In Philippi et al.’s study3 the interrater reliability of general movements observation was moderate but appeared excellent among three raters, while one of them rated differently. Do we conclude that the interrater reliability is low, or that one of the examiners needs further training?
One of our challenges for the next generation could be to give practitioners time to learn how to interpret the neurobehaviour of an infant while integrating the strengths and limitations of technical tools.
REFERENCES 1. Wusthoff CJ. How to use: the neonatal neurological examination. Arch Dis Child Educ Pract Ed 2013; 98:
predicting cerebral palsy. Dev Med Child Neurol 2014; 56:
after very preterm birth and the effect of the Infant
960–67.
Behavioural Assessment and Intervention Program. Child
4. Surveillance of Cerebral Palsy in Europe. Surveillance of
148–53. 2. El-Dib M, Massaro AN, Glass P, Aly H. Neurodevelop-
cerebral palsy in Europe: a collaboration of cerebral palsy
mental assessment of the newborn: an opportunity for
surveys and registers. Surveillance of Cerebral Palsy in
prediction of outcome. Brain Dev 2011; 33: 95–105. 3. Philippi H, Karch D, Kang K-S, et al. Computer-based analysis
of
general
movements
reveals
stereotypies
Care Health Dev 2011; 37: 195–202.
Europe (SCPE). Dev Med Child Neurol 2000; 42: 816–24. 5. Meijssen DE, Wolf MJ, Koldewijn K, van Wassenaer AG, Kok JH, van Baar AL. Parenting stress in mothers
Do children with primary complex motor stereotypies only have movement problems? JURGEN LEMIERE 1,2 1 UPC KU Leuven – Child and Adolescent Psychiatry, Leuven; 2 UZ Leuven – Paediatric Haemato-Oncology, Leuven, Belgium. doi: 10.1111/dmcn.12506 This commentary is on the original article by Mahone et al. on pages 1001–1008 of this issue.
Movement disorders in childhood are characterized by a heterogeneous variety of difficulties. One of the common movement problems, but often misidentified and/or under-diagnosed, is motor stereotypies.1 Differentiating motor stereotypies from other movement problems (such as tics) can be difficult.2 According to the DSM-5, stereotypies are ‘repetitive, seemingly driven, and non-functional motor behaviors’, but the clinical presentation can vary from more simple movements like rocking and head banging, to more complex presentations like hand and arm flapping. When these stereotypies interfere with normal activities and are present for a minimum of 4 weeks, a diagnosis of stereotypic motor disorder (SMD) is given. However, motor stereotypies often occur in the presence of other conditions, like autistic spectrum disorders, developmental delay, Rett syndrome, and blindness; but also attention-deficit-hyperactivity disorder (ADHD) and obsessive compulsive disorder (OCD).3 These stereotypies are called secondary motor stereotypies and this group represent the largest proportion. Good clinical practice of the assessment of motor stereotypies must encompass not only a thoroughly neurological evaluation, but also a psychiatric and psychosocial screening. The presence of motor stereotypies in the absence of other conditions,
called primary motor stereotypies, has been estimated to occur in up to 7% of children. In recent years, knowledge about the phenomenology of primary motor stereotypies has increased. However, some important and fundamental questions remain. According to the DSM-5, SMD is classified in the category of neurodevelopmental disorders, suggesting a neurobiological underpinning. Although the underlying neurobiological pathway is not fully understood, there is evidence that the frontostriatal circuit is affected. It is known that other conditions in which the frontostriatal pathway is involved (like ADHD, tic disorders, and OCD) are marked by neurocognitive problems. Therefore, it is clinically and scientifically relevant to investigate whether children with primary motor stereotypies demonstrate neurocognitive problems, similar to the cognitive problems seen in other neurodevelopmental disorders. In the paper by Mahone et al.4, a first step has been taken in investigating the neuropsychological profile of children with primary motor stereotypies. The results demonstrate that children with primary motor stereotypies have a largely intact neurocognitive profile, but a positive association was found between frequency and severity of motor stereotypies and parent reports of attentional and executive difficulties. Additionally, a substantial proportion of the children were rated as having motor skill difficulties consistent with developmental coordination disorder. These findings suggest screening for more subtle and less overt problems is warranted. Motor stereotypies are visible and can overshadow the presence of more subtle cognitive and/or motor problems that interfere with daily functioning. Future research Commentaries
923
needs to expand the broader phenomenology of primary motor stereotypies, including neurocognitive and motor functioning. Additional imaging studies are required to test the frontostriatal hypothesis. The neurobiological model has gained more credibility over the years, but it is a clinical and scientific pitfall to ignore psychosocial factors. There is evidence that motor stereotypies can be triggered by psychosocial factors (e.g. excitement, being focused, anxiety, or fatigue)5 and motor stereotypies can acquire a functional value, e.g. regulation of arousal.1 Interference with daily functioning is one of the criteria in the DSM-5 for diagnosis of SMD. Despite this criterion, it is unclear to what extent stereotypies (can) interfere with daily functioning. Additionally, little is known about the impact of primary motor stereotypies on the well-being and quality of life of the child.
Clarifying these issues is crucial in establishing the most appropriate treatment of motor stereotypies and some progress has been made in recent years. To date, some evidence exists for the beneficial effect of two behavioral techniques: habit reversal and differential reinforcement of other behaviors. To date, pharmacological treatment has had no therapeutic effect.3 Interestingly, habit reversal has also proven to be effective in the treatment of tic disorders.3 The research field of motor stereotypies has revealed important insights, but many challenges still need to be addressed. Currently, a solid conclusion for practitioners is that the diagnosis and treatment of motor stereotypies require an interdisciplinary approach.
REFERENCES 1. Freeman R, Soltanifar A, Baer S. Stereotypic movement disorder: easily missed. Dev Med Child Neurol 2010; 52: 733–8.
3. Zinner SH, Mink JW. Movement disorders I: tics and stereotypies. Pediatr Rev 2010; 31: 223–33.
2. Barry S, Baird G, Lascelles K, Bunton P, Hedderly T.
4. Mahone EM, Ryan M, Ference L, Morris-Berry C,
Neurodevelopmental movement disorders – an update on
Singer HS. Neuropsychological function in children with
childhood motor stereotypies. Dev Med Child Neurol
primary complex motor stereotypies. Dev Med Child Neu-
2011; 53: 979–85.
rol 2014; 56: 1001–8.
5. Muthugovindan D, Singer H. Motor stereotypy disorders. Curr Opin Neurol 2009; 22: 131–6.
Common pathways of intracranial calcification and the role of the pericyte: insights from neuropathology JOHN LIVINGSTON Department of Paediatric Neurology, Leeds General Infirmary, Leeds, UK. doi: 10.1111/dmcn.12535 This commentary is on the original article by McCartney and Squier on pages 1009–1015 of this issue.
Intracranial calcification occurs in many different contexts. These may be clearly associated with disease (e.g. congenital infection) or within a tumour, or may be physiological, occurring as part of the normal ageing process. That so many different disease processes can result in intracranial calcification, might suggest that such calcification is a nonspecific phenomenon, telling us little about the underlying pathology. Perhaps surprisingly then, neuroimaging has demonstrated that calcification may occur in a characteristic pattern in distinct disease states.1 Recognition of this fact is not only of value in diagnosis, but suggests that disease specific factors determine whether calcification occurs, and the location and pattern in which it occurs. Examples of characteristic calcification phenotypes include AicardiGoutieres syndrome (AGS), band–like calcification with simplified gyration and polymicrogyria (BLC-PMG), and idiopathic basal ganglia calcification (IBGC). Thus, the 924 Developmental Medicine & Child Neurology 2014, 56: 917–926
underlying pathophysiology may be more discrete than previously supposed, although the pathways to calcification can be very diverse: a type 1 interferonopathy in the case of AGS, a mutation in a tight junction protein in BLCPMG, and disordered inorganic phosphate homeostasis in at least some forms of familial IBGC. Prior to the 1990s when magnetic resonance imaging and molecular genetics began to revolutionize diagnostic medicine, if there was no biochemical method of reaching a diagnosis, clinicians looked to pathology to provide answers. In the past 20 years, with the exception of neurooncology, epilepsy surgery, and the increasingly rare autopsy, neuropathological studies have almost disappeared from neurological practice. The paper by McCartney and Squier2 is welcome then, not only for its consideration of the question of the genesis of intracranial calcification, but also as an example of a rare phenomenon – a paediatric neuropathology case series. In their paper, the authors describe the neuropathology observed in a heterogeneous series of paediatric cases where intracranial calcification was a major feature. They examined 28 paediatric cases, selected from the Oxford brain archive, in a standardized way using traditional neuropathology stains, but also employing specific markers for endothelium
One of our challenges for the next generation could be to give practitioners time to learn how to interpret the neurobehaviour of an infant while integrating the strengths and limitations of technical tools.
REFERENCES 1. Wusthoff CJ. How to use: the neonatal neurological examination. Arch Dis Child Educ Pract Ed 2013; 98:
predicting cerebral palsy. Dev Med Child Neurol 2014; 56:
after very preterm birth and the effect of the Infant
960–67.
Behavioural Assessment and Intervention Program. Child
4. Surveillance of Cerebral Palsy in Europe. Surveillance of
148–53. 2. El-Dib M, Massaro AN, Glass P, Aly H. Neurodevelop-
cerebral palsy in Europe: a collaboration of cerebral palsy
mental assessment of the newborn: an opportunity for
surveys and registers. Surveillance of Cerebral Palsy in
prediction of outcome. Brain Dev 2011; 33: 95–105. 3. Philippi H, Karch D, Kang K-S, et al. Computer-based analysis
of
general
movements
reveals
stereotypies
Care Health Dev 2011; 37: 195–202.
Europe (SCPE). Dev Med Child Neurol 2000; 42: 816–24. 5. Meijssen DE, Wolf MJ, Koldewijn K, van Wassenaer AG, Kok JH, van Baar AL. Parenting stress in mothers
Do children with primary complex motor stereotypies only have movement problems? JURGEN LEMIERE 1,2 1 UPC KU Leuven – Child and Adolescent Psychiatry, Leuven; 2 UZ Leuven – Paediatric Haemato-Oncology, Leuven, Belgium. doi: 10.1111/dmcn.12506 This commentary is on the original article by Mahone et al. on pages 1001–1008 of this issue.
Movement disorders in childhood are characterized by a heterogeneous variety of difficulties. One of the common movement problems, but often misidentified and/or under-diagnosed, is motor stereotypies.1 Differentiating motor stereotypies from other movement problems (such as tics) can be difficult.2 According to the DSM-5, stereotypies are ‘repetitive, seemingly driven, and non-functional motor behaviors’, but the clinical presentation can vary from more simple movements like rocking and head banging, to more complex presentations like hand and arm flapping. When these stereotypies interfere with normal activities and are present for a minimum of 4 weeks, a diagnosis of stereotypic motor disorder (SMD) is given. However, motor stereotypies often occur in the presence of other conditions, like autistic spectrum disorders, developmental delay, Rett syndrome, and blindness; but also attention-deficit-hyperactivity disorder (ADHD) and obsessive compulsive disorder (OCD).3 These stereotypies are called secondary motor stereotypies and this group represent the largest proportion. Good clinical practice of the assessment of motor stereotypies must encompass not only a thoroughly neurological evaluation, but also a psychiatric and psychosocial screening. The presence of motor stereotypies in the absence of other conditions,
called primary motor stereotypies, has been estimated to occur in up to 7% of children. In recent years, knowledge about the phenomenology of primary motor stereotypies has increased. However, some important and fundamental questions remain. According to the DSM-5, SMD is classified in the category of neurodevelopmental disorders, suggesting a neurobiological underpinning. Although the underlying neurobiological pathway is not fully understood, there is evidence that the frontostriatal circuit is affected. It is known that other conditions in which the frontostriatal pathway is involved (like ADHD, tic disorders, and OCD) are marked by neurocognitive problems. Therefore, it is clinically and scientifically relevant to investigate whether children with primary motor stereotypies demonstrate neurocognitive problems, similar to the cognitive problems seen in other neurodevelopmental disorders. In the paper by Mahone et al.4, a first step has been taken in investigating the neuropsychological profile of children with primary motor stereotypies. The results demonstrate that children with primary motor stereotypies have a largely intact neurocognitive profile, but a positive association was found between frequency and severity of motor stereotypies and parent reports of attentional and executive difficulties. Additionally, a substantial proportion of the children were rated as having motor skill difficulties consistent with developmental coordination disorder. These findings suggest screening for more subtle and less overt problems is warranted. Motor stereotypies are visible and can overshadow the presence of more subtle cognitive and/or motor problems that interfere with daily functioning. Future research Commentaries
923
needs to expand the broader phenomenology of primary motor stereotypies, including neurocognitive and motor functioning. Additional imaging studies are required to test the frontostriatal hypothesis. The neurobiological model has gained more credibility over the years, but it is a clinical and scientific pitfall to ignore psychosocial factors. There is evidence that motor stereotypies can be triggered by psychosocial factors (e.g. excitement, being focused, anxiety, or fatigue)5 and motor stereotypies can acquire a functional value, e.g. regulation of arousal.1 Interference with daily functioning is one of the criteria in the DSM-5 for diagnosis of SMD. Despite this criterion, it is unclear to what extent stereotypies (can) interfere with daily functioning. Additionally, little is known about the impact of primary motor stereotypies on the well-being and quality of life of the child.
Clarifying these issues is crucial in establishing the most appropriate treatment of motor stereotypies and some progress has been made in recent years. To date, some evidence exists for the beneficial effect of two behavioral techniques: habit reversal and differential reinforcement of other behaviors. To date, pharmacological treatment has had no therapeutic effect.3 Interestingly, habit reversal has also proven to be effective in the treatment of tic disorders.3 The research field of motor stereotypies has revealed important insights, but many challenges still need to be addressed. Currently, a solid conclusion for practitioners is that the diagnosis and treatment of motor stereotypies require an interdisciplinary approach.
REFERENCES 1. Freeman R, Soltanifar A, Baer S. Stereotypic movement disorder: easily missed. Dev Med Child Neurol 2010; 52: 733–8.
3. Zinner SH, Mink JW. Movement disorders I: tics and stereotypies. Pediatr Rev 2010; 31: 223–33.
2. Barry S, Baird G, Lascelles K, Bunton P, Hedderly T.
4. Mahone EM, Ryan M, Ference L, Morris-Berry C,
Neurodevelopmental movement disorders – an update on
Singer HS. Neuropsychological function in children with
childhood motor stereotypies. Dev Med Child Neurol
primary complex motor stereotypies. Dev Med Child Neu-
2011; 53: 979–85.
rol 2014; 56: 1001–8.
5. Muthugovindan D, Singer H. Motor stereotypy disorders. Curr Opin Neurol 2009; 22: 131–6.
Common pathways of intracranial calcification and the role of the pericyte: insights from neuropathology JOHN LIVINGSTON Department of Paediatric Neurology, Leeds General Infirmary, Leeds, UK. doi: 10.1111/dmcn.12535 This commentary is on the original article by McCartney and Squier on pages 1009–1015 of this issue.
Intracranial calcification occurs in many different contexts. These may be clearly associated with disease (e.g. congenital infection) or within a tumour, or may be physiological, occurring as part of the normal ageing process. That so many different disease processes can result in intracranial calcification, might suggest that such calcification is a nonspecific phenomenon, telling us little about the underlying pathology. Perhaps surprisingly then, neuroimaging has demonstrated that calcification may occur in a characteristic pattern in distinct disease states.1 Recognition of this fact is not only of value in diagnosis, but suggests that disease specific factors determine whether calcification occurs, and the location and pattern in which it occurs. Examples of characteristic calcification phenotypes include AicardiGoutieres syndrome (AGS), band–like calcification with simplified gyration and polymicrogyria (BLC-PMG), and idiopathic basal ganglia calcification (IBGC). Thus, the 924 Developmental Medicine & Child Neurology 2014, 56: 917–926
underlying pathophysiology may be more discrete than previously supposed, although the pathways to calcification can be very diverse: a type 1 interferonopathy in the case of AGS, a mutation in a tight junction protein in BLCPMG, and disordered inorganic phosphate homeostasis in at least some forms of familial IBGC. Prior to the 1990s when magnetic resonance imaging and molecular genetics began to revolutionize diagnostic medicine, if there was no biochemical method of reaching a diagnosis, clinicians looked to pathology to provide answers. In the past 20 years, with the exception of neurooncology, epilepsy surgery, and the increasingly rare autopsy, neuropathological studies have almost disappeared from neurological practice. The paper by McCartney and Squier2 is welcome then, not only for its consideration of the question of the genesis of intracranial calcification, but also as an example of a rare phenomenon – a paediatric neuropathology case series. In their paper, the authors describe the neuropathology observed in a heterogeneous series of paediatric cases where intracranial calcification was a major feature. They examined 28 paediatric cases, selected from the Oxford brain archive, in a standardized way using traditional neuropathology stains, but also employing specific markers for endothelium
