Reduced anterior hippocampal formation volume in hyponatremic schizophrenic patients.

Diminished hippocampal volume occurs in the anterior segment of some schizophrenic patients, and in the posterior segment in others. The significance of hippocampal pathology in general and these segmental differences in specific is not known. Several lines of evidence suggest anterior hippocampal pathology underlies the life-threatening hyponatremia seen in a subgroup of patients with schizophrenia; therefore our goal was to determine if this region was preferentially diminished in hyponatremic patients. We studied seven polydipsic hyponatremic, ten polydipsic normonatremic, and nine nonpolydipsic normonatremic schizophrenic inpatients, as well as 12 healthy controls. All underwent structural scanning on a high resolution (3.0 T) magnetic resonance imaging (MRI) scanner. Hippocampal formation, amygdala, and third ventricle volumes were manually traced in each subject. The hippocampus was divided at the posterior extent of the uncus, and all structural volumes were corrected for whole brain volume and other significant recognized factors (i.e., age, gender, height, parental education). Despite being overhydrated, anterior hippocampal formation volume was diminished in those with polydipsia and hyponatremia relative to each of the other three groups. Third ventricle volume was larger in this group than in healthy controls but similar to the two patient groups. Posterior hippocampal and amygdala volumes did not differ between groups. Other potential confounds (e.g., water imbalance) either had no effect or accentuated these differences. We conclude the anterior hippocampal formation is smaller in hyponatremic schizophrenic patients, thereby linking an important and objective clinical feature of schizophrenia to a neural pathway that can be investigated in animal models. The findings strengthen the hypothesis that anterior hippocampal formation pathology disrupts functional connectivity with other limbic structures in schizophrenia.

Reliability of serial urine HCG as a biomarker to detect early pregnancy loss.

BACKGROUND: To examine the reliability of HCG as a biomarker for early pregnancy loss, five experienced researchers independently assessed data from 153 menstrual cycles, determining whether each cycle represented 'no conception,' a 'continuing conception' or a 'conception lost.' METHODS: Urine samples were analysed by immunoradiometric assay using a combination of capture antibodies for the intact heterodimer (B109) and for an epitope common to the beta subunit and the beta core fragment (B204). For each cycle, HCG data were presented as graphs of daily assay results. Summary statistics for HCG assays from 46 women who had undergone bilateral tubal ligation represented baseline values. RESULTS: Pairwise agreement among the assessors for any of the three options ranged from 78-89%. At least three experts agreed for 147 cycles (96%), accounting for 28 conception losses and 19 continuing conceptions. The multi-rater kappa was 0.62 for the conception lost category and 0.68 for continuing conceptions, indicating substantial agreement. CONCLUSION: The main sources of disagreement involved deciding whether there was sufficient information for assessment, interpreting cycle parameters such as cycle length or bleeding event, and interpreting a distinct HCG rise pattern that does not exceed the baseline value obtained from the sterilized women.

Mortality after cerebral angiography with or without radioactive Thorotrast: an international cohort of 3,143 two-year survivors.

There are few studies on the long-term sequelae of radionuclides ingested or injected into the human body. Patients exposed to radioactive Thorotrast in the 1930s through the early 1950s provide a singular opportunity, since the administration of this radiographic contrast agent resulted in continuous exposure to alpha particles throughout life at a low dose rate. We evaluated cause-specific mortality among an international cohort of 3,143 patients injected during cerebral angiography with either Thorotrast (n = 1,736) or a similar but nonradioactive agent (n = 1,407) and who survived 2 or more years. Standardized mortality ratios (SMRs) for Thorotrast and comparison patients were calculated, and relative risks (RR), adjusted for population, age and sex, were obtained by multivariate statistical modeling. Most patients were followed until death, with only 94 (5.4%) of the Thorotrast patients known to be alive at the closure of the study. All-cause mortality (n = 1,599 deaths) was significantly elevated among Thorotrast subjects [RR 1.7; 95% confidence interval (CI) 1.5-1.8]. Significantly increased relative risks were found for several categories, including cancer (RR 2.8), benign and unspecified tumors (RR 1.5), benign blood diseases (RR 7.1), and benign liver disorders (RR 6.5). Nonsignificant increases were seen for respiratory disease (RR 1.4) and other types of digestive disease (RR 1.6). The relative risk due to all causes increased steadily after angiography to reach a threefold RR at 40 or more years (P < 0.001). Excess cancer deaths were observed for each decade after Thorotrast injection, even after 50 years (SMR 8.6; P < 0.05). Increasing cumulative dose of radiation was directly associated with death due to all causes combined, cancer, respiratory disease, benign liver disease, and other types of digestive disease. Our study confirms the relationship between Thorotrast and increased mortality due to cancer, benign liver disease, and benign hematological disease, and suggests a possible relationship with respiratory disorders and other types of digestive disease. The cumulative excess risk of cancer death remained high up to 50 years after injection with >20 ml Thorotrast and approached 50%.

The silent consumer: women's reports and ratings of abortion services.

BACKGROUND: Abortion is one of the most common surgical procedures performed on women in the United States, and its safety has been demonstrated. Little research has focused, however, on women's reports and ratings of the service. OBJECTIVES: This study explored the association of demographic factors, medical outcomes, and client ratings of service dimensions with global satisfaction. RESEARCH DESIGN: For this cross-sectional study, permission to access clinic medical records was obtained. Surveys were distributed after the procedure, with instructions to return by mail. SUBJECTS: Study subjects were 797 women who underwent an outpatient surgical abortion at 1 of 2 New England health centers in 1996 and 1997. MEASURES: Demographic data, pregnancy history, and information on the procedure were collected from medical records. Survey items measured reports of access, medical outcomes, and satisfaction ratings with service domains. RESULTS: Women with positive ratings of staff sensitivity and of the counseling process and information received and those who had the procedure at a younger gestational age were less likely to report that care could be better. Although very few women reported a medical complication, this was associated with agreement that care could have been better, as was reporting agreement that the wait between the preexamination visit and the procedure was too long. CONCLUSIONS: Satisfaction with abortion services is high. Education and counseling play very important roles. Survey items could routinely be used to monitor services.

Anemia and deficiencies of folate and vitamin B-6 are common and vary with season in Chinese women of childbearing age.

Little is known about the micronutrient status of Chinese women of childbearing age. We assessed nonfasting plasma concentrations of folic acid, vitamin B-12, vitamin B-6 (as pyridoxal-5'-phosphate), hemoglobin (Hb), ferritin and transferrin receptor (TfR) in 563 nonpregnant textile workers aged 21-34 y from Anqing, China. All women had obtained permission to become pregnant and were participating in a prospective study of pregnancy outcomes. Mean (SD) plasma concentrations were 9.7 (4.1) nmol/L folic acid, 367 (128) pmol/L vitamin B-12, 40.2 (15.8) nmol/L vitamin B-6, 108 (12. 9) g/L Hb, 42.6 (34.2) microgram/L ferritin and 5.2 (2.7) mg/L TfR. Twenty-three percent of women had biochemical evidence of folic acid deficiency, 26% were deficient in vitamin B-6 and 10% had low vitamin B-12. Overall, 44% of women were deficient in at least one B vitamin. Although anemia (Hb < 120 g/L) was detected in 80% of women, only 17% had depleted iron stores (ferritin < 12 microgram/L); 11% had elevated TfR concentrations. Distinct seasonal trends were observed in the prevalence of moderate anemia (Hb < 100 g/L) and deficiencies of folic acid and vitamin B-6, with significantly lower concentrations of folate and Hb occurring in summer and lower concentrations of vitamin B-6 occurring in winter and spring than in other seasons. We conclude that deficiencies of folic acid, vitamin B-6 and iron were relatively common in this sample of Chinese women of childbearing age and were contributing to the high prevalence of anemia. Without appropriate supplementation, these deficiencies could jeopardize the women's health and increase their risk of adverse pregnancy outcomes.

Chromosomal aberrations and hprt mutant frequencies in long-term American thorotrast survivors.

PURPOSE: Patients injected with thorotrast, a radiologic contrast medium used from the 1920s to early 1950s, received chronic internal exposure to thorium-232, an alpha-emitter. Epidemiologic studies have observed markedly elevated risks of death from hepatic and hematologic cancers and extensive chromosomal damage among these patients. Few investigations have correlated multiple measures of genetic damage to determine whether these have independent induction kinetics. The distribution of chromosomal aberrations (CA) and mutant frequencies (MF) at the hypoxanthine phosphoribosyltransferase (hprt) locus was evaluated in eight long-term thorotrast survivors (mean exposure time=47.4 years) and five individuals who received a nonradioactive contrast medium during the same era. MATERIALS AND METHODS: Peripheral blood lymphocytes were harvested from whole blood, CA were scored in 500 complete metaphases and a clonal assay was used to determine hprt MF. Symmetrical aberrations were not evaluated. Differences in frequencies and correlations between endpoints were assessed using nonparametric methods. RESULTS: Thorotrast-exposed individuals differed from the comparison group in total number of multicentrics and centric and acentric rings (per 500 cells [median, mean +/- sd]: 11, 18.3+/-23.1 vs 2, 2.4+/-1.1, p =0.04). There was no difference between the groups on hprt MF (12.6, 15.9+/-13.5 vs 16.6, 14.0+/-8.8[ x 10(-6)]; p= 1.0). Among the exposed, hprt MF was moderately correlated with the frequency of asymmetrical chromosomal aberrations, although the association was not statistically significant. CONCLUSION: Noting the limitations of small samples, long-term thorotrast survivors were observed to be at an increased risk for genetic damage.

Adrenocorticotropin inhibition by restoration of normal evening cortisol levels: a measure of putative hippocampus-mediated glucocorticoid feedback in humans.

Hippocampus-mediated glucocorticoid negative feedback is thought to be relevant to the pathophysiology of neuropsychiatric disorders, but no reliable method of measuring it in humans has been developed. Converging lines of evidence indicate that basal hypothalamic-pituitary-adrenal axis activity during the unstressed circadian trough is primarily regulated by this feedback process. To assess whether negative feedback can be demonstrated under these circumstances, we studied normal controls (n = 5) who were pretreated with metyrapone to lower their basal evening cortisol levels. On two separate occasions, in double-blind randomized order, subjects received an infusion of cortisol or of saline. Restoration of normal evening plasma cortisol by the cortisol infusion produced a drop in plasma adrenocorticotropin (ACTH) apparent in the last sample obtained at +200 min (p < 0.05). The ACTH response in schizophrenic patients (n = 4), whose mental illness may arise from hippocampal dysfunction, was relatively blunted compared to that seen in normals (p < 0.02). 11-Desoxycortisol levels paralleled the ACTH responses across conditions and subject groups. These preliminary data suggest that hippocampus-mediated glucocorticoid feedback can be measured in normal subjects and may provide an index of hippocampal dysfunction in neuropsychiatric patients.

Effect of adjunctive cortisol on serum sodium in a polydipsic hyponatremic schizophrenic patient.

1. Many polydipsic schizophrenics exhibit enhanced antidiuretic hormone (ADH) activity and thus are hyponatremic and suffer life-threatening water intoxication. Excess cortisol inhibits ADH, while cortisol insufficiency produces impairments in water balance resembling those seen in hyponatremic schizophrenics. Furthermore, hyponatremia normally upregulates cortisol receptors on the neurons which synthesize ADH, which should make them more sensitive to the effects of cortisol. 2. The author treated a hyponatremic schizophrenic, whose water imbalance was unresponsive to standard clinical interventions including clozapine, with a 4-week open trial of 60 mg cortisol daily, followed by a three week taper. 3. Mean serum sodium levels appeared to increase modestly from 114.3 to 118.5 mEq/l while the patient received adjunctive cortisol (P < .06). 4. While a modest effect was seen, the results do not suggest that adjunctive cortisol will reverse hyponatremia, and instead support other data indicating that these patients exhibit a central resistance to glucocorticoid actions.

Influence of the ventral hippocampal formation on plasma vasopressin, hypothalamic-pituitary-adrenal axis, and behavioral responses to novel acoustic stress.

The ventral hippocampal formation (vHF) seems to constrain diverse responses to psychological stimuli, and disruption of this function may underlie severe neuropsychiatric diseases. In particular, the ventral subiculum inhibits hypothalamic-pituitary-adrenal axis (HPA) activity following psychological, but not systemic, stressors. Despite the difficulty in interpreting such HPA responses, they have been relied upon to further characterize vHF function, because increased HPA axis activity is implicated in neuropsychiatric disturbances, and reliance on behavioral and cognitive data is even more problematic. Plasma arginine vasopressin (pAVP), which is inhibited by psychological stimuli and is also implicated in diverse neuropsychiatric diseases, provides a less ambiguous measure of CNS function. To test if its inhibition by psychological stress is also mediated by the vHF, we conducted two studies. In the first, pAVP and behavioral responses to novel acoustic stress were assessed in rats with bilateral excitotoxic lesions of the ventral subiculum and the ventral hippocampus. The subiculum lesions blocked the fall in pAVP and enhanced escape behaviors, whereas the hippocampal lesions produced responses intermediate to those in the subiculum-lesioned and control rats. In the second study, the pAVP response was similarly blocked by small lesions restricted to those vHF subfields which project to the neuroendocrine hypothalamus, compared to the response in animals with lesions in other vHF subfields. These results indicate that discrete projections from the vHF inhibit the pAVP response to psychological stimuli, and suggest that pAVP may provide a reliable probe of vHF activity.

Clozapine restores water balance in schizophrenic patients with polydipsia-hyponatremia syndrome.

Hyponatremia/hypoosmolemia causes marked morbidity and prolongs hospital stays in a significant subset of schizophrenic patients. Case reports with methodological limitations suggest clozapine ameliorates this water imbalance. To more conclusively assess this possibility, we completed a 24-week open-label study in 8 male polydipsic hypoosmolemic schizophrenic inpatients. Subjects were treated initially for 6 weeks with a conventional neuroleptic, which was replaced by 300, 600, and 900 (if tolerated) mg/day of clozapine for sequential 6-week periods. On clozapine, mean plasma osmolality rose an average of 15.2 mosm/kg (95% CI: 5.5-25.0). Dosage of 300 mg/day of clozapine was sufficient to normalize plasma osmolality and was generally well tolerated. Clozapine appears to be the first effective pharmacotherapy for severe water imbalance in schizophrenia.

A prospective study of reproductive factors and oral contraceptive use in relation to the risk of uterine leiomyomata.

OBJECTIVE: To investigate the risk of uterine leiomyomata in relation to reproductive factors and oral contraceptive use. DESIGN: A prospective study. SETTING: A cohort of female registered nurses from 14 states in the United States who completed mailed questionnaires in 1989, 1991, and 1993. PATIENT(S): Premenopausal nurses (n=95,061) aged 25-42 years with intact uteri and no history of diagnosed uterine leiomyomata or cancer in 1989. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Incidence of self-reported uterine leiomyomata confirmed by ultrasound or hysterectomy. In a sample of 243 cases, 93% of the self-reported diagnoses were confirmed in the medical record. RESULT(S): During 326,116 person-years of follow-up, 3,006 cases of uterine leiomyomata, confirmed by ultrasound or hysterectomy, were reported. After adjustment for other risk factors, the risk of uterine leiomyomata was significantly inversely associated with age at menarche, parity, and age at first birth, and positively associated with a history of infertility and years since last birth. The only notable association with any aspect of oral contraceptive use was a significantly elevated risk among women who first used oral contraceptives at ages 13-16 years compared with those who had never used oral contraceptives. CONCLUSION(S): Reproductive factors and oral contraceptive use at a young age influence the risk of uterine leiomyomata among premenopausal women.

PIP: The 95,061 US women enrolled in the 1989 cohort of the Nurses' Health Study II were queried, in the 1993 questionnaire, about any recent history of uterine leiomyomata. At study enrollment (at ages 25-42 years), all women were premenopausal and had intact uteri with no history of diagnosed uterine leiomyomata or cancer. During 326,116 woman-years of follow-up, 3006 new cases of uterine leiomyomata (confirmed by ultrasound or hysterectomy) were reported. After adjustment for other risk factors, the risk of uterine leiomyomata was significantly inversely associated with age at menarche, parity, and age at first birth and significantly positively associated with a history of infertility and years since last birth. The only significant oral contraceptive (OC)-related association was an elevated risk among women who first used OCs at ages 13-16 years compared with OC never-users. The excess risk persisted after controls for histories of menstrual cycle irregularity in high school and severe teenage acne--factors that may have led to the prescription of OCs in early adolescence. The increased risk among women with an early menarche and decreased risks among parous and high-parity women support the hypothesis that myometrial responses to estrogens may be important in the etiology of uterine leiomyomata. The role of exogenous hormones resulting from OC use remains unclear.

Risk of uterine leiomyomata among premenopausal women in relation to body size and cigarette smoking.

To investigate whether factors influencing ovarian function affect risk of uterine leiomyomata, we examined prospectively the association of new diagnoses confirmed by ultrasound or hysterectomy with body mass index, weight change, height, and cigarette smoking among 94,095 premenopausal women with intact uteri, who were ages 25-42 years at the start of follow-up in 1989. We assessed body mass index and cigarette smoking from responses on the study questionnaire completed just before diagnosis. During 322,775 person-years, 2,967 new cases of uterine leiomyomata confirmed by ultrasound or hysterectomy were reported. Risk among all cases confirmed by ultrasound or hysterectomy increased with increasing adult body mass index. The multivariate relative risks (RR) and 95% confidence intervals (CI) according to body mass index categories of <20.0, 20.0-21.9, 22.0-23.9, 24.0-25.9, 26.0-27.9, 28.0-29.9, and > or =30.0 were 0.90 (95% CI = 0.79-1.03), 1.00 (referent), 1.08 (95% CI = 0.97-1.21), 1.16 (95% CI = 1.03-1.31), 1.21 (95% CI = 1.05-1.40), 1.36 (95% CI = 1.16-1.59), and 1.23 (95% CI = 1.09-1.39), respectively. The RRs for hysterectomy-confirmed cases generally were higher. Similarly, risk was positively associated with weight gain since age 18 years. Body mass index at age 18 years, height, and cigarette smoking were unrelated to risk of uterine leiomyomata. Elevated adult body mass index is associated with a modest increased risk of uterine leiomyomata among premenopausal women.

Cancer mortality following treatment for adult hyperthyroidism. Cooperative Thyrotoxicosis Therapy Follow-up Study Group.

CONTEXT: High-dose iodine 131 is the treatment of choice in the United States for most adults with hyperthyroid disease. Although there is little evidence to link therapeutic (131)I to the development of cancer, its extensive medical use indicates the need for additional evaluation. OBJECTIVE: To evaluate cancer mortality among hyperthyroid patients, particularly after (131)I treatment. DESIGN: A retrospective cohort study. SETTING: Twenty-five clinics in the United States and 1 clinic in England. PATIENTS: A total of 35 593 hyperthyroid patients treated between 1946 and 1964 in the original Cooperative Thyrotoxicosis Therapy Follow-up Study; 91 % had Graves disease, 79% were female, and 65% were treated with (131)I. MAIN OUTCOME MEASURE: Standardized cancer mortality ratios (SMRs) after 3 treatment modalities for hyperthyroidism. RESULTS: Of the study cohort, 50.5% had died by the end of follow-up in December 1990. The total number of cancer deaths was close to that expected based on mortality rates in the general population (2950 vs 2857.6), but there was a small excess of mortality from cancers of the lung, breast, kidney, and thyroid, and a deficit of deaths from cancers of the uterus and the prostate gland. Patients with toxic nodular goiter had an SMR of 1.16 (95% confidence interval [CI], 1.03-1.30). More than 1 year after treatment, an increased risk of cancer mortality was seen among patients treated exclusively with antithyroid drugs (SMR, 1.31; 95% CI, 1.06-1.60). Radioactive iodine was not linked to total cancer deaths (SMR, 1.02; 95% CI, 0.98-1.07) or to any specific cancer with the exception of thyroid cancer (SMR, 3.94; 95% CI, 2.52-5.86). CONCLUSIONS: Neither hyperthyroidism nor (131)I treatment resulted in a significantly increased risk of total cancer mortality. While there was an elevated risk of thyroid cancer mortality following (131)I treatment, in absolute terms the excess number of deaths was small, and the underlying thyroid disease appeared to play a role. Overall, (131)I appears to be a safe therapy for hyperthyroidism.

Variation in the incidence of uterine leiomyoma among premenopausal women by age and race.

OBJECTIVE: To quantify the incidence of uterine leiomyoma confirmed by hysterectomy, ultrasound, or pelvic examination according to age and race among premenopausal women. METHODS: From September 1989 through May 1993, 95,061 premenopausal nurses age 25-44 with intact uteri and no history of uterine leiomyoma were followed to determine incidence rates of uterine leiomyoma. The self-reported diagnosis was confirmed in 93% of the medical records obtained for a sample of cases. Using pooled logistic regression, we estimated relative risks (RRs) of uterine leiomyoma according to race and examined whether adjustment for other potential risk factors could explain the variation in the race-specific rates. RESULTS: During 327,065 woman-years, 4181 new cases of uterine leiomyoma were reported. The incidence rates increased with age, and the age-standardized rates of ultrasound- or hysterectomy-confirmed diagnoses per 1000 woman-years were 8.9 among white women and 30.6 among black women. After further adjustment for marital status, body mass index, age at first birth, years since last birth, history of infertility, age at first oral contraceptive use, and current alcohol consumption, the rates among black women were significantly greater for diagnoses confirmed by ultrasound or hysterectomy (RR 3.25; 95% confidence interval [CI] 2.71, 3.88) and by hysterectomy (RR 1.82; 95% CI 1.17, 2.82) compared with rates among white women. We observed similar RRs when the cohort was restricted to participants who reported undergoing a screening physical examination within the 2 years before baseline. CONCLUSION: A higher prevalence of known risk factors did not explain the excess rate of uterine leiomyoma among premenopausal black women.

Anterior medial temporal lobe volumes in polydipsic schizophrenic patients with and without hypo-osmolemia: a pilot study.

The volume of certain brain structures, particularly those in the anterior medial temporal lobe, may be reduced to a greater extent in hyponatremic/hypo-osmolemic polydipsic schizophrenics than other schizophrenic patients. To explore if volume reduction is specific to this particular brain region, and if it is fundamentally associated with polydipsia, we imaged the anterior hippocampi/subicula and adjacent temporal lobes in normal males (n = 10) and polydipsic schizophrenic patients with (n = 7) and without (n = 6) hypo-osmolemia. Bilateral hippocampal/subicular (p < .01), but not temporal lobe (p < .30), volumes were diminished in the hypo-osmolemics relative to the other two groups, who resembled each other on these measures. No recognized or putative factor could explain these findings. Thus anterior medial temporal lobe structures appear to be preferentially diminished in hypo-osmolemic polydipsic schizophrenics. Additional studies are needed to more precisely define these anatomic differences and their relationship to these patients' impaired water excretion and severe mental illness.

Cancer incidence after retinoblastoma. Radiation dose and sarcoma risk.

CONTEXT: There is a substantial risk of a second cancer for persons with hereditary retinoblastoma, which is enhanced by radiotherapy. OBJECTIVE: To examine long-term risk of new primary cancers in survivors of childhood retinoblastoma and quantify the role of radiotherapy in sarcoma development. DESIGN: Cohort incidence study of patients with retinoblastoma followed for a median of 20 years, and nested case-control study of a radiation dose-response relationship for bone and soft tissue sarcomas. SETTING/PARTICIPANTS: A total of 1604 patients with retinoblastoma who survived at least 1 year after diagnosis, identified from hospital records in Massachusetts and New York during 1914 to 1984. RESULTS: Incidence of subsequent cancers was statistically significantly elevated only in the 961 patients with hereditary retinoblastoma, in whom 190 cancers were diagnosed, vs 6.3 expected in the general population (relative risk [RR], 30 [95% confidence interval, 26-47]). Cumulative incidence (+/-SE) of a second cancer at 50 years after diagnosis was 51.0% (+/-6.2%) for hereditary retinoblastoma, and 5.0% (+/-3.0%) for nonhereditary retinoblastoma. All 114 sarcomas of diverse histologic types occurred in patients with hereditary retinoblastoma. For soft tissue sarcomas, the RRs showed a stepwise increase at all dose categories, and were statistically significant at 10 to 29.9 Gy and 30 to 59.9 Gy. A radiation risk for all sarcomas combined was evident at doses above 5 Gy, rising to 10.7-fold at doses of 60 Gy or greater (P<.05). CONCLUSIONS: Genetic predisposition has a substantial impact on risk of subsequent cancers in retinoblastoma patients, which is further increased by radiation treatment. A radiation dose-response relationship is demonstrated for all sarcomas and, for the first time in humans, for soft tissue sarcomas. Retinoblastoma patients should be examined for new cancers and followed into later life to determine whether their extraordinary cancer risk extends to common cancers of adulthood.

Psychotic exacerbations and enhanced vasopressin secretion in schizophrenic patients with hyponatremia and polydipsia.

BACKGROUND: For unclear reasons, life-threatening water intoxication often coincides with acute psychosis in polydipsic schizophrenic patients with chronic hyponatremia. In contrast, most polydipsic schizophrenic patients are normonatremic and never manifest hyponatremia. To explore whether the effect of acute psychosis on water balance differs in these 2 schizophrenic subgroups, we compared their responses to drug-induced psychotic exacerbations. METHODS: Matched polydipsic schizophrenic patients with (n = 6) and without (n = 8) hyponatremia were identified based on past and current indexes of fluid intake and hydration. A transient psychotic exacerbation was induced with an infusion of the psychotomimetic methylphenidate hydrochloride (0.5 mg/kg of body weight over a 60-second period). Antidiuretic hormone levels, subjective desire for water, and factors known to influence water balance were measured at 15-minute intervals for 2 hours. RESULTS: Except for the expected differences in plasma osmolality and sodium, basal measures were similar in the 2 groups. Following methylphenidate administration, antidiuretic hormone levels increased more in the hyponatremic patients (P < .02), despite their consistently lower plasma osmolality (P < .007). No known or putative antidiuretic hormone stimulus could account for this finding. Only basal positive psychotic symptoms (P < .09) and plasma sodium (P < .18) were even marginally associated with the peak antidiuretic hormone responses, but neither factor could explain the difference in the response by the 2 groups. CONCLUSION: Psychotic exacerbations are associated with enhanced antidiuretic hormone secretion, for unknown reasons, in schizophrenic patients with hyponatremia and polydipsia, thereby placing them at increased risk of life-threatening water intoxication.

Influence of the hippocampus/subiculum on antidiuretic hormone levels during stress.

The hippocampus/subiculum has been hypothesized to restrain hypothalamically mediated neuroendocrine responses to psychological stressors. While psychological stress has been observed to restrict plasma vasopressin (AVP) secretion, the role of these brain structures has not been examined. We subjected rats with bilateral aspiration of the hippocampus and controls with bilateral aspiration of the overlying neocortex to a 45 s swim stress. Plasma AVP and relevant AVP stimuli were measured at 30 min intervals for 90 min following the stressor. Immediately following the stressor, AVP levels were similar in the two groups, and then rose in hippocampal-lesioned animals to a greater extent than in the controls. None of the measured AVP stimuli could account for this difference. We conclude that rats with hippocampal lesions demonstrate increases in plasma AVP following psychological stress.

Does minimizing neuroleptic dosage influence hyponatremia?

Neuroleptic dosage was reduced by 10% every 2 weeks in five male hyponatremic polydipsic patients with schizophrenia. Mean dose fell from 1980 +/- 1289 to 631 +/- 135 chlorpromazine equivalents/day over a mean of 12.2 weeks until behavioral relapse occurred. During this time, serum sodium did not vary from baseline levels (132.9 +/- 4.9 mEq/1), suggesting that minimizing neuroleptic dose does not alter the severity of hyponatremia in these patients.