectual, sensory impairment or active seizures) in association with their CP. Prevalence rates and the pattern of disability in populations of people with CP can only be evaluated on the basis of the methods of case definition and ascertainment. We have demonstrated the methods necessary to ensure valid, standard and detailed information on CP for the purposes of surveillance, service planning and research.

Cerebral palsy births in eastern Denmark, 1987--90: implications for neonatal care

The Cerebral Palsy Register in eastern Denmark has collected cases using a uniform data sampling procedure since birth year 1979. We have investigated changes in the rate of cerebral palsy, related to gestational age, mortality and perinatal risk factors in children born 1983--90. The total cerebral palsy birth prevalence decreased from 3.0 in the birth year period 1983--86 to 2.4 per 1000 live births (P < 0.01) in 1987--90, owing to a decrease among all preterm infants (29--19 per 1000, P < 0.001). The perinatal and early neonatal mortality in preterm infants was unchanged from 1983--86 to 1987--90. The rate of cerebral palsy in term infants was 1.5 per 1000 in all birth-year periods from 1979--90. Among the cerebral palsy infants, the proportion of very preterm babies treated with mechanical ventilation in the neonatal period decreased from 95% in 1983--86 to 61% in 1987--90 (P < 0.001), while the group treated with CPAP among the moderately preterm babies increased from 61% to 78% (P < 0.05). The significant decline in cerebral palsy rate in preterm infants born 1987--90 may be due to a change in treatment at the neonatal intensive care units using less mechanical ventilation, a hypothesis which needs further investigation.

Adaptive mechanisms of developing brain. The neuroradiologic assessment of the preterm infant

Since the 1980s, cranial sonography has been routinely performed in premature infants. This has produced a wealth of information about the more dramatic central nervous system lesions of IVH, PVL, and late VM. This information has included timing and evolution of these lesions and their eventual correlation with outcome. For two reasons the advent of MR imaging scanning has produced an interest in using this modality to evaluate these same infants. First, MR imaging gives an obviously superior image, and its ability to detect lesions is far superior to that of ultrasound. Second, the ability of cranial sonography to detect all of the children with CP or low IQ is limited. In our studies of outcome in very low-birth weight infants grade 3 to 4 IVH, PVL, or VM are able to detect only about 50% of the infants who developed CP by 3 years. This condition should be highly correlated with structural brain disease; an imaging modality that was more sensitive to central nervous system lesions should offer an advantage in predicting outcome. In the only prospective assessment of the ability of these two modalities to predict outcome at 3 years, van de Bor and colleagues found MR imaging did not do better than cranial sonography. This was largely because both modalities detected the most severe lesions, and most children with milder lesions on MR imaging had normal outcome. Studies of late (age 1 to teenage years) MR imaging scans in preterm infants show that a high percentage have white matter lesions but these lesions correlate poorly with outcome. If our concern when counseling parents is to alert them when a serious adverse outcome is likely in their child, then cranial sonography is to be favored precisely because it is less able to detect subtle lesions, which the developing brain has the capacity to overcome. On the other hand, if our aim is to detect all lesions, even though these lesions do not predict serious adverse outcomes, then MR imaging is to be favored. Research aimed at discovering etiologies and mechanisms of brain injury in these high-risk infants should use the more sensitive modality MR imaging. Finally, the interesting observation that preterm infants fare as well as they do despite MR imaging-identified lesions might stimulate research studying the adaptive mechanisms of developing brain.

A qualitative analysis of brain SPECT for prognostication of gross motor development in children with cerebral palsy

PURPOSE

In this report, the authors assessed the clinical significance of decreased regional cerebral blood flow (rCBF) in the thalamus or cerebellar hemispheres in relation to gross motor performance in the children with cerebral palsy.

MATERIALS AND METHODS

Thirty-six children with bilateral spastic cerebral palsy (BSCP) underwent brain SPECT. Visual analysis was used for the brain SPECT interpretation. The rCBF in the thalamus or cerebellum was graded as normal, mildly decreased, or severely decreased. A marked decrease or near absence of rCBF in the thalamus or cerebellum was considered as severely decreased.

RESULTS

All 36 children with BSCP had hypoperfusion in the thalamus or cerebellar hemispheres. Eight of 20 children (40%) with mildly decreased rCBF on brain SPECT had mild developmental delays. On the other hand, only 1 of 16 children (6.3%) with severe hypoperfusion in the thalamus or cerebellum had a mild developmental delay, and the remaining 15 of 16 children (93.8%) had severe developmental delays. There was good correlation between the degree of developmental delay and the severity of hypoperfusion in the thalamus or cerebellum (P = 0.023).

CONCLUSION

The measurement of rCBF by Tc-99m ethyl cysteinate dimer brain SPECT appears to be valuable in prognostication of gross motor development in children with BSCP.

Outcome of children in the indomethacin intraventricular hemorrhage prevention trial

BACKGROUND

For preterm infants, intraventricular hemorrhage (IVH) may be associated with adverse neurodevelopmental outcome. We have demonstrated that early low-dose indomethacin treatment is associated with a decrease in both the incidence and severity of IVH in very low birth weight preterm infants. In addition, we hypothesized that the early administration of low-dose indomethacin would not be associated with an increase in the incidence of neurodevelopmental handicap at 4.5 years of age in our study children.

METHODS

To test this hypothesis, we provided neurodevelopmental follow-up for the 384 very low birth weight survivors of the Multicenter Randomized Indomethacin IVH Prevention Trial. Three hundred thirty-seven children (88%) were evaluated at 54 months' corrected age, and underwent neurodevelopmental examinations, including the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), the Peabody Picture Vocabulary Test-Revised (PPVT-R), and standard neurologic examinations.

RESULTS

Of the 337 study children, 170 had been randomized to early low-dose indomethacin therapy and 167 children had received placebo. Twelve (7%) of the 165 indomethacin children and 11 (7%) of the 158 placebo children who underwent neurologic examinations were found to have cerebral palsy. For the 233 English-monolingual children for whom cognitive outcome data follow, the mean gestational age was significantly younger for the children who received indomethacin than for those who received placebo. In addition, although there were no differences in the WPPSI-R or the PPVT-R scores between the 2 groups, analysis of the WPPSI-R full-scale IQ by function range demonstrated significantly less mental retardation among those children randomized to early low-dose indomethacin (for the indomethacin study children, 9% had an IQ <70, 12% had an IQ of 70-80, and 79% had an IQ >80, compared with the placebo group, for whom 17% had an IQ <70, 18% had an IQ of 70-80, and 65% had an IQ >80). Indomethacin children also experienced significantly less difficulty with vocabulary skills as assessed by the PPVT-R when compared with placebo children.

CONCLUSIONS

These data suggest that, for preterm neonates, the early administration of low-dose indomethacin therapy is not associated with adverse neurodevelopmental function at 54 months' corrected age.

The etiology and outcome of cerebral ventriculomegaly at term in very low birth weight preterm infants

BACKGROUND

Despite improvements in survival data, the incidence of neurodevelopmental handicaps in preterm infants remains high. To prevent these handicaps, one must understand the pathophysiology behind them. For preterm infants, cerebral ventriculomegaly (VM) may be associated with adverse neurodevelopmental outcome. We hypothesized that although the causes of VM are multiple, the incidence of handicap at 4.5 years of age in preterm infants with this ultrasonographic finding at term would be high.

METHODS

To test this hypothesis, we provided neurodevelopmental follow-up for all 440 very low birth weight survivors of the Multicenter Randomized Indomethacin Intraventricular Hemorrhage (IVH) Prevention Trial. A total of 384 children (87%) were evaluated at 54 months' corrected age (CA), and 257 subjects were living in English-speaking, monolingual households and are included in the following data analysis.

RESULTS

Moderate to severe low pressure VM at term was documented in 11 (4%) of the English-speaking, monolingual survivors. High grade IVH and bronchopulmonary dysplasia (BPD) were both risk factors for the development of VM. Of 11 (45%) children with VM, 5 suffered grades 3 to 4 IVH, compared with 2/246 (1%) children without VM who experienced grades 3 to 4 IVH. Similarly, 9/11 (82%) children with VM had BPD, compared with 120/246 (49%) children without VM who had BPD. Logistic regression analysis was performed using birth weight, gestational age, gender, Apgar score at 5 minutes, BPD, sepsis, moderate to severe VM, periventricular leukomalacia, grade of IVH, and maternal education to predict IQ <70. Although maternal education was an important and independent predictor of adverse cognitive outcome, in this series of very low birth weight prematurely born children, VM was the most important predictor of IQ <70 (OR: 19.0; 95% CI: 4.5, 80.6). Of children with VM, 6/11 (55%) had an IQ <70, compared with 31/246 (13%) of children without VM. Children with VM had significantly lower verbal and performance scores compared with children without VM.

CONCLUSIONS

These data suggest that, for preterm neonates, VM at term is a consequence of the vulnerability of the developing brain. Furthermore, its presence is an important and independent predictor of adverse cognitive and motor development at 4.5 years' CA.

Prevalence of cerebral palsy in Slovenia: birth years 1981 to 1990

Changes in the prevalence of cerebral palsy (CP) in a population of Slovenian children born between 1981 and 1990 were determined. A population-based birth-cohort study was undertaken. Seven hundred and sixty-eight children with CP (aged 5 to 14 years) were identified from the National Cerebral Palsy Register in 1995. Spastic syndromes accounted for 84.8%. Of the 768 children studied, the total prevalence of CP per 1000 live births fell significantly from 3.3 in 1981 to 2.3 in 1990. This decreasing trend was observed in children born at < or = 38 weeks of gestation and in those with a birthweight of < 1500 g, but the prevalence of CP remained fairly constant in those born at > 38 weeks of gestation and in those with a birthweight of > or = 2500 g. The results show that a statistically significant improvement in the survival rate of infants born in Slovenia between 1981 and 1990 was not accompanied by an increase in the prevalence of CP. Additionally, in the group of very-low-birthweight infants the prevalence of CP considerably decreased.

Prevalence of cerebral palsy in Alberta

BACKGROUND

In spite of scattered reports to the contrary, concern is continually expressed that the frequency of cerebral palsy has not decreased with modern perinatal/neonatal care. Overall, epidemiological information on cerebral palsy is scant. The generally accepted prevalence is 2 to 2.5 per thousand school-age children.

METHODS

A population-based record linkage study of a presently living cohort of 96,359 children born from April, 1985 through March, 1988 and followed over an eight-year tracking period captured the diagnostic codes for all fee-for-service physician claims, all hospital separations and individual birth data from the Department of Vital Statistics of the Government of Alberta. The ICD-9 code "343" was used to identify subjects. The childhood prevalence and frequency by birthweight-specific sub-groups of cerebral palsy after age three years (congenital, 229 [92.3%]; probable acquired 19 [7.7%]) were identified giving an overall prevalence of 2.57 per 1000. Seventy percent were diagnosed before their third birthday. Cohort prevalence of cerebral palsy for low birthweight children (< 2500 grams) was 17.7, very low birthweight (< 1500 grams), 78.5; and extremely low birthweight (< 1000 grams), 98.4. Low birthweight children made up just over one-third of cases in this study.

CONCLUSIONS

Cerebral palsy continues to affect a significant number of children suggesting the prevalence of cerebral palsy has not decreased. The proportion of affected children with low birthweight in this study is less than that reported in the literature.

The changing panorama of cerebral palsy--bilateral spastic forms in particular

Our Swedish population-based cerebral palsy (CP) project started 25 years ago and today covers the birth years 1954-1990, with over 1400 CP cases. This large series (1, 2, 3) has opened new perspectives on time trends and aetiological background factors, where two areas of successively increasing knowledge stand out as particularly helpful. One is the growing amount of biological and clinical data from the continuously increasing cohorts of surviving very preterm infants, the other is the rapidly expanding and refined information from neuroimaging. Bilateral spastic CP (BSCP), including spastic and ataxic diplegia, tetraplegia and spastic-dyskinetic CP, is the most prevalent clinical group of CP syndromes, present in around 75% of preterm and 45% of term CP, and has shown the most significant prevalence changes over time. In this presentation we, therefore, focus on BSCP, also analysed in a collaborative study between southwest Germany and western Sweden and recently presented in a series of four papers (4, 5, 6, 7).

The changing panorama of cerebral palsy in Sweden. VII. Prevalence and origin in the birth year period 1987-90

This seventh Swedish population-based cerebral palsy (CP) report comprises 216 children born between 1987 and 1990. The crude live birth prevalence was 2.36 per 1000, indicating a break in the continuous increase since 1970. Excluding 10 postnatally-derived cases, gestational-age specific prevalences were 80 for extremely, 54 for very and 8 for moderately preterms and 1.4 for term children per 1000. Birth weight-specific prevalences were 57 for birth weights < 1000 g, 68 for 1000-1499 g, 14 for 1500-2499 g and 1.4 for > or = 2500 g per 1000. The aetiology was considered prenatal in 8%, peri/neonatal in 54% and unclassifiable in 38% of preterms and 33, 28 and 39% of term children. Hemiplegic, diplegic and tetraplegic syndromes accounted for 22, 66 and 7% of preterms and 44, 29 and 10% of term children. Non-walking, mental retardation, epilepsy, severe visual impairment and infantile hydrocephalus were present in 39, 39, 26, 18 and 23% of preterms; and 38, 44, 36, 14 and 5% of term children, respectively. The entire series of 1408 cases born in 1954-90 revealed three distinct trend eras for preterms, clearly related to changes in perinatal care and shifts in type of CP manifestations.

Intrauterine growth and gestational age in preterm infants with cerebral palsy

In a case-control study, gestational age and intrauterine growth of 191 preterm singleton infants 1971-82 with cerebral palsy were compared to all preterm live-born singletons in Denmark in 1982 (N = 2203). The distribution of gestational age among preterm cases was slightly bimodal with maximum values at 29 and 32 weeks. The risk for cerebral palsy was highest in the infants with gestational age 28-30 weeks (OR = 5.6 (4.0-7.8), 95% confidence interval). Birth weight deviation, in the 34-36 weeks infants, expressed as the number of standard deviations from the mean birth weight for gestational age, was more negative in cases than in controls (P < 0.001). The frequency of small for gestational age (SGA) was 13% in cases and 9% in controls (OR = 1.5 (0.96-2.3), 95% confidence interval). The odds for cerebral palsy being SGA, was lower in 28-30 weeks (OR = 0.22 (0.06-0.86), 95% confidence interval), the same in 31-33 weeks (OR = 0.83 (0.35-2.0), 95% confidence interval) and higher in 34-36 weeks (OR = 5.2 (2.9-9.5), 95% confidence interval). In conclusion, preterm infants with cerebral palsy are born earlier than other preterm infants. Small for gestational age is associated with cerebral palsy in preterm infants only above 33 weeks.