The gold standard for the evaluation of sleep-related disorders is polysomnography, and that of sleepiness is the multiple sleep latency test. However, only a small number of institutions can perform these examinations in Japan, and fewer pediatricians have experience of them. The test using polysomnography, sleep stages on electroencephalogram, electrooculogram and electromyography of the mentalis muscle, and rules of scoring arousal and scoring respiratory events unique to children will be explained based on the latest manual of the American academy of sleep medicine. In addition, the multiple sleep latency test required to diagnose central disorders of hyposomnolence will be explained including the important parameters : the sleep latency and sleep onset REM period.

  Objective: This study investigated the clinical features, neuroimaging and prognosis of cerebral sinovenous thrombosis (CSVT) in children. Methods: We retrospectively evaluated five patients with CSVT based on their medical records. Results: The subjects were two males and three females. One subject was a neonate. The other four were infants who had underlying diseases or prothrombotic factors, but the neonate had no risk factors. All children had anticoagulation therapy in the acute phase and their neurological outcomes were favorable. D-dimer was elevated in all cases, but it did not correlate with their outcomes. Susceptibility-weighted imaging (SWI) obtained in three patients clearly visualized venous congestion, bleeding and thrombosis. Conclusions: Clinical symptoms of CSVT in children are usually nonspecific. Accurate diagnosis with neuroimaging and anticoagulation therapy during the acute phase are necessary. SWI sensitively detects venous congestion, bleeding and thrombosis and is a useful method for diagnosing CSVT.

  Vertebral artery dissection (VAD) commonly results in stroke in children, however, the specific luminal findings of VAD are seldom visualized through imaging study during the acute phase. Herein, we report two pediatric cases with multiple infarctions caused by VAD. The findings of magnetic resonance angiography (MRA) changed over time and MRA was invaluable in diagnosing VAD. Both cases comprised multiple infarctions in the posterior circulation territory, which were atraumatic. Typical VAD findings were not clear at the onset. However, on MRA, the appearance of vessels in the V3 segment of the extracranial arteria vertebralis subsequently changed over time within 2 months for the first patient, within 1 year 8 months after onset for the second patient which resulted in repeated cerebral infarctions. The first patient received first-line treatment with aspirin. However, new ischemic lesions appeared in a few weeks, accordingly, treatment was changed to anticoagulants, which yielded good progress. However, the second patient received first-line treatment with anticoagulants, thereafter, treatment was gradually changed to aspirin. He did not experience relapse even after withdrawal therapy. Since VAD commonly affects the extracranial segment including V3, imaging must include the craniocervical region with V2-V3 segments for diagnosis over time. In addition, our cases suggest the efficacy of anticoagulants as an acute treatment for VAD. Future studies are required to establish the treatment for ischemic stroke in children.

  COL4A1 encodes the α1 chain of type IV collagen and is associated with porencephaly and schizencephaly. We report the case of a patient with COL4A1-related disorder who displayed a variety of abnormal findings on brain MRI but not porencephaly and schizencephaly. The patient was a 21-year-old woman who was born at term without asphyxia by cesarean section due to placenta previa. During infancy, psychomotor retardation and microcephaly were identified. At 7 months old, she developed West syndrome. Brain MRI showed diffuse white matter lesions, dilated ventricles, cerebellar atrophy and cerebral calcification. No cause of these findings was evident, and she was diagnosed with spastic quadriplegia. At 19 years old, she presented with lacunar infarcts as well as small cerebral hemorrhage and cerebral aneurysms. The ischemic and hemorrhagic lesions led us to suspect COL4A1-related disorder. After genetic counseling, analysis of COL4A1 identified a heterozygous novel de novo mutation (c.2504G>A ; p.Gly835Glu). COL4A1-related disorders may be present but undiagnosed in patients with palsy of unknown origin. Genetic counselling before diagnosis is important because of the autosomal dominant inheritance of this pathology.

  During the outbreak of enterovirus D68 (EV-D68)-associated respiratory diseases in North America in autumn 2014, a number of cases of acute flaccid paralysis (AFP) were reported. Similarly, the accumulation of AFP cases was observed in Japan during the outbreak of EV-D68 in autumn 2015. During this season, we cumulatively experienced three cases of acute flaccid myelitis (AFM) in Nagasaki. A 12-year-old girl, a 4-year-old boy and a 2-year-old girl developed AFP 4-9 days after antecedent infections. T2-weighted images of spinal magnetic resonance imaging showed high-intensity lesions, particularly affecting the anterior horns in all three cases. Cerebrospinal fluid studies indicated pleocytosis in all three and increased protein levels in two. Peripheral nerve conduction studies showed a reduction in the F wave incidence in all three patients. They were treated with intravenous immunoglobulin, methylprednisolone pulse therapy, and plasma exchange, none of which appeared effective. They all had mild-to-severe sequelae, but became less severe by rehabilitation. Rehabilitation is important for AFM that not have effective therapy in acute phase. Although EV-D68 has been strongly suspected to be an etiological agent of AFM in previous reports, we were unable to detect EV-D68 in any of our patients. Since EV-D68 can be detected only in the early stage of infection, sample collection from our cases might have been too late. Further studies are needed to clarify the role of EV-D68 in the pathogenesis of AFM.

  We herein describe a patient with pharmacoresistant atypical benign partial epilepsy (ABPE) and continuous spikes and waves during slow wave sleep (CSWS) who responded well to ketogenic diet therapy. The patient was a 6-year-5-month-old boy who started to have atypical absence seizures at 1 year and 5 months of age, and atonic seizures at 2 years of age. The seizures were resistant to various antiepileptic drugs, causing dysarthria and ataxia. EEG initially showed high amplitude sharp-slow discharges from the left centrotemporal regions, which later became frequent and spread diffusely, escalating to CSWS. He was referred to our hospital at 5 years and 8 months of age, and underwent a long-term video-polygraphic study. He was diagnosed with ABPE with CSWS and successfully responded to 3 : 1 ketogenic diet (KD) therapy. His seizures and CSWS have remained excellently controlled for 1 year since the introduction of KD, resulting in improvements in dysarthria and ataxia as well as gross and fine motor abilities. The introduction of KD therapy is recommended for patients with pharmacoresistant ABPE with CSWS.

  Choroid plexus cysts (CPCs) are common neuroepithelial cysts that are typically small and asymptomatic, and are discovered incidentally. Symptomatic CPCs are rare. CPCs are difficult to detect on routine computed tomography (CT) and magnetic resonance imaging (MRI) scans, because of their thin non-enhancing walls and cerebrospinal fluid (CSF)-like fluid content. The authors report a case of symptomatic CPC diagnosed with steady-state coherent imaging sequence in a 2-year-old boy who presented with status epilepticus. Although he underwent emergency ventricular drainage for acute hydrocephalus, conventional MRI demonstrated no obvious lesions immediately after the operation. We used steady-state coherent imaging sequence to investigate his continuous intracranial hypertension postoperatively, and a unilocular cystic lesion in the third ventricule, occluding the cerebral aqueduct was detected. Subsequently, he underwent endoscopic resection of the cyst with third ventriculostomy, and recovered his consciousness. Wall biopsy indicated CPC. Steady-state coherent imaging sequence has the advantage of excellent spatial resolution and fewer artifacts of vessel pulsation and CSF flow, and enables the visualization of flow abnormalities in CSF pathways or small intraventricular lesions. If routine CT and MRI reveal hydrocephalus of unknown origin, steady-state coherent imaging sequence can be useful for the precise identification of lesions.

  The Cockayne syndrome (CS) is a very rare disease with symptoms including short stature, mental retardation, microcephaly, pigmentary degeneration of the retina, premature senility, renal dysfunction, and photosensitivity. These symptoms tend to appear slowly, and the disease often cannot be diagnosed at the early stages. Here, we describe the cases of elder sister and younger brother with the Cockayne syndrome A (CSA) presenting the same homozygous mutation with the inversion and deletion of ERCC8. Only one genetic analysis of CSA has been reported previously in Japan, showing that three out of five patients present this type of mutation. Thus, we concluded that this mutation must be a founder effect of CSA in Japan.