Can we safely administer the recommended dose of phenobarbital in very low birth weight infants?

Aim

We investigated whether the recommended phenobarbital loading dose of 15–20 mg/kg with maintenance of 3–4 mg/kg/day can safely be administered to very low birth weight preterm newborns with seizures.

Methods

Twenty-four convulsive preterms of <1,500 g were enrolled in the study. Phenobarbital was administered intravenously with a loading dose of 15 mg/kg in approximately 10–15 min. After 24 h, the maintenance dose of 3 mg/kg/day was administered as a single injection. Blood samples were obtained 2, 24, 48, 72, and 96 h after the phenobarbital loading dose was administered, immediately before the next phenobarbital dose was injected.

Results

None of the cases had plasma phenobarbital concentrations above the therapeutic upper limit of 40 μg/mL on the 2nd hour; one case (4.7 %), on the 24th; 11 cases (45.8 %), on the 48th; 15 cases (62.5 %), on the 72nd; and 17 cases (70.8 %), on the 96th hour. A negative correlation was detected between the serum concentrations of phenobarbital and gestational age on the 72th (p, 0.036; r, ?0.608) and 96th hour (p, 0.043; r, ?0.769).

Conclusions

We suggest that particular attention should be done while administering phenobarbital in preterms, as blood levels of phenobarbital are higher than the reference ranges that those are often reached with the recommended doses in these groups of babies.     

Posthemorrhagic hydrocephalus in very low birth weight infants—a new gentle surgical technique for external ventricular drainage

Objective  

The germinal matrix hemorrhage in premature infants is related to the immaturity of the subependymal vascular bed. Posthemorrhagic ventricular dilation (PVD) in extremely low birth weight infants (ELBI) is a medical challenge and is associated with a high risk of long-term disability. Our aim was to find a safe and gentle surgical technique for external ventricular drainage implantation for this patient population.     

Cerebellar hemorrhage in extremely low birth weight siblings: is there a familial disposition?

Cerebellar hemorrhage is an underrecognized complication in the preterm neonate. It is multifactorial including combined maternal, intrapartum, and early postnatal factors. We present the case of 2 preterm brothers, 24 + 1 and 24 + 3 weeks of gestation, who both died because of cerebellar hemorrhage. We sought familial pathogenic factors predisposing to cerebellar hemorrhage. Cerebral imaging performed by ultrasonography through the anterior fontanel was normal and showed no signs of bleeding or brain edema. Postmortem neuropathologic findings confirmed cerebellar hemorrhagic lesions in both infants. Cerebellar vessels showed no signs of morphologic disorders or malformations. There might be a hint to a familial disposition. Neonatal cranial ultrasound protocols should include brainstem and posterior fossa examination with specific scans through the mastoid fontanel.     

Do environments in infancy moderate the association between stress and inflammation in adulthood? Initial evidence from a birth cohort in the Philippines

Chronic inflammation is a potentially important pathway through which psychosocial stressors increase risk for cardiovascular disease. However, prior research on stress and inflammation has been conducted almost exclusively in high income, industrialized populations with low levels of infectious disease. In this study we test the hypothesis that psychosocial stressors are associated with elevated concentrations of C-reactive protein (CRP) among young adults in the Philippines (n = 1622), who have grown up in an ecological and epidemiological setting that differs substantially from that of the US. In addition, we apply a developmental, ecological perspective to consider whether microbial and nutritional environments in infancy alter patterns of association between stressors and CRP. Data come from the Cebu Longitudinal Health and Nutrition Survey, a prospective cohort study that began collecting data in 1983–1984 when participants were in utero. A series of regression models indicate trends toward significant interactions between perceived stress and environmental factors in infancy, including exposure to animal feces, season of birth, and birth weight. Parental absence in childhood was a significant predictor of CRP in adulthood in interaction with exposure to animal feces in infancy. Positive associations between stressors and CRP were only evident for individuals with lower levels of microbial exposure in infancy, or lower birth weight. These results suggest that early environments influence the development of inflammatory phenotypes in ways that moderate sensitivity to psychosocial stressors in adulthood, and they underscore the value of a comparative, developmental approach to research on social environments, inflammation, and disease.     

Do deaf people see better? Texture segmentation and visual search compensate in adult but not in juvenile subjects.

The research concerning the visual perception in deaf subjects has led to contradictory results: Deaf subjects have been reported to show enhanced visual perceptual skills compared to hearing subjects (Neville & Lawson, 1987). On the other hand, there are indications that acoustic deprivation may produce an inferiority in all sensory modalities (Myklebust, 1964). These contradictions may be due to methodological differences: The investigators selected different conditions (e.g. attentive/nonattentive) and various samples of deaf subjects (e.g., different age, language, and aetiology groups). In our study, we tested a large sample of deaf subjects with texture segmentation and visual search conditions, which allowed us to differentiate between visual processing with and without attentional load. All deaf subjects had profound hearing loss within the first year of life. Our results suggest that the visual processing capacity of deaf children and adolescents does not exceed that of age- and gender-matched hearing subjects. Rather, deaf school children show deficits in visual processing in conditions with and without attentional load. Age (6 to 20 years), language used (oral, sign, oral + sign), and aetiology for deafness (genetic, maternal rubella, perinatal, infection in the first year of life, unknown) did not consistently influence the results. The deficits in visual processing were partially compensated for in adult deaf subjects. The performances of deaf and hearing adults in trials that could be solved preattentively did not differ statistically significantly, but in attention-dependent trials the deaf subjects were more efficient than the hearing controls. We conclude that visual compensation for deafness is limited to attention-dependent tasks and does not develop until adulthood.     

Face recognition by brain-injured patients: A dissociable ability?

Patients with right posterior cerebral injuries did more poorly than patients with other unilateral injuries and normal control subjects in recognizing different faces. When the faces were presented upside-down, however, those with the other unilateral injuries did worse than the right posterior group and the normal controls. This dissociation between upright and inverted presentations was not found with pictures of another common object, houses of similar architecture. The results support the notion that, among the disorders caused by right posterior injuries, there does exist a material-specific deficit in recognizing faces.     

Do fearful eyes activate empathy-related brain regions in individuals with callous traits?

Psychopathy, a developmental disorder characterized by profound social disturbance, is associated with impaired recognition of distress cues. Since distress processing and moral socialization are closely linked, uncovering techniques to improve distress recognition could have positive treatment implications for developmental disorders that feature empathy impairments. Previous studies demonstrate that fear-recognition deficits can be remedied by redirecting attention to critical cues (the eyes for fearful faces). However, it remains unclear whether this manipulation increases activity in empathy-related brain regions, or has an alternate compensatory effect that may not promote prosocial behaviours. In this fMRI study, a community sample of individuals with high vs low callous traits completed an emotion recognition task that varied whether the most or least socially meaningful facial features were visible (the eyes were isolated or occluded). For fearful faces, individuals with high callous traits showed significantly less amygdala and medial prefrontal cortex activity than those with low callous traits when the eyes were occluded, but not when they were isolated. Consistent with recent models of the amygdala that emphasize orientation to disambiguate stimuli rather than represent distress, individuals with low trait empathy showed greater amygdala activity to the least vs most socially meaningful features of fearful faces.     

Through your eyes or mine? The neural correlates of mental state recognition in Huntington's disease

Huntington's disease (HD) can impair social cognition. This study investigated whether patients with HD exhibit neural differences to healthy controls when they are considering mental and physical states relating to the static expressions of human eyes. Thirty‐two patients with HD and 28 age‐matched controls were scanned with fMRI during two versions of the Reading the Mind in the Eyes Task: The standard version requiring mental state judgments, and a comparison version requiring judgments about age. HD was associated with behavioral deficits on only the mental state eyes task. Contrasting the two versions of the eyes task (mental state > age judgment) revealed hypoactivation within left middle frontal gyrus and supramarginal gyrus in HD. Subgroup analyses comparing premanifest HD patients to age‐matched controls revealed reduced activity in right supramarginal gyrus and increased activity in anterior cingulate during mental state recognition in these patients, while manifest HD was associated with hypoactivity in left insula and left supramarginal gyrus. When controlling for the effects of healthy aging, manifest patients exhibited declining activation within areas including right temporal pole. Our findings provide compelling evidence for a selective impairment of internal emotional status when patients with HD appraise facial features in order to make social judgements. Differential activity in temporal and anterior cingulate cortices may suggest that poor emotion regulation and emotional egocentricity underlie impaired mental state recognition in premanifest patients, while more extensive mental state recognition impairments in manifest disease reflect dysfunction in neural substrates underlying executive functions, and the experience and interpretation of emotion.     

Do fixation cues ensure fixation accuracy in split-fovea studies of word recognition?

Many studies have claimed that hemispheric processing is split precisely at the foveal midline and so place great emphasis on the precise location at which words are fixated. These claims are based on experiments in which a variety of fixation procedures were used to ensure fixation accuracy but the effectiveness of these procedures is unclear. We investigated this issue using procedures matched to the original studies and an eye-tracker to monitor the locations actually fixated. Four common types of fixation cues were used: cross, two vertical gapped lines, two vertical gapped lines plus a secondary task in which a digit was presented at the designated fixation point, and a dot. Accurate fixations occurred on <35% of trials for all fixation conditions. Moreover, despite the usefulness often attributed to a secondary task, no increase in fixation accuracy was produced in this condition. The indications are that split-fovea theory should not assume that fixation of specified locations occurs in experiments without appropriate eye-tracking control or, indeed, that consistent fixation of specified locations is plausible under normal conditions of word recognition.     

Do animals and furniture items elicit different brain responses in human infants?

One of the earliest categorical distinctions to be made by preverbal infants is the animate–inanimate distinction. To explore the neural basis for this distinction in 7–8-month-olds, an equal number of animal and furniture pictures was presented in an ERP-paradigm. The total of 118 pictures, all looking different from each other, were presented in a semi-randomized order for 1000 ms each. Infants’ brain responses to exemplars from both categories differed systematically regarding the negative central component (Nc: 400–600 ms) at anterior channels. More specifically, the Nc was enhanced for animals in one subgroup of infants, and for furniture items in another subgroup of infants. Explorative analyses related to categorical priming further revealed category-specific differences in brain responses in the late time window (650–1550 ms) at right frontal channels: Unprimed stimuli (preceded by a different-category item) elicited a more positive response as compared to primed stimuli (preceded by a same-category item). In sum, these findings suggest that the infant’s brain discriminates exemplars from both global domains. Given the design of our task, we conclude that processes of category identification are more likely to account for our findings than processes of on-line category formation during the experimental session.     

Do I fit in? Psychosocial ramifications of low gender typicality in early adolescence

The current longitudinal study was designed to examine one of the possible underlying mechanisms that can help account for why low gender typicality (i.e., not feeling like a typical boy or girl) is related to subsequent psychosocial adjustment problems: peer victimization. Relying on a large (N = 5,991, 52% female), ethnically diverse U.S. sample, the results suggested that peer victimization at 7th grade partially accounts for associations between 7th grade gender typicality and 8th grade social anxiety, somatic complaints, and externalizing behavior, when controlling for earlier (e.g., 6th grade) levels of adjustment. Associations were similar across ethnic groups. Peer victimization mediated associations for boys and girls across all outcomes; however, girls showed stronger associations with somatic complaints and boys showed stronger associations with externalizing behavior. These results suggest that attempts to improve adjustment for youth feeling low gender typicality should focus in part on reducing peer victimization.     

Is improved survival of very‐low‐birth weight infants in the 1980s and 1990s associated with increasing intellectual deficit in surviving children?

To investigate whether the decrease in mean birthweight of the smallest infants surviving with a very low birthweight (VLBW) in the past two decades is associated with an increase in intellectual deficit rates, we compared the results obtained in two different follow-up studies: one included a cohort of children of VLBW (<1500g; n=102, 52% male) born in the early 1980s; the other included a cohort of children of extremely low birthweight (ELBW; <1000g; n=183, 46% male) born in the mid-1990s. Intellectual development was evaluated in both cohorts. McCarthy Scales of Children's Abilities were used in the cohort from the early 1980s; Wechsler's Preschool and Primary Scale of Intelligence--Revised was used in the cohort from the mid-1990s. The children were assessed at age 4-5 years, and a control group was included for each of the two studies. Mean scores in the measures of intelligence found at the assessment were recalculated to standard deviation scores from the two control groups. We found no difference in the standard deviation scores between the two cohorts despite the mean birthweight being 353g (p<0.001) lower in the cohort from the mid-1990s, and the overall survival rate of infants of VLBW having increased. Our results suggest that the improved survival of the smallest babies in the 1980s and 1990s has been achieved without an increase in the intellectual deficit in the surviving children.     

Do adults with mental retardation show pictorial superiority effects in recall and recognition?

We examined memory for pictures and words in adults with mental retardation and a control group of adults of normal intelligence. During acquisition, sets of simple line drawings and matching words were presented for study using an intentional learning procedure. The principle dependent measures were free recall and recognition. Measures of working memory span were also administered. Pictorial superiority effects occurred in free recall and recognition for both intelligence-level groups. Correlational analyses indicated that working memory span was primarily related to recall performance, irrespective of stimulus format. These data strongly suggest that persons with mental retardation can utilize nonverbal memory codes to support long-term retention as effectively as do adults of normal intelligence.