Influence of young maternal age and parity on term and preterm low birthweight

Data on 4496 singleton births to young women (19 years or less) are reported by maternal age and parity with birthweight and gestation cross-classified to yield rates of preterm and term low birthweight. After adjustment, the risk of preterm low birthweight was increased with very young maternity (15 years or less); preterm low birthweight and term low birthweight were each increased with young multiparity. These data suggest that the identification of factors associated with preterm birth and their incorporation into the prenatal care regimen may be important in improving pregnancy outcome in young women.     

Rate and amount of weight gain during adolescent pregnancy: associations with maternal weight-for-height and birth weight

This study presents information on the course and rates of weight gain and the associations among weight gain, prepregnancy weight-for-height, and infant birth weight, based on a total sample of 1419 uncomplicated term deliveries to adolescents. The distribution of cumulative weight gain indicates that for adolescents not only is the median gain at term (14.2-15.5 kg) significantly in excess of that reported for adults, but also weight-gain velocity is greater from the beginning of pregnancy. Although the contributions of prepregnancy weight-for-height and weight gain to birth weight may be independent, they are not necessarily additive. Birth weight does not appear improved for the infants of overweight adolescents except when weight gain is low (less than 11.1-12.3 kg at term), and, for Puerto Rican and black adolescents, birth weight is not further improved at any maternal prepregnancy body mass index (weight-for-height) with excessive weight gains (greater than 17.9-19.3 kg at term).     

Identifying Risk Factors for HIV-Associated Neurocognitive Disorders Using the International HIV Dementia Scale

HIV-associated neurocognitive disorders (HAND) persist despite great advancements in combination antiretroviral therapy (cART). The gold standard for diagnosing cognitive impairment consists of a time-consuming neuropsychological battery of tests given by a trained neuropsychologist, however in the outpatient HIV clinic this is not feasible. The International HIV Dementia Scale (IHDS) was developed to help identify individuals with cognitive impairment in the outpatient setting. The IHDS is moderately sensitive for detecting more symptomatic forms of HAND but sensitivity has been shown to be poor in mild impairment. The IHDS has not been evaluated in developed countries in large cohort populations. We conducted a prospective cross-sectional study of only HIV+ individuals in an urban clinic and evaluated the prevalence of HAND and associated risk factors for cognitive impairment using the IHDS. A total of 507 HIV+ individuals participated in the study of which the majority were male (65 %) and African American (68 %); and 41 % had cognitive impairment. On multivariate analysis, African American race (p?=?2.21), older age (p?=?1.03), high school education or less (p?=?2.03) and depression (p?=?1.05) were associated with cognitive impairment. The high prevalence of HAND in this group suggests that more severe forms of HAND persist despite cART. Identified risk factors were non-HIV-related and suggest that environmental and sociodemographic factors have a significant impact on cognitive functioning and should be given more attention. The IHDS should be further evaluated in large cohort HIV+ and HIV- populations in the United States, as there remains a significant need to identify an effective brief screening tool for cognitive impairment.     

Aging: impact upon local cerebral oxygenation and blood flow with acute isovolemic hemodilution

Data from the neurosurgical critical care arena demonstrate a correlation between cerebral oxygenation, survival, and cognitive function. Transfusion may increase and hemodilution decrease cerebral oxygenation. Both acute and chronic anemia have been associated with cognitive dysfunction. Aggressive blood conservation protocols have been instituted across all age groups without conclusive evidence for their impact upon outcome. Aged subjects are at the greatest risk of cognitive sequelae after major surgery associated with significant blood loss. We hypothesize that cerebral physiologic changes associated with "normal" aging may compromise cerebral oxygenation in the presence of severe anemia.Fischer 344 rats, the NIH National Institute of Aging normal aging rat model, underwent a stepwise isovolemic hemodilution protocol. Age groups (Age Grp) studied were as follows: Age Grp-A (3 months), n=14; Age Grp-B (9 to 12 months), n=14; and Age Grp-C (24 months), n=14. Brain oxygen tension (PBrO2), laser Doppler flow, and mean arterial pressure were measured. Final hemoglobin averaged 6.1+/-0.9 g/dL. PBrO2 levels decreased from a baseline of 18.1+/-4.1 to 17.5+/-6.8 mm Hg (P=0.49), and laser Doppler flow increased by 18+/-20% (P<0.0001) after hemodilution. Employing repeated measures multiple regression, Age Grp (P=0.30) was not a significant controlling covariate of PBrO2 in response to isovolemic hemodilution. PBrO2 levels were actually higher in Age Grp-C animals at all time points of the hemodilution protocol, although this was not statistically significant. Aged animals were also fully capable of mounting a robust local cerebral hyperemic response to the anemic challenge that was not separable from the response of younger animals.     

Downbeating nystagmus and muscle spasms in a patient with glutamic-acid decarboxylase antibodies

PURPOSE: To report the ophthalmic findings and response to treatment in a patient with glutamic-acid decarboxylase antibodies. DESIGN: Case report. METHODS: A 55-year-old woman developed progressive, painful, low back muscle spasms, vertical diplopia, downbeating nystagmus, and asymmetric appendicular ataxia. RESULTS: Downbeating nystagmus was present in primary gaze with an alternating skew deviation in lateral gaze. Serum and cerebrospinal fluid GAD antibodies were detected. Treatment with diazepam led to resolution of spasticity, whereas repeated courses of intravenous immunoglobulin improved cerebellar function, including appendicular ataxia and downbeating nystagmus. CONCLUSIONS: Patients with GAD antibodies may have elements of both Stiff-person syndrome (muscle rigidity and spasms) and prominent cerebellar dysfunction. Treatment with diazepam rapidly improved Stiff-person symptoms, whereas IVIg was partially effective at the early stage of cerebellar dysfunction.     

Early uncoupling of cerebral blood flow and metabolism after bilateral thalamic infarction

Cerebral blood flow and metabolism may be uncoupled in the early phases after stroke onset. Prior reports of bilateral thalamic stroke have described subsequent coupling of blood flow and metabolism during the chronic stage. We chronicled the evolving relationship of blood flow and metabolism with concomitant single photon emission CT and positron emission tomography from the subacute to chronic phase following bilateral thalamic infarction.     

Acute carotid occlusion alters the activation flow coupling response to forepaw stimulation in a rat model

BACKGROUND AND PURPOSE: To determine whether the hemodynamic response to functional stimulation is sensitive to proximal arterial occlusion, we measured the activation flow coupling response in a rat model of acute reversible vascular occlusion. METHODS: In alpha-chloralose-anesthetized rats (n=18), laser Doppler measurements were made through a thinned skull over the somatosensory cortex in response to electrical forepaw stimulation. Signal-averaged responses to 4 and 8 seconds of electrical forepaw stimulation were obtained before, during, and shortly after acute unilateral or bilateral carotid occlusion produced with the use of a surgically placed snare. RESULTS: Baseline cerebral blood flow was significantly decreased over the forepaw region of the somatosensory cortex after both occlusion of the carotid contralateral to the stimulated forepaw and bilateral occlusion compared with preocclusion (P<0.05). Postocclusion and ipsilateral occlusion led to a nonsignificant increase in baseline cerebral blood flow compared with preocclusion. Contralateral carotid occlusion and bilateral occlusion significantly prolonged the temporal characteristics of the flow response, especially the delay to peak (P<0.05), compared with preocclusion, whereas ipsilateral carotid occlusion significantly shortened the delay to peak (P<0.05). Only contralateral carotid occlusion produced a significant reduction in the peak amplitude of the flow response compared with preocclusion (P<0.05). CONCLUSIONS: These findings suggest that temporal characteristics of functional activation responses are sensitive to alterations in the proximal arterial supply and, conversely, that functional activation studies must be interpreted with consideration of proximal arterial disease.