Birth insult alters dopamine-mediated behavior in a precocial species, the guinea pig. Implications for schizophrenia. (17/328)

Schizophrenia is associated with increased birth complications, suggesting that birth complications might alter CNS dopaminergic activity later in life. In rats, Caesarean section (C-section) birth can produce long term changes in dopaminergic biochemistry and behavior. However rat brain is somewhat immature compared to human brain at birth. The current study tested if mild birth complications also alter dopamine-mediated function in a species with a more mature CNS at birth, the guinea pig. As adults, guinea pigs born by C-section showed increased amphetamine-induced locomotion and disruption of prepulse inhibition (PPI) of acoustic startle, compared to vaginally born controls. Guinea pigs born by C-section with 1 min of added global anoxia showed reduced amphetamine-induced locomotion and disrupted PPI, while a C-section plus 2 min anoxia group showed no change in amphetamine-induced locomotion but increased amphetamine-induced startle. No group differences in effects of amphetamine or apomorphine on PPI were observed. Taken with previous findings, these results indicate that mild birth complications can cause long term changes in dopamine-mediated behavior in both guinea pig and rat, two species spanning the level of human brain maturity at birth.  (+info)

Quantitative analysis of MR images in asphyxiated neonates: correlation with neurodevelopmental outcome. (18/328)

BACKGROUND AND PURPOSE: MR imaging has been shown to be of prognostic significance in the evaluation of asphyxiated neonates. The purpose of this project was to determine whether the use of intensity ratios in key regions of the brain might better detect regions of injured brain and thus improve the correlation of imaging findings with 12-month neurodevelopmental outcome. METHODS: Prospectively acquired MR studies of 53 asphyxiated neonates were reviewed retrospectively. Signal intensities from standard T1- and T2-weighted images of seven major brain regions that are affected in asphyxia were measured. Intensity ratios were calculated by dividing the signal intensity of each brain region by the signal intensity of the ocular vitreous. The intensity ratios were then correlated with 12-month neurodevelopmental outcome. These results were compared with correlations determined by a qualitative scoring system. RESULTS: The only significant statistical correlation between the intensity ratios and 12-month neurodevelopmental outcome were those of anterior watershed injury with the Mental Development Index of the Bayley Scales of Infant Development II. The qualitative measurements showed a strong correlation with many outcome parameters. CONCLUSION: Standard qualitative assessment is more predictive of neurodevelopmental outcome than is quantitative analysis. This finding most likely reflects the inability of the quantitative assessment of intensity ratios to compensate for the day-to-day evolution of signal intensity of the injured neonatal brain. Anterior watershed injury may be predictive of abnormal cognitive outcome; examination of these patients at age 30 months will be important to determine the accuracy of this observation.  (+info)

Birth trauma to muscles in babies born by breech delivery and its possible fatal consequences. (19/328)

Dissection and histological examination was made of the muscles of 86 babies who died after breech delivery, and of 38 babies who died after vertex presentation. A control group of 50 surviving breech-delivered babies was examined clinically and the results compared. It was concluded that the most common type of birth trauma to a baby born by breech delivery is injury to muscles and soft tissues of the back and lower extremities, which is often extensive. In some severly injured babies histological examination of organs revels signs of crush syndrome and disseminated intravascular coagulation. It is suggested that the extensive muscle trauma forms the background of these fatal conditions.  (+info)

Congenital subependymal pseudocysts: own data and meta-analysis of the literature. (20/328)

BACKGROUND: Congenital subependymal pseudocysts are incidental findings that are found in 0.5-5.2% of neonates during postmortem examination or head ultrasonography. In our institution we detected 10 neonates with CSEPC. OBJECTIVE: To investigate associated etiological factors, morphologic characteristics and outcome of CSEPC. METHODS: We performed a meta-analysis of the literature on CSEPC (1967-98), including our 10 cases. RESULTS: A total of 256 cases of CSEPC were analyzed. Ultrasound diagnosed 77.6% of CSEPC; 48.8% were bilateral and 53.4% were located in the caudothalamic groove or head of caudate nucleus. Altogether, 93.5% resolved during 1-12 months of ultrasonographic follow-up. Compared to the general neonatal population, the following features were more prevalent in the CSEPC population: prematurity, maternal vaginal bleeding, preeclamptic toxemia, intrauterine growth restriction, asphyxia, fetal cytomegalovirus and rubella infections, congenital malformations, chromosomal aberrations, infant mortality, and neurodevelopmental handicap. The risk for neurodevelopmental handicap was significantly higher when CSEPC were associated with fetal infections, IUGR, malformations and chromosomal aberrations, or persistence of CSEPC during follow-up. CSEPC infants without any of these four conditions had a low risk for neurodevelopmental handicap. CONCLUSIONS: CSEPC are morphologic features of various underlying conditions encountered in the fetus. Association of CSEPC with IUGR, fetal infections, malformations and chromosomal aberrations or persistence of CSEPC indicates a higher risk for future neurodevelopmental handicaps, probably because of the deleterious effects on the fetal brain that are inherent in these conditions. A favorable outcome is expected in the absence of these risk factors.  (+info)

Deciding for imperilled newborns: medical authority or parental autonomy? (21/328)

The ethical issues around decision making on behalf of infants have been illuminated by two empirical research studies carried out in Scotland. In-depth interviews with 176 medical and nursing staff and with 108 parents of babies for whom there was discussion of treatment withholding/withdrawal, generated a wealth of data on both the decision making process and the management of cases. Both staff and parents believe that parents should be involved in treatment limitation decisions on behalf of their babies. However, whilst many doctors and nurses consider the ultimate responsibility too great for families to carry, the majority of parents wish to be the final arbiters. We offer explanations for the differences in perception found in the two groups. The results of these empirical studies provide both aids to ethical reflection and guidance for clinicians dealing with these vulnerable families. They demonstrate the value of empirical data in the philosophical debate.  (+info)

The effects of bilateral hippocampal damage on fMRI regional activations and interactions during memory retrieval. (22/328)

Using functional magnetic resonance imaging (fMRI) we examined successful retrieval of real-world memories in a patient (Jon) with selective bilateral hippocampal pathology resulting from perinatal hypoxia compared with healthy control subjects. Jon activated the same brain regions during memory retrieval as control subjects, both medial and lateral on the left. In contrast to controls, Jon also activated many homologous regions on the right. In spite of having 50% volume loss bilaterally in his hippocampi, retrieval in Jon was associated with increased activation of the hippocampi. Furthermore, hippocampal activity, as with the controls, was differential, being most responsive to retrieval of autobiographical events compared with other memory types (autobiographical facts, public events, general knowledge). Jon made a distinction between events that the control subjects did not make, namely that some of the autobiographical and public events he clearly remembered, while others he found that he knew about but did not truly remember. His hippocampi and medial frontal cortex were significantly more active during retrieval of events for which he had clear and conscious recollection compared with those he knew as much about, including the context, but could not remember experiencing. Although Jon activates the same network of brain regions as the controls (albeit bilaterally), and with the same pattern of response in the hippocampus, the communication between regions differs from controls with regard to hippocampal-cortical connectivity. In controls there was increased effective connectivity between parahippocampal cortex and hippocampus, specifically during the retrieval of autobiographical events. In contrast, this increase was not apparent in Jon; rather, retrieval of autobiographical events elicited greater interaction between the hippocampus and retrosplenial cortex, and also increased interaction between retrosplenial and medial frontal cortex. This study underlines the value of scanning patients using fMRI while they undertake tasks they can perform, in this case allowing us to confirm the functionality of remaining tissue in the damaged hippocampi, and to appreciate the neural basis of a distinction (remember/know) that control subjects do not make. Besides refining our knowledge of the hippocampal role in autobiographical event memory, this study indicates that recruitment of bilateral regions during memory retrieval, and altered patterns of effective connectivity between brain regions may be important indicators of disordered memory.  (+info)

Proton spectroscopy and diffusion imaging on the first day of life after perinatal asphyxia: preliminary report. (23/328)

BACKGROUND AND PURPOSE: MR techniques have proved useful in assessing brain injury from perinatal asphyxia when the injury is subacute or chronic. Recent advances in understanding the molecular mechanisms of brain injury have made medical intervention plausible, creating a need for assessment of the brain within the first few hours of life. We report the results of early (first 24 hours after birth) MR imaging in seven patients, including proton MR spectroscopy in six. METHODS: MR studies were performed within the first 24 hours of life in seven consecutive patients who were encephalopathic after complicated deliveries. Standard T1-, T2-, and diffusion-weighted sequences were performed in all patients; single-voxel MR spectroscopy was performed in two locations in six of the seven patients. Follow-up MR studies were performed in four patients at ages 7, 8, 9, and 15 days, respectively. RESULTS: T1-weighted images were normal in all seven patients. T2-weighted images were normal in three patients and showed T2 prolongation in the basal ganglia or white matter in the other four. Diffusion images showed small abnormalities in the lateral thalami or internal capsules in all seven patients. Comparison with clinical course in all seven patients and with follow-up MR studies in four showed that the diffusion images underestimated the extent of brain injury. Proton MR spectroscopy showed substantial lactate elevation in all six of the patients studied. Two patients died in the neonatal period and the other five were left with clinically significant neurologic impairment. CONCLUSION: MR spectroscopy performed in the first 24 hours after birth is sensitive to the presence of hypoxic-ischemic brain injury, whereas diffusion imaging may help identify but underestimate the extent of the injury. Further studies are ongoing in an attempt to expand upon this observation.  (+info)

Signs of asphyxia at birth and risk of schizophrenia. Population-based case-control study. (24/328)

BACKGROUND: Previous research has found an association between obstetric complications and schizophrenia, but in many studies the sample size was limited, and no assessment of specific exposures was possible. AIMS: To assess the role of different complications, and in particular to distinguish between disordered foetal development and hypoxia at birth. METHOD: From the Stockholm County In-Patient Register and community registers, we identified 524 cases of schizophrenia and 1043 controls, matched for age, gender, hospital and parish of birth. Data on obstetric complications were obtained from birth records. RESULTS: There was a strong association between signs of asphyxia at birth and schizophrenia (OR 4.4; 95% C11.9-10.3) after adjustment for other obstetric complications, maternal history of psychotic illness and social class. CONCLUSIONS: Signs of asphyxia at birth are associated with an increased risk of schizophrenia in adults.  (+info)