Application Of General Movements (GMs) Assessment In High Risk Infant Follow-up For Motor Development

Due to the advance of perinatal technique in the past 20 years in China, the survival rate has increased apparently.But the risk of adverse neurodevelopmental outcomes also increased including severe disabilities such as cerebral palsy and mental retardation and minor neurological disorder. Thus it is very important to carry out the high risk infant follow-up for the neurological development.The goal of the follow-up is to early detect children with abnormal neurological development and to provide early rehabilitative intervention.In the past ten years increasing attention has been paid to high risk infant follow-up in China.Cerebral palsy(CP) is the most important disease which leads to motor disability in children.Also it is one of the severe sequela of perinatal brain injury and it is the focus of the pediatric professionals and many families of high risk infants.The number of new CP children is about 40,000 every year in China,which puts heavy burden on the whole society.Base on the theory of key period and plasticity in the brain development,it is crucial to get early prediction and diagnosis in order to acquire the best rehabilitation effects.Nowadays various techniques are available to assess the brain at an early age.These techniques vary from clinical bedside neurological assessments, more sophisticated technical assessments(brain ultrasound type B,MRI and CT) and neurophysiological assessments(EEG and evoked potentials).The sensitivities,specificities and accuracies of all these techniques show a large difference,which points to the need for more advanced and accurate methods to predict developmental outcome.During the past several decades,research in developmental neurology has provided the concept of ontogenetic adaptation,which means that during the development the function of the developing neural structure must meet the needs of the organism itself and its environment.During each stage the developing organism must adapt the needs of the internal and external environments.As the result of age-specific difference of the developing nervous system,the age-adequate diagnostic procedures are required. General movements(GMs) assessment takes full account of the age-specificity and the ontogenetic adaptation.Spontaneous movements in fetuses and young infants possess important clinical significance which can effectively assess the function of young neural system.GMs are the most frequently occurring and most complex spontaneous pattern,which begin at 9 weeks postmenstrual age and last until 5 to 6 months postterm age.Developmental course of GMs includes foetal and preterm GMs,writhing movements and fidgety movements.If the nervous system is impaired,GMs lose their complex and variable character and show various abnormal character.Many studies in abroad during last 20 years have proved GMs assessment as a new tool to sensitively detect specific neurological and motor impairments and provide early prediction of developmental disorders such as cerebral palsy.Two specific abnormal GMs patterns have high predictive value for later cerebral palsy:cramped-synchronized GMs and absence of fidgety movements.GMs assessment is a nonintrusive,noninvasive,simple methods. 11 studies on 358 infants assessed by 90 observers proved an agreement between 89%and 93%.Analysis of 20 GMs assessments with a two -year interval showed a 100%test-retest reliability for global judgment and an 85% reliability for detailed judgment.Several studies showed an overall sensitivity as 94%.Specificity of GMs assessments was relatively lower(46-93%)during the preterm period and writhing movements and increased(82-100%) during the third month(fidgety movements period).Altogether,since GMs assessment is a reliable and valid tool for early prediction,it is necessary to introduce this technique into China and to develop it according Chinese conditions.The research includes two parts.The first part is research of methodology, which includes three parts:reliability of GMs assessments in training course; reliability of GMs assessments in clinical practice;reliability of direct GMs assessment and its clinical significance.The second part includes predictive validity of GMs assessment and motor development follow-up of high risk infants with different GMs.Methods and results of the first part are as following: 1.Reliability of GMs assessment during training courseMethods 30 pediatric professionals,who attended the Europe "GMs assessment basic training course" organized by our hospital,assessed the GMs videos used in the course separately.Each GMs video lasted for one and a half minutes.360 GMs assessments were obtained altogether.Interscorer reliability was tested by analyzing the correlations between the results of different observers.Results High agreement was found between the results of different observers,with good reliability during preterm and writhing movements period(ICC=0.99) and fidgety movements period(ICC=0.97). Results show GMs assessment has high interscorer reliability and is easy to learn,which provides the evidence of later extensive training of GMs assessment in China.2.Reliability of GMs assessment during clinical practice.Methods 47 high risk infants participated the study.Their GMs videos were recorded by clinical standard.Three rehabilitation professionals with the GMs certificate participated the studies of interscorer reliability and test-retest reliability.Results 47 GMs records were tested for interscorer reliability,20 for writhing period GMs and 27 for fidgety period GMs.54 GMs records were tested for test-retest reliability,19 for writhing period GMs and 35 for fidgety period GMs.Results show good interscorer and test-retest reliabilities (ICC=0.83-0.90).Also the simple,uniform and clear reference standard of GMs assessment in clinical practice was formed,which will be useful for the spread of GMs assessment in China.3.Reliability of direct method of GMs assessmentMethods Video method and direct method were carried out to assess GMs and reliabilities of the two methods were analyzed.Results 92 GMs were tested for interscorer reliability of direct method,23 for writhing period GMs and 69 for fidgety period GMs.306 GMs records were used for test-retest reliability between direct and video methods,90 for writhing period GMs and 216 for fidgety period GMs.Results showed direct method of GMs assessment had good interscorer and test-retest(with video method) reliabilities. Comparing with the traditional video method,direct method is more convenient (not requiring any equipment) which is helpful to the spread of GMs assessment in China.Methods and results of the second part of the research are as following:1.Predictive validity of GMs assessmentMethods According to inclusive and exclusive criterion 187 high risk young infants were recruited from those who were evaluated by GMs assessment in our rehabilitation clinic from Sept.of 2003 to Feb.of 2009,with male 118, female 69 and preterm 102.Predictive validity(sensitivity,specificity,positive predictive value and negative predictive value) of GMs assessment(writhing period and fidgety period) for adverse motor outcome(cerebral palsy and motor delay) were analyzed.Also predictive value of single and sequential methods of GMs assessment during fidgety period for CP outcome were analyzed and compared.Results Negative predictive value of GMs assessment during writhing period was high(93.0%).Negative predictive value of GMs assessment during fidgety period(82.9%) was lower than during writhing period.Sensitivity of GMs assessment during fidgety period(72.4%) was lower than during writhing period(88.9%).Positive predictive value of GMs assessment during fidgety period(90.2%) was much higher than during writhing period(69.6%).Negative predictive value of GMs assessment during writhing period was very high(100.0%) for outcome of not being cerebral palsy. Positive predictive value of GMs assessment(PR and CS) during writhing period was relatively low(52.2%) for cerebral palsy.Positive predictive value of GMs assessment(CS alone) during writhing period for cerebral palsy increased apprarently(87.5%).GMs assessment during fidgety period possess the best sensitivity(98.0%) and specificity(91.7%) for cerebral palsy. Negative predictive value of GMs assessment during fidgety period was very high(99.2%) for outcome of not being cerebral palsy.Single and sequential methods of GMs assessment during fidgety period have similar predictive validity,which proved the advantage of single method as the most quick and simple way when practising clinical GMs assessment. 2.Motor development follow-up of high risk infants with different GMs in fidgety period.Methods According to inclusive and exclusive criterion 297 high risk young infants were recruited from those who were evaluated by GMs assessment in our rehabilitation clinic from Sept.of 2003 to Dec.of 2008,with male 176, female 121 and preterm 173.Predictive validity(sensitivity,specificity,positive predictive value and negative predictive value) of GMs assessment(writhing period and fidgety period) for adverse motor outcome(cerebral palsy and motor delay) were analyzed.Based on the results of GMs assessment and scores of motor development(GMQ and FMQ of Peabody Developmental Motor Scale), The profile of motor development follow-up of high risk infants with different GMs in fidgety period was described and analyzed.Results Gross motor quotient(from 4-6 months on) and fine motor quotient(from1-3 months on) were lower in Group F-(Absence of fidgety movements) than in Group F+(normal fidgety movements).The differences were gradually more apparent with increasing age.Results show motor development rate in Group F- mainly comprised of CP children was much more delayed than in Group F+ mainly comprised of normal children.Early rehabilitation intervention should be carried on those infants with F-GMs and combination of gross motor and fine motor training should be emphasized.Conclusions1.GMs assessments possess good interscorer and test-retest reliabilities in both studies(training course and clinical practice).Simple,uniform and clear reference standard of GMs assessment formed in clinical practice will be useful for the spread of GMs assessment in China.2.Results showed direct method of GMs assessment had good interscorer and test-retest(with video method) reliabilities.Comparing with the traditional video method,direct method is more convenient(not requiring any equipment) which is helpful to the spread of GMs assessment in China.3.Single method of GMs assessment during fidgety period was proved its advantage as the most quick and simple way when practising clinical GMs assessment. 4.Cramped-Synchronized GMs and absence of fidgety movements possess very high predictive value for CP outcome.In writhing period,CS has a high probability to develop into cerebral palsy,which indicates early rehabilitative intervention especially for CP should be applied.High risk Infants with PR should be followed into fidgety period.Abnormal GMs(F-) of fidgety period will probably develop into outcomes of CP and motor delay.Differential diagnosis and special early rehabilitative intervention should be applied in clinic.5.Motor development rate in Group F-(Absence of fidgety movements) mainly comprised of CP children was much more delayed than in Group F+(normal fidgety movements) mainly comprised of normal children.Early rehabilitation intervention should be carried on those infants with F- GMs.