Search PubMed⌕ Search

Biomedical subjects

T Ichiyama

Publications and source records attributed to T Ichiyama.

At least 73 records · Page 4Linked to original sources
PubMed1992

Evaluation by colour Doppler and pulsed Doppler sonography of blood flow velocities in intracranial arteries during the early neonatal period.

Using a colour pulsed Doppler flow mapping system, we examined the intracranial arteries of 40 healthy infants. The anterior cerebral, basilar, intracranial internal carotid and middle cerebral arteries were visualized clearly enough to evaluate flow velocity at the success rates of 100%, 87.5%, 65% and 82.4%, respectively. In the anterior cerebral, intracranial internal carotid and middle cerebral arteries, the maximum blood flow velocity slightly decreased to a minimum at around 4-6 h after birth, and then gradually increased. The minimum blood flow velocity pattern was similar. The maximum blood flow velocity in the basilar artery decreased from 0-3 h, rapidly increased from 4-6 h, and remained at a steady level thereafter. A possible mechanism for the chronological changes in the intracranial blood flow velocity is discussed.

Blood Flow Velocity↗
PubMed1992

Reverse flow in the intracranial arteries--the possible significance of comparative flow in the anterior cerebral and the basilar arteries.

Four infants with reverse flow patterns of the intracranial arteries are reported. Two with severe brain damage, had a reverse flow pattern in the anterior cerebral artery, which was recorded during the recovery stage from cardiac arrest. The other two patients showed a reverse flow pattern in the basilar artery and had a good prognosis. Reverse flow in the anterior cerebral artery suggests severe brain damage, but that in the basilar artery does not.

Basilar Artery↗
PubMed1992

[Orbicularis oculi electromyogram in a girl with ocular myasthenia gravis].

A 12-month-old girl with ocular myasthenia gravis was reported. Electromyograms (EMG) of the orbicularis oculi muscle were studied during a period of 16 months. The degree of the waning phenomenon on EMG correlated well with that of her clinical symptoms. The study of post-tetanic exhaustion after repetitive electrical stimulation at 20 Hz for 4 seconds, was the most sensitive technique in the evaluation of the function of neuromuscular junction. EMG showed the waning phenomenon in the initial worsening after a high dose methylprednisolone therapy, and at the symptom-free stage without medication after the steroid therapy. In our patient, orbicularis oculi EMG was useful in the estimation of the severity of ocular myasthenia gravis and the effect of its treatment.

Electromyography↗
PubMed1991

Ultrasonic measurements of the posterior cranial fossa structures in neonates and infants.

The structures in the posterior cranial fossa of neonates and infants were visualized ultrasonically via the anterior fontanelle. The diameters of the cerebellar vermis, pons, fourth ventricle and cisterna vermis were measured in the midsagittal plane in neonates (n = 76), 1-month-old infants (n = 61) and 3- to 6-month-old infants (n = 35). The normal values obtained will be useful for evaluation of morphological abnormalities in the posterior cranial fossa.

Anthropometry↗
PubMed1991

Hearing impairment in two boys with I-cell disease.

Auditory brainstem responses (ABR) were analyzed in 2 boys with I-cell disease. Both patients showed a prolonged latency of wave I, a normal I-V interpeak latency and an elevated threshold of wave V. The intensity-latency curve had a steep slope. These abnormal ABR findings reflect the presence of conductive hearing impairment associated with the cochlear component in I-cell disease.

Evoked Potentials, Auditory, Brain Stem↗
PubMed1991

[Cerebral infarction in a boy with subdural abscess].

A 13-year-old boy was reported with a subdural abscess in the left anterior cranial fossa and an infarction in the lesion supplied by the left middle cerebral artery. Cranial computed tomography revealed a gradual increase of a low density area with surrounding capsule formation, and later another low density area which indicated in occlusion of the left middle cerebral artery. Cerebral angiography disclosed a stenosis at the trifurcated portion of the left internal carotid artery near the abscess. These findings suggested the occurrence of infarction due to angiitis of the internal carotid artery.

Adolescent↗
PubMed1991

[Quantitative evaluation of pseudohypertrophy in Duchenne muscular dystrophy].

In order to evaluate pseudohypertrophy of the calves in Duchenne muscular dystrophy (DMD) quantitatively, we measured the circumference of the thigh, knee, calf, and ankle in total 7 patients with DMD whose ages ranged from 3 to 5 years, and 165 healthy boys aged 3 to 6 years. Simple value of the calf circumference was not useful to evaluate pseudohypertrophy in DMD, because the circumference was variable following to the nutrition (Kaup index) in healthy boys. Various ratios were then tested for the calf circumference in relation to the thigh, knee, or ankle circumference. Of these, the calf/knee circumference ratio was the most informative; the values of 13 out of 14 affected legs were above the mean + 2SD.

Age Factors↗
PubMed1991

[The relation between one-sided occipital flattening and laterality of rolling-over].

The rolling-over of the body is one of the developmental mile-stones. Several infants have the laterality of rolling-over in early state and the dominant side in later state. The abilateral occipital flattening is thought to be caused by head positioning in the neonatal period and early infancy. Asymmetrical development of rolling-over was studied in relation with head positioning, relating skull occipital flattening. We examined 2919 infants aged 7 months with the questionnaire about the side of skull occipital flattening and the initial turning side of rolling-over. 1975 infants had the dominant side of rolling-over; the left side 45.4%, and the right side 47.7%. 761 infants had one-sided occipital flattening; left-side 41.3%, and right-side 54.8%, 520 infants had dominant-sided rolling-over accompanied with one-sided occipital flattening. The positive relationship between the side of rolling-over and the side of occipital flattening could not be proved by chi-square statistical analysis. These findings suggest that laterality of rolling-over, one of asymmetrical motor developments is not related to the head positioning in early infancy.

Dominance, Cerebral↗
PubMed1990

A possible Japanese male case of Pelizaeus-Merzbacher disease.

A boy with an abnormal auditory brain stem response showing only a wave I-II pattern, congenital nystagmus, psycho-motor retardation, pyramidal tract signs and muscular hypotonia was reported. The auditory brain stem response, short latency somatosensory-evoked potential, somatosensory-evoked potential and visual-evoked potential indicated an intramedullary disorder of conduction. Magnetic resonance imaging revealed marked high signal intensity of the cerebral white matter in T2-weighted images, suggesting hypomyelination. A muscle biopsy specimen showed neurogenic changes with mild myogenic changes.

Brain↗
PubMed1989

A case of acute cerebellar ataxia with an MRI abnormality.

A 5-year-old boy with acute cerebellar ataxia was examined by means of magnetic resonance imaging (MRI) and was found to have a lesion showing low and high signal intensity in T1- and T2-weighted images, respectively, in the left cerebellar peduncle in the acute phase. The lesion disappeared in the convalescent phase.

Cerebellar Ataxia↗
PubMed1989

Cerebral venous thrombosis associated with recurrent epilepsy-like attacks.

A 9-year-old girl with recurrent episodes of unconsciousness, with or without convulsions, was reported. The episodes, which have been observed 9 times over the last 6 years, were characterized by generalized or hemi-convulsions, associated features of headache and vomiting, disturbance of consciousness lasting for a few days, slow activity on EEG continuing for a few weeks after the episodes and no prophylactic effect of anticonvulsants. Repeated EEG examinations revealed no epileptic discharges. Cerebral angiography showed corkscrew-like veins in the frontal region. Cerebral venous thrombosis is strongly suggested as the underlying cause of her episodes.

Aspirin↗
PubMedDate not supplied

Two possible cases of Alexander disease. Multimodal evoked potentials and MRI.

We describe two unrelated girls with slowly progressive leukodystrophy with macrocephaly. On MRI, both patients exhibited diffuse involvement of the cerebral white matter, excluding the internal capsule and optic radiation. Their visual-evoked potentials were normal. Short-latency somatosensory-evoked potentials exhibited the absence of early scalp components. Auditory brainstem responses in both patients showed intramedullary conduction disturbance. These MRI and electrophysiological findings are similar to those in infantile Alexander disease.

Adolescent↗
PubMedDate not supplied

Developmental changes of contralateral brainstem auditory evoked potentials: evaluation of brainstem maturation.

Bilateral recordings of brainstem auditory evoked potentials obtained on monaural stimulation were studied in 147 normal subjects, aged 0 days to 21 years. We analyzed contralateral (opposite side to stimulation) wave forms in particular. The latencies of the contralateral wave II' and III' complex were shorter than those of ipsilateral wave III. The latencies of wave V on the ipsilateral side were shorter than those on the contralateral side. The contralateral wave II' and III' complex tended to separate into two divided peaks with age and could be classified into three types, i.e. a single slow peaked wave, a trapezium-like broad peaked wave and a double peaked wave. We called these wave forms the infantile, transient and adult types, respectively. The infantile type was seen in subjects aged under 14 months, the transient type between 1 month and 15 years, and the adult type over 13 months. Analysis of the contralateral wave forms of brainstem auditory evoked potentials may be useful for evaluation of functional maturation of the brainstem.

Adolescent↗
PubMedDate not supplied

Hearing impairment in two boys with Cornelia de Lange syndrome.

We analyzed brainstem auditory evoked potentials in 2 boys with Cornelia de Lange syndrome. One patient showed no responses with 100 dB hearing level (HL) stimuli. The other showed a normal latency of wave I, a normal I-V interpeak latency with 80 dB HL stimuli, and an elevated threshold of wave V (40 dB HL). It is likely that these abnormal findings reflect the presence of sensorineural hearing impairment.

Child, Preschool↗