Spastic cerebral palsy: clinical magnetic resonance imaging correlation of 129 children

Incidence of Cerebral Palsy, Risk Factors, and Neuroimaging in Northeast Mexico

BACKGROUND

Cerebral palsy (CP) comprises a group of lifelong motor and postural development disorders that can cause static motor encephalopathy. The etiology of CP is attributed to nonprogressive lesions of the central nervous system during fetal or infant brain development. A diagnosis of CP is based on a combination of clinical and neurological signs, typically identified between 12 and 24 months. A medical history, several available standardized tools, including the Neoneuro assessment, and the Hammersmith infant neurological examination (HINE) can be used to predict risk. Magnetic resonance imaging (MRI) can contribute to the diagnosis of CP. The incidence of CP is 2 to 3 per 1000 live births, and in Western industrialized nations, it is 2.0-2.5 per 1000 live births; to our knowledge, no epidemiological studies have reported the incidence of CP in Mexico.

AIM

To assess the incidence of CP in children aged up to 18 months in northeast Mexico and analyze the risk factors and neuroimaging findings.

METHODS

This was a multicenter, randomized, prospective, cohort, analytical study of newborn children in three community hospitals and an early intervention and CP center in Nuevo Leon, Mexico, from 2017 to 2021. This study included 3861 newborns randomly selected from a population of 75,951 mothers in the immediate puerperium. According to the Neoneuro tool, high-risk children (n = 432) had abnormal neurological results at birth; they were followed and assessed with the Spanish version of the HINE test by a pediatric neurologist and underwent neuroimaging studies. Neonates with normal results were randomly selected to be in the low-risk group (n= 864). These neonates were followed and assessed with the HINE by a neonatologist.

RESULTS

The incidence of CP was 4.4 of 1000 up to 18 months old, which was higher than that reported in developed countries. Perinatal risk factors were predominantly recognized in the etiology of CP, such as brain hemorrhage, and prematurity, in addition to congenital anomalies. The most frequent neuroimaging findings were ventricular dilation/cortical atrophy and intraventricular/subependymal hemorrhage and periventricular leukomalacia on MRI.

CONCLUSIONS

This study is the first on the incidence/prevalence of CP in Mexico, and there are no formal studies in this field in other Latin American countries either. The incidence of CP in northeast Mexico is higher than that reported in developed countries. The follow-up of high-risk young children must be reinforced in the Mexican population, as children with disabilities have high and sequential health-care needs and may usually be lost to follow-up. Neuroimaging of PVL was the more frequent finding by MRI in this population.

Evaluation of the relationship between cranial magnetic resonance imaging findings and clinical status in children with cerebral palsy

Background/aim

The objective of this study was to evaluate the relationship between cranial magnetic resonance imaging (MRI) findings and clinical features in cerebral palsy (CP).

Materials and methods

Children aged 3 to 18 years, who were followed with the diagnosis of CP between January 2012 and September 2015, were included. The type of CP was classified using the European Cerebral Palsy Monitoring Group’s classification system and then, patients were divided into two groups as spastic or nonspastic groups. The Gross Motor Function Classification System (GMFCS) was used to determine the level of mobility. According to the GMFCS, levels 1, 2, and 3 were grouped as mobile, and levels 4 and 5 were grouped as immobile. Cranial MRI findings were reevaluated by a voluntarily radiologist and grouped as periventricular leukomalacia (PVL) (grades 1, 2, and 3), cerebral atrophy, migration anomaly, cerebellar involvement, basal ganglion involvement, and normal MRI findings.

Results

Sixty-two patients were enrolled. The rate of mobile patients did not differ between the spastic and nonspastic groups. The incidence of PVL was significantly higher in cases of prematurity and spastic CP (p < 0.05). The rate of mobilization was significantly lower and the rate of epilepsy was significantly higher in patients with PVL. Immobile patients were more common among cases of grade 3 PVL (p < 0.05).

Conclusion

The most common cranial MRI pathology was PVL, and the presence of PVL and its grade might help clinically assess the patient’s CP type and level of mobilization. While pathology was observed mostly in cranial MRI in cases of CP with similar clinical features, the fact that cranial MRI was completely normal for 14.5% of the cases suggests that there may be some pathologies that we could not identify with today’s imaging technology.

MRI classification system (MRICS) for children with cerebral palsy: development, reliability, and recommendations

AIM

To develop and evaluate a classification system for magnetic resonance imaging (MRI) findings of children with cerebral palsy (CP) that can be used in CP registers.

METHOD

The classification system was based on pathogenic patterns occurring in different periods of brain development. The MRI classification system (MRICS) consists of five main groups: maldevelopments, predominant white matter injury, predominant grey matter injury, miscellaneous, and normal findings. A detailed manual for the descriptions of these patterns was developed, including test cases (www.scpenetwork.eu/en/my-scpe/rtm/neuroimaging/cp-neuroimaging/). A literature review was performed and MRICS was compared with other classification systems. An exercise was carried out to check applicability and interrater reliability. Professionals working with children with CP or in CP registers were invited to participate in the exercise and chose to classify either 18 MRIs or MRI reports of children with CP.

RESULTS

Classification systems in the literature were compatible with MRICS and harmonization possible. Interrater reliability was found to be good overall (k=0.69; 0.54-0.82) among the 41 participants and very good (k=0.81; 0.74-0.92) using the classification based on imaging reports.

INTERPRETATION

Surveillance of Cerebral Palsy in Europe (SCPE) proposes the MRICS as a reliable tool. Together with its manual it is simple to apply for CP registers.

Optimization of MRI-based scoring scales of brain injury severity in children with unilateral cerebral palsy

BACKGROUND

Several scoring systems for measuring brain injury severity have been developed to standardize the classification of MRI results, which allows for the prediction of functional outcomes to help plan effective interventions for children with cerebral palsy.

OBJECTIVE

The aim of this study is to use statistical techniques to optimize the clinical utility of a recently proposed template-based scoring method by weighting individual anatomical scores of injury, while maintaining its simplicity by retaining only a subset of scored anatomical regions.

MATERIALS AND METHODS

Seventy-six children with unilateral cerebral palsy were evaluated in terms of upper limb motor function using the Assisting Hand Assessment measure and injuries visible on MRI using a semiquantitative approach. This cohort included 52 children with periventricular white matter injury and 24 with cortical and deep gray matter injuries. A subset of the template-derived cerebral regions was selected using a data-driven region selection algorithm. Linear regression was performed using this subset, with interaction effects excluded.

RESULTS

Linear regression improved multiple correlations between MRI-based and Assisting Hand Assessment scores for both periventricular white matter (R squared increased to 0.45 from 0, P < 0.0001) and cortical and deep gray matter (0.84 from 0.44, P < 0.0001) cohorts. In both cohorts, the data-driven approach retained fewer than 8 of the 40 template-derived anatomical regions.

CONCLUSION

The equal or better prediction of the clinically meaningful Assisting Hand Assessment measure using fewer anatomical regions highlights the potential of these developments to enable enhanced quantification of injury and prediction of patient motor outcome, while maintaining the clinical expediency of the scoring approach.

Relationship between characteristics on magnetic resonance imaging and motor outcomes in children with cerebral palsy and white matter injury

In a population cohort of children with white matter injury (WMI) and cerebral palsy (CP), we aimed to describe the magnetic resonance imaging (MRI) characteristics, identify key structure-function relationships, and classify the severity of WMI in a clinically relevant way. Stratified on MRI laterality/symmetry, variables indicating the extent and location of cerebral abnormalities for 272 children with CP and WMI on chronic-phase MRI were related to gross motor function and motor topography using univariable and multivariable approaches. We found that symmetrical involvement, severe WM loss in the hemispheres and corpus callosum, and cerebellar involvement were the strongest predictors of poor gross motor function, but the final model explained only a small proportion of the variability. Bilateral, extensive WM loss was more likely to result in quadriplegia, whereas volume loss in the posterior-mid WM more frequently resulted in diplegia. The extent and location of MRI abnormalities differed according to laterality/symmetry; asymmetry was associated with less extensive hemispheric involvement than symmetrical WMI, and unilateral lesions were more focal and located more anteriorly. In summary, laterality/symmetry of WMI, possibly reflecting different pathogenic mechanisms, together with extent of WM loss and cerebellar abnormality predicted gross motor function in CP, but to a limited extent.

Relationship between brain structure on magnetic resonance imaging and motor outcomes in children with cerebral palsy: a systematic review

Magnetic resonance imaging (MRI) is recommended in all children with cerebral palsy (CP) where the aetiology has not been established, and the major presenting problem in CP is reduced motor capacity. A systematic review of the literature was performed to investigate the relationship between brain structure on MRI and motor outcomes in children with CP. A total of 37 studies met inclusion criteria, and were analysed in terms of (a) population characteristics, (b) MRI data, (c) motor outcome data, and (d) the relationship between MRI data and motor outcomes. All studies used a qualitative system to classify brain lesions; however, few reported information about the location and extent of lesions. Valid and reliable classifications of motor abilities were not always used, and three studies did not link motor findings to MRI features. There was, however, a relationship between the type of brain lesion on MRI and two specific motor outcomes, namely gross motor functional classification (using GMFCS) and motor type. This relationship could aid in the prediction and optimisation of early interventions for children with CP. There is also need for a quantitative MRI classification measure which includes detailed information about the location and severity of lesions.

Brain magnetic resonance imaging and motor and intellectual functioning in 86 patients born at term with spastic diplegia

AIM

To investigate the association between magnetic resonance imaging (MRI) patterns and motor function, epileptic episodes, and IQ or developmental quotient in patients born at term with spastic diplegia.

METHOD

Eighty-six patients born at term with cerebral palsy (CP) and spastic diplegia (54 males, 32 females; median age 20 y, range 7-42 y) among 829 patients with CP underwent brain MRI between 1990 and 2008. The MRI and clinical findings were analysed retrospectively. Intellectual disability was classified according to the Enjoji developmental test or the Wechsler Intelligence Scale for Children (3rd edition).

RESULTS

The median ages at diagnosis of CP, assignment of Gross Motor Function Classification System (GMFCS) level, cognitive assessment, and MRI were 2 years (range 5 mo-8 y), 6 years (2 y 8 mo-19 y), 6 years (1 y 4 mo-19 y), and 7 years (10 mo-30 y) respectively. MRI included normal findings (41.9%), periventricular leukomalacia, hypomyelination, and porencephaly/periventricular venous infarction. The frequency of patients in GMFCS levels III to V and intellectual disability did not differ between those with normal and abnormal MRI findings. Patients with normal MRI findings had significantly fewer epileptic episodes than those with abnormal ones (p=0.001).

INTERPRETATION

Varied MRI findings, as well as the presence of severe motor dysfunction and intellectual disability (despite normal MRI), suggest that patients born at term with spastic diplegia had heterogeneous and unidentified pathophysiology.

Motor cortical functional geometry in cerebral palsy and its relationship to disability

OBJECTIVE

To investigate motor cortical map patterns in children with diplegic and hemiplegic cerebral palsy (CP), and the relationships between motor cortical geometry and motor function in CP.

METHODS

Transcranial magnetic stimulation (TMS) was used to map motor cortical representations of the first dorsal interosseus (FDI) and tibialis anterior (TA) muscles in 13 children with CP (age 9-16 years, 6 males.) The Gross Motor Function Measure (GMFM) and Melbourne upper extremity function were used to quantify motor ability.

RESULTS

In the hemiplegic participants (N = 7), the affected (right) FDI cortical representation was mapped on the ipsilateral (N = 4), contralateral (N = 2), or bilateral (N = 1) cortex. Participants with diplegia (N = 6) showed either bilateral (N = 2) or contralateral (N = 4) cortical hand maps. The FDI and TA motor map center-of-gravity mediolateral location ranged from 2-8 cm and 3-6 cm from the midline, respectively. Among diplegics, more lateral FDI representation locations were associated with lower Melbourne scores, i.e. worse hand motor function (Spearman's rho = -0.841, p = 0.036).

CONCLUSIONS

Abnormalities in TMS-derived motor maps cut across the clinical classifications of hemiplegic and diplegic CP. The lateralization of the upper and lower extremity motor representation demonstrates reorganization after insults to the affected hemispheres of both diplegic and hemiplegic children.

SIGNIFICANCE

The current study is a step towards defining the relationship between changes in motor maps and functional impairments in CP. These results suggest the need for further work to develop improved classification schemes that integrate clinical, radiologic, and neurophysiologic measures in CP.

Schizencephaly as a cause of spastic cerebral palsy

PURPOSE

The objective was to investigate the clinical features of schizencephaly in children with spastic cerebral palsy.

MATERIAL AND METHODS

The present study included 180 children with cerebral palsy, spastic tetraplegia, diplegia, and hemiplegia. All magnetic resonance (MR) scans were obtained using a 1.5 T MR scanner with the use of a standard circularly polarized head coil.

RESULTS

Significant abnormalities relevant to cerebral palsy were evident on MRI in 95%. Periventicular leukomalacia was detected more frequently in children with spastic diplegia than in other patients. Cerebral atrophy was found more often in tetraplegic patients. Porencephalic cysts were detected more often in children with spastic hemiplegia. Congenital brain anomalies were evident in 20 (11.1%) children with spastic cerebral palsy. Twelve patients had schizencephaly with cerebral palsy. Children with spastic diplegia and tetraplegia had bilateral schizencephaly; patients with spastic hemiplegia only had unilateral schizencephaly. Most patients with schizencephaly had epilepsy.

CONCLUSIONS

Schizencephaly occurred more often in patients with spastic hemiplegia. Early detection of brain abnormalities in children with cerebral palsy may help in the prognosis and in the introduction of appropriate therapy.

Stem cell-derived neurotrophic support for the neuromuscular junction in spinal muscular atrophy

IMPORTANCE OF THE FIELD

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by specific degeneration of α-motor neurons in the spinal cord. The use of cell transplantation to restore lost function through cell replacement or prevent further degeneration of motor neurons and synapses through neurotrophic support heralds tremendous hope in the SMA field.

AREAS COVERED IN THIS REVIEW

Much research has been carried out in the last decade on the use of embryonic stem cells in cell replacement strategies for various neurodegenerative diseases. Cell replacement is contingent on the ability of transplanted cells to integrate and form new functional connections with host cells. In the case of SMA, cell replacement is a tall order in that axons of transplanted cells would be required to grow over long distances from the spinal cord through growth-averse terrain to synapse with muscles in the periphery. The efficacy of neurotrophic support is contingent on the ability of transplanted cells to secrete neurotrophins appropriate for degenerating motor neurons in the spinal cord or development/stability of the neuromuscular junction (NMJ) in the periphery.

WHAT THE READER WILL GAIN

The reader will gain an understanding of the potential of neurotrophins to promote development of the NMJ in a diseased or injured environment.

TAKE HOME MESSAGE

Neurotrophins play a major role in NMJ development and thus may be a key factor in the pathogenesis of NMJs in SMA. Further research into the signaling mechanisms involved in NMJ maturation may identify additional mechanisms by which transplanted cells may be of therapeutic benefit.

Are incidental findings on brain magnetic resonance images in children merely incidental?

The purpose of this study was to test the hypothesis that children with developmental delay without regression of unknown etiology are more likely to have intracranial incidental findings than are children with autistic spectrum disorder or children with normal development. Of 771 patients with magnetic resonance images, 363 (47.1%) patients had developmental delay, 55 (7.1%) had autistic spectrum disorders, and 353 (45.8%) were developmentally normal. Developmentally delayed children were more likely than those with normal development (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.5; P < .001) or those with autistic spectrum disorder (OR, 2.1; 95% CI, 1.1-4.1; P = .019) to have an intracranial incidental finding. We report a higher prevalence of intracranial incidental findings in children with developmental delay as compared with those children with normal development. Future study should confirm whether the result of this study is merely incidental or truly related to a subgroup of children with developmental disability.

[Presentation of a handicap, impairment and disability: the example of cerebral palsy]

This article, co-authored by a functional therapist and a neuroradiologist, proposes a definition as well as a general overview of epidemiological, legal and clinical concerns related to the handicap followed by a more in-depth study of subjects with cerebral palsy or other brain motor handicap. This patient population contains an increasing number of adults. The effects of aging and the increased incidence of letal malignancies in this population will be reviewed.The role of imaging in the management of these patients, its key features and related pitfalls are discussed. Finally, the role of MR imaging of the brain in patients with cerebral palsy is discussed with emphasis on the relation between lesion type and impairment, imaging characteristics and injury mechanism.

Functional connectivity for somatosensory and motor cortex in spastic diplegia

Functional connectivity (fcMRI) was analyzed in individuals with spastic diplegia and age-matched controls. Pearson correlations (r-values) were computed between resting state spontaneous activity in selected seed regions (sROI) and each voxel throughout the brain. Seed ROI were centered on foci activated by tactile stimulation of the second fingertip in somatosensory and parietal dorsal attention regions. The group with diplegia showed significantly expanded networks for the somatomotor but not dorsal attention areas. These expanded networks overran nearly all topological representations in somatosensory and motor areas despite a sROI in a fingertip focus. A possible underlying cause for altered fcMRI in the group with dipegia, and generally sensorimotor deficits in spastic diplegia, is that prenatal third trimester white-matter injury leads to localized damage to subplate neurons. We hypothesize that intracortical connections become dominant in spastic diplegia through successful competition with diminished or absent thalamocortical inputs. Similar to the effects of subplate ablations on ocular dominance columns (Kanold and Shatz, Neuron 2006;51:627-638), a spike timing-dependent plasticity model is proposed to explain a shift towards intracortical inputs.

Applications of positron emission tomography in the newborn nursery

Positron emission tomography (PET) is a relatively noninvasive imaging test that is able to detect abnormalities in different organs based on derangements in the chemical functions and/or receptor expression at the cellular level. PET imaging of the brain has been shown to be a powerful diagnostic tool for detecting neurochemical abnormalities associated with various neurologic disorders as well as to study normal brain development. Although its use in detecting neurological abnormalities has been well described in adults and pediatrics, its application in the newborn nursery has not been explored adequately. Early detection of brain injury secondary to intrauterine and perinatal insults using PET imaging can provide new insight in prognosis and in instituting early therapy. In this review, the authors describe applications of PET imaging in the newborn nursery specifically related to the detection of metabolic changes seen in hypoxic ischemic encephalopathy, neonatal seizures, and neuroinflammation in the neonatal period.

Preoperative MRI findings and functional outcome after selective dorsal rhizotomy in children with bilateral spasticity

PURPOSE

To identify MRI characteristics that may predict the functional effect of selective dorsal rhizotomy (SDR) in children with bilateral spastic paresis.

METHODS

We performed SDR in a group of 36 patients. The gross motor functioning measure-66 (GMFM-66) was applied before and after SDR. Available cerebral MRIs were retrospectively classified into three diagnostic groups: periventricular leucomalacia (PVL; n = 10), hydrocephalus (n = 2), and normal (n = 6). In patients with PVL, we scored the severity of the MR abnormalities. We compared the changes in the GMFM-66 after SDR in the diagnostic groups. In patients with PVL, we correlated the severity of the MR abnormalities with the changes in the GMFM-66.

RESULTS

The mean follow-up period was 5 years and 4 months (range, 1 year and 1 month to 9 years). The best improvement in gross motor function was observed in patients with normal MRI, and the slightest improvement was observed in patients with hydrocephalus. The severity of the PVL did correlate with the GMFM-66 score before SDR but not with the functional effect of SDR.

CONCLUSION

We conclude that with respect to gross motor skills, the improvements after SDR are good in patients with no MRI abnormalities. In the patients with hydrocephalus, the improvements after SDR were insignificant. In patients with PVL, the improvements were intermediate and did not correlate with the degree of PVL.

Intrauterine endotoxin administration leads to white matter diffusivity changes in newborn rabbits

Maternal intrauterine inflammation has been implicated in the development of periventricular leukomalacia and white matter injury in the neonate. We hypothesized that intrauterine endotoxin administration would lead to microstructural changes in the neonatal rabbit white matter in vivo that could be detected at birth using diffusion tensor magnetic resonance imaging (MRI). Term newborn rabbit kits (gestational age 31 days) born to dams exposed to saline or endotoxin in utero on gestational day 28 underwent diffusion tensor imaging, and brain sections were stained for microglia. Comparison between normal and endotoxin groups showed significant decreases in both fractional anisotropy and eigenvalue (e(1)) in all periventricular white matter regions that showed an increase in the number of activated microglial cells, indicating that after maternal inflammation, microglial infiltration may predominantly explain this change in diffusivity in the immediate neonatal period. Diffusion tensor imaging may be a clinically useful tool for detecting neuroinflammation induced by maternal infection in neonatal white matter.

Magnetic resonance imaging in children with bilateral spastic forms of cerebral palsy

We analyzed the relationship between magnetic resonance image findings in children with bilateral spastic cerebral palsy and its stages of severity in term and preterm children. Magnetic resonance image findings of 102 children (66 male and 36 female) with bilateral spastic cerebral palsy (median age, 2.5 years; range, 3 months to 15 years) were reevaluated. The study group consisted of children with confirmed perinatal asphyxia. Hypoxic-ischemic events were diagnosed in 64% of the children. Significant abnormalities relevant to cerebral palsy were evident on imaging in 85/102 (83%) children (in 77% of term and 93% of preterm children). Enlargement of the ventricles alone (48%) or accompanied by periventricular white-matter damage (25%) was the most frequent finding in term and preterm children, but was more highly expressed in preterm children (P < 0.05). White-matter damage was more often found in preterm children (P < 0.05). Enlargement of the lateral ventricles and periventricular leukomalacia may be attributable to ischemic damage to the neonatal brain. Significant correlations were found between magnetic resonance image findings and severity of cerebral palsy (P < 0.05). Detection of brain abnormalities in children with cerebral palsy may prove useful in prognoses as well as in medical consultations and management.