Hydrocephalus and epilepsy: an actuarial analysis.

OBJECTIVE: To determine the prevalence of epilepsy among patients with hydrocephalus and to identify risk factors. METHODS: Retrospective chart review at a single institution was conducted. The definition of epilepsy used was long-term administration of antiepileptic drugs (AEDs) for suppression of seizures. Actuarial methodology was used, with initiation of AED therapy as the endpoint of the analysis. RESULTS: Insertion or revision of cerebrospinal fluid (CSF) shunts was performed on 464 patients at the study institution from 1976 through 1989. At the time of initial CSF shunt insertion, 12% of patients had already been treated with AEDs. After the 2nd year, the hazard rate for initiation of AED treatment was a constant 2% per year, and by 10 years after initial shunt insertion the estimated prevalence of AED treatment had risen to 33%. The cause of the hydrocephalus was a strong determinant of the prevalence of AED treatment, but most of the statistical effect of the cause was already manifest at the time of initial CSF shunt insertion. Age of patient at diagnosis of hydrocephalus, burr hole site, number of CSF shunt operations during follow-up, and history of shunt infection were factors that had no detectable association with AED treatment. CONCLUSION: Epilepsy is common among patients with hydrocephalus, and the risk of the development of epilepsy continues indefinitely for those patients. The complications of CSF shunt surgery seem to play a relatively minor role in the development of epilepsy in this patient population.

A search for determinants of cerebrospinal fluid shunt survival: retrospective analysis of a 14-year institutional experience.

All cerebrospinal fluid (CSF) shunt operations performed at Oregon Health Sciences University from 1976 through 1989 were reviewed retrospectively. There were 727 insertions or revisions of CSF shunts. Outcomes from these operations were studied using statistical techniques for analysis of survival data. There were 671 simple, linear shunts and 56 complex shunt systems incorporating 3-way connectors or consisting of multiple independent linear shunts. The overall estimated median survival of simple CSF shunts was 73 months, whereas the median survival of complex shunts was only 11 months (p = 0.0069). Only simple shunts were subjected to further analysis. The most important determinant of risk of obstruction was the age of the patient: children less than 2 years old were at higher risk than older patients (p < 0.00005). The risk of obstruction of a revised shunt was not different overall from the risk of failure of a new shunt, but revision of a shunt after an interval shorter than 6 months encountered a higher risk (p < 0.00005) of failure than either new shunts or shunts revised after a longer interval. The following factors had no significant influence on risk of obstruction: attending surgeon, etiology of hydrocephalus, duration of operation, time of day of operation, and whether the patient had epilepsy. Totally revised shunts lasted no longer than partially revised shunts. In children less than 2 years old, trends were observed favoring new shunts over revised shunts (p = 0.0355) and flat bottom valves over Hakim valves (p = 0.0255). The risk of shunt infection by 1 year was 8.5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzyl alcohol toxicity: impact on mortality and intraventricular hemorrhage among very low birth weight infants.

Benzyl alcohol preservative in intravascular flush solutions has been reported to cause neurologic deterioration and death in very low birth weight infants. Following the widespread discontinuation of the use of such solutions in newborns, scattered reports of decreased mortality and decreased incidence of intraventricular hemorrhage among small premature infants appeared in the pediatric literature. To better assess the true impact of benzyl alcohol toxicity in this group of infants, we undertook a detailed review of the medical records of all babies less than 1,250 g birth weight admitted to our neonatal intensive care unit for 13 months before and 13 months after the use of solutions containing benzyl alcohol was stopped. Significant decreases were found in both mortality rate (from 80.7% to 45.7%) and incidence of grade III/IV intraventricular hemorrhage (from 46% to 19%) among infants less than 1,000 g birth weight who did not receive the preservative compared with those who did. No significant changes were found in several other prenatal factors that could have contributed to this improvement in survival. We conclude that benzyl alcohol toxicity contributed significantly to both mortality and the occurrence of major intraventricular hemorrhage among infants weighing less than 1,000 g at birth and that solutions containing benzyl alcohol should never again be used in the care of such infants.

Feto-placental steroid metabolism in growth retarded human fetuses.

The goal of the study was the determination of the relative roles of the placenta and the fetus in causing low serum estriol (E3) levels in women bearing fetuses with intrauterine growth retardation (IUGR). Umbilical venous levels of E3 and dehydroepiandrosterone sulfate (DHAS) were measured in 31 samples from fetuses with IUGR, 21 of whom were vaginally delivered and 10 who were delivered by cesarean section. In addition, estrone (E1) and estradiol (E2) were measured in 11 of the samples. The results were compared with 11 samples from cesarean section delivered control term infants and 54 samples from vaginally delivered control infants. The vaginally delivered IUGR group had a significantly lower mean umbilical venous DHAS level than did their control group (2128 +/- 158 ng/ml SEM versus 2645 +/- 130, p less than 0.05). Both the vaginally delivered and cesarean section delivered IUGR infants had umbilical venous E3 levels significantly lower than in their control groups (70 +/- 10 ng/ml SEM versus 144 +/- 10, p less than 0.001, and 46 +/- 11 ng/ml SEM versus 136 +/- 23, p less than .01, respectively). Umbilical venous E1 and E2 levels were not different from the control values. E1, E2, E3, and DHAS were measured in eight maternal venous samples obtained from mothers bearing fetuses with IUGR. In comparison with 11 control mothers, only E3 was significantly different (10.7 +/- 3.0 ng/ml SEM in mothers with IUGR fetuses versus 25.0 +/- 4.9 in control mothers p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Fetoplacental steroid metabolism in prolonged pregnancies.

The response to an intravenous load of 50 mg of dehydroepiandrosterone sulfate given to women with a pregnancy prolonged to more than 42 weeks was compared to the response in control pregnant women at 40 weeks. The half-life of dehydroepiandrosterone sulfate was longer in the prolonged pregnancy group than in the control group (mean +/- SEM, 3.64 +/- 0.24 hour versus 2.78 +/- 1.08 hour, p less than 0.05), and the rises of serum free estrone and free estradiol 4 hours after infusion were less in the prolonged pregnancy group than in the control group. Maternal venous and umbilical venous estrone, estradiol, free estriol, and dehydroepiandrosterone sulfate levels were compared in samples from control, postmature, and postterm groups. Umbilical estriol concentrations were significantly less in the postmature group (67.8 +/- 9.5 ng/ml, mean +/- SEM) than in the control group (136 +/- 22.8 ng/ml, mean +/- SEM, p less than 0.01), but there were no significant differences between dehydroepiandrosterone sulfate, estrone, and estradiol levels. Maternal venous estriol levels were lower in the postmature group (13.3 +/- 2.1, p less than 0.05) than in the control group (25.0 +/- 4.9). A reduction in overall placental estrogen production was indicated by the results of the dehydroepiandrosterone sulfate loads in the patients with prolonged pregnancy, yet the normal umbilical venous estrone and estradiol levels do not fit this conclusion. There is no explanation for the discrepancy at this time.

Selenium and vitamin E sufficiency in premature infants requiring total parenteral nutrition.

A randomized prospective study of LBW infants was undertaken to evaluate the effect of parenteral lipid infusions upon their antioxidant systems. Ten babies received a parenteral nutrition regimen with lipid emulsion, and ten received a regimen without lipid. Although the addition of lipid emulsion to the total parenteral nutrition regimen led to a rise in vitamin E levels, the selenium levels fell in both groups. Neither group showed evidence of deficient antioxidant systems by the peroxide hemolysis test or thiobarbituric acid test. There did not seem to be any adverse effect of the lipid infusion upon the clinical course of the infants except for hyperlipidemia. There was a better weight gain in infants receiving lipid.

Adrenal cortical function in the postmature fetus and newborn infant.

The umbilical venous blood concentrations of cortisol, dehydroepiandrosterone sulfate (DHAS), and unconjugated estriol were compared in 54 normal, 37 postterm, and 22 postmature newborns. Pre- and postadrenocorticotropic hormone (ACTH) stimulation levels of serum cortisol and DHAS were compared in the first 2 to 4 days of life in 19 postterm and 15 postmature infants. Comparison was also made between vaginally an cesarean section delivered postterm and postmature newborns. There were significantly greater cord blood cortisol levels in th postmature [260 +/- 22 ng/ml (+/- S.E.)], than in the normal (193 +/- 11 ng/ml) (P less than 0.01) or postterm (193 +/- 18 ng/ml) (0.01 less than P less than 0.05) vaginally delivered infants. There were no significant differences in the mean cord blood DHAS levels in the three groups (normal, 2645 +/- 130 ng/ml; postterm 2323 +/- 188 ng/ml; postmature, 2310 +/- 224 ng/ml). Cortisol and DHAS responses to ACTH stimulation were the same in the postterm and postmature groups. There was a significantly lower mean umbilical venous unconjugated estriol level in the vaginally delivered postmature group (75 +/- 11 ng/ml) as compared to values in vaginally delivered postterm [120 +/- 14 ng/ml (P = 0.01)] and normal [144 +/- 10 ng/ml (P less than 0.002)] newborns. Stressed postmature infants delivered by cesarean section had higher unconjugated estriol levels (83 +/- 12 ng/ml) than their unstressed, postterm cesarean section controls [40 +/- 9 ng/ml (P less than 0.01)], but levels were still below those from vaginally delivered postterm infants. These findings substantiate normal adrenal function in the postmature fetus and newborn. Lowered umbilical venous unconjugated estriol levels in the postmature infants at birth appear to be a function of limited aromatizing activity of the placenta rather than due to the low levels of fetal adrenal-derived neutral steroid substrate.