Late-onset neuropsychological symptoms in a Japanese patient with megalencephalic leukoencephalopathy with subcortical cysts.

We herein report a Japanese patient with megalencephalic leukoencephalopathy with subcortical cysts (MLC) who developed late-onset neuropsychological symptoms. He demonstrated characteristic clinical features of MLC during childhood, such as slowly progressive megalencepaly, motor impairment with ataxia and spasticity, mild mental retardation, and well-controlled epilepsy. Thereafter, he showed specific neuropsychological symptoms, such as motor and vocal tics, compulsive behavior, perseveration, acquired stuttering, and dystonia since the age of 12. His performance abilities had been unchanged but his verbal abilities had degraded during the past 14 years. Higher cortical dysfunction tests revealed a frontal lobe dysfunction. On repeated brain MRI, a leukoencephalopathy with subcortical cysts remained stationary from infancy. On single photon emission computed tomography (SPECT), a hypoperfusion in the frontal lobe was detected at the age of 3.5 and 17, but the severity of hypoperfusion was also unchanged, respectively. Our results indicate that the frontal lobe dysfunction may be relevant to the late-onset neuropsychological symptoms with MLC.

A functional magnetic resonance imaging study during sentence reading in Japanese dyslexic children.

A functional magnetic resonance imaging (fMRI) study during Japanese 'kana' readings was performed on Japanese dyslexic children. Five dyslexic children (aged 9-12 years) and five healthy children (aged 9-11 years) were investigated. The fMRI examination was performed by getting these children to read sentences constructed from Japanese phonograms, 'kana', compared with staring at meaningless figures as a control task. All control subjects showed activation of the left middle temporal gyrus. In the dyslexic children, the activation of the middle temporal gyrus was rather vague. However, other distinctively activated regions were detected as follows: the bilateral occipital cortex in two dyslexics, the inferior part of the frontal regions in two other dyslexics, and both the bilateral occipital cortex and the inferior part of precentral gyrus in the remaining one. These results indicate compensatory management processes for the unskilled reading ability of dyslexic children. The present results were similar to previous ones for adult dyslexia with the Roman alphabet, and suggest that brain malfunction in dyslexia during the task of reading must be common despite differences in languages.

Cognitive and neurophysiological evaluation of Japanese dyslexia.

Seven Japanese dyslexic boys were evaluated as to their pedagogic performance on the pupil rating scale (PRS), and psychological and neurophysiological characteristics. One of them suffered from severe English dyslexia despite that his Japanese dyslexia was feeble. PRS did not successfully reveal their reading difficulties. Psychological examination (WISC-R and K-ABC) revealed their cognitive dysfunction, but the results were heterogeneous. The Token test was most useful for detecting their poor reading comprehension. Electroencephalogram (EEG) coherence analysis showed high inter- and intra-hemispheric values. These findings may imply hyperconnectivity of the cerebral white matter in dyslexia. We assumed that the Token test demonstrates the discrepancy between reading and hearing comprehension best of all among these psychological tests and that connectivity between non-functional cortical lesions remains in dyslexic children.

[Distribution in normal subjects of performance in Token test: a basic study for the diagnosis of learning disabilities].

For the diagnosis of specific reading disorder (SRD) we studied the distribution in 187 elementary school children of the scores of Token test. Token test was performed under two conditions: listening and reading by presenting the same sentences. The diagnosis required a normal score under the listening condition, an abnormally low score under the reading condition and significantly large discrepancy between them. This test is valid and convenient for the diagnosis of SRD.

Effects of prestimulus respiratory levels on inhibitory respiratory response by nociceptive muscular afferents.

We have previously shown that the inhibitory respiratory response, which we call post-stimulus suppression, is induced by nociceptive muscular afferents. This phenomenon is thought to be caused by a negative feedback induced by excessive afferent inputs. In the present study, we investigated whether augmented levels of prestimulus respiration would influence the magnitude of poststimulus suppression by recording the phrenic nerve discharges in chloralose-urethane anesthetized, vagotomized, paralyzed and artificially ventilated cats. The respiratory level was augmented by means of either hypercapnia, hypoxia or naloxone administration, all of which markedly facilitated the peak amplitude (PK) of integrated phrenic discharges, neural tidal volume. When the electrical stimulation of thin-fiber muscular afferents was performed at these augmented PK levels, the magnitude of poststimulus suppression in the PK was markedly attenuated without consistently altering the facilitatory response during the stimulation period. It seems that the facilitatory component of the augmented level of resting respiration may reduce the inhibitory component of poststimulus suppression. The results indicate that prestimulus respiratory activity is an important factor in determining the magnitude of poststimulus suppression.

Experimental actinomycosis caused by Actinomyces-like bacteria in mice and a sow.

The present experiment was performed to test the pathogenicity of Actinomyces-like bacteria in experimental animals and swine. Two rough (R) strains of Actinomyces-like bacteria isolated from a site of arthritis and from the tonsil in pigs were used as inocula. To investigate their susceptibility to Actinomyces-like bacteria, BALB/c, SS and ddY mice and guinea-pigs were inoculated intraperitoneally with the strains of Actinomyces-like bacteria. The ddY mice were used for the long-term observation of Actinomyces-like bacteria lesions and the mammary tissue of a sow was inoculated with Actinomyces-like bacteria isolated from swine tonsil. Macroscopic observation revealed many abscesses on the surfaces of the abdominal and/or thoracic organs in the mice, but not on those of the guinea-pigs. The sow developed firm nodules at the inoculation site in the mammary glands. Histopathologically, the lesions in the mice were characterized as actinomycotic abscesses in the early stage and as pus-forming granuloma (PFG) in the advanced stage; the lesions were accompanied by crystalloid particles. Actinomyces-like bacteria induced granulomatous mastitis in the sow, and the lesion was characterized as PFG. The characteristic actinomycotic lesions in swine mammary glands were reproduced by experimental infection.

A patient with cerebral palsy whose mother had a traffic accident during pregnancy: a diffuse axonal injury?

A 16-year-old girl had spastic cerebral palsy (CP) with triplegia and focal epilepsy. The patient's past history included her mother's lower abdominal trauma caused by a traffic accident at the 7th month of gestation. Brain examination with magnetic resonance imaging (MRI) revealed encephalomalacia at the bilateral parieto-temporal lobes and the left caudate nucleus, segmental narrowing of the splenium of the corpus callosum, dilatation of the left lateral ventricle and an abnormally high intensity at the right posterior portion of the internal capsule. These findings might indicate a diffuse axonal injury (DAI), but not an asphyxic brain damage. In this patient, CP might be caused by an intrauterine DAI when her mother was involved in the accident.

[What has medical science resolved learning disabilities (LD) into?: introductory remarks].

What can medicine contribute to learning disabled (LD) children? In this symposium, most distinguished speakers in Japan discuss the following issues: the incidence of LD in children with preterm birth, biochemical aspect in LD children neurophysiological examinations for LD and speech therapy for specific reading disorders. Brain dysfunctions in LD children should be clarified to facilitate remedial interventions. It is expected that medical insurance supports LD children and their family.

[Learning disabilities; toward adequate treatment and education].

The medical staff can serve learning disabled (LD) children by ruling out progressive and regressive diseases, and by treating concurrent disorders, such as attention deficit hyperactivity disorders (ADHD). Teachers and even some medical members in Japan have confused ADHD with LD. Although looking similar, these two disorders are completely different. We should further clarify the brain dysfunction in LD children, thereby contributing to remedial education.

Central motor reorganization in cerebral palsy patients with bilateral cerebral lesions.

Transcranial magnetic stimulation (TMS) has been used to describe cortical plasticity after unilateral cerebral lesions. The objective of this study was to find out whether cortical plasticity occurs after bilateral cerebral lesions. We investigated central motor reorganization for the arm and leg muscles in cerebral palsy (CP) patients with bilateral cerebral lesions using TMS. Seventeen patients (12 with spastic diplegia, 1 with spastic hemiplegia, and 4 with athetoid CP) and 10 normal subjects, were studied. On CT/MRI, bilateral periventricular leukomalacia was observed in all spastic patients with preterm birth. In two normal subjects, motor responses were induced in the ipsilateral tibialis anterior, but no responses were induced in any normal subject in the ipsilateral abductor pollicis brevis (APB) or biceps brachii (BB). Ipsilateral responses were more common among CP patients, especially in TMS of the less damaged hemisphere in patients with marked asymmetries in brain damage: in 3 abductor pollicis brevis, in 6 BBs, and in 15 tibialis anteriors. The cortical mapping of the sites of highest excitability demonstrated that the abductor pollicis brevis and BB sites in CP patients were nearly identical to those of the normal subjects. In patients with spastic CP born prematurely, a significant lateral shift was found for the excitability sites for the tibialis anterior. No similar lateral shift was observed in the other CP patients. These findings suggest that ipsilateral motor pathways are reinforced in both spastic and athetoid CP patients, and that a lateral shift of the motor cortical area for the leg muscle may occur in spastic CP patients with preterm birth.

Screening of urine by one-dimensional and pulsed-field gradient two-dimensional 1H NMR spectroscopy: intoxication by propylene glycol in an infant patient.

1H NMR spectroscopy is a promising method for the analysis of physiological fluids in clinical medicine. In the course of screening the urine of patients by 1D- and pulsed-field gradient 2D 1H NMR spectroscopy at 500 MHz, we encountered a case with a very high excretion of propylene glycol compared to others who received similar doses of the medication. In this case, the propylene glycol was scarcely metabolized by the patient. Propylene glycol is widely used as a safety material which is transformed into pyruvate and lactate in the healthy body. In this paper, we discuss how NMR spectroscopy can be a useful method for screening a patient intoxicated with propylene glycol.

Low interhemispheric and high intrahemispheric EEG coherence in migraine.

Twenty women with migraine were evaluated by EEG coherence analysis. In comparison with controls, the migrainous subjects showed lower interhemispheric coherence values at C3-C4 for the delta band (P=0.0030) and at F3-F4 (P=0.0055) and C3-C4 (P=0.0018) for the beta band frequency (Wilcoxon criterion). In contrast, 22 intrahemispheric coherence pairs were significantly higher in the migraine group than in the control group (P<0.01). The subjects with visual aura showed lower interhemispheric coherence at O1-O2 and T5-T6 for the alpha band than the subjects without the aura. Discriminant analysis revealed that 95% of the subjects with migraine and 85% of the controls were correctly classified into their proper groups. We suggest that EEG coherence analysis is a sensitive parameter in the detection of electrophysiological abnormalities in patients with migraine.

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.

Epidemiology of spina bifida in Tottori Prefecture, Japan, 1976-1995.

The authors studied the epidemiology of spina bifida in Tottori Prefecture, Japan, from 1976 to 1995. Thirty-four patients (16 men and 18 women) were registered in this study. Consanguineous marriages, familial occurrence, and abnormalities in prenatal history were not observed. The incidence rate in the entire prefecture and in the eastern, central, and western regions was 0.234, 0.148, 0.425, and 0.230 per 1,000 live births, respectively. The incidence rate in the central region was greater than that in the eastern region with statistical significance (P < 0.05), but the cause of the cluster is unknown. The incidence rate of 0.234 per 1,000 live births for 20 years is compatible with the previous two studies of 1922-1940 and 1948-1954 in Japan. Such apparently stable trends suggest that environmental factors have affected the Japanese less than genetic factors. Seasonal variations are not demonstrated.

Immunohistochemical detection for Actinomyces sp. in swine tonsillar abscess and granulomatous mastitis.

The tonsils of eleven pigs and the mammary glands of a sow were used to investigate actinomycotic lesions due to Actinomyces sp. infection. At necropsy, there was no abnormality on these tonsils, on the other hand, numerous abscesses containing sulfur granules were found in the mammary. Histopathologically, the Actinomyces sp. lesions were noted as crypt abscesses in the tonsils and as pus-forming granulomas in the mammary glands. The microorganisms in both lesions were composed of bead-like cocci, bacillary cells and short, branching filaments, those cells being positive by the Gram's and Grocott's methods. Clubs were formed around the microbial clumps in these lesions. Immunohistochemically, there were cross-reactions between antibodies of Actinomyces sp. Chiba 101 (101) and swine actinomycetes of 7 species: A. bovis, A. hyovaginalis, A. israeli, A. naeslundii, A. pyogenes, A. suis) formerly Eubacterium suits) and A. viscosus. However it was possible to differentiate Actinomyces sp. 101 from them by absorption and dilution of the antiserum, then the microorganisms in the tonsillar crypt abscesses and the granulomatous mastitis were labelled with an immunoperoxidase technique using the absorbed Actinomyces sp. 101 antiserum. Thus, these immunolabelling properties are suggestive of the presence of 'A. suis' (Grässer) Franke 1973.