[Marked efficacy of steroid pulse therapy in an infant with acute encephalopathy having elevated cerebrospinal fluid level of neopterin].
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Biomedical subjects
Publications and source records attributed to A Nezu.
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Of the 75 patients with infection-related acute encephalopathy or encephalitis treated by us in the last 10 years, 28 had acute onset encephalitis. The results of clinical studies on these 28 patients were as follows: (1) The number of cases who exhibited CNS manifestations during (A) and after pyrexia (B) were 15 and 13, and the ages of predilection were infancy and school age, respectively. (2) MRI studies in cases of A revealed multifocal CNS lesions in 1 case, localized lesions in 7 and normal findings in 7. In B, there were 3 cases with multifocal lesions, 8 of focal lesions and 2 of normal findings. (3) The 7 cases of localized lesions in A were divided into 5 of herpes encephalitis and 2 of suspected vasculitis. Vasculitis was suspected in 3 of 8 cases of localized lesions in B. Thus, vasculitis is considered to be an important cause of encephalitis. (4) Brain lesions in the 5 cases of herpes encephalitis were occipital dominant in 4. Only one case had a temporal lesion. (5) All cases with focal MRI lesions and CSF pleocytosis, having evidence of direct viral invasion, were herpes encephalitis. Direct viral invasion was not proven in any other cases. (6) Although the term encephalitis is often used in clinical practice, the process by which the CNS lesions occur in acute viral infection is still unknown. Therefore it is not easy to establish the diagnosis. The diagnostic criteria of encephalitis should be reconsidered. New specific methods to analyze the cause of CNS lesions are necessary.
We reported here a 5-year-old girl with Sotos syndrome who developed acute shock encephalopathy syndrome (ASES), and differentiated ASES from Reye syndrome (RS). Abrupt onset of shock and status epilepticus developed and these were followed by disseminated intervascular coagulation (DIC) and liver damage. Gradual elevation of hepatic enzymes, high serum bilirubin value, and normal serum ammonia value in acute phase were incompatible with typical RS. Liver histology showed severe, diffuse necrosis of hepatocytes consisting of granular and vacuolar degeneration, which were quite different from those of RS. Thus, the disease process of ASES was shown to be different from those of RS.
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The effects of the beta-adrenoceptor agonist isoproterenol on the distribution of cytosolic Ca2+ concentrations were studied with digital imaging microscopy in fura-2-loaded rat parotid acinar cells. At concentrations < 10 microM, isoproterenol did not cause any measurable change in cytosolic Ca2+ concentration ([Ca2+]i). Monitoring of [Ca2+]i in selected areas of the acinar cells failed to show that stimulation with isoproterenol causes a localized rise in [Ca2+]i at the apical region close to the lumen. As the maximum response of amylase exocytosis is observed at 0.1 or 1 microM isoproterenol [Tanimura, A., Matsumoto, Y., Tojyo, Y., 1990. Evidence that isoproterenol-induced Ca2+-mobilization in rat parotid acinar cells is not mediated by activation of beta-adrenoceptors. Biochim. Biophys. Acta, 1055, pp. 273-277], the data obtained here indicate that the isoproterenol-induced amylase exocytosis is not accompanied by Ca2+ mobilization. The high concentration (100 microM) of isoproterenol caused a small but significant increase in [Ca2+]i, particularly in the apical region. This response was completely attenuated by the alpha-adrenoceptor antagonist phentolamine, but not by the beta-adrenoceptor antagonist propranolol, indicating that the isoproterenol-induced increase in [Ca2+]i resulted from an activation of alpha-adrenoceptors. Further, the effect of cyclic AMP on Ca2+ release from intracellular Ca2+ stores was studied in saponin-permeabilized acinar cells using the lipophilic Ca2+ indicator Calcium Green C18. Cyclic AMP had no effect on the Ca2+ release, while the same acinar cells responded strongly to inositol 1,4,5-trisphosphate. This result does not support the hypothesis that cyclic AMP directly stimulates Ca2+ mobilization in rat parotid acinar cells.
To evaluate conduction abnormalities of the corticospinal tracts (CSTs) in Pelizaeus-Merzbacher disease (PMD), magnetic stimulation at three levels was carried out in 3 boys with PMD aged between 9 and 12 years. They were all diagnosed as having a duplicated proteolipid protein gene. The motor cortex and cervical spinal roots were stimulated with a round coil, whereas a double cone coil was used for brain-stem stimulation. Surface electromyographic (EMG) recording was performed on the first dorsal interosseous muscles. Despite a normal EMG response to cervical stimulation, magnetic shock of the motor cortex elicited no EMG activity, even in the case with less motor symptoms. This discrepancy between the electrophysiological and clinical findings is likely due to slowing conduction, which reduces the temporal summation of multiple descending volleys magnetically elicited. A partial conduction block may also occur because of the lack of an EMG response to brain-stem stimulation. Thus, we speculated that the spastic paresis in PMD is associated with both slowing conduction and a partial conduction block in the CSTs.
Earlier reports on T2-weighted magnetic resonance imaging (MRI) in the classical form of Pelizaeus-Merzbacher disease seemed to divide the patterns of the high-intensity lesions in the white matter into three subtypes: type I, diffusely hemispheric and corticospinal; type II, diffusely hemispheric without brainstem lesions; and type III, patchy in the hemispheres. The four boys presented in our study, between 10 and 17 years of age, with classical Pelizaeus-Merzbacher disease, who all had a duplicated proteolipid protein gene, invariably manifested type I despite their various clinical severities. Follow-up MRI after an interval of 5 years and proton magnetic resonance spectroscopy was performed in three of the patients. The white matter on the last MRI was unchanged in volume and the distribution of high-intense areas. Proton magnetic resonance spectroscopy revealed no abnormal peaks. These results were consistent with the lack of definite neurologic regression in the last 5 years and with the pathologic characteristics of well-preserved axons and the absence of sclerosis. Further study is required to precisely determine whether the patterns of MRI findings can be divided into subtypes corresponding to those of proteolipid protein gene abnormalities.
The findings of surface electromyography (s-EMG) in a female with benign paroxysmal torticollis in infancy (BPT) are reported. This disease is characterized by (1) a self-limiting condition that appears in early infancy and disappears spontaneously, (2) recurrent episodes of sudden, stereotypic torticollis, usually alternating from side to side, and (3) episodes that usually continue for several hours to a few days. The pathogenesis of this disease has not been determined. During episodes in the patient, continuous electrical discharges over the sternocleidomastoid muscle on the same side as the torticollis were observed on s-EMG, indicating that the torticollis was a dystonic phenomenon. The findings are clinically consistent with BPT, and the patient should be categorized as having an idiopathic paroxysmal dystonia in infancy.
The neuroradiologic findings of the brain lesions in eight infants with exanthema subitum were normal in three, suspected vascular lesions in two, and symmetric thalamic lesions with or without diffuse brain edema in the other three. In addition, diffuse brain edema or focal cerebral lesions were observed in 13 previously reported Japanese infants. These findings suggest that the pathogeneses of the brain lesions related to exanthema subitum are variable.
To pathophysiologically evaluate the corticospinal tracts (CSTs) in Rett syndrome (RS), transcranial magnetic stimulation (TMS) was performed in 3 patients aged 4, 6 and 13 years. The two younger cases exhibited the clinical characteristics of the pseudostationary stage (stage III), while ambulation was lost in the oldest case at the age of 11 years (stage IV). The motor cortex and cervical spinal roots were magnetically stimulated to obtain motor evoked potentials (MEPs) from the relaxed first dorsal interosseous muscle. Compared with the central motor conduction time (CMCT) in age-matched normal children, CMCT in the stage III cases was significantly short (6.9-7.1 ms, P < 0.05). In the stage IV case, CMCT was markedly short but not significantly so (6.6 ms, P = 0.06), which was partly due to a significant increase in the threshold intensity of TMS (100%, P < 0.05). Thus, the CMCT shortening, which implied unique cortical hyperexcitability, was considered consistent and characteristic of RS. The CSTs in the stage IV case were certainly impaired, corresponding well to the progressive spastic paresis.
We report a 14-year-old girl who developed chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) during the course of myasthenia gravis. Myasthenia gravis, which was clinically of ocular type, but with waning phenomenon of the extremities, occurred at 2 years and 4 months of age. Muscle weakness of the lower extremities gradually developed over the next 6 years. The electrophysiological and pathological findings fulfilled the criteria of "possible CIDP" with severe axonal involvement. The signs of myasthenia gravis and CIDP fluctuated synchronously. A common immunological abnormality was suggested to underlie this rare association of myasthenia gravis and CIDP in childhood.
BACKGROUND: Influenza-related encephalopathy or encephalitis is not rare in children. However, it is not well understood why the brain lesion develops from influenza infection. The purpose of this study was to clarify its pathogenesis by analyzing the clinical and neuroradiological findings in patients having influenza-related brain lesions. METHODS: The clinical findings in 10 children with influenza-related brain lesions were analyzed. Eight patients had findings consistent with the diagnosis of acute encephalopathy and two had postinfectious focal encephalitis. RESULTS: The results from magnetic resonance imaging (MRI) or computed tomography were divided into five categories: normal (category 1); diffuse involvement of the cerebral cortex (category 2); diffuse brain edema (category 3); symmetrical involvement of the thalamus (category 4); and postinfectious focal encephalitis (category 5). Patients in categories 2-4 had symmetrical or diffuse brain lesions without leukocytosis in their cerebrospinal fluid, and there were no inflammatory reactions in the brains of two autopsied patients. Furthermore, serum concentrations of GOT were high in all, and disseminated intervascular coagulation was present in 4 of 5. CONCLUSIONS: These findings suggested that the pathogenesis of the brain lesions in these cases was toxic or metabolic damage due to multisystemic organ diseases induced by the influenza virus. The MRI findings in patients in category 2 suggested diffuse cortical cell necrosis. On the other hand, the thalamic lesions in category 4 patients reflected hyperpermeability of the blood vessels followed by severe edema with or without microhemorrhages. The pathogenesis of lesions of category 5 included allergic angitis of a self-limiting nature. These findings indicated that the pathogenesis of brain damage induced by influenza infection was very variable.
We report two cases with exanthem subitum in which hemioaresis developed during the acute infectious phase. Magnetic resonance imaging (MRI) demonstrated a cerebral ischemic infarct in the territory of the right lenticulostriate artery in one patient. Along the right temporal and parieto-occipital cortex of the other patient, there were high-signal-intensity lesions on T2-weighted images, which showed marked enhancement by gadolinium on T1-weighted images. These findings suggested that the brain lesions were caused by vasculopathy that accompanied human herpes virus-6 infection.
The present study elucidated the precise mechanism of 5-hydroxytryptamine (5-HT)-induced increase of intracellular Ca2+ concentration ([Ca2+]i) in cultured vascular smooth muscle cells isolated from rat aortic media. [Ca2+]i was measured using fluorescent Ca2+ indicator, fura-2. 5-HT caused a dose-dependent increase in [Ca2+]i, which was completely inhibited by ketanserin. alpha-Methyl-5-HT had an equipotent effect to 5-HT. Diltiazem at 10 microM partially suppressed the 5-HT-induced increase in [Ca2+]i. 5-HT also augmented Mn2+ influx, when monitored by Mn2+ quenching of fura-2 fluorescence. When extracellular Ca2+ (1.3 mM) was removed, a decrease in resting level and a small, transient increase in [Ca2+]i were observed. 5-HT stimulation also induced an increase in the production of inositol triphosphate. 5-HT-induced increase in [Ca2+]i was significantly, but partially inhibited by staurosporin and H-7. Phorbol 12-myristate 13-acetate induced an increase in [Ca2+]i, which was abolished by removal of extracellular Ca2+. 5-HT-induced increase in [Ca2+]i was not affected by the pretreatment with pertussis toxin (PTX), and was not accompanied by a change in cyclic AMP content. These results suggest that, in cultured rat aortic smooth muscle cells, 5-HT increases [Ca2+]i via 5-HT2 receptor subtype by inducing influx of extracellular Ca2+ partially through L-type voltage-dependent Ca2+ channel, as well as by mobilizing Ca2+ from its intracellular stores. Activation of protein kinase C may be positively involved in the regulatory mechanism of Ca2+ influx, but PTX-sensitive G protein and cyclic AMP seem to be not involved.
The findings on magnetic resonance imaging (MRI) or computed tomographic scan in 35 children with acute encephalopathy (AE) induced by infections were categorized into five groups: (1) normal findings (11 cases), (2) normal findings in the acute phase followed by mild brain atrophy (1 case), (3) severe brain edema which developed within 48 hours after the onset of AE (7 cases), (4) diffuse cortical necrosis which appeared around 4 days after the onset of AE (9 cases), and (5) symmetric thalamic lesions (7 cases). Their outcomes were as follows: three cases developed epilepsy in (1) and (2); six died and one had a sequel of severe brain damage (SBD) in (3); all cases survived but had SBD in (4), and four died, one had SBD, and 2 recovered in (5). Serum AST were elevated in 7.7 and 6 cases in (3), (4) and (5), respectively. In all of them, there were more than one case having liver histologies consistent with Reye syndrome.
The effects of DHA treatment on intracellular Ca2+ dynamics in aortic smooth muscle cells isolated from young stroke-prone spontaneously hypertensive rats (SHRSP) and age-matched normotensive Wistar Kyoto rats (WKY) were investigated. The resting intracellular Ca2+ concentration ([Ca2+]i) before stimulation and the peak [Ca2+]i induced by 5-HT, angiotensin II and depolarizing concentration of KC1 were higher in SHRSP than in WKY. When added to the culture medium for 2 days, DHA at a concentration of 30 microM significantly suppressed the peak [Ca2+]i induced by these stimulants in aortic smooth muscle cells isolated from WKY, whereas smooth muscle cells of SHRSP were refractory to the suppression. DHA had no suppressive effect on the 5-HT-induced increase in the inositol triphosphate production. The present study indicates that DHA can suppress receptor-mediated Ca2+ influx, at least, through the voltage-dependent channel, in vascular smooth muscle cells. Since the intracellular Ca2+ plays an important role in regulating vascular tone, the suppressive effect of DHA on [Ca2+]i in vascular smooth muscle cells may be contributed to the beneficial properties of DHA on cardiovascular disorders. The precise mechanisms of action remain to be elucidated.
Motor cortical excitability was studied using transcranial magnetic stimulation (TMS) in 10 age-matched controls, and 13 children with benign childhood epilepsy with centro-temporal spikes (BECT), with a mean age of 11.2 +/- 2.0 years (five untreated, and eight treated with sodium valproate (VPA) and well controlled). Motor evoked potentials (MEPs) elicited by TMS through a circular coil were recorded from the first dorsal interosseous muscle (FDI) while relaxed. There was no significant difference in latency or duration of MEPs, or central motor conduction time among controls, untreated and treated patients. The threshold intensity for TMS in the untreated patients (63.0 +/- 14.8%, mean +/- SD) was similar to that in controls (63.0 +/- 12.5%), while the threshold intensity in the treated patients (79.4 +/- 11.8%) was significantly higher than that in the other groups. A significant increase in threshold intensity (15 +/- 4.1%) was also observed in the untreated patients retested after starting VPA treatment. No adverse effects occurred during TMS in any subjects. Thus, motor cortical hyperexcitability in BECT was not recognized in the present TMS study, while VPA was confirmed to have an effect on the threshold intensity for TMS.
We report two children with acute confusional migraine (ACM) and another with migrainous infarction (MI), aged 7-12 years. There was a family history of migraine in all patients. The patients, who were all right-handed, all manifested sudden onset of consciousness disturbance and other neurological deficits as the first aura in their life. The symptoms in all cases almost completely resolved spontaneously within 24 h, but transient occipital slowing on EEG with laterality corresponding to the side of migrainous origin lasted more than 24 h. In the cases of ACM in the critical phase, although MRI and MR angiography showed no abnormal findings, IMP-SPECT performed within 48 h of migraine attacks revealed a regional change in cerebral blood flow, which is one particular case demonstrated hypoperfusion in the left posterior cerebral artery (PCA) territory. Therefore, although ACM was diagnosed clinically by exclusion, SPECT was thought helpful for the diagnosis of ACM. We speculated that transient hypoperfusion affecting the dominant-sided PCA territory involving the medial temporal structures was responsible for the confusion with amnesia in ACM, in contrast to the lack of confusion or amnesia in the case of MI showing cystic encephalomalacia in the right thalamic and hippocampal regions.