Haemodynamic Responses to Spontaneous Neural Activity on the Electroencephalogram in Preterm Infants.

Delta brushes are spontaneous neural activities observed in preterm electroencephalograms (EEGs) and are thought to reflect the activities of subplate neurons in the developing brain. We investigated the haemodynamic responses associated with delta brushes in five preterm infants at two time points (at 33 or 34, and 36 weeks of postmenstrual age), using simultaneous EEG-functional near-infrared spectroscopy (NIRS). An automated detection algorithm was developed to identify the brush components of delta brushes in the bipolar EEG envelope; we placed eight EEG electrodes. An eight-channel NIRS device was placed around the head of each infant to measure changes in oxy- and deoxy-haemoglobin (Hb) concentrations. Haemodynamic grand averages were calculated for local brushes in each NIRS channel. We classified the responses into five patterns based on changes in oxy- and deoxy-Hb signals (positive in-phase/anti-phase, negative in-phase/anti-phase, and unclassified) and evaluated the relationship between the locations of NIRS measurements and those of brushes, as well as the haemodynamic response patterns and infant age at the time of recording. In all the 10 recordings, we found that positive responses (oxy-Hb increases) predominated, not only in the corresponding areas but also in remote areas. Particularly, notable responses were observed in the bilateral temporal areas. Among the positive responses, the proportion exhibiting an anti-phase pattern was 12% at 33 to 34 weeks of postmenstrual age and 54% at 36 weeks of postmenstrual age. Our unexpected finding of remarkable temporal responses to localised neuronal activity supports the hypothesis that the insula is the most strongly interconnected hub in the developing brain.

Color density spectral array findings on continuous EEG during therapeutic hypothermia in children with acute encephalopathy.

BACKGROUND: Quantitative EEG is frequently used to monitor children affected by acute encephalopathy (AE), with the expectation of providing comprehensive insights into continuous EEG monitoring. However, the potential of quantitative EEG for estimating outcomes in this context remains unclear. We sought reliable prognostic markers within the color density spectral array (CDSA) of the continuous EEG for AE-affected children undergoing therapeutic hypothermia (TH). METHODS: This retrospective study analyzed CDSA data from eight scalp electrodes of 15 AE-affected children undergoing TH. Two CDSA features were investigated-high-frequency lines (HFLs) and periodic elevation in the low frequency band (PLFB)-along with the corresponding EEG characteristics. The inter-rater reliability for CDSA was assessed by four pediatric neurologists. Outcomes were grouped into either no/mild or severe decline in motor and cognitive functions, then compared with CDSA features. RESULTS: The median EEG recording time was 114 (81-151) h per child. While at least 41 % of HFLs corresponded to typical sleep spindles, 94 % of PLFB aligned with cyclic changes in the amplitude of delta/theta waves on the raw EEG. Inter-rater reliability was higher for HFLs than for PLFB (kappa values: 0.69 vs. 0.46). HFLs were significantly more prevalent in children with no/mild decline than in children with severe decline (p = 0.017), whereas PLFB did not differ significantly (p = 0.33). CONCLUSIONS: This study provides preliminary evidence that reduced HFLs on CDSA predict unfavorable outcomes in AE-affected children undergoing TH. This suggests that maintaining high-frequency waves is critical for optimal brain function.

Sleep state-dependent development of resting state functional connectivity during the preterm period.

STUDY OBJECTIVES: The brains of preterm infants exhibit altered functional connectivity (FC) networks, but the potential variation in sleep states and the impact of breathing patterns on FC networks are unclear. This study explores the evolution of resting-state FC from preterm to term, focusing on breathing patterns and distinguishing between active sleep and quiet sleep. METHODS: We recruited 63 preterm infants and 44 healthy-term infants and performed simultaneous electroencephalography and functional near-infrared spectroscopy. FC was calculated using oxy- and deoxyhemoglobin signals across eight channels. First, FC was compared between periodic breathing (PB) and non-PB segments. Then sleep state-dependent FC development was explored. FC was compared between active sleep and quiet sleep segments and between preterm infants at term and term-born infants in each sleep state. Finally, associations between FC at term, clinical characteristics, and neurodevelopmental outcomes in late infancy were assessed in preterm infants. RESULTS: In total, 148 records from preterm infants and 44 from term-born infants were analyzed. PB inflated FC values. After excluding PB segments, FC was found to be elevated during active sleep compared to quiet sleep, particularly in connections involving occipital regions. Preterm infants had significantly higher FC in both sleep states compared to term-born infants. Furthermore, stronger FC in specific connections during active sleep at term was associated with unfavorable neurodevelopment in preterm infants. CONCLUSIONS: Sleep states play a critical role in FC development and preterm infants show observable changes in FC.

Underlying Disorders in Children With Infection-Related Acute Encephalopathy.

BACKGROUND: Various factors contribute to the development of infection-related acute encephalopathy (AE) in children, such as infectious agents and chronic underlying disorders. We studied underlying disorders in children with AE to identify predisposing factors of AE. METHODS: We investigated underlying disorders or past histories in patients with two types of AE from the database in the Tokai area of Japan between 2009 and 2022: 204 patients with AE with reduced subcortical diffusion (AED) and 137 with clinically mild encephalopathy with a reversible splenial lesion (MERS). We compared them with 89 patients with acute disseminated encephalomyelitis (ADEM) to clarify the specific disorders in the two AE types. RESULTS: The prevalence of underlying disorders in AED (34%, 70 patients) was significantly higher than that in ADEM (12%, 11 patients) (P < 0.01). The prevalence of underlying disorders in MERS was 23% (32 patients). The underlying disorders included seizure disorders, premature birth, genetic/congenital disorders, and endocrine/renal diseases. In patients with seizure disorders in AED, five patients (18%) had Dravet syndrome and four (15%) had West syndrome, whereas none with MERS had these syndromes. Twenty-five (12%) of 204 patients with AED, three (2%) with MERS, and one (1%) with ADEM were preterm or low birth weight. CONCLUSIONS: The high prevalence of seizure disorders suggests that seizure susceptibility is an important predisposing factor in AED. Premature birth also has an impact on the development of AED. Caution is required regarding the development of AE in patients with chronic seizure disorders or premature birth.

Reading impairment after neonatal hypoglycemia with parieto-temporo-occipital injury without cortical blindness: A case report.

BACKGROUND: Perinatal brain injury may lead to later neurodevelopmental disorders, whose outcomes may vary due to neuroplasticity in young children. Recent neuroimaging studies have shown that the left parietotemporal area (which includes the left inferior parietal lobe) is associated with phonological awareness and decoding skills, which are essential skills for reading acquisition in children. However, the literature on the effect of perinatal cerebral injury on the development of phonological awareness or decoding ability in childhood is limited. CASE SUMMARY: We report the case of an 8-year-old boy who presented with reading difficulty following a perinatal injury in the parieto-temporal-occipital lobes. The patient was born at term and was treated for hypoglycemia and seizures during the neonatal period. Diffusion-weighted brain magnetic resonance imaging on postnatal day 4 revealed cortical and subcortical hyperintensities in the parieto-temporo-occipital lobe. At the age of 8 years, physical examination was unremarkable, aside from mild clumsiness. Despite occipital lobe injury, the patient had adequate visual acuity, normal eye movement, and no visual field defects. Full-scale intelligence quotient and verbal comprehension index on Wechsler Intelligence Scale for Children-Fourth Edition were 75 and 90, respectively. Further assessment revealed adequate recognition of Japanese Hiragana letters. However, he had significantly slower reading speed in the Hiragana reading test than control children. The phonological awareness test revealed significant errors (standard deviation +2.7) in the mora reversal task. CONCLUSION: Patients with perinatal brain injuries in the parietotemporal area require attention and may benefit from additional reading instructions.

Two Cases of Juvenile Myelomonocytic Leukemia and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an autoimmune demyelinating disorder that often manifests after infections or vaccinations. We report two patients who developed MOGAD out of eight patients with juvenile myelomonocytic leukemia (JMML) that has never been reported. METHODS: We investigated two patients with JMML who developed MOGAD among 127 patients with leukemia from 2012 to 2021. RESULTS: Patient 1 was treated for JMML and developed fever and impaired consciousness at two years and one month of age. Magnetic resonance imaging revealed high-intensity lesions in the left frontal and left occipital white matter. The serum anti-MOG antibody test was positive, while the test was negative in the stored serum 45 days before the onset of encephalopathy. He had relapse of MOGAD after steroid therapy and plasmapheresis. Patient 2, who was treated for JMML, became apathetic and mute at three years and seven months of age. Magnetic resonance imaging revealed left frontoparietal subcortical high-intensity lesions. Anti-MOG antibody at the onset of encephalopathy was positive, while it was negative in stored serum 57 days before and 47 days after the onset. CONCLUSION: We treated two patients who developed MOGAD out of eight patients with JMML and none with MOGAD out of 119 patients with acute lymphocytic leukemia, acute myelocytic leukemia, or chronic myelocytic leukemia. The activated autoimmune process via the RAS pathway abnormality may have led to the formation of the anti-MOG antibody and the onset of MOGAD. MOGAD can occur in children with JMML, and abnormalities of the RAS pathway possibly contribute to its onset.

Effectiveness of lacosamide in children and young adults previously treated with other sodium channel blockers.

PURPOSE: This multicenter study examined the effectiveness and tolerability of lacosamide (LCM) for children and young adults with epilepsy, particularly in patients who had previously been treated with other sodium channel blockers (SCBs) and the difference in effectiveness and tolerability when using other concomitant SCBs. METHODS: We retrospectively studied the clinical information of patients aged <30 years given LCM to treat epilepsy. The effectiveness and adverse events (AEs) of LCM and the other SCBs were investigated. Factors related to the effectiveness and AEs of LCM, such as the number of antiepileptic drugs (AEDs) tried before LCM and concomitantly used SCBs, were also studied. RESULTS: We enrolled 112 patients (median age = 11 years). One year after starting LCM, 29% of the patients were seizure free, and 50% had a ≥50% seizure reduction. Of the patients, 17% experienced AEs, the most common being somnolence. A ≥50% seizure reduction was observed for LCM in 30% of patients in whom other SCBs had not been effective. Lacosamide produced a ≥50% seizure reduction in 35% of the patients taking one concomitant SCB. By contrast, no patients had ≥50% seizure reduction, and 33% developed AEs, when LCM was administered concomitantly with two SCBs. CONCLUSIONS: Lacosamide was effective in 30% of children and young adults in whom other SCBs had not been effective. The effectiveness of LCM may differ from that of other SCBs, and it is worth trying in patients with epilepsy resistant to other AEDs.