Proton magnetic resonance spectroscopy in children with spastic diplegia

Imaging Developmental and Interventional Plasticity Following Perinatal Stroke

Perinatal stroke occurs around the time of birth and leads to lifelong neurological disabilities including hemiparetic cerebral palsy. Magnetic resonance imaging (MRI) has revolutionized our understanding of developmental neuroplasticity following early injury, quantifying volumetric, structural, functional, and metabolic compensatory changes after perinatal stroke. Such techniques can also be used to investigate how the brain responds to treatment (interventional neuroplasticity). Here, we review the current state of knowledge of how established and emerging neuroimaging modalities are informing neuroplasticity models in children with perinatal stroke. Specifically, we review structural imaging characterizing lesion characteristics and volumetrics, diffusion tensor imaging investigating white matter tracts and networks, task-based functional MRI for localizing function, resting state functional imaging for characterizing functional connectomes, and spectroscopy examining neurometabolic changes. Key challenges and exciting avenues for future investigations are also considered.

Amino acid metabolic processes in the temporal lobes assessed by proton magnetic resonance spectroscopy (1H MRS) in children with Down syndrome

Down syndrome (DS), or trisomy 21, is one of the most common autosomal mutations. The overexpression of the β-amyloid precursor protein gene, located on chromosome 21, causes an increased production of the specific amyloid. The current study is a continuation of our earlier investigations relating to the profile of metabolic changes in the frontal lobes of DS patients as assessed by proton magnetic resonance spectroscopy ((1)H MRS). The aims of the study were the morphological assessment of the brain using magnetic resonance imaging (MRI) and the evaluation of metabolic disorders of the temporal lobes using (1)H MRS in DS children. The study group included 20 children with DS aged 3-15 years and treated in the Department of Pediatric Neurology and Rehabilitation, Medical University of Białystok. The control group included healthy children (n = 20). MRI scans of the heads of DS children were performed using a 1.5 T MR scanner under standard conditions. (1)H MRS investigations were also carried out to assess metabolic changes in the temporal lobes. Metabolites, such as N-acetylaspartate (NAA), glutamate-glutamine complex (Glx), choline (Cho), myoinositol (mI) and γ-aminobutyric acid (GABA), were determined in both temporal lobes with reference to the internal marker creatine (Cr). Results were compared with the control group.We found a statistically significant decrease in NAA/Cr, Cho/Cr, mI/Cr and GABA/Cr ratios. The Glx/Cr ratio in both temporal lobes of DS patients did not differ from the control group. Our results indicate metabolic neurotransmitter disorders in the central nervous system in children with DS.

Disproportionate correlation between imaging and outcome in an infant with cerebral abscess

Brain abscesses represent organized foci of suppuration within the parenchyma. In this paper, we describe the case of a 3-month old girl with a large, complicated cerebral abscess. In addition, the course of treatment is presented. The patient’s recovery was excellent. The follow-up MRI showed only subtle porencephalic changes as the only parenchymal sequels, which may have been due to central nervous system (CNS) plasticity in infants.

An age and gender dependency of metabolite concentrations in basal ganglia in children with spastic diplegia: proton magnetic resonance spectroscopy study

We determined metabolite profile in spastic diplegic children compared to controls in left basal ganglia of brain in using proton magnetic resonance spectroscopy in correlation with age and gender. Twenty-four patients with spastic diplegia and twenty-six healthy children were examined. The relative concentrations of N-acetylaspartate, choline, and myoinositol were measured in relation to creatine and different combinations of metabolites within 8-cm(3) brain voxel. Children with spastic diplegia showed reduced ratios of N-acetylaspartate/creatine, N-acetylaspartate/ choline, and N-acetylaspartate/myoinositol in the basal ganglia compared to the control group. Patients and controls subjects demonstrated a significant age-dependent increase in N-acetylaspartate/creatine, N-acetylaspartate/choline in the basal ganglia. No gender-dependent difference was shown in children with cerebral palsy for all tested metabolite ratios. Gender-related differences because of increased ratio N-acetylaspartate/choline in girls in controls were detected. These results indicate that maturation of brain exists in cerebral palsy and healthy children to a higher degree in healthy children.

Clinical and neuroimaging profile of congenital brain malformations in children with spastic cerebral palsy

PURPOSE

Analysis of the incidence of congenital brain malformations in children with spastic cerebral palsy (CP) in a hospital-based study.

MATERIAL AND METHODS

The present study included 74 boys and 56 girls with spastic tetraplegia, diplegia, and hemiplegia CP. Magnetic resonance imaging MRI findings were analyzed in children with CP.

RESULTS

Significant abnormalities relevant to the CP were evident on MRI in 124 (95.3%) subjects. Periventicular leukomalacia (PVL) was detected more frequently in children with spastic diplegia than in patients with tetraplegia or hemiplegia. Cerebral atrophy was found more often in the tetraplegic group compared to the diplegic patients. Porencephalic cysts were detected more often in children with spastic hemiplegia. Congenital brain anomalies were evident in 15 (10.7%) children with spastic CP. Brain malformations included: schizencephaly (5), agenesis corpus callosum (4), polymicrogyria (2), holoprosencephaly (2) and lissencephaly (2). Intractable epilepsy and mental retardation were observed more often in children with brain anomalies. Twelve patients with congenital brain malformations were born at term and three born at preterm.

CONCLUSIONS

Neuroimaging results in children with CP may help determine the etiology and make better prognosis of CP.

Proton magnetic resonance spectroscopy in patients with normal pressure hydrocephalus

The objective of this prospective study was the application of proton magnetic resonance spectroscopy (1HMRS) in patients with normal pressure hydrocephalus (NPH) to determine the metabolite profile in the white matter next to left lateral ventricle and to assess the relationship of this profile with Evan's index. The study included 26 patients with NPH. Diagnosis of NPH was confirmed by clinical symptoms such as gait disturbance, dementia or urinary incontinence and CT study with ventricular enlargement. Ratios of NAA/Cr, Cho/Cr, Lac/Cr and mI/Cr from deep white matter were measured and compared with Evan's index and diameter of the IIIrd ventricle. Patients with hydrocephalus showed decreased ratios of N-acetylaspartate (NAA)/Cr (creatine), and increased ratios of Lac(lactate)/Cr in the white matter near the left frontal horn of the lateral ventricle compared with a well-matched control group. There was no correlation between NAA/Cr, Ch/Cr, Lac/Cr, mI (myo-Inositol)/Cr and Evan's index. A significant correlation was found between Lac/Cr and third ventricle diameter. A positive correlation was noted between Cho/Cr and dementia in patients with NPH. Our preliminary results of 1 H MRS support the idea that NPH is associated with white matter ischemia. Proton MRS is a very useful tool for evaluating major changes in metabolic levels in deep white matter in NPH patients.

Metabolite profile in the basal ganglia of children with cerebral palsy: a proton magnetic resonance spectroscopy study

This prospective study determined metabolite profile in the left and right basal ganglia of children with spastic cerebral palsy (CP) compared with children without disabilities, by using proton magnetic resonance spectroscopy (1HMRS). Twenty-three patients with spastic CP (12 males, 11 females; mean age 11y 9mo [SD 4y 2mo], range 4-17y) were examined. Twenty children had spastic diplegia and three had quadriplegia. Twenty-four normally developing children (13 females, 11 males; mean age 10y 3mo [SD 4y 8mo], range 4-17y) served as a comparison group. The relative concentrations of N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), and gamma-aminobutyric acid (GABA) were measured relative to creatine (Cr) and different combinations of metabolites within 8cm3 brain voxels. Children with CP showed reduced ratios of NAA:Cr, NAA:Cho, NAA:mI, and GABA:Cr in the basal ganglia relative to a matched comparison group. Patients demonstrated a significant age-dependent increase in NAA:Cr and NAA:Cho in the basal ganglia. No sex-dependent difference was shown in children with CP nor in the comparison group for all tested metabolite ratios. Significant correlation between Apgar score and ratio of mI:Cr in the group with CP was found. None of the tested metabolite ratios were correlated with the severity scale of CP in children with CP. NAA:Cr ratios were negatively correlated with learning disability in patients with CP. Results indicate the association of the metabolite ratios in basal ganglia with learning disability.

Neurophysiologic and neuroimaging studies of brain plasticity in children with spastic cerebral palsy

Patients with cerebral palsy (CP) may have some problems other than this motor impairment: mental retardation, epilepsy and sensory disturbance. Healthy children and children with CP have an enhanced capacity for learning and memory compared to adults. There are few tools for brain plasticity investigations. The utility of the neurophysiologic and MRI techniques in the determination of brain reorganization and repair in patients with cerebral palsy is described. The authors discuss their results of quantitative EEG and spectroscopy MRI studies in children with CP. Quantitative EEG and spectroscopy MRI can be useful tools in the determination of these processes in children with CP.

A comparison of spastic diplegic and tetraplegic cerebral palsy

The aim of this study was to compare spastic diplegic and tetraplegic cerebral palsy. Thirty-eight children had spastic diplegic cerebral palsy and 48 spastic tetraplegic cerebral palsy. Risk factors of cerebral palsy, seizures, severity of cerebral palsy, electroencephalogram, and magnetic resonance imaging findings were analyzed. Gestational history, low birth weight, and perinatal pathologies were present in similar percentages in both groups. Lower values of the Apgar score were recorded more often in the tetraplegic cerebral palsy group than the diplegic group. The children with spastic diplegia were classified more frequently into levels I and II of the Gross Motor Function Classification System, but patients with spastic tetraplegia were classified more frequently into levels IV and V. Similarly, mental retardation was observed more frequently in the patients with spastic tetraplegia. In magnetic resonance imaging, periventricular leukomalacia was detected in a higher proportion of children with spastic diplegia than in patients with tetraplegia. Cerebral atrophy occurred more frequently in the tetraplegic group compared with diplegic patients. Twenty-four (50.0%) children with spastic tetraplegia had epilepsy compared with six children with spastic diplegia. The incidence of intractable epilepsy was higher in the tetraplegic patients than in the children with spastic diplegia.