Non-REM-sleep instability in recurrent sleepwalking in pre-pubertal children

BACKGROUND AND PURPOSE: We questioned whether or not the sleep of pre-pubertal children with recurrent sleepwalking was different from that recorded in normal children. PATIENTS AND METHODS: Twelve pre-pubertal chronic sleepwalkers were compared to age- and gender-matched normal children. All children had a clinical evaluation covering pediatric, sleep, neuropsychiatric and otolaryngological fields. Two standardized sleep questionnaires were administered, and a minimum of two successive polysomnograms were performed with monitoring of sleep electroencephalographic (EEG) and cardiorespiratory variables. The research investigations were performed on nights without sleepwalking to search for the presence of other sleep disorders, including upper airway resistance syndrome (UARS). Sleep was scored using standard atlases, but it was also evaluated for the cyclic alternating pattern (CAP) rate. RESULTS: All sleepwalkers presented with either obstructive sleep apnea (n=2) or UARS (n=10). Compared to normal children, sleepwalkers had shorter total sleep time but no significant change in wake after sleep onset when considering all arousals > 3 s. CAP analysis showed a significantly higher CAP rate than in controls. CONCLUSIONS: Chronic sleepwalkers have instability of non-rapid eye movement (NREM) sleep detectable only by the calculation of CAP rate. Instability of NREM sleep was seen even on nights without sleepwalking and is probably related to the presence of the associated sleep disorders. We hypothesize that chronic NREM-sleep instability is a risk factor for occurrence of sleepwalking when further sleep disruption is triggered by external events.     

Heart rate variability, sympathetic and vagal balance and EEG arousals in upper airway resistance and mild obstructive sleep apnea syndromes

BACKGROUND AND PURPOSE: We questioned the role of respiratory events in obstructive sleep apnea syndrome (OSAS) and of upper airway resistance syndrome (UARS) on heart rate (HR) during sleep, paying specific attention to the termination of the abnormal breathing events and examining the presence of arousals or termination with only central nervous system (CNS) activation. PATIENTS AND METHODS: Twenty patients, 10 with UARS and 10 with mild OSAS, were studied. A nocturnal polysomnogram was performed including measurement of respiratory variables and pulse transit time (PTT). According to the presence or absence of a PTT event indicative of autonomic nervous system (ANS) activation, 148 events were extracted after having been randomly chosen in each represented sleep stage, with or without an electroencephalogram (EEG) arousal >1.5s. RR interval (RRI) in electrocardiogram (ECG) recordings, as well as heart rate variability, was calculated during 60 and 120s, respectively. Period amplitude analysis (PAA) was applied for RR-interval analysis, and fast Fourier transformation (FFT) was applied to perform HR variability analysis. RESULTS: Visually scored EEG arousal was significantly associated with an increase in sympathetic index of heart rate, while PTT was associated with a drop in parasympathetic index, after the respiratory events. Patients with mild OSAS presented persistently shorter RRI when compared to patients with UARS. The latter also exhibited a significant decrease in parasympathetic index (High Frequency (HF)) at the termination of a respiratory event. CONCLUSION: The HF component was only significantly decreased in patients with UARS, which indicates a predominant involvement of the parasympathetic tone in patients with UARS in comparison to those with OSAS.     

Branching projections of ventrolateral reticular neurons to the medial preoptic area and lumbo-sacral spinal cord

Different findings indicate that rostral ventrolateral reticular nucleus (RVL) is neuronal substrate of integration and regulation of the cardiovascular functions. Some efferent RVL neurons project to the thoraco-lumbar spinal cord and excite preganglionic sympathetic neurons, to the spinal phrenic motor neurons involved in inspiratory function and increase the activity of vasoconstrictor fibres innervating blood vessels in the skin and skeletal muscle. Our study was aimed at revealing presence of neurons within RVL supplying branching collateral input to the medial preoptic area (MPA) and to the lumbo-sacral spinal cord (SC-L) in the rat. All animal experiments were carried out in accordance with current institutional guidelines for the care and use of experimental animals. We have employed double fluorescent-labelling procedure: the projections were defined by injections of two retrograde tracers: Rhodamine Labelled Bead (RBL) and Fluoro Gold (FG) in the MPA and SC-L, respectively. Our results showed the presence of few single FG neurons and single RBL neurons in the RVL. The size of FG-neurons and RBL-neurons was medium (25–30 μm) and large (50 μm).     

Transfusion related acute lung injury: a pediatric perspective

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated mortality. TRALI occurs in children and adults, but the syndrome has not been reviewed from a pediatric perspective. We reviewed the literature on TRALI from a pediatric perspective. TRALI has been documented in pediatric patients, especially in the setting of hematologic malignancy. Additional TRALI cases have been reported in pediatric patients with a variety of diagnoses. TRALI is likely to be much more common than previously appreciated in the pediatric patient population. TRALI should be considered in the differential diagnosis of all pediatric patients who develop new acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) during or within six hours of a blood product transfusion. When a case of TRALI is suspected, a transfusion reaction report to the blood bank is important to initiate the investigation and identify the implicated donor.     

Clinical trials in myeloproliferative disorders: looking forward

Although far from perfect, randomized clinical trials (RCTs) are the best mechanism available for evaluating the risk/benefit profile of a particular therapy. Given this, it is particularly unfortunate that there have been few clinical trials of therapy for myeloproliferative diseases (MPDs) as these therapies are often based on agents with unclear long-term safety. A complex profile of MPD uncertainties requires a simple, but articulated strategy of care and research to allow a reasonable transfer of the best available validated knowledge and a timely investigation of the most relevant questions. The multi-country, collaborative RCTs are key to generating valid data. The prerequisite for success is the close interaction of the clinical community and the research community studying the same patients. Data to be collected, criteria, contents, frequency of follow-up, and documentation of the events should be as similar as possible to those used in routine clinical care. One of the greatest achievements of the multicenter trials with this orientation has been to produce a "core" of data and practices, on which the main analyses will be made, but which at the same time reflect an optimal level of patient care for the majority of patients.     

Effects of housing and nicotine on shuttle-box avoidance in male NMRI mice

The present study aimed to evaluate whether housing condition could interact with nicotine administration in influencing the acquisition of a two-way active avoidance task. Male NMRI mice were either group- or individually housed for 30 days and, after this period, evaluated both in the actimeter and, 24h later, in the elevated plus-maze. On the basis of the percentage of time spent in the open arms of the plus-maze, both group- and individually housed mice were sub-classified into three groups with high, moderate or low anxiety baseline levels. Effects of nicotine on the acquisition of the two-way active avoidance task was assessed in each of these groups of mice using an automated shuttle-box. Mice were treated with nicotine (0.35 mg/kg) or vehicle before each daily training session in the shuttle-box (30 trials) over 5 days. The results showed that motor activity counts were significantly higher in individually housed mice than in group-housed counterparts. The factor "anxiety" in the active avoidance test did not reach statistical significance but the factor "housing" did. The number of avoidances was higher in individually housed than in group-housed mice. Separate analyses performed for individually and group-housed animals indicated that group-housed nicotine-treated mice displayed fewer number of avoidances than saline-treated counterparts. It was concluded that housing condition may be a useful variable in evaluating the effects of nicotine on learning tasks. Indeed, the two-way active avoidance task seems to be sensitive to housing condition.     

Chronic treatment with the mGlu5R antagonist MPEP reduces the functional effects of the mGlu5R agonist CHPG in the striatum of 6-hydroxydopamine-lesioned rats: possible relevance to the effects of mGlu5R blockade in Parkinson's disease

This study was designed to test whether chronic treatment with the metabotropic glutamate receptor 5 (mGlu5R) antagonist MPEP showed antiparkinsonian effects in rats unilaterally lesioned with 6-hydroxydopamine (6-OHDA) (a "classic" model of Parkinson's disease, PD), and to evaluate whether chronic MPEP influenced the functional properties and/or the expression of striatal mGlu5Rs. Wistar rats were lesioned with 6-OHDA and then treated with MPEP (3 mg/kg/day, i.p.) or its vehicle over 2 weeks. Chronic MPEP did not induce measurable antiparkinsonian effects, since no differences were found between MPEP- and vehicle-treated animals in the pattern of L-DOPA-induced contralateral rotations. In corticostriatal slices taken from animals chronically treated with MPEP, the functional effects of the mGlu5R agonist CHPG were significantly reduced in the lesioned vs. the intact side, while no changes were found in slices taken from vehicle-treated rats. The binding of [3H]MPEP to striatal membranes showed that neither the maximal number of binding sites (Bmax) nor the dissociation constant (Kd) were changed by the lesion and/or by chronic MPEP. While chronic MPEP did not potentiate L-DOPA-induced turning in a classical model of PD, its ability to reduce mGlu5R-associated signal could help to explain the neuroprotective/antiparkinsonian effects observed in other models of PD.     

Pitfalls in the clinical and electroencephalographic diagnosis of ceroid lipofuscinosis

Neuronal ceroid lipofuscinosis (NCL) were traditionally classified according to age of onset and clinical features in four main groups. Recently, a combination of clinical, ultra structural and genetics data led to the recognition of eight forms of NCL, providing a more precise framework to classify atypical cases. By the other hand, it was shown that mutations in the same gene could be responsible for a large variety of clinical phenotypes. The objective of this study is to describe two brothers with clinical and electroencephalographic abnormalities characteristic of juvenile NCL, but with ultra structural abnormalities suggestive of late infantile NCL. Electroencephalogram is useful for clinical diagnosis of NCL but it is not helpful in its classification.