Visual cortical responses to the input from the amblyopic eye are suppressed during binocular viewing.

Amblyopia is a visual disorder caused by an anomalous early visual experience. It has been suggested that suppression of the visual input from the weaker eye might be a primary underlying mechanism of the amblyopic syndrome. However, it is still an unresolved question to what extent neural responses to the visual information coming from the amblyopic eye are suppressed during binocular viewing. To address this question we measured event-related potentials (ERP) to foveal face stimuli in amblyopic patients, both in monocular and binocular viewing conditions. The results revealed no difference in the amplitude and latency of early components of the ERP responses between the binocular and fellow eye stimulation. On the other hand, early ERP components were reduced and delayed in the case of monocular stimulation of the amblyopic eye as compared to the fellow eye stimulation or to binocular viewing. The magnitude of the amblyopic effect measured on the ERP amplitudes was comparable to that found on the fMRI responses in the fusiform face area using the same face stimuli and task conditions. Our findings showing that the amblyopic effects present on the early ERP components in the case of monocular stimulation are not manifested in the ERP responses during binocular viewing suggest that input from the amblyopic eye is completely suppressed already at the earliest stages of visual cortical processing when stimuli are viewed by both eyes.

A Closer Investigation of the Synchronous Bilateral Pattern of MRI Lesions in Acute Necrotizing Encephalopathy Type 1.

We observed a lesion pattern in a series of 4 cases of RANBP2-mutation-linked acute necrotizing encephalopathy, which appears to be specific for this condition. The setting of synchronous bilateral mammillary, amygdaloid, and lateral geniculate lesions, along with claustro-parahippocampal lesions, can serve as a diagnostic tool in this condition. We add several further details to the MR imaging features of the typical brain lesions encountered in this disease.

Using diffusion MRI for measuring the temperature of cerebrospinal fluid within the lateral ventricles.

AIM: Hypothermia is often induced to reduce brain injury in newborns, following perinatal hypoxic-ischaemic events, and in adults following traumatic brain injury, stroke or cardiac arrest. We aimed to devise a method, based on diffusion-weighted MRI, to measure non-invasively the temperature of the cerebrospinal fluid in the lateral ventricles. METHODS: The well-known temperature dependence of the water diffusion constant was used for the estimation of temperature. We carried out diffusion MRI measurements on a 3T Philips Achieva Scanner involving phantoms (filled with water or artificial cerebrospinal fluid while slowly cooling from 41 to 32 degrees C) and healthy adult volunteers. RESULTS: The estimated temperature of water phantoms followed that measured using a mercury thermometer, but the estimates for artificial cerebrospinal fluid were 1.04 degrees C lower. After correcting for this systematic difference, the estimated temperature within the lateral ventricles of volunteers was 39.9 degrees C. Using diffusion directions less sensitive to cerebrospinal fluid flow, it was 37.7 degrees C, which was in agreement with the literature. CONCLUSION: Although further improvements are needed, measuring the temperature within the lateral ventricles using diffusion MRI is a viable method that may be useful for clinical applications. We introduced the method, identified sources of error and offered remedies for each.

[Neonatal bronchogenic cyst diagnosed by ultrasound]. / Ultrahanggal diagnosztizált újszülöttkori bronchogen cysta.

This is the description of a patient who presented in the neonatal period with respiratory difficulties, caused by a bronchogenic cyst. In this context attention is drawn to the significance of ultrasonography in the diagnosis of mediastinal tumors, lobar emphysema, atelectasis and therapy-resistant pneumonias.

[Childhood dancing eye syndrome in occult neuroblastoma]. / Gyermekkori "dancing eyes syndroma" occult neuroblastomában.

The case of a two year-old boy is described with dancing eyes syndrome (DES) together with ganglioneuroblastoma. Surgical removal of the tumour and ACTH therapy resulted in rapid improvement, and an almost symptome-free condition. The literature is reviewed. Need of vigorous search for an occult neuroblastoma in DES is pointed out, since the early diagnosis and tumour's surgery can significantly improve the outcome.

[Septo-optic dysplasia (de Morsier syndrome)]. / Septo-opticus dysplasia (de Morsier syndroma).

Authors report a rare central nervous system malformation on giving account of three of their cases. The possibility of septo-optic dysplasia should be raised in children with unilateral or bilateral hypoplasia of the optic nerve. The use of neuroimaging technics is necessary for establishing the diagnosis. Knowing the disease is important because of the hypopituitarism which can accompany it, and which can necessitate an early hormone replacement therapy.

[Androgen-producing adrenocortical adenoma in childhood. Pitfalls of differential diagnosis]. / Androgént termeló mellékvesekéreg adenoma gyermekkorban. A differenciáldiagnosztika buktatói.

A two-year-old girl presented with clitoromegaly and an abdominal mass. Diagnostic procedures including sonography, computerized tomography, scintigraphy and measurement of catecholamines in urine excluded neuroblastoma, but suspected Wilms-tumor. Before completing the steroid measurements therapy was initiated according to Wilms-tumor (preoperative cytostatic therapy followed by surgical removal of the tumor). Morphology of the tumor, the serum and urinary steroid profile proved a benign adrenocortical adenoma producing mainly delta 5-steroids including the weak androgen, dehydroepiandrosterone.

Aortic thrombosis diagnosed by ultrasound.

A neonate developed aortic thrombosis following catheterization of the umbilical artery. The thrombus was identified and followed up by ultrasonography. Fibrinolytic therapy led to the almost complete disappearance of the aortic thrombus but the child died of cerebral haemorrhage. Physicians should be alerted to the possibility of aortic thrombosis in neonates following umbilical arterial catheterization. Ultrasonography is an appropriate method for diagnosis and follow-up in these cases.

Changes in echogenicity of spinal subarachnoid space associated with intracranial hemorrhage: new observations.

PURPOSE: The role of subarachnoid blood and secondary, sterile inflammation in the pathogenesis of posthemorrhagic hydrocephalus (PHH) is not well understood. The aims of this study were to study the frequency and rate of spread of blood into the spinal subarachnoid space (SSS) and to evaluate the relationship of this finding and PHH. MATERIALS AND METHODS: Nine premature babies with major intracerebral hemorrhage (ICH, grade 3 or higher), and ten premature infants with minor ICH (grade 1) or no evidence of ICH (control group) were identified and underwent serial cranial and spinal sonography at the time of initial diagnosis, 12-24 h after the ICH and weekly thereafter for at least 9 weeks. Sagittal and axial scans of the thoracolumbar spine were obtained and evaluated for the presence of echogenic debris in the dorsal SSS. Six additional patients who had cranial and spinal sonography died within the 1st week of life and underwent post-mortem examinations. RESULTS: The SSS was echo-free (normal) in all cases at the time of initial sonographic diagnosis of ICH. Within 24 h, all babies with major ICH had developed increased echogenicity of the cervical and thoracic SSS. Echogenicity of the SSS decreased gradually over several weeks. Although transient ventricular dilatation was present in every patient, only one patient had rapidly progressive PHH requiring shunt placement. Transient cysts of the cervicothoracic subarachnoid space were identified in two patients 6-7 weeks after ICH. The subarachnoid space remained echo-free in all control infants At autopsy, all four infants with echogenic spinal debris had blood or blood products in the spinal subarachnoid space, whereas two infants with echo-free spinal images did not. CONCLUSIONS: Spread of blood from the ventricular system into the spinal subarachnoid space after ICH is common and can be seen within 24 h of initial ICH. Subarachnoid blood is associated with post-hemorrhagic ventricular dilatation and transient spinal subarachnoid cyst formation.

Effects of low-dose dopamine infusion on cardiovascular and renal functions, cerebral blood flow, and plasma catecholamine levels in sick preterm neonates.

Effects of 2 and 4 micrograms/kg/min dopamine infusion on cardiovascular and renal functions, cerebral blood flow (CBF) and plasma catecholamine levels were studied in sick preterm neonates during the first four days of life. Preterm infants were found to have an enhanced responsiveness to the pressor effects of dopamine during this period. Comparison of the renal effects of 2 and 4 micrograms/kg/min dopamine in 61 preterm infants indicate that 2 micrograms/kg/min dopamine induces maximum diuresis and natriuresis during the first day of life provided that systemic blood pressure is within the predicted normal range. Although administration of 4 micrograms/kg/min dopamine induces further increases in blood pressure and glomerular filtration rate, urine output and sodium excretion remain similar to that on 2 micrograms/kg/min of the drug. These findings demonstrate that the direct tubular effects of dopamine play an important role in the diuretic and natriuretic action of the drug in the one-day old preterm infant. In five preterm neonates, changes in CBF transiently paralleled the dopamine-induced alterations in systemic blood pressure indicating that autoregulation of CBF is impaired but not completely ineffective in the one-day old preterm infant. In eight term neonates, increases in blood pressure had no effect on CBF. Measurements of plasma dopamine and norepinephrine levels in 14 preterm neonates and five children suggest that decreased metabolism of dopamine may contribute to the enhanced pressor responsiveness to dopamine in sick preterm infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in spinal fluid drainage in infants with hydrocephalus.

We describe two cases of hydrocephalus in which spinal sonography revealed underlying causes responsible for the failure of therapeutic lumbar punctures.

Echodense spinal subarachnoid space in neonates with progressive ventricular dilatation: a marker of noncommunicating hydrocephalus.

OBJECTIVE: Our purpose was to evaluate the frequency and clinical significance of echogenic debris in the spinal subarachnoid space of neonates at risk for progressive ventricular dilatation. SUBJECTS AND METHODS: Spinal sonography was performed on 15 neonates with severe intracranial hemorrhage (n = 10) or bacterial meningitis (n = 5). Spinal sonography also was performed on 16 control neonates. Images were analyzed for the presence and location of echogeric debris within the thoracolumbar subarachnoid space. Lumbar punctures were performed on all 31 neonates, and CSF was analyzed for cell count and protein content. Ten of 15 neonates required ventricular drainage procedures. RESULTS: Progressive ventricular dilatation occurred in 11 of 15 neonates with intracranial hemorrhage or meningitis. Echogenic debris was present in the thoracolumbar subarachnoid space on spinal sonography in every neonate with progressive ventricular dilatation compared with none of the 16 control neonates (p < .0001 by chi-square analysis). In addition, the 11 neonates with echogenic subarachnoid space had significantly higher protein and RBC contents in the lumbar CSF (p < .04). CONCLUSION: Echogenic subarachnoid space revealed by sonography is associated with progressive ventricular dilatation after severe intracranial hemorrhage or bacterial meningitis and is caused by high protein and RBC contents in the subarachnoid space. This finding may be helpful in identifying neonates who will not benefit from serial lumbar punctures for treatment of hydrocephalus.