Measurement of laryngeal elevation time using a flexible surface stretch sensor.

BACKGROUND: Dysphagia is a growing health problem in aging societies. An observational cohort study targeting community-dwelling populations revealed that 16% of elderly subjects present with dysphagia. There is a need in elderly communities for systematic dysphagia assessment. OBJECTIVE: This study aimed to verify whether laryngeal elevation in the pharyngeal phase could be measured from the body surface using thin and flexible stretch sensors. METHODS: Thirty-two elderly subjects (17 males, 15 females; mean age ± SD: 89.2 ± 6.2 years) with suspected dysphagia underwent a swallowing contrast examination in which seven stretch sensors were attached to the front of the neck. The elongation of the sensors was measured and compared to the laryngeal elevation time values obtained using videofluorography. The sensor signal detected the laryngeal elevation start time, conclusion of the descent of the larynx, and the laryngeal elevation time. The respective laryngeal elevation times obtained using videofluorography and using the sensor were compared using the Bland-Altman method. RESULTS: The laryngeal elevation time was 1.34 ± 0.46 s with the stretch sensor and 1.49 ± 0.56 s with videofluorography. There was a significant positive correlation between the duration obtained by both methods (r = .69, P < .0001). A negative additional significant bias of -0.15 s (95% confidence interval -0.30 to -0.03, P = .046) was noted in the laryngeal elevation time from the videofluorography measurement. CONCLUSION: Laryngeal elevation time can be measured non-invasively from the neck surface using stretch sensors.

[A woman with beta-propeller protein-associated neurodegeneration identified by the WDR45 mutation presenting as Rett-like syndrome in childhood].

Beta-propeller protein-associated neurodegeneration (BPAN) is one of the neurodegenerative disorders characterized by iron deposition in the brain and is the only known disease in humans to be caused by an aberration in autophagocytosis. Here, we present the case of a 42-year-old woman with BPAN identified by the WDR45 mutation. From early childhood, she was recognized as having global developmental delay, and she frequently sucked her hand, which was considered to be a stereotypical movement. She had a febrile convulsion at 6 months of age but there was no history of epilepsy. The delay in language development was more severe than the delay in motor development; she was able to dress herself, walk unaided, and follow simple instructions until adolescence. After the age of 20, her movement ability rapidly declined. By the time she was 42 years old, she was bedridden and unable to communicate. Brain magnetic resonance imaging (MRI) at 21 years revealed no abnormality except non-specific cerebral atrophy. However, MRI at 39 years revealed abnormalities in the globus pallidus and substantia nigra, with neurodegeneration and iron accumulation in the brain. Genetic analysis for WDR45 revealed that she had a splice site mutation (NM_007075.3: c.830 + 2 T > C) which was previously reported, and a diagnosis of BPAN was confirmed. For specific therapies to be developed for BPAN in the future, it is necessary to establish early diagnosis, including genetic analysis.

[Supplementation of L-carnitine to the severe motor and intellectual disabilities fed with enteral carnitine-deficient formulas for years].

OBJECTIVE: We clarified the asymptomatic deficiency of serum free-carnitine in the severe motor and intellectual disabilities (SMIDs) fed with enteral carnitine-deficient formulas for years, and investigated the adequate method to supply enteral L-carnitine and maintain its normal levels. METHODS: In 45 SMIDs who has been fed with carnitine-deficient formulas and/or receiving valproate, the serum free-carnitine levels were examined. To the carnitine deficient cases we introduced L-carnitine and/or a carnitine-supplemented formula to normalize and maintain the serum free-carnitine levels. RESULTS: Thirty-one out of 34 cases (91.2%) fed with carnitine-deficient formulas for years had serum free-carnitine deficiency. Supplement of 15 - 30 mg/kg/day L-carnitine was effective to normalize the serum free-carnitine levels within 3 months. After successful supplementation, smaller dosage of L-carnitine (100 or 300 mg/day) was enough to maintain the normal levels. Replacement of the carnitine-deficient formulas to carnitine-supplemented ones was also useful to normalize the serum free-carnitine levels. CONCLUSIONS: Smaller dosage of L-carnitine or a carnitine-supplemented formula is sufficient to normalize and maintain the serum free-carnitine levels in SMIDs fed with carnitine-deficient formulas for years.

The first Japanese familial Sotos syndrome with a novel mutation of the NSD1 gene.

Sotos syndrome is caused by the haploinsufficiency of the NSD1 gene located in 5q35. More than 70% of the Japanese cases carry microdeletions encompassing of this gene, while point mutations are common in Caucasians. Only 15 familial cases of Sotos syndrome have been reported and all cases shown to have not microdeletions but point mutations. We identified the first Japanese familial case (mother and 3 children). They carry the same mutation at splice donor site of intron 13 (IVS13+1G>A), which results in the in-frame skipping of exon 13. This is also the first familial case caused by the mutation of the splice donor site. Each member of this family showed variable phenotypes and mental development. The present report will contribute to further understanding of genotype-phenotype correlation in Sotos syndrome.

PDGF-alpha receptor expression following hypoxic-ischemic injury in the neonatal rat brain.

Hypoxia-ischemia (HI) causes injury to oligodendrocytes (OLs), cells which create the myelin sheath in the developing brain. OLs pass successively through progenitor and immature stages during differentiation into mature OLs. Only the OLs in the progenitors stage can express the platelet-derived growth factor-a receptor (PDGF-R(alpha)) so that its expression is one of the cellular markers of OL progenitors. Activation of PDGF-R(alpha) results in OL proliferation, but not OL differentiation. To study the response of OL progenitors after neonatal HI brain injury, we investigated the expression of PDGF-R(alpha) in a neonatal rat stroke model (combination of left common carotid artery ligation and exposure to 8% O2 for 2 h). In the injured cerebral cortex, PDGF-R(alpha) mRNA levels increased significantly (p<0.01) with a peak at 0.5 h after HI insult, and returned to baseline levels within 48 h post-injury. PDGF-R(alpha) protein levels increased significantly at 72-96 h (p<0.05) and then returned to basal levels. Immunohistochemistry showed clear staining of PDGF-R(alpha) only in the injured cerebral cortex at 72 h after HI insult. In contrast, no staining was observed in the cortex of sham-operated controls. These results indicate that the expression of PDGF-R(alpha) increases rapidly and transiently only in the injured cerebral cortex after HI insult and may play a protective role through modulating the glial differentiation under the condition of cellular damage in the developing brain.

Molecular genetics of spinal muscular atrophy: contribution of the NAIP gene to clinical severity.

Spinal muscular atrophy (SMA) is one of the most common autosomal recessive disorders characterized by degeneration of anterior horn cells in the spinal cord, and leads to progressive muscular weakness and atrophy. At least three SMA-related genes have been identified: SMN1, NAIP and p44t. We analyzed these genes in 32 SMA patients and found that the SMN1 gene was deleted in 30 of 32 patients (94 %), irrespective of clinical type. The NAIP gene was deleted in 6 patients and its deletion rate was higher in type I patients than that in type U or V. Further, in type I patients lacking the NAIP gene, deterioration in their respiratory function is more rapid than in those type I patients retaining the NAIP gene. Since complete p44t deletion was observed in only 3 patients, the correlation between the p44t deletion and severity of SMA remained ambiguous. We concluded that the NAIP deletion was closely related to the clinical severity of SMA and was a predictive marker of SMA prognosis, while the SMN1 deletion did not correlate with clinical severity.

[Evaluation of the developing human visual system using flash-visual evoked potential].

Flash visual evoked potential (Flash-VEP) is easily recorded in preterm infants. However, its clinical application has not been established due to its great variability in response. Our longitudinal studies on the two components of the N1 wave facilitated peak definition and established normal ranges that are clinically valuable. The N1a (early component of the N1) peak latency decreases at about 4.6 msec/week between 30 and 40 weeks postmenstrual age. A flash-VEP study in the preterm period enables us to observe the neuronal development in the human visual system that normally proceeds in utero. Flash-VEP analyses on preterm infants demonstrated that the decrease in the N1a peak latency reflects the progress of myelination in the visual pathway according to the developmental program irrespective of preterm birth. The developmental changes of the N1 wave configuration reflect the maturation of the neuronal networks in the visual cortex, which is accelerated by extrauterine visual experience. Using improved methodology and peak denomination that we proposed, flash-VEP can be applied to preterm infants safely, and should provide us with neuro-developmental information of the human cerebrum.

Clinical features of infants with subependymal germinolysis and choroid plexus cysts.

BACKGROUND: Periventricular cysts are not rare findings in neonates. However, they are sometimes associated with serious clinical complications, such as congenital viral infections and anomalies. METHODS: We performed a retrospective follow-up study on newborns who had periventricular cysts on routine cranial ultrasound examination. RESULTS: We followed 13 infants (three preterm) with periventricular cysts. Ten had single or multiple germinolysis cysts and the remaining three had choroid plexus cysts. All infants had various kinds of underlying complications, including congenital viral infection (two with cytomegalovirus and one with rubella),Sotos syndrome (n = 4), intrauterine growth retardation (n = 5), large-for-dates(n = 4), congenital heart disease (n = 1),myelomeningocele (n = 1) and other minor anomalies. All cases of germinolysis except for one developed a neurodevelopmental abnormality and/or delay. In contrast,all three cases with choroid plexus cysts appeared to develop well,despite the underlying complications. CONCLUSIONS: Germinolysis cysts seem to be associated with systemic diseases and should be treated as a high-risk sign for impaired neurological development.