Enrico Biagioni

The effects of preterm infant massage on brain electrical activity

Aim  Early intervention programmes based on the manipulation of the extra‐uterine environment have been used in preterm infants with the aim of improving development and functional outcome. Infant massage, among them, has proved effective for weight gain and reduced length of stay in the neonatal intensive care unit. We have recently shown that infant massage accelerates brain maturation of low‐risk preterm infants without brain abnormalities as measured by global parameters of electroencephalography (EEG) activity. In the present study we further analyse the same cohort of preterm infants, testing the hypothesis that massage determines changes in EEG spectral activity, a highly sensitive index of brain maturation.

Neuroimaging and functional outcome of neonatal leukomalacia

Leukomalacia is a major cause of neurological impairment in the high-risk newborn. It can be identified during the early postnatal period by means of ultrasound (US) imaging of the brain, through the anterior fontanel. Magnetic resonance imaging (MRI) permits an optimal differentiation of brain tissue and of its abnormalities, without resorting to ionizing radiation or intravenous contrast. It is particularly appropriate for following the evolution of leukomalacia, after fontanel closure. Ninety-five fullterm and preterm infants with cystic and non-cystic leukomalacia, documented by US, were clinically followed-up until at least 12 months of corrected age. Thirty-two had a severe neurological outcome (mainly cerebral palsy, sometimes associated with mental retardation and/or cerebral visual impairment). The prognosis was worse in cystic leukomalacia than in prolonged flare. Electroencephalogram (EEG) carried out in the first 2 weeks of life provided valuable indexes of further outcome, especially for US findings of more uncertain prognosis. MRI was carried out at around 12 months of corrected age, by means of an apparatus operating at 0.5 Tesla. The main categories of abnormalities observed were the following: cystic lesions, enlarged ventricles with irregular outlines, delayed myelination, high intensity areas in the long TR (repetition time) images within the white matter, cortical atrophy. MRI findings correlated well with the results of US imaging and often with motor, cognitive and visual impairments. Nevertheless, clinical features cannot be predicted by neuroimaging alone and a comprehensive approach, including longitudinal functional and electrophysiological testing, is highly recommended.

Constantly discontinuous EEG patterns in full-term neonates with hypoxic-ischaemic encephalopathy

OBJECTIVES Selected EEG features were evaluated in 21 constantly discontinuous tracings recorded on the same number of full-term neonates with hypoxic-ischaemic encephalopathy. METHODS The tracings were examined without using interval amplitude as the basis for distinguishing between burst-suppression and nonburst-suppression patterns. RESULTS The results were related to outcomes and other clinical parameters (severity of hypoxic-ischaemic encephalopathy, pO2 levels and drug intake). CONCLUSIONS Features defining the grade of EEG discontinuity (i.e. maximum interval duration, minimum burst duration and interval amplitude) significantly related to outcome and, in most cases, to the grade of hypoxic-ischaemic encephalopathy. Other features (amplitude of slow waves within the burst and incidence of abnormal EEG transients) related to PO2 levels. The consumption of anticonvulsant drugs increased EEG discontinuity, but this effect did not seem dose-related. Finally, the persistence of a constantly discontinuous EEG pattern after the first week of life is a sign of unfavourable prognosis. In full-term neonates with hypoxic-ischaemic encephalopathy quantitative analysis of all constantly discontinuous EEGs seems more useful than only describing burst-suppression patterns on the basis of interval amplitude.

Electroclinical correlation in neonatal seizures

A dissociation between clinical and electroencephalographic phenomena is often observable in neonatal seizures. This finding raises important questions, including those related to the management of these patients. Another characteristic of neonatal convulsions is represented by their increased tendency towards status epilepticus. In order to examine the electroclinical correlation and its possible relationship to the occurrence of status epilepticus, recorded video-electroencephalograms of 17 newborns were submitted to detailed analysis. Time of onset, duration and other characteristics of all clinical and electrical events were noted. Five degrees of correlation were observed, from constant concurrence to complete dissociation. Examining the role of different parameters, it was observed that the incidence of electric discharges related significantly to the occurrence of electroclinical dissociation.

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

Summary:  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.

Activity patterns assessed throughout 24-hour recordings in preterm and near term infants.

The motility of 10 low-risk infants, aged between 34 and 40 weeks of postmenstrual age, has been continuously recorded for 24 h. Four codes were distinguished: code 1 (absence of motility or occasional occurrence of startles), code 2 (presence of small general or isolated body movements, startles, smiles, grimaces, and other facial activity), code 3 (forceful and prolonged general movements, startles, and stretches), code 4 (vigorous and abrupt general body movements accompanied by crying). Changes with age concern mainly the increase of the duration of code 1 (quiescence) episodes. Confrontation between day and night showed higher levels of motility during the night than during the day. The last weeks before term represent a time for increase in the ability to sustain a quiet behavior and to reorganize day-night motility distribution.

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.

Brain before Cognition: EEG Maturation in Preterm Infants

Spontaneous electrical activity of the brain in humans can be easily recorded from the scalp. The recording reflects the neurophysiological activity of many neurons located under the electrodes and they change according to neural level of the activity.

Callosal Agenesis: Postnatal Sonographic Findings

In the last decade, cranial ultrasound scanning (US) has become a routine examination in neonatal intensive care units (NICUs). This technique allows a noninvasive quick visualization of newborns’ brains, even in very low birth weight infants admitted to intensive care. The examination is conducted directly at the cot or in the incubator by means of a transportable real-time US-apparatus, thus making it unnecessary to move the baby. A 5 MHz (or 7.5 MHz) transducer is applied over the anterior fontanel which remains open during the first several months of life. Coronal and sagittal scans are usually performed, allowing a good visualization of supratentorial and subtentorial structures. Only the regions located immediately below cranial bones are not well seen. The most hypoechoic structures (i.e. cerebro-spinal fluid) appear black and the most hyperechoic ones (i.e. bones) appear white, whereas tissues with intermediate echogenicity are represented by different shades of grey.

PREDICTIVE VALUE OF THE EEG IN PRETERM INFANTS - A STUDY ON NEONATES WITH PERIVENTRICULAR ECHODENSITIES

Electroencephalogram (EEG) is not a routine examination in most Neonatal Intensive Care Units (NlCUs). This exam is often carried out on fullterm asphyxiated infants or when neonatal seizures are suspected, whereas it is more rarely executed on infants born prematurely, especially during the first days of life. Difficulties encountered in recording brain electrical activities in newborns submitted to intensive care and in interpreting peculiar EEG patterns which modify rapidly after birth may account for the limited use of this technique in preterm infants. On the contrary, cranial Ultrasound (US) is usually carried out on all neonates born before term or at risk of cerebral lesions. This technique is non-invasive and easy to perform; many studies have shown its diagnostic and prognostic value, especially in relation to periventricular leukomalacia (6). In order to provide reliable Information, repeated US controls are recommended in preterm infants, from the first hours after birth until discharge from the hospital. An increased echogenicity of the periventricular white matter, often called periventricular echodensity (PVE), is often observed during the first days of life. This finding may disappear within few days or persist longer. In some cases two or four weeks later cysts may appear in these previously echogenic areas. Unfortunately, it is hard to predict whether areas of PVE will resolve, persist or evolve into more or less extensive cystic lesions (5). The aim of this study is to evaluate the prognostic value of EEG recorded on preterm infants with PVE in the period of still uncertain US findings.