Hippocampal dysfunction in Gulf War Syndrome. A proton MR spectroscopy study

The pathogenesis of Gulf War Syndrome (GWS) is not clearly understood. Data exist to suggest that GWS may originate from a combination of chronic fatigue and sensitivity to the exposure of exogenous agents. Since the head region of hippocampus is highly vascularized and thus vulnerable to toxic substances in circulation, we postulated that hippocampal impairment occurs in GWS. To test this, single volume localized in vivo proton MR spectroscopy (MRS) studies of the left and right hippocampi of consenting Gulf War veterans (N=15; 10 with GWS, and 5 without GWS) and control Vietnam veterans (N=6) were conducted in accordance with approved human study protocols. The N-acetyl aspartate (NAA) to creatine and choline to creatine ratios were computed from the spectra. The NAA/creatine ratio of the GWS group (N=10) was found to be significantly lower than that of the entire control group (N=11) or the unaffected GW control group (N=5). No laterality differences were observed among any of the three groups. The choline/creatine ratio of the GWS group was not different from that for either control group. To check the existence of any relationship between age and the NAA/creatine ratios, the entire study population was grouped into those below or above the median age (44.3 years). It was found that the NAA/Cre ratio of the younger group (only Gulf War veterans) was significantly lower than that of the older group. The lower NAA/creatine ratio for the GWS group points to the existence of hippocampal dysfunction.

Health-related quality of life in patients with schizophrenia during treatment with long-acting, injectable risperidone

BACKGROUND

We investigated the impact of treatment with long-acting, injectable risperidone versus placebo on health-related quality of life (HRQoL) in patients with schizophrenia. Results are discussed in the context of HRQoL in the general U.S. population.

METHOD

Patients with DSM-IV schizophrenia entered a randomized, double-blind, placebo-controlled trial. After screening, previous antipsychotics were discontinued, and oral risperidone was titrated up to a dose of 4 mg/day over 1 week. Patients were then randomly assigned to receive placebo [N = 92] or long-acting risperidone (25 [N = 93], 50 [N = 97], or 75 mg [N = 87] every 2 weeks) for 12 weeks. HRQoL was measured using the Medical Outcomes Study Short-Form 36-item questionnaire (SF-36).

RESULTS

At week 12, patients receiving long-acting risperidone had improved significantly (p <.05) in 5 domains of the SF-36 (bodily pain, general health, social functioning, role-emotional, and mental health) compared with patients receiving placebo. The effect was greatest for the 25-mg group, with significant improvement versus placebo in 6 domains (p <.05). At baseline, all SF-36 domain scores except bodily pain were significantly lower (p <.05) than normal values in all groups. With placebo, scores in all 8 domains remained below normal values after 12 weeks, while patients receiving long-acting risperidone showed improvement in HRQoL toward normal levels, with clinically meaningful improvements in all mental-health domains. In the 25-mg group, scores in 7 domains were not statistically different from normal values after 12 weeks.

CONCLUSIONS

Long-acting, injectable risperidone improved HRQoL toward normal levels. After 12 weeks, HRQoL of patients receiving 25 mg was not significantly different from normal.

Factors in antipsychotic drug selection: tolerability considerations

With the widespread use of atypical antipsychotics over the past several years, adverse metabolic effects have emerged as the most serious medical consequences of pharmacotherapy with some of these agents. Initially, weight gain and obesity were observed (especially with clozapine and olanzapine), but subsequently, type 2 diabetes and dyslipidemia became apparent as well. Further, many reports suggest that sudden and severe (occasionally fatal) diabetes ketoacidosis (DKA) can emerge during treatment with some atypical antipsychotics, even in the absence of adiposity. A marked increase of serum lipids (especially triglycerides) has also been reported, to varying degrees, with different atypicals. This article reviews the data regarding metabolic dysfunction in patients with psychosis (schizophrenia and bipolar disorder). Populations with psychosis have a 2-3-fold higher prevalence of diabetes even before treatment with any antipsychotics, suggesting a possible genetic linkage or comorbidity; this was confirmed with glucose regulation studies in schizophrenia and mania. The induction of type 2 diabetes with atypicals has further increased the prevalence of noninsulin-dependent diabetes from about 6% to 8% to 11% to 15% according to recent studies, and even higher rates of subclinical hyperglycemia. Serious weight gain (eg, 26-29 lbs after 1 year of clozapine or olanzapine treatment) is an important risk factor, but sudden DKA has now been reported in patients with minimal weight gain, suggesting alternative mechanisms, such as insulin resistance, as a direct effect of some atypicals. Psychiatrists can reduce the risk of metabolic disorders in schizophrenia and bipolar disorder by avoiding the use of certain atypicals as first-line treatment in patients with a personal or family history of diabetes, obesity, and hyperlipidemias. Regulatory agencies in some countries have already taken action in this regard.

Antipsychotic-induced type 2 diabetes: evidence from a large health plan database

Case evidence suggests that some of the atypical antipsychotics may induce type 2 diabetes. The objective of this study was to evaluate the association of antipsychotic treatment with type 2 diabetes in a large health plan database. Claims data for patients with psychosis within a health plan of nearly 2 million members were analyzed using logistic regression. Frequencies of newly treated type 2 diabetes in patients untreated with antipsychotics and among patients treated with quetiapine, risperidone, olanzapine, and conventional antipsychotics were compared. Based on exposure measured in months of antipsychotic treatment, quetiapine and risperidone patients had estimated odds of receiving treatment for type 2 diabetes that were lower than those of patients untreated with antipsychotics (not statistically significant); patients treated with conventional antipsychotics had estimated odds that were virtually equivalent to those of patients untreated with antipsychotics; olanzapine alone had odds that were significantly greater than those of patients untreated with antipsychotics (P = 0.0247). Odds ratios based on 8 months of screening for pre-existing type 2 diabetes and assuming 12 months of antipsychotic treatment were: risperidone = 0.660 (95% CI 0.311-1.408); olanzapine = 1.426 (95% CI 1.046-1.955); quetiapine = 0.976 (95% CI 0.422-2.271); and conventional antipsychotics = 1.049 (95% CI 0.688-1.613). Case reports, prospective trials, and other retrospective studies have increasingly implicated olanzapine and clozapine as causing or exacerbating type 2 diabetes. Few have implicated risperidone while evidence on quetiapine has been limited. This study supports earlier findings on risperidone versus olanzapine and builds evidence on quetiapine. Additional studies are needed to evaluate the association of antipsychotic treatment with type 2 diabetes.

Treatment of bipolar disorder

Management strategies for bipolar disorder often entail relatively long-term, complex medication regimens that combine primary mood stabilizers, antipsychotic agents, antidepressants, and other medications, such as benzodiazepines. New strategies for the management of bipolar disorder have recently been evaluated in controlled clinical trials, including using newer anticonvulsants, replacing conventional antipsychotics with atypical antipsychotics, and using novel combination treatments. This article provides an overview of current management strategies for patients with bipolar disorder and describes how these approaches can be incorporated into clinical practice.

Single-voxel proton MR spectroscopy of right versus left hippocampi in PTSD

Previous magnetic resonance (MR) volume imaging and proton MR spectroscopy studies have suggested a reduction in the hippocampal size and/or neuronal/axonal density in posttraumatic stress disorder (PTSD). The lack of agreement on the laterality of the hippocampal dysfunction prompted this study. A total of 20 veterans (18 men and two women) and one female non-veteran participated in this study conducted in accordance with approved human study protocols. Six of the male veterans and the female non-veteran were without PTSD. Vietnam veterans formed a large subset of the study subjects. Single-voxel proton MR spectra were obtained from the hippocampal region bilaterally on a clinical MR scanner operating at 1.5 T. Analysis of the proton MR spectra showed a decrease in hippocampal NAA/creatine ratio in PTSD subjects significantly higher on the left than the right for the entire study group, as well as for the Vietnam subset. It was concluded that the hippocampal dysfunction in PTSD is lateralized with the left side being more impaired than the right.

Efficacy, safety, and tolerability of quetiapine in patients with schizophrenia

Schizophrenia is a serious and disabling psychiatric disorder affecting approximately 1% of the world's population, with its economic cost in the United States alone estimated to exceed that of all cancers combined. The new generation of atypical antipsychotics introduced over the past decade have comparable or greater efficacy than traditional antipsychotics in treating the psychotic symptoms of schizophrenia and a much improved neurologic side effect profile. Quetiapine, the fourth atypical antipsychotic marketed in the United States, was approved by the U.S. Food and Drug Administration in September 1997 and is also currently approved in over 70 countries worldwide for the treatment of psychosis associated with schizophrenia. This article will review the clinical trials examining the efficacy, safety, and tolerability of quetiapine in the treatment of patients with schizophrenia.

Pharmacoeconomic implications of adverse effects during antipsychotic drug therapy

The pharmacoeconomic implications of adverse effects caused by antipsychotic drugs during the treatment of schizophrenia are discussed. When new treatment options are considered by a health system, a comprehensive assessment is required that includes not only the cost of treating the disease but also the ancillary costs of treating adverse effects and comorbidities associated with treatment. Atypical antipsychotic drugs constitute a significant advance over conventional antipsychotics in terms of broader efficacy and lower rates of extrapyramidal symptoms and tardive dyskinesia. However, these agents appear to be associated with certain adverse medical conditions that can increase overall treatment costs. These adverse effects include serious weight gain, dyslipidemia, diabetes, and changes in cardiac conduction. The available data suggest that the risk of these events is not uniform among the drugs. A comprehensive evaluation of risk factors, outcomes, and costs should be include in economic evaluations of antipsychotic drugs so that realistic strategies for reducing costs and improving health can be identified.

Differential effects of risperidone, olanzapine, clozapine, and conventional antipsychotics on type 2 diabetes: findings from a large health plan database

BACKGROUND

Case series suggest that some antipsychotics may induce or exacerbate type 2 diabetes. This study measured the association of antipsychotic treatments with diabetes at a population level.

METHOD

Claims data for psychosis patients (ICD-CM-9 290.xx-299.xx) within health plans encompassing 2.5 million individuals were analyzed. Patients reporting preexisting type 2 diabetes up to 8 months prior to observation were excluded. The frequency of newly reported type 2 diabetes in untreated patients and among patients treated with antipsychotics from 5 categories (risperidone, olanzapine, clozapine, and high-potency and low-potency conventionals) was compared. Logistic regression models compared the odds of diabetes based on exposure to each of the antipsychotic categories.

RESULTS

Based on 12 months of exposure, the odds of type 2 diabetes for risperidone-treated patients (odds ratio = 0.88, 95% CI = 0.372 to 2.070) was not significantly different from that for untreated patients, whereas patients receiving other antipsychotics had a significantly greater risk of diabetes than untreated patients (p < .05): olanzapine, 3.10 (95% CI = 1.620 to 5.934); clozapine, 7.44 (95% CI = 0.603 to 34.751); high-potency conventionals, 2.13 (95% CI = 1.097 to 4.134); and low-potency conventionals, 3.46 (95% CI = 1.522 to 7.785). Older age and greater use of non-antipsychotic psychotropic medications also contributed to risk of type 2 diabetes. Olanzapine also showed significantly higher (p < .01) odds of diabetes associated with increasing dose.

CONCLUSION

Consistent with previously published literature, these data suggest that olanzapine, clozapine, and some conventional antipsychotics appear to increase the risk of acquiring or exacerbating type 2 diabetes and that the effect may vary by drug. In contrast to these agents, risperidone was not associated with an increased risk of type 2 diabetes.

Iatrogenic disorders associated with conventional vs. atypical antipsychotics

Pharmacotherapy is an indispensable component of the management of schizophrenia and related psychotic disorders. Antipsychotic drugs are used for their efficacy in controlling the symptoms of psychosis. However, the side effects of antipsychotic drugs can have a deleterious impact on the course of the illness by inducing iatrogenic symptoms of various severity. The side effects of first-generation or conventional antipsychotic drug were often so intolerable to patients with schizophrenia that their compliance was consistently poor, leading to frequent relapse, chronicity, and impaired functioning. The second-generation (atypical) antipsychotics, introduced 40 years after the advent of the older-generation, are proving to have better outcomes in psychosis not only because of broader symptom efficacy but also because their side-effect profile is more tolerable, leading to higher compliance and fewer relapses. The authors review the side effects of the old and the new antipsychotics and conclude that the improved tolerability of the new antipsychotics is associated with greater effectiveness, not just efficacy. Differences in tolerability among the new antipsychotics are described.

Neuropsychological performance in asymptomatic HIV infection

This study compared 74 human immunodeficiency virus (HIV)-negative and 131 HIV-positive asymptomatic homosexual or bisexual men on an extensive neuropsychological test battery. HIV-positive subjects' performance was significantly worse on verbal memory and psychomotor skills. The prevalence of mild but persistent neurobehavioral impairment in the HIV-positive group was approximately twice that in HIV-negative patients, consistently across several criteria for impairment. There was evidence that degree of neuropsychological impairment was related to patients' perceptions of dysfunction in daily life. Findings were not related to degree of depression or to medication effects. These data suggest that approximately 10% to 20% of HIV-positive asymptomatic men suffer mild neuropsychological impairment that influences their daily lives.

Clinical correlates of response to valproate in geriatric inpatients

The efficacy of valproate for the management of adults with bipolar disorder has been repeatedly demonstrated in several studies. Patients with mixed states, rapid cycling, and EEG abnormalities have been shown to respond favorably to valproate. Valproate is also being increasingly used in disorders with aggressive or agitated features, such as the behavioral disorders of dementia; yet, few studies have documented the utility of valproate in geriatric patients. The need to document safe and effective pharmacologic agents to treat geriatric mood and behavioral disorders continues to increase with the growing elderly population. We conducted a retrospective study of the use of valproate in patients consecutively hospitalized over a 5-year period on a psychiatric unit. Thirty-nine patients over age 60 were identified and then categorized into non-, partial, and full responders based on Clinical Global Impression ratings. Information on diagnosis, age, valproate dose and serum concentration, psychiatric symptoms, medical comorbidity, concurrent psychotropic medications, and side effects was collected. Results suggest that responders to valproate (full or partial) over the age of 60 years were more likely to be female, younger, carry a diagnosis of bipolar disorder, and achieve higher serum valproate concentrations. Full responders had fewer psychotic symptoms but usually displayed manic symptoms. The date of this study suggests the need for controlled clinical trials to clarify the utility and clinical predictors of response to valproate in the geriatric population.

Neuropsychological correlates of negative, disorganized and psychotic symptoms in schizophrenia

Recent studies suggest that three dimensions (negative, disorganized and psychotic) categorize schizophrenic symptoms. A developing literature indicates distinct cerebral correlates of each symptom cluster, but few investigations have determined their neuropsychological correlates. In the present study, the Schedules of Negative and Positive Symptoms measured symptom severity in 62 schizophrenics, and a subsequent principal components analysis revealed three symptom dimensions. Factor scores, age and parental socio-economic status were simultaneously entered into regression equations to explain variance across a broad neuropsychological test battery. Negative symptoms were associated with deficits involving intelligence, executive function, memory, sustained-attention and sensory-motor function, whereas disorganized symptoms correlated with decreased intelligence, attention-span and sensory-motor function. Psychotic symptoms were unrelated to deficits. These data are consistent with hypotheses that these three symptom dimensions have distinct neurobehavioral correlates.

The volume of the entorhinal cortex in schizophrenia: a controlled MRI study

1. The entorhinal cortex (EC), part of the limbic temporal lobe, is a critical link between the cerebral cortex and the hippocampus, and is considered one of the most important cortical "association" areas. Several postmortem abnormalities in the EC have been reported. 2. Here, the authors report the first in vivo study of the volume of the EC in schizophrenia using magnetic resonance imaging (MRI) scans. 3. The authors compared 57 schizophrenic patients and 35 healthy controls. No overall difference in the mean EC volume was found between controls and schizophrenic patients, but there was a strong trend (p = .078) for the schizophrenic females to have a large mean EC than control females and for the early onset schizophrenia group to have a smaller (EC (p = .07) than late onset schizophrenia subjects. 4. The implications of the findings are discussed.

Postpartum mood disorders: clinical perspectives

Mood disorders are common in women. A prepregnancy personal history of mood disorder (bipolar or major depression), premenstrual syndrome, or (possibly) postpartum blues places a woman at high risk for a postpartum exacerbation of symptoms. Untreated or unrecognized postpartum mood disorders can lead to serious psychologic and social consequences, in some cases even leading to suicide or infanticide. Women at risk for postpartum mood disorders need to be referred for psychiatric consultation before pregnancy and parturition. Informed, professional collaboration offers the best opportunities for prevention, as well as the earliest recognition and treatment of emergent symptoms.

Cognitive deficits distinguish patients with adolescent- and adult-onset schizophrenia

Recent studies have shown that patients with schizophrenia who have an adolescent-symptom onset (before age 21) have a worse clinical course and greater frequency of cerebral abnormalities than those with an adult-onset (after age 25). However, little is known about the neuropsychological functioning of these groups. A comprehensive neuropsychological examination was administered to groups of patients with schizophrenia with either an adolescent- or adult symptom-onset and a healthy control group. The adolescent-onset group performed worse than the adult-onset and control groups, particularly on measures of memory and executive function. The adult-onset group also performed worse than the controls, but to a lesser extent than did the adolescent-onset group. Results are discussed with reference to hypotheses that adolescent-onset schizophrenia represents a distinct neurodevelopmental disease entity.

The P50 evoked potential component and mismatch detection in normal volunteers: implications for the study of sensory gating

Sensory gating is a complex, multistage, multifaceted physiological function believed to be protecting higher cortical centers from being flooded with incoming irrelevant sensory stimuli. Failure of such mechanisms is hypothesized as one of the mechanisms underlying the development of psychotic states. Attenuation of the amplitude of the P50 evoked potential component with stimulus repetition is widely used to study sensory gating. In the current study, we investigated the responsiveness of the P50 component to changes in the physical characteristics of ongoing trains of auditory stimuli. Forty normal volunteers were studied in a modified oddball paradigm. At all cerebral locations studied, P50 amplitudes were higher in response to infrequent stimuli. We postulate that the increase in P50 amplitude reflects the system's recognition of novel stimuli or "gating in" of sensory input. The ratio of the amplitude of the responses to the infrequent stimuli to those of the frequent stimuli was significantly higher for the posterior temporal regions. This finding provides further evidence that the temporal lobes may be significantly involved in sensory gating processes. Although this study only included normal subjects, the data generated contribute to the understanding of sensory gating mechanisms that may be relevant to psychotic states.

Evoked potentials in subjects at risk for Alzheimer's disease

Evoked potential (EP) changes accompanying dementing processes have been documented in a number of studies. However, EPs have not been studied in subjects who are at heightened risk for the development of Alzheimer's Disease (AD). Nineteen volunteers with no immediate family members with a history of AD and 33 healthy subjects with at least one first-degree relative with AD were studied. Of the 33 subjects with a positive family history of AD, the illness of the sick relative was classified as possible AD in 10 subjects, probable AD in 17 subjects, and definite (autopsy-proven) AD in 6 subjects. Mid-latency evoked potentials (P50, N100, and P200) and P300 event-related potentials were recorded in an oddball paradigm. The amplitudes of the P50 responses to the frequent stimuli and of the P300 responses were significantly higher in the subjects whose relatives had definite AD as compared with the other three groups. The amplitude of the N100 component was also larger in the same group, but the difference was only statistically significant from the group of healthy volunteers without a family history of AD. A process of increased sensitivity to incoming stimuli may be reflected in the increased P50, N100, and P300 amplitudes in the subjects at increased risk for developing AD.

Impact of desertification on temperature trends in the Middle East

The intense interest in desertification and climate change has stimulated detailed studies of temperature records in many areas of the world. In this investigation, the temperature records from the Middle East region are analyzed over the period 1950-1990. Results reveal a linear, statistically significant temperature increase of 0.07 °C/decade over the 41-year period. An analysis of spatial controls on these temperature changes reveals a warming effect associated with both overgrazing and the degree of human-induced desertification. The results of this study are consistent with theoretical and empirical studies predicting and demonstrating a warming signal associated with these land surface changes in the world's dryland areas.

Neuropsychological performance and CD4 levels in HIV-1 asymptomatic infection

The performance of 68 HIV-1 seropositive asymptomatic (HIV+) subjects stratified on CD4 levels were compared with 82 HIV-1 seronegative (HIV-) subjects on a battery of neuropsychological, mood state, and perceived health status measures. The neuropsychological test battery included measures of attention, reaction time, memory, intellectual ability, psychomotor speed, frontal lobe or "executive" function, and decision time. None of the HIV+ subjects were taking antiviral agents. The groups did not differ for age, mood state, or WAIS-R Verbal and Performance IQ scores. Due to group differences for education and weekly ethanol consumption, both variables were used as covariates in multivariate analyses of variance. Relatively few differences were observed between subgroups of HIV+ patients or between these subgroups and control subjects. These data suggest that factors other than absolute levels of immunosuppression as expressed by CD4 levels alone, appear to be responsible for the deficits observed in HIV+ asymptomatic patients.

Proton magnetic resonance spectroscopy (1H MRS) of the hippocampal formation in schizophrenia: a pilot study

BACKGROUND

Recent post-mortem and magnetic resonance imaging (MRI) studies strongly suggest a decrease in the volume of the hippocampus and other limbic temporal structures in schizophrenia. Therefore, we hypothesised that N-acetyl aspartate (NAA) which is found mainly in neurons and which can be measured by proton magnetic resonance spectroscopy (1H MRS) would be decreased in the limbic temporal region in schizophrenia.

METHOD

Consenting subjects fulfilling DSM-III-R criteria for schizophrenia (n = 11) and matched healthy volunteers (n = 11) who were recruited in a tertiary university referral centre, participated in a 1H MRS brain study. Proton MRS spectra were obtained from a 12 cm3 voxel (2 x 2 x 3 cm) in the right and left hippocampus/amygdala region. A researcher blind to the source of the spectra, measured the NAA intensity in all subjects, which were then statistically compared across the two groups.

RESULTS

NAA intensities were significantly reduced in the right hippocampus/amygdala region of schizophrenic patients (P = 0.038). The difference of the left side did not reach significance at the 95% confidence level.

CONCLUSIONS

The findings of decreased NAA in this study suggest that there may be a decrement in neuronal number or tissue volume of the right hippocampal/amygdala region in schizophrenia. Biochemical alterations in the metabolism of NAA in schizophrenia may be an alternative explanation. The findings are consistent with other types of post-mortem and in vivo evidence for hypoplasia of the limbic temporal structures in schizophrenia, postulated to be of neurodevelopmental pathogenesis.