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Biomedical subjects

F Guzzetta

Publications and source records attributed to F Guzzetta.

At least 37 records · Page 2Linked to original sources
PubMed1996

Visual outcome in children with congenital hemiplegia: correlation with MRI findings.

Fourteen children with congenital hemiplegia were studied with a detailed assessment of various aspects of vision (linear acuity, stereopsis, visual fields) and MRI. The aim of this study was to evaluate the effect of a congenital lesion on visual function. The results showed a very high incidence (78%) of children who had abnormal results on at least one of the visual tests. Visual abnormalities were not correlated with the clinical severity of hemiplegia or with a specific pattern of lesion on MRI. Similarly no constant association could be found between visual structures (optic radiations and primary visual cortex) and visual function. Finally, our results would suggest that all the children with congenital hemiplegia need to be investigated irrespective of the clinical severity or of the type or the extent of the lesion. This would help to identify children with minor visual abnormalities which can affect everyday life performance.

Adolescent↗
PubMed1995

Mechanisms and evolution of the brain damage in neonatal post-hemorrhagic hydrocephalus.

There are three main mechanisms of poor outcome in children with post-hemorrhagic hydrocephalus: (1) brain injuries due to ventricular dilatation, (2) shunt-related complications, and (3) primary cerebral hypoxic-ischemic and hemorrhagic lesions. The authors give a short up-to-date report, focusing mainly on the third mechanism, with reference to personal studies.

Brain Injuries↗
PubMed1995

The effect of behavioural states on visual evoked responses in preterm and full-term newborns.

There is no general agreement about the influence of the behavioural states on the visual evoked responses. In the present study visual evoked potentials (VEP) were recorded in 6 preterm and 6 full-term newborns in the different behavioural states. A significant increase in the amplitude was observed from sleep to awake states in both preterm and full-term infants. The results supply information in favour of the utility of the behavioural assessment when VEP are recorded. It reduces the variability of the results providing for more reliable normative data.

Evoked Potentials, Visual↗
PubMed1995

Demyelinating hereditary neuropathies in children: a morphometric and ultrastructural study.

Twenty-three cases of hereditary demyelinating neuropathies are reported, 13 with different types of hereditary motor and sensory neuropathy (HMSN) and 9 with globoid cell or meta-chromatic leucodystrophies. Ultrastructural and morpho-metric studies showed some critical pathological features emphasizing: 1) the variability of the recessive forms of HMSN; 2) the morphological distinction between HMSN type I and type III; and 3) differences between these types of HMSN and other "onion bulb" neuropathies such as those found in leucodystrophies, which account for distinct underlying mechanisms.

Adolescent↗
PubMed1994

Multimodality evoked responses in the neurological assessment of the newborn.

In recent years increased attention has been devoted to evoked potentials (EP) in newborns. This paper reviews the literature and data from our research group in an attempt to assess the diagnostic and prognostic value of evoked responses in the first weeks of life and their use in different age-specific clinical conditions. The results show that EP are a very sensitive measure of the integrity of the sensory pathways. They make it possible to follow normal physiological maturation and the abnormalities of development resulting from neurological lesions. Repeated measurements of visual evoked potentials and somatosensorial evoked potential are prognostically useful in term infants, but seem much more limited in preterm newborns in predicting neurodevelopmental outcome.

Evoked Potentials↗
PubMed1993

Surgical indication in children with congenital hemiparesis.

Nine children with perinatal occlusion of the middle cerebral artery, resulting in unilateral enlargement of one lateral cerebral ventricle associated with cortical atrophy and subcortical cavity formation, were operated on because of intractable epilepsy. All subjects exhibited mild to severe hemiparesis, localized in the right side of the body in six instances and in the left side in the three cases. All but one patient presented with some degree of psychomotor retardation. The surgical treatment consisted of the removal of the atrophic cerebral cortex. One child died after surgery because of disseminated intravascular coagulation. All the remaining eight children benefited from the operation, with a decrease in the hypertonia of the affected limbs and an improvement in dexterity and gait as well as in intellectual performance. Five patients could be considered seizure-free following the surgical treatment, and the remaining three experienced a significant reduction in the frequency of the seizures.

Atrophy↗
PubMed1993

Familial unilateral and bilateral occipital calcifications and epilepsy.

No familial cases of epilepsy associated with bilateral occipital calcifications (EBOC) have been reported so far. This paper describes the clinical, electrophysiological and radiological study of two sisters affected by partial epilepsy, one with unilateral and the other with bilateral occipital calcifications. Celiac disease was excluded in both patients, even though they presented the same HLA pattern usually found in coeliac subjects.

Adolescent↗
PubMed1993

Cognitive assessment of infants with West syndrome: how useful is it for diagnosis and prognosis?

Thirty-one infants with West syndrome were followed up. Their cognitive competence was assessed before the onset of the disease, and during and after the acute stage. Two kinds of cognitive impairment were identified: the first was transitory, linked to the acute stage and mainly consisting of arousal disturbances; the second was the well known long-term sequela. It is not possible to exclude the aetiological role of a persistent, severe epileptic change: however, this study emphasizes the prognostic value of previous mental impairment. In serial cognitive assessment during the acute stage, the progression of the developmental quotient was the best indicator of a good mental outcome, and vice versa.

Brain↗
PubMed1992

Nonprogressive type II hereditary sensory autonomic neuropathy: a homogeneous clinicopathologic entity.

Two different clinical subtypes were previously identified within hereditary sensory autonomic neuropathy (HSAN) type II: a stable congenital form and a progressive one. This paper discusses two clinicopathologic cases of nonprogressive HSAN type II with morphometric correlations. In addition, a retrospective literature search was carried out to locate other cases where an accurate histologic examination, including ultrastructural features, was available in order to relate clinical and pathologic aspects of the disease. The combined data support the individualization of this neuropathic form as a homogeneous disease, as has been suggested during the last century and underline the clinical importance of this concept for the prognosis and investigation of sensory, auditory, autonomic, and motor functions in children with sensory neuropathies.

Biopsy↗
PubMed1986

Familial dysautonomia in a non-Jewish girl, with histological evidence of progression in the sural nerve.

A case of typical familial dysautonomia (HSN, type III) in a non-Jewish girl is reported. The number of unmyelinated fibres was found to be reduced and sural nerve biopsy showed evidence of past axonal degeneration. There was also marked endoneurial fibrosis and a lack of the largest myelinated fibres. Signs of histological progression not yet described in the sural nerve and other clinical and morphological features could be explained by different penetrance degrees of the disease.

Child↗
PubMed1986

Periventricular intraparenchymal echodensities in the premature newborn: critical determinant of neurologic outcome.

Controversy exists concerning the degree of importance of periventricular intraparenchymal echodensities (IPE) observed on neonatal ultrasound scans in the determination of subsequent neurologic disability in premature infants. In this report, IPE was studied in 75 infants weighing less than 2,000 g at birth to determine the basic characteristics of the lesion, the likely pathogenesis, the outcome, and the aspects of the ultrasonographic appearance in the acute period of neonatal illness that are important for prediction of outcome. IPE was defined as any periventricular echodensity greater than 1 cm in at least one dimension. IPE was strikingly associated with large areas of intraventricular hemorrhage (IVH) (81% of cases). IPE was distinctly asymmetric. Thus, the lesion was either exclusively unilateral (67%) or bilateral with marked predominance on one side. The associated IVH was asymmetric in approximately 80% of cases, and in all 50 cases of large asymmetric IVH, IPE occurred on the same side as the larger amount of intraventricular blood. Moreover, more than 50% of such cases of IPE associated with large asymmetric IVH were progressive. Neuropathologic correlation showed that IPE represented hemorrhagic necrosis of periventricular tissue. Concerning pathogenesis, these data raise the possibility that large asymmetric IVH is related etiologically to IPE. Outcome varied with the severity of the IPE. Thus, the mortality rate among the 38 infants with extensive IPE was 79%. Of the survivors with extensive IPE, all had subsequent major motor deficits and all but one exhibited cognitive function less than 80% of normal. Among the 37 infants with localized IPE, the mortality rate was 38%. Of the survivors, although 79% had major motor deficits, 43% had cognitive function greater than 80% of normal. Thus, the findings demonstrate that with extensive IPE there is little or no chance for survival with normal neurologic and cognitive outcome, but with localized IPE, although major motor deficits are common, an appreciable proportion of infants have cognitive function in the normal range. Careful, quantitative assessment of the ultrasonographic features of IPE in the acute period of illness in the premature infant is of major value in estimating outcome.

Brain↗
PubMed1985

Morphometric studies of normal sural nerves in children.

Quantitative histologic studies of biopsies of normal sural nerves were performed on nine children aged 4 days to 17 years. Stereologic computerized procedures were used to determine total endoneurial area, size distribution and number of myelinated, unmyelinated fibers and Schwann cell nuclei per nerve and per square millimeter, and the ratio of myelin thickness to axonal diameter. There was an inverse linear relationship between the number of myelinated fibers per square millimeter and increasing age. A stronger correlation was found between the number of Schwann cell nuclei per nerve (P less than 0.01) and per square millimeter (P less than 0.001) and the logarithm of age. The slope of myelin thickness/axon diameter regression lines (P less than 0.001) changed with age in linear relationship (correlation coefficient: P less than 0.001). There were no age-dependent changes in the number and density of unmyelinated fibers, but the number of unmyelinated axons per Schwann cell subunit decreased with age. Size distribution histograms for myelinated fibers showed a unimodal profile in the newborn. A second peak at 6-7 micron appeared at age 3 months, shifting progressively to 9-11 micron at 14 years. The distribution of unmyelinated fibers was unimodal, with a peak around 0.8 micron, irrespective of age. There were marked individual variations in endoneurial area.

Adolescent↗
PubMed1985

Congenital neuropathy with prevailing axonal changes. A clinical and histological report.

A case of congenital neuropathy associated with an unclassified chronic brain disorder is described. Morphological findings differ from the reported congenital neuropathies where primary myelin change have been usually found. In contrast, sural nerve biopsy showed marked signs of active or past axonal degeneration; at the teasing and morphometric analysis there was also some evidence of segmental demyelination. Atypical onion bulb formations (Evans and Murray type) and a very poor demyelination activity stressed the prevailing axonal involvement with possibly secondary segmental demyelination.

Axons↗
PubMed1982

Congenital hypomyelination polyneuropathy. Pathological findings compared with polyneuropathies starting later in life.

Biopsies from patients with congenital hypomyelination polyneuropathy (Group I) and with late infantile (Group II) and juvenile (Group III) forms of hereditary motor and sensory neuropathy (HMSN) type III were compared, using morphometric methods and ultrastructural analysis. In congenital polyneuropathies (Group I), myelin sheaths were practically absent and onion bulbs, essentially made of multiple laminae of double layered basement membrane, surrounded every axon in the size range of normal myelinated axons. The number of these axons was markedly reduced. Serial sectioning of an isolated fibre showed that the territory of successive clusters of Schwann cell nuclei was considerably reduced when compared with the biopsies in Groups II and III and with normal controls. Fibres without myelin surrounded by multiple layers of basement membrane represented between 25 and 50 per cent of the entire population of fibres in the size range of myelinated fibres in Group II and were practically absent in Group III. The number of "myelinated' fibres (that is, fibres with myelin, and amyelinate or demyelinated fibres) was normal in Groups II and III. Although there is no indication that congenital hypomyelination onion bulb polyneuropathy is a separate entity, it can be considered as a subtype of Dejerine-Sottas disease (HMSN type III). In this disease there is a gradient of severity both in clinical expression and in the disorder of Schwann cells. In the severe congenital form, all Schwann cells are affected and are incapable of forming myelin. The diminution of the number of nerve fibres in the "myelinated' fibre size range, whether or not related to a prenatal involvement of Schwann cells, is another expression of the gravity of this form. The proportion of amyelinate fibres, i.e. with Schwann cells incapable of forming myelin, becomes less in the more benign late infantile and juvenile forms of the disease in which a process of demyelination and remyelination takes place. The literature on the congenital neuropathies, a heterogeneous assembly of diseases, is reviewed.

Adolescent↗