Motoyuki Minamitani

Neuronal intranuclear hyaline inclusion disease with polyglutamine-immunoreactive inclusions

Abstract Neuronal intranuclear hyaline inclusion disease (NIHID) is a group of neurodegenerative disorders characterized by the presence of intranuclear inclusions in neurons (NIs). We report here clinicopathological findings of a 25-year-old female patient who died after 13 years of a clinical course characterized by progressive gait disturbance and movement disorders. Histological examination revealed widespread NIs with neuronal loss in restricted regions; neuronal loss was severe in the subthalamic nucleus, internal pallidum, substantia nigra, Edinger-Westphal nucleus and Purkinje cell layer. Quantification of the NIs combined with a graded evaluation of neuronal loss revealed an overall tendency for more severe neuronal loss to be accompanied by a lower frequency of NIs. A morphological similarity to the nuclear inclusions recently identified in several CAG repeat diseases prompted us to examine the immunolocalization of ubiquitin and expanded polyglutamine stretches, which demonstrated the presence of ubiquitin at the periphery of most NIs. An expanded polyglutamine stretch was seen in the center of limited number of NIs. These findings indicate that abnormal fragments such as expanded polyglutamine regions are incorporated into the inclusion, aggregated in its center, and thereby metabolized by a ubiquitin-dependent proteolytic pathway. Although it remains to be elucidated how the formation of NIs is related to neuronal degeneration, our findings suggest that NIs are formed in the process of sequestering or degrading abnormal protein fragments and formation of NIs may not be immediately toxic to neurons.

Intravenous lidocaine for status epilepticus during childhood

The clinical efficacy of lidocaine for convulsive status epilepticus in 53 convulsive episodes was examined in 37 children (17 males, 20 females). Mean age of patients receiving lidocaine was 3 years 7 months (SD 3y 5mo). Lidocaine administration achieved control of status epilepticus in 19 of 53 convulsive episodes (35.8%). Seizures ceased within 5 minutes of lidocaine administration in all 19 patients who were responsive to the drug. Regarding aetiology of status epilepticus and types of seizures, there was no statistical difference in effectiveness. Mild decrease of oxygen saturation, monitored by pulse oximetry, was observed in one patient, which improved by oxygenation using a mask. Lidocaine is a useful anticonvulsive agent; however, the response rate to lidocaine appears to be quite low, as less than half of the seizures were effectively controlled by lidocaine. Favourable properties of the drug include prompt responses, less alteration of consciousness, and fewer adverse effects, including less respiratory depression.

Immunohistochemistry of neuronal inclusions in the cerebral cortex and brain‐stem in Lewy body disease

Three cases of Lewy body disease were investigated in order to compare the morphological and immunohistochemical characteristics of the neuronal inclusions in the cerebral cortex (CC) and brain‐stem (BS). Ultrastructurally, the CC contained intermediate‐sized filaments with variable amounts of granular material and other organelles, whereas the BS consisted of an electron‐dense core and an outer area with radially oriented filaments. The cerebral cortex was immuno‐reactive with antibodies against tyrosine hydroxylase (TH) and tau protein, and differed from BS. In addition, although the CC were antigenically similar to BS in their neurofilament (70, 160 and 200 kDa) and ubiquitin contents, the localization of neurofilament immunoreactivity differed between them, being confined positively to the core of CC, but to the periphery of the BS. Although Lewy bodies (LB) in idiopathic Parkinsons disease are morphologically similar to BS, they have been reported to differ in their immunoreactivity with antibodies against tau. It has been reported that CC differ from LB with regard to immunoreactivity with antibodies against TH and tropomyosin. It is inferred that these inclusions (CC, BS and LB) differ in morphogenesis.

Regional cerebral blood flow and developmental outcome in cryptogenic west syndrome

Summary:  Purpose: To elucidate the relation between alterations of regional cerebral blood flow (rCBF) by adrenocorticotropic hormone (ACTH) therapy and developmental outcomes of cryptogenic West syndrome.

Peculiar eosinophilic inclusions within astrocytes in a patient with malformed brain

At autopsy, we observed eosinophilic inclusions within the astrocytic cytoplasm in areas of polymicrogyria and heterotopic gray matter in a 17-year-old female with severe mental retardation and physical handicaps who had died of respiratory failure. The inclusions stained with acid fuchsin, azocarmine, Holzers stain and phosphotungstic acid hematoxylin (PTAH). They reacted with anti-S-100 protein antibody. The cytoplasm of the astrocytes containing the inclusions reacted with antibody to GFAP. The inclusions were amorphous masses that consisted of aggregated clusters of osmiophilic coarse granules about 30 nm in diameter. Some rough endoplasmic reticulum was observed on the inside and outside of the inclusions and in the cytoplasm of the astrocytes lacking such inclusions. We suggest that these inclusions resulted from an abnormality at or near the rough endoplasmic reticulum.

Effectiveness and safety of non-intravenous high-dose phenobarbital therapy for intractable epilepsy during childhood

High-dose phenobarbital (PB) therapy is effective for refractory status epilepticus. We reviewed medical records of patients with intractable partial epilepsies on whom performed non-intravenous high-dose PB therapy. Thirteen patients received PB rectally or orally at a dosage of 20-30mg/kg/day initially, and the PB dosage was gradually reduced to a maintenance dosage of 5-10mg/kg/day orally. We evaluated the effectiveness and safety of this procedure after 14days at the maintenance dosage level. Twelve patients had partial seizures and one had secondary generalized seizures. In six of 13 patients (46%), seizure frequencies decreased more than 50%, and two of 13 patients (15%) became seizure free. In five of seven patients who were treated by continuous midazolam infusion therapy, we were able to discontinue the midazolam therapy. Adverse effects were found in seven of 13 patients. We were able to continue high-dose PB therapy in six patients because their adverse effects were transient and improved after a decrease in PB concentration, but we discontinued this therapy in the patient who developed Stevens-Johnson syndrome. Respiratory depression and hypotension were not found in our study. We conclude that high-dose PB therapy is effective and may be considered as an additional treatment for intractable partial epilepsy in childhood.

Bax-induced apoptosis not demonstrated in the congenital toxoplasmosis in mice

A prominent neuropathological change observed in a murine model of congenital toxoplasmosis is cerebral cortical hypoplasia. In the early embryonic life of toxoplasmosis mice, the number of apoptotic cell observed in cerebral cortex is increased, indicating that increased number of apoptotic cells might relate to the pathogenetic mechanism of the cortical hypoplasia. Immunohistochemical expression of apoptosis-related factors, Bcl-2 and Bax has been studied in fetal murine brains infected with toxoplasma and in controls. Paraffin sections of the fetal brains on embryonic day (ED) 10, 12, 14, 16 and 18 were applied for the immunostains of Bcl-2 and Bax. Totally, 47 experimental animals (ED10: n=8, ED12: n=6, ED14: n=12, ED16: n=6, ED18: n=15) and 48 control animals (ED10: n=6, ED12: n=8, ED14: n=9, ED16: n=9, ED18: n=16) were examined. Bcl-2 positive cells were detected on ED10, whereas Bax positive cells appeared on ED14. No difference of Bcl-2 and Bax expression between toxoplasmosis and control groups was detected, suggesting that there is no clear relation between Bax-induced apoptosis and cortical dysplasia in congenital toxoplasmosis.

Pathomechanism of cerebral hypoplasia in experimental toxoplasmosis in murine fetuses

In order to elucidate the pathological mechanism of cerebral hypoplasia in congenital toxoplasmosis, fetal toxoplasmosis was induced by intraperitoneal injection of Toxoplasma gondii into five pregnant mice on embryonal Day 5 (E5). The maternal and fetal brains were examined histologically and immunohistochemically; six fetuses were examined on E16 and 21 on E18. T. gondii organisms were immunohistochemically detected in the maternal brains, placentas and the ventricular zone of the fetal cerebrum. In none of the fetal brains was any gross deformity observed, except for cerebral hypoplasia. On E16 and E18, the cerebral cortices were seen to consist of immature laminations, and the cells had less cytoplasm and rounder hyperchromatic nuclei than those in the control mice. The cerebral walls and the cortical layers, except in the ventricular zone, were thinner than in the controls (P < 0.01 in each case). On E18, the proliferating cell nuclear antigen immunolabeling index was higher, and the cytoplasm of more cells in the cortical plate was immunoreactive with anti-beta-tubulin antibody compared with control mice. Using an in situ end-labeling technique, apoptotic cells were not observed in the cortices in mice of both groups. It is suggested that the cerebral hypoplasia following Toxoplasma infection is related to delayed maturation.

Iomazenil hyperfixation in single photon emission computed tomography study of malformations of cortical development during infancy.

We present 2 cases of malformations of cortical development and early onset epilepsy. The first case is of a patient with left hemimegalencephaly who developed focal epilepsy at the age of 2 days and cluster spasms at 1.5 months. After left functional hemispherectomy, seizures originated from the contralateral hemisphere, which had shown normal signals in the preoperative magnetic resonance imaging study. The second case is of a patient with lissencephaly, caused by a missense mutation in the doublecortin gene, who developed West syndrome at the age of 5 months. In both the cases, (123)I-iomazenil single photon emission computed tomography performed during infancy showed significant hyperfixation in the dysplastic lesions. This finding indicates the immaturity of the affected neurons and a gamma-aminobutyric acidergic involvement in epileptogenesis associated with malformations of cortical development during infancy.

Interictal cerebral blood flow abnormality in cryptogenic West syndrome

Purpose:  To elucidate the abnormality of interictal regional cerebral blood flow (rCBF) of West syndrome at the onset.