Valproate-induced biochemical abnormalities in pregnancy corrected by vitamins: a case report.

PURPOSE: Valproate (VPA) is a teratogenic anticonvulsant (AED), but vitamin supplementation has been suggested to limit the effect of VPA on the fetus. Maternal urinary metabolites were monitored to assess the metabolic effects of VPA before and after vitamin supplementation. METHODS: A pregnant woman with epilepsy receiving VPA and ethosuximide (ESM) was given high-dose multivitamins from 13 to 28 weeks' gestation. Maternal urinary metabolites were measured throughout the pregnancy by gas chromatography/mass spectrometry. RESULTS: Before multivitamin supplementation began, the patient had significantly increased excretion rates of alpha-ketoglutarate, beta-lactate, pyruvate, lactate, methylmalonate, and other metabolites compared with normal pregnant women. During multivitamin supplementation, many previously increased excretion rates decreased significantly. Fetal head growth was normal up to 30 weeks, but then lagged. Bitemporal narrowing was noted at birth. CONCLUSIONS: VPA may cause metabolic abnormalities in pregnancy. Many biochemical abnormalities attributable to VPA in this patient were corrected with high-dose multivitamin supplementation. The specific relation between biochemical abnormalities and VPA teratogenesis remains to be determined.

Time quantified detection of fetal movements using a new fetal movement algorithm.

Primarily, the objective is to develop an automated ultrasound fetal movement detection system that will better characterize fetal movements. Secondarily, the objective is to develop an improved method of quantifying the performance of fetal movement detectors. We recorded 20-minute segments of fetal movement on 101 patients using a UAMS-developed fetal movement detection algorithm (Russell algorithm) and compared this to a Hewlett-Packard (HP) M-1350-A. Movements were recorded on a second-per-second basis by an expert examiner reviewing videotaped real-time ultrasound images. Videotape (86,592 seconds) was scored and compared with the electronic movement-detection systems. The Russell algorithm detected 95.53% of the discrete movements greater than 5 seconds, while the HP system (M-1350-A) detected only 86.08% of the discrete movements (p = 0.012). Both devices were less efficient at detecting the short discrete movements, obtaining sensitivities of 57.39 and 35.22, respectively. Neither system fully identifies fetal movement based on the second-per-second system. Improved methods of quantifying performance indicated that the Russell algorithm performed better than the HP on these patients.

Height changes in the organ of Corti after noise exposure.

To determine whether or not exposure to noise causes an alteration in the height of the organ of Corti (OC), 16 cochleas which had been exposed for one or two hours to an octave band of noise with a center frequency of 4 kHz and a sound pressure level of 108 dB were examined microscopically as whole mounts. These specimens were divided into four groups: early ears (N = 3) recovered less than 0.6 hours following the exposure; intermediate ears (N = 5) recovered 0.6-4.0 hours; 1-day ears (N = 3) recovered 24 hours; and late ears (N = 5) recovered 2-21 days. Height was measured at three positions across the OC and at multiple percentage locations from apex to base. The OC-height data from the noise-exposed cochleas were compared statistically to those from ten control cochleas. A significant reduction (P < or = 0.01) in OC height at the third outer hair cell (OHC) was first evident in the early ears in the region 65-95% distance from the apex. The height was reduced even further in the intermediate ears and included a region from 15-25% distance from the apex as well as the 65-95% region. In the late ears, heights had returned to control values, except within focal OC lesions. Height at the first row of OHCs was less affected than at the third row, and height at the inner hair cell (IHC) was least affected. These height changes were accompanied by distortion of the shape and position of OHCs, the shape of Deiters' cells and buckling of inner and outer pillar bodies. Sometimes IHCs had distorted shapes and were displaced from their usual positions. Although no functional measures were obtained from these ears, data from the literature indicate that the exposure described above would have produced a sizable threshold shift. Transient reduction in OC height likely accounts for some portion of noise-induced threshold shifts.

Use of phase contrast microscopy to determine the height of the organ of Corti in whole-mount preparations.

A technique has been developed to measure the height of the organ of Corti (OC) in the whole-mount preparations of the cochlear duct. The technique corrects for variations in the microscope system, such as the magnification of the objective lens and the mechanical properties of the fine-focus knob, as well as the refractive index of the embedding medium and the angle of specimens with respect to the optical axis of the microscope. At 11 percentage locations from apex to base, the height of the OC in ten chinchilla cochleas was measured at three positions: (1) the lateral edge of the inner hair cell (IHC); (2) the medial edge of the first row outer hair cell (OHC1); and (3) the lateral edge of the third row outer hair cell (OHC3). These measurements were compared to measurements made on radial sections from five other cochleas, with very good agreement at IHC and OHC3, and fairly good agreement at OHC1. The height at OHC3 varied almost linearly with percentage distance along the OC, ranging from 96 microns (apical end) to 51 microns (basal end). The height at the OHC1 varied from 77 to 49 microns, but did not vary linearly. The height of the IHC was relatively constant, from 50 to 60 microns, except at the basal end, where it decreased to 42 microns.

Relative frequency of inferior vestibular schwannoma.

Until quite recently, acoustic tumors were not diagnosed until they had reached relatively large size. Vestibular function tests were positive in a large percentage of these cases. Since vestibular function tests are limited to lesions of the superior branch of the vestibular nerve, it was thought that 90% of vestibular schwannomas arose from the superior vestibular nerve. Recently, as the diagnostic efficiency of auditory tests has improved, many small tumors are being detected. As the size of the tumors decreases, the efficiency of vestibular function testing has also decreased. A review of histologic and surgical literature demonstrates that the earlier estimate is inaccurate, and that only 50% of vestibular schwannomas originate on the superior branch of the vestibular nerve. This warrants a critical review of the value of vestibular function tests in the evaluation of suspected vestibular schwannomas.