Yukihiko Konishi

Functional lateralization of sensorimotor cortex in infants measured using multichannel near-infrared spectroscopy.

Multichannel near-infrared spectroscopy (MNIRS) was used for the functional imaging of the sensorimotor cortex of newborn infants during passive knee and elbow movement under sedated sleep. Contralateral knee and elbow movement caused a marked increase in the concentration of oxyhemoglobin ([oxyHb]) from the baseline values at site within the sensorimotor area in all infants. During ipsilateral knee and elbow movement, [oxyHb] showed smaller changes, equivalent to 64 ± 23 and 66 ± 28% of the changes that occurred with contralateral stimulation, respectively. The mean times corresponding to maximal changes in [oxyHb] were 16.1 ± 3.3 s for contralateral knee movement and 17.9 ± 5.7 s for contralateral elbow movement. No significant difference was noted between the mean latencies showing the maximal changes in [oxyHb] between contralateral and ipsilateral movement. There was a significant difference in the area and degree of response between the contralateral and ipsilateral movement. MNIRS could be a useful tool to understand the pathophysiology of the developing brain and monitor cortical responses in various clinical situations.

The effect of blood transfusion on cerebral hemodynamics in preterm infants

Anemia of prematurity commonly occurs in infants with very low birth weight; blood transfusion is an important treatment. However, there is no clear evidence to support the criteria currently widely used, based on blood hemoglobin (bHb) and hematocrit indices. Previous studies showed that overtransfusion or a low threshold for transfusion could induce complications or neurologic sequelae, respectively. We hypothesized that a cerebral hemodynamic index may provide an appropriate criterion for determining the need for transfusion in anemic preterm infants.

Simultaneous measurement of cerebral hemoglobin oxygen saturation and blood volume in asphyxiated neonates by near-infrared time-resolved spectroscopy.

BACKGROUND Hypoxic-ischemic encephalopathy (HIE) usually results in a poor clinical outcome even when treated with hypothermic therapy (HT). Early postnatal changes in cerebral blood oxygenation and hemodynamics may be critical determinants of brain injury and the efficacy of HT. OBJECTIVES We measured cerebral hemoglobin oxygen saturation (ScO2) and cerebral blood volume (CBV) by near-infrared time-resolved spectroscopy (TRS) in HT-treated and non-HT-treated neonatal HIE patients to assess the influence of these parameters on clinical outcome. METHODS We retrospectively compared ScO2, CBV, and clinical outcomes of 11 neonates with HIE: 5 were treated by HT (HT-treated; 33.5°C±0.5°C for 72h starting approximately 6h after delivery) and 6 were not (non-HT-treated). Both CBV and ScO2 were measured by TRS at 6, 24, 48, and 72h after birth. Magnetic resonance imaging (MRI) was performed 1-2weeks after birth to assess brain injury. RESULTS Five neonates had adverse outcomes (3 HT-treated, 2 non-HT-treated). Of these, 1 died within 3days of birth and 4 had abnormal MRI findings, including basal ganglia, white matter, and/or thalamic lesions. The other 6 neonates had normal MRI findings (favorable outcome). At 6h after birth, CBV was significantly higher in neonates with adverse outcomes compared with those with a favorable outcome. At 24h after birth, ScO2 was significantly higher in neonates with adverse outcomes. Furthermore, we found that combined CBV at 24h after birth plus ScO2 had the best predictive ability for neurological outcome: sensitivity, specificity, positive predictive value, and negative predictive value were all 100%. CONCLUSION Early postnatal CBV and ScO2 elevations were predictive of a poor outcome in HIE. Therefore, measuring combined CBV plus ScO2 at 24h after birth can allow more precise prediction of neurological outcome. Control of postnatal CBV and ScO2 is critical for effective HIE treatment.

Does ethnicity have an effect on fetal behavior? A comparison of Asian and Caucasian populations.

Abstract Aim: This study aimed to evaluate the ethnic difference in fetal behavior between Asian and Caucasian populations. Methods: Fetal behavior was assesed by Kurjak’s antenatal neurodevelopmental test (KANET) using four-dimensional (4D) ultrasound between 28 and 38 weeks of gestation. Eighty-nine Japanese (representative of Asians) and seventy-eight Croatian (representative of Caucasians) pregnant women were studied. The total value of KANET score and values of each parameter (eight parameters) were compared. Results: The total KANET score was normal in both populations, but there was a significant difference in total KANET scores between Japanese (median, 14; range, 10–16) and Croatian fetuses (median, 12; range, 10–15) (P<0.0001). When individual KANET parameters were compared, we found significant differences in four fetal movements (isolated head anteflexion, isolated eye blinking, facial alteration or mouth opening, and isolated leg movement). No significant differences were noted in the four other parameters (cranial suture and head circumference, isolated hand movement or hand to face movements, fingers movements, and gestalt of general movements). Conclusion: Our results suggest that ethnicity should be considered when evaluating fetal behavior, especially during assessment of fetal facial expressions. Although there was a difference in the total KANET score between Japanese and Croatian populations, all the scores in both groups were within normal range. Our results indicate that ethnical differences in fetal behaviour do not affect the total KANET score, but close follow-up should be continued in some borderline cases.

Extrauterine environment influences spontaneous low-frequency oscillations in the preterm brain

Low-frequency oscillations in cerebral blood flow that are suggestive of resting-state brain activity have recently been reported, but no study on the development of resting-state brain activity in preterm infants has been performed. The objective of this study was to measure the cerebral blood flow oscillations, which are assumed to represent brain function in the resting state, in preterm and term infants of the same postconceptional age. The subjects were 9 preterm infants who had reached full term (gestational age (GA): 23-34 weeks, postconceptional age: 37-46 weeks) and 10 term infants (GA: 37-40 weeks, postconceptional age: 37-41 weeks). Their changes in concentration of oxyhemoglobin ([oxyHb]) and deoxyhemoglobin ([deoxyHb]) were measured in the parieto-temporal region during quiet sleep using multi-channel near-infrared spectroscopy, and the power spectral densities (PSD) of the oscillations in the concentrations of these molecules were analyzed and compared. The preterm infants displayed a higher proportion of 0.06-0.10 Hz low frequency oscillations of [oxyHb] and [deoxyHb] than the term infants, and the gestational age and the proportion of low frequency oscillations were inversely correlated. These findings suggest that resting-state cerebral blood flow oscillations differ between preterm and term infants, and that the development of circulatory regulation and nerve activity in preterm infants are influenced by the extrauterine environment.

Changes in 99mTc-ECD SPECT and Magnetic Resonance Angiography With Sporadic Hemiplegic Migraine in a Child

Sporadic hemiplegic migraine is rare in childhood. We followed a patient with Tc-ECD (Tc-ethyl cysteinate dimer) SPECT and magnetic resonance angiography (MRA). At the age of 8 years, he developed left hemiplegia. The MRA showed vasoconstriction of the posterior right middle cerebral artery. Hemiplegia disappeared in a few hours, and the MRA normalized. At the age of 10 years, right hemiplegia was observed, disappearing completely after a few days. During this second migraine attack, MRA demonstrated left middle cerebral artery vasoconstriction, and SPECT revealed decreased left hemisphere blood flow. Findings normalized as the patient recovered.

Hypoplastic hippocampus in atypical Rett syndrome with a novel FOXG1 mutation

The forkhead box G1 (FOXG1) gene encodes a brain-specific transcription factor and is associated with a congenital variant of atypical Rett syndrome (RTT); several FOXG1 mutations have been identified. The congenital variant of RTT shows a hypoplastic corpus callosum, delayed myelination, and frontal and temporal atrophy. Although no report has described a hippocampal abnormality in humans, the current study suggests that FOXG1 also regulates neurogenesis in the postnatal hippocampus. In the present case, severe developmental delay was observed in a patient with a congenital variant of RTT from about 4months, in conjunction with acquired microcephaly, hypotonia, limited motor function, absent purposeful hand use, and repetitive jerky movements of the upper limbs. A novel missense mutation was identified in FOXG1 on gene analysis (c. 569T>A, p. Ile190Asn). The patient showed not only the typical cerebral abnormalities of a congenital variant of RTT, but also a hypoplastic hippocampus. This novel mutation and cerebral findings may provide new insights into the pathophysiology of the congenital variant of RTT.

Incidence of infantile spinal muscular atrophy on Shikoku Island of Japan

BACKGROUND Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by homozygous mutations in the SMN1 gene. SMA has long been known to be the most common genetic cause of infant mortality. However, there have been no reports on the epidemiology of infantile SMA (types 1 and 2) based on genetic testing in Japan. In this study, we estimated the incidence of infantile SMA on Shikoku Island, which is a main island of Japan and consists of four prefectures: Ehime, Kagawa, Tokushima and Kochi. METHODS A questionnaire was sent to 91 hospitals on Shikoku Island to investigate the number of SMA infants born from 2011 to 2015. A second questionnaire was then sent to confirm the diagnoses of SMA based on clinical and genetic features. RESULTS Responses were received from all of the hospitals, and four patients were diagnosed with infantile SMA among 147,950 live births. We estimated the incidence of infantile SMA patients as 2.7 per 100,000 live births (95% confidence interval, 0.1-5.4). A comparison of the four prefectures indicated that the incidence of infantile SMA was significantly higher in Ehime Prefecture than in the other three prefectures; 5.6 per 100,000 live births (95% confidence interval, -0.7 to 11.9) in Ehime Prefecture and 1.1 per 100,000 live births (95% confidence interval, -1.0 to 3.1) in the other prefectures. CONCLUSION We estimated the incidence of infantile SMA in an isolated area of Japan. For more precise determination of the incidence of infantile SMA, further studies that include neonatal screening will be needed.

Evans syndrome after autologous peripheral blood stem cell transplantation for recurrent Hodgkin lymphoma

There have been a number of recent reports on the occurrence of autoimmune conditions after autologous hematopoietic stem cell transplantation. We describe a rare case of Evans syndrome (ES) that developed in a 16‐year‐old patient >1 year after autologous peripheral blood stem cell transplantation for recurrent Hodgkin lymphoma. ES is a rare and frequently refractory condition. No therapy for the condition has been established, and it can often be fatal. In the present case, i.v. cyclosporine A injection was significantly effective against the ES, which has not recurred.

A developmental change of the visual behavior of the face recognition in the early infancy

The purpose of this study was to examine developmental changes in visuocognitive function, particularly face recognition, in early infancy. In this study, we measured eye movement in healthy infants with a preference gaze problem, particularly eye movement between two face stimulations. We used the eye tracker system (Tobii1750, Tobii Technologies, Sweden) to measure eye movement in infants. Subjects were 17 3-month-old infants and 16 4-month-old infants. The subjects looked two types of face stimulation (upright face/scrambled face) at the same time and we measured their visual behavior (preference/looking/eye movement). Our results showed that 4-month-old infants looked at an upright face longer than 3-month infants, and exploratory behavior while comparing two face stimulations significantly increased. In this study, 4-month-old infants showed a preference towards an upright face. The numbers of eye movements between two face stimuli significantly increased in 4-month-old infants. These results suggest that eye movements may be an important index in face cognitive function during early infancy.