Transient extreme spindles in a case of subacute Mycoplasma pneumoniae encephalitis.

We describe a 4-year-old boy with delirium including somnolence, irritability, agitation and visual hallucination, associated with Mycoplasma pneumoniae (MP) encephalitis. The MP encephalitis was diagnosed from increased MP-antibody (> 1:1280). Electroencephalography during sleep revealed continuous 9 Hz fast wave activity over the bilateral frontocentral regions, which was thought to represent extreme spindles. These extreme spindles were in parallel with the degree of delirium. Transient extreme spindles have not previously been reported in MP or other encephalitis.

Morphological study of the brainstem in Fukuyama type congenital muscular dystrophy.

We have observed sudden clinical death due to Fukuyama-type congenital muscular dystrophy (FCMD). In FCMD, brain abnormalities, such as polymicrogyria, leptomeningeal neuroglial heterotopia and abnormal course of the corticospinal tracts, are well known. We investigated the brainstem of 10 FCMD and 7 control cases. Among the control cases, 5 with Duchenne type muscular dystrophy died of heart failure and 2 died accidental death. In the brainstem, the catecholaminergic neurons characterized by reaction with antiserum to tyrosin hydroxylase showed notable reduction in the reticular formation, vagal nuclei, and nucleus tractus solitarius. Delays or aberrations of neural control may contribute to the pathogenesis of sudden infant death syndrome, and medullary gliosis occurs in the reticular formation of sudden infant death syndrome. The pathogenesis of neurons in the brainstem in FCMD may be similar to that in sudden infant death syndrome. These findings suggest neuronal dysfunction in the brainstem and may be related to respiratory, circulatory, or sleep-wake regulation disorders.

[Short somatosensory evoked potentials in patients with Fukuyama type congenital muscular dystrophy--a comparison with CT and MRI findings].

Seven patients with Fukuyama type congenital muscular dystrophy were studied. Low density areas (LDs) in the cerebral white matter on cranial CT were present in all 4 patients younger than 13 years of age and in 1 of 3 adult patients. LDs corresponded to low signals on T1 weighted MRI image and high signals on T2 weighted MRI image. The follow-up MRI showed a decreased tendency of the abnormal signals in 2 patients. Short somatosensory evoked potentials (SSEPs) in two infants, aged 4 months and 8 months, showed absent or depressed N1 amplitudes and delayed interpeak latencies from P3 to N1. N1 amplitudes increased on follow-up studies. SSEPs of five patients, who were older than 2 years of age, showed normal N1-P3 latencies. Amplitude of N1 was low in 2 patients with LD. Since the absent or depressed amplitude and delayed latency of N1 improved with the decrease of abnormal signals on MRI, we considered that N1 abnormalities show delayed myelination.

Cerebellar leptomeningeal astroglial heterotopia in neurofibromatosis type 1.

Leptomeningeal astroglial heterotopia (LAH) was found in the cerebellum of 2 patients with neurofibromatosis type 1 (NF 1). This LAH was clearly and widely demonstrated with glial fibrillary acidic protein (GFAP) immunohistochemistry and was connected with parenchymal astroglial fibers. These findings suggest that NF 1 involves the dysplasia or overgrowth of astrocytes in the cerebellar leptomeninges.

Immunohistochemical expression of peroxisomal enzymes in developing human brain.

The immunohistochemistry of peroxisomes was examined in human brains from fetal to adult ages using antibodies against catalase (CAT), acyl-CoA oxidase (AOX), and 3-ketoacyl-CoA thiolase (PT) on conventional formalin-fixed paraffin-embedded sections. Positive staining neurons first appeared in the basal ganglia, thalamus, and cerebellum at 27-28 wk of gestation, and in the frontal cortex at 35-36 wk of gestation. They increased in number with gestational age and the intensity of immunostaining increased with enlargement of perikaryonal size. Positively staining glial cells first appeared in the deep white matter at 31-32 wk of gestation, their appearance showing a shift from the deep to the superficial white matter with increasing age. This developmental change in the peroxisomal immunoreactivities in glial cells corresponds with that in myelination glia. Therefore, the results suggest that peroxisomes are closely related to neuronal growth and myelinogenesis in the developing human brain. Also, our results as to myelinogenesis may explain one pathogenetic factor of dysmyelination in peroxisomal disorders.

Peroxisomal disorders in children: immunohistochemistry and neuropathology.

Immunohistochemical studies with antisera against four peroxisomal enzymes, catalase and beta-oxidation enzymes (acyl-coenzyme A oxidase, bifunctional protein, and 3-ketoacyl-CoA thiolase), were performed on brain, liver, and kidney specimens from patients with peroxisomal disorders, as well as specimens from three control subjects, by using conventional paraffin-embedded autopsy material. The patients included eight with Zellweger syndrome and one with neonatal adrenoleukodystrophy. In the liver and kidney specimens from all patients, except one with Zellweger syndrome, diffuse immunostaining with all antisera in the cytoplasm of hepatocytes and renal tubular epithelium suggested an absence of peroxisomes but the presence of peroxisomal enzymes. Examination of brain specimens indicated a weak or negative reaction of neurons in the cerebral cortex and a weak reaction of glial cells in the white matter, which suggested maturational delay compared with control subjects. The delayed immunoreactive pattern of peroxisomal enzymes in Zellweger syndrome and neonatal adrenoleukodystrophy may be related to the significant neuropathologic features of polymicrogyria and dysmyelinogenesis. One patient with Zellweger syndrome had a unique finding of a positive granular catalase reaction and a negative reaction with antisera to 3-ketoacyl-coenzyme A thiolase, which suggested a diagnosis of pseudo-Zellweger syndrome. This study validates the application of these immunohistochemical methods to the study of peroxisomal enzymes. Use of these methods improves the accuracy of diagnosis of peroxisomal disorders.

Clinicopathologic studies on leptomeningeal glioneuronal heterotopia in congenital anomalies.

Leptomeningeal glioneuronal heterotopia was observed in 40 of 129 autopsied infants (31%). It was present in 49% of patients who had congenital anomalies in general and in 65% of patients who had central nervous system malformations. Most of the leptomeningeal glioneuronal heterotopias appeared in the base of the brain (62.5%), midbrain (40%), frontal lobe (37%), and pons (35%). Leptomeningeal glioneuronal heterotopia is closely related to migration disorders on the basis of frequent association with polymicrogyria or neuronal heterotopias.

Developmental change in type VI collagen in human cerebral vessels.

Vascular development in the human brain was studied by immunohistochemistry using an anti-type VI collagen antibody. Positive vessels were evident from an early gestational age in the meninges, from 21 weeks gestation in the basal ganglia and deep white matter, and from 38 weeks gestation in the cerebral cortex and superficial white matter; however, type VI collagen never appeared in the subependymal germinal layer. The absent or scarce type VI collagen in the subependymal germinal layer may be one of the important factors of subependymal/intraventricular/periventricular hemorrhage in premature neonates. The earlier appearance of positive vessels in the deep white matter than in the cortex and superficial white matter suggests that the medullary vein develops earlier than the cortical and subcortical veins and arteries. These characteristics of the developing vascular structure may be one cause of perinatal brain damage.

[Neuropathology of peroxisomal disorders; Zellweger syndrome and neonatal adrenoleukodystrophy].

Neuropathology of peroxisomal disorders showed polymicrogyria in the cerebral and cerebellar cortices, neuronal heterotopia in the cerebral white matter, dysplasia of the inferior olivary nucleus and subependymal cyst in 6 cases of Zellweger syndrome (ZS), and diffuse loss of myelin sheath and mild polymicrogyria in a case of neonatal adrenoleukodystrophy. Developmental immunohistochemistry of catalase, acyl-CoA oxidase and ketoacyl-CoA thiolase revealed that positive reaction appears with neuronal and glial maturation. Diffuse dysmyelination may be related to maldevelopment of oligodendroglia, and migration disorder to abnormality of endothelial cells or radial glia, because both cells were positively stained in fetuses of 20 weeks of gestation and endothelial cells were rarely stained in ZS.

Monitoring of immature rabbit brain during hypoxia with near-infrared spectroscopy.

Continuous monitoring of the cerebral blood flow, oxyhemoglobin, deoxyhemoglobin, total hemoglobin, oxidized cytochrome a, a3, and tissue pH during prolonged CO2 or N2 loading in 2-week-old rabbits was performed by near-infrared spectroscopy, the thermocouple method, and a tissue pH meter. Near-infrared spectroscopy demonstrated decreases in oxyhemoglobin and oxidized cytochrome a, a3 and increases in deoxyhemoglobin and total hemoglobin in the early stage within 5 min, which gradually lessened with time on both 10% concentration of inspired O2 with CO2 and N2. CBF increased with venous retention in the early stage and then slowly decreased in parallel with blood pressure and oxidized cytochrome a, a3 on abolition of autoregulation. These changes were more remarkable during the 10% concentration of inspired O2 with CO2 than N2 which may be caused by marked acidosis and hypotension associated with hypercarbia. Oxidized cytochrome a, a3, however, demonstrated a gradual decrease in 10% concentration of inspired O2 with N2 rather than CO2; therefore, the continuous monitorings demonstrated hemodynamic and oxygenation changes despite the same extent of prolonged hypoxic loading. These changes in prolonged hypoxic conditions may occur in human intrapartum asphyxia which develops into postnatal hypoxic-ischemic encephalopathy.

Development of myelination in the human fetal and infant cerebrum: a myelin basic protein immunohistochemical study.

The early development of myelination was studied by means of myelin basic protein (MBP) and luxol fast blue (LFB) stainings of large sections of the cerebral hemispheres. Myelination first occurs in the globus pallidus, pallidothalamic fibers of the posterior internal capsule and the thalamus at 25 weeks, which may be related to the cellular maturation in the globus pallidus and thalamus. Then myelination is observed in the striatum, and precentral and postcentral gyri at 35 weeks, and the anterior internal capsule and optic radiation at 37 weeks. Immunoreactivity with MBP is observed earlier and more strongly in the early myelination period than that with LFB. Thus, MBP may play an important role in myelination and its delay. The macroscopic positivity as to MBP as well as LFB staining may be related to the development of high signal intensity observed in a T1-weighted magnetic resonance imaging, which was observed 1 to 3 months after the first microscopic appearance of myelin.

Continuous comparison of cerebral blood flow velocity and volume on hypoxia.

Cerebral blood flow velocity (CBFV) in the basilar artery, monitored by Doppler sonography, and cerebral blood flow (CBF) in the parietal cortex, monitored by Laser Doppler flowmetry, were continuously recorded and compared during and after hypoxic loading with nitrogen (N2) or carbon dioxide (CO2). On severe hypoxic loading (10% O2) of N2, CBFV and CBF increased with an increase in blood pressure (BP). On the other hand, with 18% and 15% O2 with CO2, CBFV and CBF increased with BP. However, there was a difference between CBF and CBFV in the recovery stage. CBF continued to be elevated for a long time, while CBFV rapidly normalized after loading. With 10% O2 with CO2, CBFV, CBF and BP decreased at first, and then increased during loading. Also, the difference between CBF and CBFV in the recovery stage being more definite. Thus, on continuous measurement, CBFV shows similar changes to CBF in response to hypoxia. However, CBFV shows different changes from CBF in association with dilatation or constriction of cerebral vessels. Resistance index (RI) shows different changes and have a different significance from CBF and CBFV.

Developmental immunohistochemistry of catalase in the human brain.

The immunohistochemical studies on a peroxisomal enzyme, catalase, were done on brains from human fetuses to adults. The catalase-positive neurons appeared in the basal ganglia, thalamus and cerebellum at 27-28 weeks of gestation, and in the frontal cortex at 35 weeks. They then increased in number with gestational age. The extent of immunopositive staining increased with enlargement of perikaryonal size. However, the extent gradually decreased with postnatal age. On the other hand, catalase-positive glia appeared in the deep white matter at 31-32 weeks of gestation, their appearance shifting from the deep to the superficial white matter with increasing age. These results suggest that peroxisomes are closely related to neuronal growth and myelinogenesis in the human brain during development.

Scanning electron microscopic observations on muscle cells of experimental mitochondrial myopathy produced by 2, 4-dinitrophenol.

The morphological changes of the skeletal muscle cells of the rat experimental myopathy induced by 2, 4-dinitrophenol were examined by scanning electron microscopy in comparison with the ultrastructure of normal muscle cells. Specimens were prepared by the Aldehyde-Osmium-DMSO-Osmium method which permits the three-dimensional demonstration of intracellular structures under SEM. In the specimen prepared by the method, myofibrils having been completely dissolved, intracellular membranous structures such as the sarcoplasmic reticulum, T-tubules and mitochondria were clearly demonstrated in three dimensions. In the experimental mitochondrial myopathy, large accumulations of mitochondria were observed at the subsarcolemmal region. Mitochondria in the perinuclear and intermyofibrillar region showed swelling and occasionally accompanied abnormal concentric cristae. The sarcoplasmic reticulum which showed regular network in normal muscle cells entirely disappeared in the mitochondrial myopathy. Although the mitochondrial changes obtained in this study were almost identical to those previously reported by transmission electron microscopy, the changes in the sarcoplasmic reticulum have not been described in previous works.

Cortical cytoarchitectural and immunohistochemical studies on Zellweger syndrome.

In two cases of Zellweger syndrome, Golgi studies revealed an irregular neuronal arrangement, the presence of immature neurons, poor dendritic arborization and poor spine development, all of which suggest abnormal morphogenesis and delayed maturation. In immunohistochemical studies with antisera against human catalase, negative staining of neurons suggested a decrease of catalase due to defects of microperoxisomes, and positive staining of myelination glia only in the internal capsule may have been related to delayed myelination. Abnormal peroxisomal membrane or its related metabolites may cause a migration disorder in intrauterine development and myelination disturbance in perinatal maturation.

[Hypoxic-ischemic brain damage: detection of early stage].

The type of hypoxic-ischemic brain damage is determined by the distribution of lesions, which has different mechanism in each. Neuroimaging is important for detection of the lesions, but morphological changes appear 12 hours after hypoxic episodes even in neuropathology. Hemodynamic, biochemical and neurophysiological changes during the acute stage are also valuable for earlier diagnosis of the lesions. Doppler sonography and near-infrared spectroscopy, reflected intracranial hemodynamics and metabolism. In our clinicopathological studies, the infants with pontosubicular necrosis showed significantly high incidence in severe hypocarbia, which may be associated with hypoperfusion. Thus, the monitoring of brain hemodynamics and metabolism may be important for early treatment as well as prevention of the brain damage.

Immunohistochemical study of the vasculature in the developing brain.

In this study, the developmental proliferation of human brain vessels, from the fetal to the adult stage, was analyzed by immunohistochemical methods using antitype IV collagen, antilaminin, and antifibronectin antibodies. Examination of the frontal lobe indicates that these antibodies bind to the vessels, both arteries and veins. During cortical angiogenesis, the density and diameter of vessels increase rapidly from about 26 weeks gestation and peak at 35 weeks; after 35 weeks, the density and diameter of vessels are the same as those in adult brain. The white matter demonstrates no major changes in vessel density, although the pattern of the changes in vessel diameter resembles that of the cortex. Small immunopositive spots suggesting neovascularization reveal the same developmental tendency as the density of vessels in the cortex and white matter; therefore, it appears that neovascularization in the fetal brain during development is more rapid than cortical expansion and is equal to the growth of white matter. Neovascularization may be closely related to normal brain development and may play an undefined role in perinatal cerebrovascular insults.

Structure in lissencephaly determined by immunohistochemical staining.

The brains of patients with lissencephaly were examined by peroxidase-antiperoxidase immunohistochemical staining of synaptophysin, myelin basic protein, and glial fibrillary acidic protein. In contrast to the normal cortical pattern, the cortex, with a smooth surface, demonstrated quite different staining patterns in the molecular, superficial cellular, sparsely cellular, and deep cellular layers. The molecular layer was abnormally positive with synaptophysin staining. The superficial cellular layer was also diffusely stained for synaptophysin; there was a positive reaction in the linearly arranged myelin sheaths. The sparsely cellular layer revealed less staining for synaptophysin, but was perivascularly positive for glial fibrillary acidic protein. In the deep cellular layer, synaptophysin staining had multiple neuronal columns and myelin basic protein-staining had a reticular pattern around neuronal columns. These results suggest that the sparsely cellular layer may correspond to the molecular layer and white matter in normal brain; neurons with forming myelin sheaths in the superficial cellular layer regularly penetrate the surface of the molecular layer, forming arrested cortical columns in the deep cellular layer.