Spectroscopy In Children Research Articles

Proton magnetic resonance spectroscopy in children with some neurological and mental disorders accompanied by mental and speech development delay: a prospective study

Proton magnetic resonance spectroscopy in children with some neurological and mental disorders accompanied by mental and speech development delay: a prospective study

Brain metabolic profile assessed by magnetic resonance spectroscopy in ‎‎children with Down syndrome: Relation to intelligence quotient.

Down syndrome (DS) is one of the most common causes of intellectual disability. Children with DS have varying intelligence quotient (IQ) that can predict their learning abilities. To assess the brain metabolic profiles of children with DS and compare them to standard controls, using magnetic resonance spectroscopy (MRS) and correlating the results with IQ. This case-control study included 40 children with DS aged 6-15 years and 40 age and sex-matched healthy children as controls. MRS was used to evaluate ratios of choline/creatine (Cho/Cr), N-acetyl aspartic acid/creatine (NAA/Cr), and myoinositol/creatine (MI/Cr (in the frontal, temporal, and occipital lobes and basal ganglia and compared to controls and correlated with IQ. Children with DS showed significant reductions in NAA/Cr and MI/Cr and a non-significant reduction in Cho/Cr in frontal lobes compared to controls. Additionally, we observed significant decreases in NAA/Cr, MI/Cr, and Cho/Cr in the temporal and occipital lobes and basal ganglia in children with DS compared to controls. Furthermore, there was a significant correlation between IQ and metabolic ratios in the brains of children with DS. Brain metabolic profile could be a good predictor of IQ in children with DS.

The added value of brain MR spectroscopy in children with Crigler-Najjar syndrome type-I: correlation with demographic, neurodevelopmental, and laboratory findings.

The aim of this study is to demonstrate the role of proton magnetic resonance spectroscopy (1H-MRS) in the detection of brain microstructural changes in patients with Crigler-Najjar syndrome type-I (CNs-I), and its correlation with demographic, neurodevelopmental and laboratory findings. Prospective study was conducted on 25 children with CNs-I and 25 age and sex-matched children, who served as control. They underwent multivoxel 1H-MRS of basal ganglion at echo time 135-144 ms. N-acetyl aspartate/Creatine (NAA/Cr) and Choline (Ch)/Cr were calculated and correlated with demographic, clinical, and laboratory findings of patients with CNs-I. There was a significant difference in NAA/Cr and Ch/Cr between patients and controls. The cut-off value for NAA/Cr and Ch/Cr used to differentiate patients from controls were 1.8 and 1.2 with an area under the curve (AUC) of 0.91 and 0.84 respectively. There was a significant difference in MRS ratios between patients with neurodevelopmental delay (NDD) and patients without NDD. The cut-off values for NAA/Cr and Ch/Cr used to differentiate between patients with NDD and patients without NDD were 1.47 and 0.99, with AUC of 0.87 and 0.8 respectively. The NAA/Cr and Ch/Cr were well correlated with family history (p = 0.006 and p < 0.001) respectively, consanguinity (p < 0.001 and p = 0.001), neurodevelopmental delay (p = 0.001 and p = 0.004), serum bilirubin level (r = -0.77, p < 0.001), (r = -0.49, p = 0.014), phototherapy (p < 0.001 and p = 0.32), blood transfusion (p < 0.001 and p = 0.001) respectively. 1H-MRS can be a useful tool in the detection of neurological changes in patients with CNs-I; NAA/Cr and Ch/Cr parameters are well correlated with demographic, clinical, and laboratory findings. Our study is the first report on using MRS in assessing neurological manifestations in CNs. 1H-MRS can be a useful tool in the detection of neurological changes in patients with CNs-I.

The effect of hyperventilation versus normoventilation on cerebral oxygenation using near infrared spectroscopy in children undergoing posterior fossa tumor resection: A randomized controlled cross-over trial

BackgroundThis study aims to compare the effect of two different ventilation strategies on cerebral oxygenation in children undergoing posterior fossa tumor excision surgeries. MethodsChildren scheduled for posterior fossa tumor surgeries were enrolled in this randomized, double-blinded, controlled cross-over trial. After induction of general anesthesia and positioning, participants were randomized to have mild hyperventilation for 30 min (phase 1) followed by normal ventilation for another 30 min (phase2) (early hyperventilation group, n = 23), or normal ventilation for 30 min (phase 1) followed by hyperventilation for 30 min (phase 2) (early normoventilation group, n = 19). Our primary outcome was cerebral oxygenation, measured using near-infrared spectroscopy (NIRS). Other outcomes included the intracranial pressure (ICP), brain relaxation score at the end of phase 1, and frequency of nadir NIRS. ResultsForty-two children were available for final per protocol analysis. The cerebral oxygenation decreased after the hyperventilation phase compared to the baseline values and the corresponding phases of normoventilation. The mean difference [95% confidence intervals (CI)] in cerebral oxygen saturation between the hyperventilation and normal ventilation readings was 13.45 ± 1.14% [11.14–15.76] and 11.47 ± 0.96% [11.14–15.76] in the left and right sides, respectively (p-values <0.0001). Both carryover and period effects were not significant. The ICP at the end of phase 1 did not differ between the two groups: 22.12 ± 3.75 mmHg vs. 23.26 ± 4.33, mean difference [95%CI]: −0.78 [−3.05 to 1.5], p = 0.49. Brain relaxation score was similar in the two groups. ConclusionIn children undergoing posterior fossa craniotomy, moderate hyperventilation reduced cerebral oxygenation without significant improvement of the surgical brain relaxation or the ICP.

Monitoring of gastrointestinal dysfunction by near-infrared spectroscopy in children with sepsis: a prospective study

To investigate the incidence and mortality of gastrointestinal dysfunction in children with sepsis, the application of near-infrared spectroscopy (NIRS) in monitoring mesenteric regional tissue oxygen saturation (rSO2), and the association between rSO2 and gastrointestinal dysfunction. In this prospective study, 79 children with sepsis in the pediatric intensive care unit (sepsis group) and 40 children who underwent physical examination in the Department of Child Healthcare (healthy control group) from January to December, 2021 were enrolled as subjects. The related medical data were collected, including general information on admission and at discharge, treatment during hospitalization, and laboratory examination results. NIRS was used to measure mesenteric rSO2. Clinical characteristics were compared between the patients with and without gastrointestinal dysfunction. For the 79 children with sepsis, the incidence rate of gastrointestinal dysfunction was 49% (39/79), and the mortality rate of the children with gastrointestinal dysfunction was 26% (10/39). The children with gastrointestinal dysfunction had a longer duration of mechanical ventilation and a higher 28-day mortality rate (P<0.05). The children with gastrointestinal dysfunction had a significantly lower median rSO2 (64%) than the children without gastrointestinal dysfunction (72%) and the healthy control group (78%) (P<0.05). There are high incidence and mortality rates of gastrointestinal dysfunction in children with sepsis, and the reduction in rSO2 may be associated with the development of gastrointestinal dysfunction.

Proton magnetic resonance spectroscopy in children with delayed mental and speech development associated with focal temporal lobe epilepsy

Background. The delays in mental and speech development are caused by epilepsy, and a special place among the forms of which is focal temporal epilepsy. The study of biomarkers of the considered pathological condition using proton magnetic resonance spectroscopy as indicators amenable to objective assessment and measurement determines the practical relevance of this work.&#x0D; Aim. The aim of the study was to determine the role and place of proton magnetic resonance spectroscopy in clinical practice in children with mental and speech retardation associated with temporal lobe epilepsy.&#x0D; Materials and methods. 37 children aged 2 to 10 years were studied. Of these, 15 children with a diagnosis of mental and speech development delay, structural focal temporal epilepsy were included in the first comparison group. The second comparison group consisted of 12 children without CNS pathology undergoing 1H-MRI examination to exclude somatic diseases. The third comparison group consisted of 10 children with structural focal temporal epilepsy, without mental and speech development delay.&#x0D; Discussion. Multivoxel proton magnetic resonance spectroscopy (method PRESS) was used to determine the concentration of neurometabolites in the brain tissues of patients. In patients with mental and speech development delay associated with temporal epilepsy, a decrease in the ratio of NAA/Cr concentrations (p 0.05) was revealed in the postcentral gyrus on the right, temporal lobe on the right and hippocampus and inner capsule on both sides, due to a decrease in the concentration of N-acetylaspartate; an increase in the ratio of Cho/Cr concentrations (p 0.05) in the prefrontal cortex, postcentral gyrus and inner capsule on both sides, due to an increase in the concentration of choline. Two patients also showed lipid peaks on the lesion side when compared with EEG data.&#x0D; Conclusions. The revealed metabolic changes in patients with delayed mental and speech development associated with temporal lobe epilepsy may be useful as an additional method of differential diagnosis with other forms of mental and speech development delay.

Clinical significance of assessing cerebral blood volume by time-domain near-infrared spectroscopy in children with congenital heart disease.

Despite providing cerebral tissue oxygen saturation (StO2 ), the lack of quantitative information for continuous wave near-infrared spectroscopy (CW-NIRS) is an obstacle in evaluating cerebral hemodynamic conditions. Time-domain NIRS (TD-NIRS) provides both StO2 and cerebral blood volume and has recently become clinically available. To investigate if the additional monitoring of cerebral blood volume by TD-NIRS facilitates the understanding of cerebral hemodynamic conditions in patients with congenital heart disease. Preoperative TD-NIRS values were retrospectively reviewed in patients who underwent a cardiac surgery or catheter examination. We compared the values between patients with single and two ventricles. Moreover, we investigated the association of these values with the demographic and clinical variables. There was no significant difference in StO2 between single ventricle and two ventricles groups (median: 59.9 vs. 54.4, median difference [95% CI]: -4.06 [-9.90 to 2.90], p=.37). However, cerebral blood volume was significantly higher in the single ventricle group (median: 4.68 vs. 2.84, median difference [95% CI]: -2.01 [-2.88 to -1.06], p<.001). Spearman's rank correlation analysis demonstrated an association between StO2 and postmenstrual age (r=0.35, p=.03). In contrast, cerebral blood volume was correlated with single ventricle physiology (r=0.62, p<.001), postmenstrual age (r=0.74, p<.001), central venous pressure (r=0.38, p=.02), and SaO2 (r=-0.38, p=.02). The multivariable regression analysis identified the postmenstrual age, single ventricle physiology, and SaO2 as independent factors associated with cerebral blood volume. In the logistic analysis, cerebral blood volume was identified as a significant predictor of unfavorable conditions. Cerebral blood volume monitoring detected differences in cerebral hemodynamic conditions, related to the age and the type of ventricle physiologies. However, the differences were not apparent in StO2 . The additional monitoring of cerebral blood volume by TD-NIRS would facilitate a better understanding of cerebral hemodynamic conditions in patients with congenital heart disease.

Clinical Applications of Functional Near-Infrared Spectroscopy in Children and Adolescents with Psychiatric Disorders.

The purpose of this review is to examine the clinical use of functional near-infrared spectroscopy (fNIRS) in children and adolescents with psychiatric disorders. Many studies have been conducted using objective evaluation tools for psychiatric evaluation, such as predicting psychiatric symptoms and treatment responses. Compared to other tools, fNIRS has the advantage of being a noninvasive, inexpensive, and portable method and can be used with patients in the awake state. This study mainly focused on its use in patients with attention-deficit/hyperactivity disorder and autism spectrum disorder. We hope that research involving fNIRS will be actively conducted in various diseases in the future.

Age-related parietal GABA alterations in children with autism spectrum disorder.

GABA is the primary inhibitory neurotransmitter in the brain, and is essential to the balance of cortical excitation and inhibition. Reductions in GABA are proposed to result in an overly excitatory cortex that may cause, or contribute to, symptoms of autism spectrum disorder (ASD). This study employed a cross-sectional design to explore GABA+ differences in ASD and the impact of age, comparing 4-12 year olds with ASD (N=24) to typically developing children (N=35). GABA+ concentration was measured using edited magnetic resonance spectroscopy in the left parietal lobe. This study used a mixed model to investigate group differences between children with ASD and typically developing children. There was a significant difference in GABA+ levels between the groups, a significant effect of age and interaction between age and diagnostic group. The ASD group showed an association between GABA+ and age, with GABA+ levels gradually increasing with age (r=0.59, p=0.003). Typically developing children did not show age-related change in GABA+ concentration (r=0.09, p =0.60). By the age of 9, children with ASD showed GABA+ levels that were comparable to their typically developing peers. This study suggests that children with ASD have initially lower levels of GABA+ in the left parietal lobe compared to typically developing children, and that these initially lower levels of GABA+ increase with age in ASD within this region. It is suggested that this developmental shift of GABA+ levels within the left parietal lobe provides a possible explanation for the previously found reductions in childhood that does not persist in adults. LAY SUMMARY: This study measured levels of GABA in the left parietal lobe using magnetic resonance spectroscopy in children with ASD and typically developing children. GABA levels were initially lower in the ASD group, and increased with age, while GABA did not change with age in the typically developing group. This suggests that alterations in GABA signaling may be associated with ASD in childhood. Autism Res 2021, 14: 859-872. © 2021 International Society for Autism Research, Wiley Periodicals LLC.

Proton magnetic resonance spectroscopy in children with atypical autism comorbid with psychomotor disinhibition syndrome

To study the relationship of N-acetylaspartate (NAA) metabolism and choline (Cl) metabolism in different parts of the brain based on magnetic resonance spectrography (1H-MRS) with clinical manifestations of autism spectrum disorders (ASD). Twenty-two children (16 boys, 6 girls), aged 2-10 years, were studied. Russian-language adapted versions of the Autism Treatment Evaluation Checklist (ATEC) and the Nisonger Child Behavior Rating Form (NCBRF) were administered. The ratio of metabolites NAA/creatine (Cr), Cho/Cr, Cho/NAA in the prefrontal cortex, postcentral gyrus and temporal lobes was studied using 1H-MRS. The following correlations were found: 1) between the NAA/Cr value and the Sensory/Cognitive Awareness scale in the prefrontal cortex on the left (ρ=0.479) and on the right (ρ=0.483); the Health/Physical Behavior scale in the precentral gyrus on the left (ρ=0.572) and on the right (ρ=0.463); the Sociability scale in the temporal lobe on the left (ρ=0.481) and on the right (ρ=0.796); the Speech/Language/Communication scale in the right temporal lobe (ρ=-0.552); 2) between the Cho/Cr value and the Adaptive Social scale in the postcentral gyrus on the left (ρ=-0.466) and on the right (ρ=-0.518); the Compliant/Calm scale in the prefrontal cortex on the right (ρ=0.624) and on the left (ρ=-0.541); 3) between the Cho/NAA ratio and the Speech/Language/Communication scale in the right pre-central (ρ=-0.471) and post-central gyrus (ρ=-0.507); the Self-Isolated/Ritualistic» scale in the left (ρ=-0.486) and right temporal lobe (ρ=-0.596). Thus, the predominant localization of disorders of N-acetylaspartate metabolism in communication disorders (bilaterally in the temporal lobes), cognitive, behavioral and somatic manifestations (bilaterally in the prefrontal regions) was established. Increased CI metabolism has identified deficits in interaction skills in both postcentral gyrus, and reveals bilateral differences in the effect on behavioral control in the prefrontal cortex. The results confirm the previously established numerous patterns between abnormal activation of the prefrontal cortex and neuronal dysfunction in ASD. But unlike other studies, it was possible to trace these relationships within a narrower phenotype of disorders - atypical autism comorbid with psychomotor disinhibition.

Clinical Relevance of Fluid Volume Status Assessment by Bioimpedance Spectroscopy in Children Receiving Maintenance Hemodialysis or Peritoneal Dialysis.

Bioimpedance spectroscopy (BIS) is a noninvasive method used to evaluate body fluid volume status in dialysis patients, but reports on its effectiveness in pediatrics are scarce. We investigated the correlation between BIS and clinical characteristics and identified the changes in patients whose dialysis prescription was modified based on BIS. The medical records of children on maintenance dialysis who had undergone BIS between 2017 and 2019 were reviewed. Of the 49 patients, 14 were overhydrated, based on the >15% proportion of overhydration relative to extracellular water (OH/ECW) measured by BIS. Intake of ≥two antihypertensive medications was noted in the majority (85.7%) of children with fluid overload and only in 48.6% of those without fluid overload (p = 0.017). Elevated blood pressure despite medication use was significantly more common in patients with fluid overload than in those without fluid overload (78.6% vs. 45.7%, p = 0.037). Of the 14 overhydrated children, 13 (92.9%) had significant changes in body weight, OH/ECW, the number of antihypertensive drugs, left ventricular end-diastolic diameter, and cardiothoracic ratio after the change in dialysis prescription. BIS is a useful and noninvasive method to assess fluid status in dialysis children. Long-term follow-up and correlation with a more objective clinical indicator of fluid overload is necessary to verify the clinical effectiveness of BIS.

Magnetic Resonance Spectroscopy in Children With Developmental Delay: Time to Look Beyond Conventional Magnetic Resonance Imaging (MRI).

Developmental delay (DD) is an important long-term neuromorbidity owing to various insults to the developing brain and neuroimaging plays a key role in evaluating these children. Magnetic resonance spectroscopy (MRS) is the only noninvasive method to determine the levels of various metabolites in the brain which aids in delineating the underlying abnormalities. A total of 48 children aged between 6 months to 6 years with developmental delay were included and evaluated with neuroimaging in our study. Sensitivity of MRS in children with DD and DD plus (DD along with seizures, abnormal motor findings, behavior, brainstem evoked response audiometry, visual assessment, and microcephaly) was 81.2% and 89.6% respectively. 86.6% of children with microcephaly had abnormal MRS. MRS detected abnormalities in two-thirds of children with normal magnetic resonance imaging (MRI). Children with behavioral abnormalities had significantly lower N-acetyl aspartate (NAA)-creatine and NAA-choline ratios on MRS. Thus, MRS is additive to MRI in delineating the underlying pathophysiology in children with DD.

Clinical Relevance of Fluid Volume Status Assessment by Bioimpedance Spectroscopy in Children on Maintenance Dialysis

Clinical Relevance of Fluid Volume Status Assessment by Bioimpedance Spectroscopy in Children on Maintenance Dialysis

Tracking hydration status changes by bioimpedance spectroscopy in children on peritoneal dialysis.

This 6-month prospective longitudinal study investigates the association between hydration status changes using bioimpedance spectroscopy (BIS) and systolic blood pressure (SBP), pulse pressure (PP), and serum albumin (sAlb) changes in children on peritoneal dialysis (PD). Thirteen patients (median age: 12.58 years) were enrolled. Normal hydration, moderate hydration, severe overhydration, and dehydration were defined as -7% ≤ relative overhydration (Re-OH) < +7%, +7% ≤ Re-OH < +15%, Re-OH ≥ +15%, and Re-OH < -7%, respectively. Automated office blood pressure z-score, sAlb, and weight z-score were recorded. Fifty-two Re-OH measurements were recorded: three in five, four in five, five in two, and seven in one patient, respectively. SBP was higher and sAlb lower in cases with severe overhydration (9 readings) (p < 0.001, p < 0.001), but distribution of these parameters did not differ between normal hydration/dehydration (28 readings) and moderate overhydration (15 readings) cases. In patients with hydration status change, SBP and PP were higher while sAlb lower in cases with higher hydration status level (p = 0.026, p = 0.05, and p = 0.109, respectively). In all patients, visit-to-visit SBP, PP, and sAlb changes were correlated to Re-OH changes (rs = 0.693, p < 0.001; rs = 0.643, p < 0.001; rs = -0.444, p = 0.008, respectively) but not to weight changes (rs = 0.052, p = 0.754; rs = 0.034, p = 0.838; rs = -0.156, p = 0.378, respectively). Visit-to-visit Re-OH changes, which were >+4% or <-4%, were linearly correlated to SBP (r = 0.858, p < 0.001), PP (r = 0.757, p < 0.001), and sAlb (r = -0.699, p = 0.002) changes. In children on PD, longitudinal Re-OH changes are superior to weight changes in assessing volume-dependent variations of SBP, PP, and sAlb. Routine BIS application, rather than single BIS measurements, seems useful in the intra-patient monitoring of hydration status.

Measuring Cerebral Carbon Dioxide Reactivity With Transcranial Doppler and Near-Infrared Spectroscopy in Children With Ventricular Septal Defect

Neurologic impairment is frequently observed in children with congenital heart disease. Impairment in cerebrovascular carbon dioxide reactivity (CO2R) is related with poor neurologic outcomes. The present study examined CO2R measured with transcranial Doppler (TCD) and near-infrared spectroscopy (NIRS) in children with ventricular septal defect undergoing cardiac surgery. Prospective, paired controlled study. Operating room of a tertiary care center. Twenty children with ventricular septal defect and younger than 1 year were enrolled, and 17 children were studied (age: 6.0 ± 2.0 mo, weight 5.9 ± 1.0 kg). After induction of anesthesia and tracheal intubation, the lungs were ventilated and mechanical ventilation was initiated. Partial pressure of end-tidal carbon dioxide (PETCO2) was adjusted at 4 different levels (30, 35, 40, and 45 mmHg). Paired measurements of middle cerebral artery mean blood flow velocity (VMCA) by TCD and tissue oxygen index (TOI) by NIRS were recorded at each level of PETCO2. CO2R was calculated as the percentage change of VMCA and TOI per mmHg change in PETCO2. Systemic hemodynamic parameters were recorded. As PETCO2 rose from 30 to 45 mmHg, VMCA and TOI increased linearly (p < 0.001 for both), and CO2R-TCD and CO2R-NIRS were calculated to be 2.8% ± 0.9%/mmHg and 1.2% ± 0.3 %/mmHg, respectively. CO2R-NIRS was significantly lower compared with CO2R-TCD (p < 0.001). Significant correlations were found between VMCA and TOI (r = 0.487; p < 0.001) and between ΔVMCA and ΔTOI (r = 0.693; p < 0.001), but not between CO2R-TCD and CO2R-NIRS (r = 0.18; p = 0.24). With the increase of PETCO2, cardiac index, systemic vascular resistance index, and mean arterial pressure remained constant (p > 0.05 for all) and the heart rate decreased significantly (p = 0.018). During anesthesia, CO2R remains preserved in children with a ventricular septal defect. Even though there is lack of correlation between CO2R-TCD and CO2R-NIRS, changes in TOI and VMCA were correlated as the PETCO2 changed. NIRS may be used as a surrogate to investigate CO2R when the ultrasound window is poor.

β-Hydroxybutyrate Detection with Proton MR Spectroscopy in Children with Drug-Resistant Epilepsy on the Ketogenic Diet.

The ketogenic diet, including both classic and modified forms, is an alternative to antiepileptic medications used in the treatment of drug-resistant epilepsy. We sought to evaluate the utility of proton MR spectroscopy for the detection of β-hydroxybutyrate in a cohort of children with epilepsy treated with the ketogenic diet and to correlate brain parenchymal metabolite ratios obtained from spectroscopy with β-hydroxybutyrate serum concentrations. Twenty-three spectroscopic datasets acquired at a TE of 288 ms in children on the ketogenic diet were analyzed with LCModel using a modified basis set that included a simulated β-hydroxybutyrate resonance. Brain parenchymal metabolite ratios were calculated. Metabolite ratios were compared with serum β-hydroxybutyrate concentrations, and partial correlation coefficients were calculated using patient age as a covariate. β-hydroxybutyrate blood levels were highly correlated to brain β-hydroxybutyrate levels, referenced as either choline, creatine, or N-acetylaspartate. They were inversely but more weakly associated with N-acetylaspartate, regardless of the ratio denominator. No strong concordance with lactate was demonstrated. Clinical MR spectroscopy in pediatric patients on the ketogenic diet demonstrated measurable β-hydroxybutyrate, with a strong correlation to β-hydroxybutyrate blood levels. These findings may serve as an effective tool for noninvasive monitoring of ketosis in this population. An inverse correlation between serum β-hydroxybutyrate levels and brain tissue N-acetylaspartate suggests that altered amino acid handling contributes to the antiepileptogenic effect of the ketogenic diet.

MR spectroscopy in children: protocols and pitfalls in non-tumorous brain pathology.

Proton nuclear magnetic resonance spectroscopy (MRS) delivers information about cell content and metabolism in a noninvasive manner. The diagnostic strength of MRS lies in its evaluation of pathologies in combination with conventional magnetic resonance imaging (MRI). MRS in children has been most widely used to evaluate brain conditions like tumors, infections, metabolic diseases or learning disabilities and especially in neonates with hypoxic-ischemic encephalopathy. This article reviews some basic theoretical considerations, routine procedures, protocols and pitfalls and will illustrate the range of spectrum alterations occurring in some non-tumorous pediatric brain pathologies.

MRI and proton spectroscopy in children with late infantile neuronal ceroid lipofuscinosis: Preliminary results

Aim of the study was to characterize findings on magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy ( 1 H-MRS) in children with late infantile neuronal ceroid lipofuscinosis (NCL) and the relationship between these results and duration of the disorder. Three children with late infantile NCL and six age-matched controls were examined with MRI and by localized 1 H-MRS. Voxel regions studied were periventricular frontal white matter, thalami and cerebellar deep white matter. N-acetylaspartate/creatine (NAA/Cr) and choline/creatine (Cho/Cr) ratio was calculated. MRI showed various degrees of cortical atrophy and increased periventricular white matter signal intensity on T2- and -fluid attenuated inversion recovery-weighted images. There was no significant volume loss in the brainstem. Metabolic ratio (NAA/Cr and Cho/Cr) showed progressive decrease with longer disease duration in thalamic and cerebellar voxels and exhibited a negative relationship in frontal voxels. In conclusion, the most significant changes on neuroimaging in late infantile NCL are progressive cortical and cerebellar atrophy, which are more pronounced in the cerebellum. Decreased signal intensity in the thalami may also be observed as in other forms of NCL. 1 H-MRS is the most sensitive method for measuring metabolic changes. The decreased level of NAA although

Prefrontal cortex hemodynamics and age: a pilot study using functional near infrared spectroscopy in children.

Cerebral hemodynamics reflect cognitive processes and underlying physiological processes, both of which are captured by functional near infrared spectroscopy (fNIRS). Here, we introduce a novel parameter of Oxygenation Variability directly obtained from fNIRS data —the OV Index—and we demonstrate its use in children. fNIRS data were collected from 17 children (ages 4–8 years), while they performed a standard Go/No-Go task. Data were analyzed using two frequency bands—the first attributed to cerebral autoregulation (CA) (<0.1 Hz) and the second to respiration (0.2–0.3 Hz). Results indicate differences in variability of oscillations of oxygen saturation (SO2) between the two different bands. These pilot data reveal a dynamic relationship between chronological age and OV index in CA associated frequency of <0.1 Hz. Specifically, OV index increased with age between 4 and 6 years. In addition, there was much higher variability in frequencies associated with CA than for respiration across subjects. These findings provide preliminary evidence for the utility of the OV index and are the first to describe the relationship between cerebral autoregulation and age in children using fNIRS methodology.

Quality of 186 child brain spectra using motion and B0 shim navigated single voxel spectroscopy.

To evaluate B0 shim and motion navigated single voxel spectroscopy in children. Assess the repeatability of metabolite concentrations in three regions: medial frontal grey matter, peritrigonal white matter, and basal ganglia. Determine the extent of intra- and interacquisition movement in this population. Linewidth and signal to noise ratio were calculated to assess spectral quality of 186 spectra at 3 Tesla. Repeatability was assessed on 31 repeat scans. Navigator images were used to assess localization errors, while navigator motion and shim logs were used to demonstrate the efficacy of correction needed during the scans. Average linewidths ± standard deviations of N-acetyl aspartate are 3.8 ± 0.6 Hz, 4.4 ± 0.5 Hz, and 4.7 ± 0.8 Hz in each region, respectively. Scan-to-scan measurement variance in metabolite concentrations closely resembled the expected variance. A total of 73% and 32% of children moved before and during the acquisition, causing a voxel shift of more than 10% of the voxel volume, 1.5 mm. The predominant movement directions were sliding out of the coil and nodding (up-down rotation). First-order B0 corrections were significant (>10 μT/m) in 18 % of acquisitions. Prospective motion and B0 correction provides high quality repeatable spectra. The study found that most children moved between acquisitions and a substantial number moved during acquisitions.