Nozomi Sano

Electroencephalographic Study of Rat Hyperthermic Seizures

Summary: The behavior and EEG of rat hyperthermic convulsions was studied. We found that a long run of high‐voltage slow waves without convulsions, high‐voltage irregular activity consisting of spikes and waves with intermittent myoclonus, and rapid spike and wave bursts accompanied by generalized clonic convulsions occurred sequentially. This behavioral and EEG activity is analogous to human febrile convulsions and supports the usefulness of this model for studies of human febrile convulsions. Rats frequently showed arrest of locomotion concurrently with paroxysmal EEG theta bursts before development of generalized convulsions. We speculate that this paroxysmal activity is a type of seizure discharge.

Hyperthermia-induced seizures with a servo system: Neurophysiological roles of age, temperature elevation rate and regional GABA content in the rat

A servo system including a microwave generator was applied to raise a rats body temperature at a pre-set rate. Using this system the effects of age and the temperature elevation rate upon febrile seizures in rats were studied. The relationship between the brain GABA content and hyperthermia was also studied. From the results of the present study, the seizure occurrence rate was found to be highest at the age of 20 days, brain damage was speculated to be severe after hyperthermia-induced seizures with a slow temperature rise, and the regional GABA concentration in subcortical structures was found to increase during hyperthermia. These data indicate that a servo system with a microwave generator is useful for experimental febrile convulsions, and that GABA neurotransmission in subcortical structures might contribute to feed-back regulation against seizures during hyperthermia.

Successful botulinum toxin treatment of dysphagia in a spinal muscular atrophy type 2 patient

Prominent dysphagia is seen among patients with spinal muscular atrophy (SMA) type 2, especially at the late stage of their disease progression. Nasogastric tube feeding and gastrostomy are commonly utilized to maintain their nutritional status. However, choosing a treatment strategy to maintain appropriate nutritional status is often complicated by multiple factors, such as physical conditions and social aspects. We report a 21-year-old man with SMA type 2 who has been suffering from severe dysphagia. The findings at video-fluoroscopic swallow study (VSS) were consistent with a diagnosis of cricopharyngeal dysphagia. His dysphagia was successfully treated with percutaneous injection of botulinum toxin A (BTA) into the cricopharyngeal muscle. Our result demonstrates that administration of BTA is one of the effective treatment choices for dysphagia in SMA patients.

A case of multiple sclerosis with multi-ring-like and butterfly-like enhancement on computerized tomography

We report a case of multiple sclerosis in which CT showed multiple ring-like enhancement and butterfly-like distribution of a low density area with marginal enhancement. The latter finding is found in other demyelinating disorders but is less common in tumors or abscesses. Therefore, it seems to have some diagnostic value in multiple sclerosis.

A morphometric analysis of extracellular space in the developing spinal cord of the chick embryo

The developmental changes in the amount and distribution of the expanded extracellular space (ECS) (i.e. wider than 100 nm) were analyzed in the cervical spinal cord of chick embryos between stage 9 and 29, using electron micrograph montages, which cover one half of the cross-sectional area of the cord. The percentage of the ECS expansion to the whole cross-sectional area of the cord was 11.0% at stage 9, 7.7% at stage 11, 7.8% at stage 15, and 9.7% at stage 17. It decreased markedly to 3.0% at stage 22 and 1.3% at stage 29. The highest percentage at stage 9 may reflect the dynamic structural changes associated with neural groove closure which takes place around this time. The marked decrease after stage 22 is associated with the rapid overall growth of the cord. Until stage 19, the ECS expansions were mostly elongated and arranged radially with respect to the central canal. The ECS became scarce and arranged randomly thereafter. Throughout the stages examined, especially between stages 17 and 19, percentage was higher in the outer half of the cord than in the inner half. The outer glial limiting membrane was not established by stage 29. Between stages 17 and 22, the percentage was higher in the dorsal region than in the ventral region. This appears to be associated with the regional difference in neuronal maturation. The first blood vessels penetrated the ventromedial portion of the cord around stage 22, where the ECS expansions were relatively scarce. The successive rapid decrease in the amount of ECS expansions can be correlated to the development of vascularization.

Impaired muscle fiber type differentiation in a child with nemaline myopathy

SINCE NEMALINE MYOPATHY was first described by Shy et al., 1 a n u m b e r of cases have been reported. The disorder is charac ter ized clinically by generalized muscle hypotonia f rom early infancy and by muscle weakness predominant ly involving the neck and face. Al though the presence of rod (nemal ine) bodies in the small-cal ibered fibers is a character is t ic and diagnostic finding in nemal ine myopathy, the n u m b e r of rod bodies per se is occasionally out of proport ion to the clinical severity. In additon, most of t h e pat ients have shown abnormal fiber type distribution, including hypoplast ic type 1 fibers and type 1 fiber p redominance . The abnormal muscle histochemistry, probably induced by an impaired neural influence on the developing muscles, and muscle fiber immatur i ty have been assumed to generate muscle weakness. 2-6 We describe an incidence of nemaline myopathy t ha t followed a typical course but produced extremely severe neck muscle weakness. In addit ion to the presence of numerous rod bodies in the muscle fibers, most (96%) of the fibers behaved as type 2C on ATPase staining, indicat ing impaired muscle fiber differentiat ion from immature type 2C fibers into ei ther ma tu re type 1, 2B, or 2A fibers.

Clinical Usefulness of Serum Krebs von den Lungen-6 for Detecting Chronic Aspiration in Children with Severe Motor and Intellectual Disabilities

OBJECTIVE To determine whether the serum level of Krebs von den Lungen-6 (KL-6), a circulating high-molecular weight glycoprotein and a diagnostic biomarker of interstitial lung diseases, is a clinically useful biomarker for detecting chronic aspiration in children with severe motor and intellectual disabilities (SMIDS). STUDY DESIGN Children with SMIDS undergoing videofluorography for assessment of dysphagia were prospectively evaluated. Based on the videofluorography results, the participants were classified into aspiration and non-aspiration groups. Age, sex, white blood cell count, and serum levels of C-reactive protein, lactate dehydrogenase, albumin, and KL-6 were compared between the 2 groups. Binary logistic regression was performed to identify factors independently associated with the presence of aspiration. RESULTS A total of 66 patients participated in this study, 37 who were classified as the aspiration group and 29 as the non-aspiration group. The serum KL-6 level in the aspiration group was significantly higher than that in the non-aspiration group (median, 344 U/mL vs 207 U/mL, P < .01). Logistic regression modeling showed that the number of prescribed antiepileptic drugs (OR, 1.978; 95% CI, 1.217, 3.214; P < .01) and serum KL-6 level (OR, 1.012; 95% CI, 1.005, 1.019; P < .01) were independent predictors of aspiration. CONCLUSIONS The study demonstrated that the KL-6 level is significantly higher in children with SMIDS who aspirate than in those who do not. KL-6 shows promise as a biomarker for chronic lung disease due to aspiration in these children.

A novel STXBP1 mutation causes typical Rett syndrome in a Japanese girl

Rett syndrome (RTT) is a neurodevelopmental disorder mostly caused by mutations in Methyl-CpG-binding protein 2 (MECP2); however, mutations in various other genes may lead to RTT-like phenotypes. Here, we report the first case of a Japanese girl with RTT caused by a novel syntaxin-binding protein 1 (STXBP1) frameshift mutation (c.60delG, p.Lys21Argfs*16). She showed epilepsy at one year of age, regression of acquired psychomotor abilities thereafter, and exhibited stereotypic hand and limb movements at 3 years of age. Her epilepsy onset was earlier than is typical for RTT patients. However, she fully met the 2010 diagnostic criteria of typical RTT. STXBP1 mutations cause early infantile epileptic encephalopathy (EIEE), various intractable epilepsies, and neurodevelopmental disorders. However, the case described here presented a unique clinical presentation of typical RTT without EIEE and a novel STXBP1 mutation.

Neuroimaging and neuropathological characteristics of cerebellar injury in extremely low birth weight infants

OBJECTIVE To determine the morphological characteristics and pathogenic factors of cerebellar injury in extremely low birth weight infants (ELBWI). SUBJECTS AND METHODS Neuroimaging examination was performed on 17 eligible surviving ELBWI. Their MR images were assessed and classified its pattern of cerebellar injuries. Brain pathology was examined on 15 patients, who isolated this neuroimaging subjects. The trend of brain pathologies was revealed. RESULTS Four types of morphological pattern were recognized: (i) the absence of major portions in the cerebellum (6/17 cases); (ii) focal cerebellar tissue loss (2/17); (iii) unilateral cerebellar atrophy/hypoplasia (3/17); (iv) small cerebellum with entrapped fourth ventricle (6/17). In cerebellar pathology, the most common findings were focal or widespread cerebellar subarachnoid hemorrhage (12/15) and olivocerebellar degeneration (12/15). In addition, one-third of the cases indicated remote cerebellar parenchymal hemorrhage. CONCLUSION In MRI-defined lesions, the absence of major portions or focal tissue loss was associated with cerebellar parenchymal hemorrhage and/or hemorrhagic infarction, that is destructive lesion. On the other hand, small cerebellum or unilateral atrophy/hypoplasia, that is impaired development, may be related to the cerebellar neuron loss due to hemosiderin deposits in the surface of the cerebellum. The cerebellar injury in ELBWI is probably caused by not only environmental factors such as hemorrhage, hypoxia-ischemia, or other deleterious effect, but also immaturity of the rapidly growing cerebellum in particular gestational age.

Infantile sudanophilic leukodystrophy: computed tomography demonstration

SummaryWe report a female case of infantile sudanophilic leukodystrophy whose evolution was followed by CT