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Biomedical subjects

Andrea Guzzetta

Publications and source records attributed to Andrea Guzzetta.

10 recordsLinked to original sources
PubMed2005

Can clinical signs identify newborns with neuromuscular disorders?

OBJECTIVE: To evaluate retrospectively the prevalence of neuromuscular disorders in 83 newborns referred to a tertiary care center because of hypotonia and weakness and/or contractures, with a possible diagnosis of neuromuscular disorder. We also aimed to establish whether clinical signs could help to identify infants with neuromuscular disorders. STUDY DESIGN: Sixty-six of the 83 infants who fulfilled the inclusion criteria (79.5%) had an identifiable disorder, which was a neuromuscular disorder in 39 (46.9%). RESULTS: Absent or extremely reduced antigravity movements were mainly found in infants with neuromuscular disorders (sensitivity and specificity 97.4% and 75%), whereas partial range antigravity movements were more frequent in infants with other diagnosis. Contractures were mainly found in infants with peripheral nerve or muscle involvement but also were relatively frequent in infants with genetic or metabolic syndromes (sensitivity 69.2%, specificity 61.3%). Reduced fetal movements and abnormal liquor were frequent but not present consistently in infants with neuromuscular disorders (sensitivity 46.1% and 38.4%) and were found rarely in infants with other disorders (specificity 88.6% and 75.0%). CONCLUSIONS: Severe muscle weakness and contractures are the most reliable indicators of a neuromuscular disorder and should be carefully assessed in an infant with neonatal hypotonia.

Algorithms↗
PubMed2005

Cognitive competence at the onset of West syndrome: correlation with EEG patterns and visual function.

The aim of this study was to evaluate cognitive development at the onset of West syndrome (WS) with regard to electroencephalogram (EEG) patterns and visual function. Twenty-five patients (14 males, 11 females) at the onset of spasms (T0) in WS and 2 months later (T1) underwent a full clinical evaluation, including neuroimaging, cognitive assessment, video-EEG, and visual function. Mean age of the patients at spasm onset was 5.9 months (SD 2.5; range 2 to 13mo). Cognitive development, assessed with Griffiths Mental Development Scales (GMDS), was generally impaired at T0 and was significantly related to visual function (p<0.001) at both T0 and T1. In general, there was a specific major impairment in the eye-hand coordination scale of the GMDS which tended to disappear after 2 months in less severe cases. At the onset of spasms, sleep EEG organization seemed to be better related to cognitive abilities than awake hypsarrhythmia. These results support a close link between visual function and cognitive competence in WS and provide additional information to improve the understanding of possible mechanisms underlying cognitive impairment.

Child Development↗
PubMed2004

Neurological examination in healthy term infants aged 3-10 weeks.

OBJECTIVES: The neurodevelopmental progress of newborn term infants is checked routinely at around 6 weeks of postnatal age. The maturation of neurological signs in this age range however has not been systematically studied and normative data are not available. The aim of this study was to document any changes in posture, tone, reflexes, behaviour and movements in low-risk full-term infants between 3 and 10 weeks of postnatal age. STUDY DESIGN: We performed a structured neurological examination previously standardised in full-term newborns in the first 48 h after birth. In the current study, a total of 76 examinations were performed between 3 and 10 weeks of age in low-risk full-term infants. RESULTS: The results of the examinations were divided according to postnatal age. In most items, the scores changed with time, with a definite shift in their distribution occurring around 6 weeks. At this age, a reduction in flexor tone of the limbs was observed, together with an increase in active neck tone. Visual orientation in contrast had already improved by 3 weeks when all infants were able to follow a target in a full circle compared to newborns that are often only able to follow a target in an arc. CONCLUSIONS: Our results suggest that 6 weeks post-term birth is an important milestone for changes in neurological signs, particularly those related to muscle tone and posture, probably reflecting maturation of the nervous system. These findings provide important guidelines for the interpretation of the neurological examination performed at this age.

Child Development↗
PubMed2004

Visual function in infants with West syndrome: correlation with EEG patterns.

PURPOSE: Several studies have reported behavioral and electrophysiological evidence of visual impairment during the active stage of West syndrome. The underlying mechanisms are, however, poorly understood, and little has been reported about the correlation between visual impairment, EEG patterns, and brain lesions. The aim of the study was to assess visual function at the onset of spasm and 2 months thereafter and relate visual findings to brain lesions and EEG features. METHODS: Twenty-five infants with West syndrome were enrolled and studied with (a) a full clinical assessment including a battery of tests specifically designed to assess visual function, (b) a video-polygraphic study, and (c) brain magnetic resonance imaging (MRI). Besides brain neuroimaging and EEG comparison with visual function, an intra-EEG analysis was performed to investigate the possible relation of EEG patterns to fluctuating visual behavior (fixation and following). RESULTS: Twenty-two children had at least one abnormal result on one or more of the tests assessing visual function at T0. Visual impairment at the spasm onset was related to the sleep disorganization rather than to the hypsarrhythmic pattern in awake EEG. After 2 months, both EEG features become significantly linked to visual function. Visual function improved in several cases after 2 months, in parallel with the seizure regression. No relation was found between EEG patterns and fluctuating visual behavior. CONCLUSIONS: The study supplies new evidence of the involvement of visual function in West syndrome. The presence of abnormal visual findings in infants without lesions on brain MRI suggests that visual abnormalities are due not only to brain injury but also to epileptic disorder per se. New insight is also provided into the possible mechanisms underlying clinical and EEG abnormalities.

Brain↗
PubMed2004

Neonatal cerebral infarction and neuromotor outcome at school age.

OBJECTIVE: The aim of this study was to assess neuromotor function at school age in children who had cerebral infarction on neonatal magnetic resonance imaging (MRI). DESIGN: Twenty-two children with evidence of cerebral infarction on neonatal brain MRI (18 with arterial infarction and 4 with border-zone lesions) were assessed at school age with a structured neurologic examination and the Movement Assessment Battery for Children, a battery of tests designed to assess motor function. RESULTS: Of the 22 children, 6 (30%) had hemiplegia and a further 7 (30%) showed some neuromotor abnormality such as asymmetry on the neurologic examination (n = 4) or poor scores on the neuromotor test without any sign of asymmetry (n = 3). The remaining 9 children had a normal motor outcome. Hemiplegia was found only in children who had concomitant involvement of hemisphere, internal capsule, and basal ganglia on brain MRI. Children with involvement of the internal capsule, associated either with basal ganglia or hemispheric lesions, did not show hemiplegia but still had motor difficulties. CONCLUSIONS: Our results suggest that although hemiplegia occurs in a relatively small proportion of children with neonatal cerebral infarction, other signs of neuromotor impairment can be present, and these become more obvious at school age when a more specific assessment can be performed. These results also suggest that the involvement of the internal capsule on neonatal MRI can predict the presence of these abnormalities.

Brain↗
PubMed2003

Neurologic examination of preterm infants at term age: comparison with term infants.

OBJECTIVES: The aim was to establish the range of neurologic findings in preterm infants reaching term age, their relation to gestational age at birth, and the possible differences with healthy term newborns tested during the first days of life. STUDY DESIGN: The Dubowitz neonatal neurologic examination was performed at term age in 157 low-risk preterm infants born between 25 and 34 weeks' gestation who had cranial ultrasonograms that were normal or showed minor abnormalities. Infants were subdivided in 3 groups according to their gestational age at birth. RESULTS: Within the preterm cohort, the range of scores for the 3 gestational age subgroups was different from each other for 21 of the 34 items, although the median scores were different only in 10 of the 34 items. The range of scores and their median in preterm infants however was wider than that found in term infants. Preterm infants examined at term were also more hyperexcitable and tended to have less flexor tone in the limbs and less extensor tone in the neck in the sitting posture. CONCLUSIONS: The distribution of scores provides useful guidelines when a preterm infant is examined at term.

Female↗
PubMed2002

Dorsal and ventral stream sensitivity in normal development and hemiplegia.

Form and motion coherence thresholds can provide comparable measures of global visual processing in the ventral and dorsal streams respectively. Normal development of thresholds was tested in 360 normally developing children aged 4-11 and in normal adults. The two tasks showed similar developmental trends, with some greater variability and a slight delay in motion coherence compared to form coherence performance, in reaching adult levels. To examine the proposal of dorsal stream vulnerability related to specific developmental disorders, we compared 24 children with hemiplegic cerebral palsy with the normally developing group. Hemiplegic children performed significantly worse than controls on the motion coherence task for their age, but not on the form coherence task; however, within this group no specific brain area was significantly associated with poor motion compared to form coherence performance. These results suggest that extrastriate mechanisms mediating these thresholds normally develop in parallel, but that the dorsal stream has a greater, general vulnerability to early neurological impairment.

Adult↗
PubMed2002

Development of visual attention in West syndrome.

PURPOSE: To study prospectively the evolution of visual attention in children with West syndrome to evaluate its development before the onset of spasms, its possible deterioration as a consequence of epileptic disorders, and its outcome at the age of 2 years, and the possible relation between the impairment of visual attention and cognitive development. METHODS: Infants with symptomatic West syndrome were examined before the onset of spasms and until age 24 +/- 2 months. Visual attention study (through a clinical observation and the fixation-shift test), cognitive assessment, and complete clinical examination including brain magnetic resonance imaging were performed. RESULTS: A maturation defect of fixation shift skills was generally observed in infants with West syndrome. In some cases, the impaired visual-attention abilities paralleled a cognitive deterioration, even months before the onset of spasms. During the acute stage of West syndrome, infants lost the previously acquired visual and cognitive abilities, with a typical fluctuation of arousal. Usually at 2 years, there was a persistent defective visual attention detected with the fixation-shift test. CONCLUSIONS: The parallel defect of visual attention and of cognitive competencies is a constant finding in infants with West syndrome; these can precede the clinical onset of epileptic spasms. The severity and persistence of visual inattention might be explained by the age of visual maturation, corresponding to the usual onset of West syndrome.

Age of Onset↗
PubMed2002

Leukoencephalopathy with bilateral anterior temporal lobe cysts: a further case of this new entity.

The introduction of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy into clinical practice has permitted advances in the definition and categorization of unknown leukodystrophies in children. We report a new type of leukodystrophy, defined by particular MRI and clinical findings, in a child with uneventful pre- and perinatal histories, spasticity, severe mental impairment with absence of language, and deafness. Brain MRI showed lobar white-matter signal abnormalities with extensive cysts in the anterior temporal lobe. The results of all metabolic screening tests, including the specific investigations for leukodystrophy, have been negative. Six years of clinical and MRI-magnetic resonance spectroscopy patient follow-up indicate a nonprogressive clinical and magnetic resonance picture. Owing to the striking similarities with the previous eight patients reported, this additional case supports the identification of a new leukodystrophy.

Brain Diseases↗