Background: Conflicting results have been reported on the association of plasma total homocysteine (tHcy) and cholesterol levels in Alzheimer disease (AD). The objective of this study was to determine the relationship between cognitive performance and plasma levels of tHcy and its biological determinants folate and vitamin B₁₂, and lipids in clinically diagnosed AD patients. Methods: A cross-sectional database review was performed on two separate groups of patients (n = 191). Mini-Mental State Exam (MMSE) scores, plasma levels of tHcy, vitamin B₁₂, folate, cholesterol, and triglycerides were analyzed. Results: The MMSE scores were inversely correlated with age, plasma levels of tHcy and LDL cholesterol. However, only the inverse relationship between MMSE scores and LDL cholesterol levels persisted after adjustment for age, sex, and status of statin treatment. Plasma tHcy levels increased significantly with age and were inversely related to vitamin B₁₂ and folate levels, which modified the relationship between MMSE scores and plasma tHcy levels. Conclusions: The plasma tHcy levels appeared to relate more to aging than to cognition. Cognitive performance was inversely associated with plasma LDL cholesterol levels in AD patients. Our findings provide further evidence that high LDL cholesterol levels may play a role in the pathogenesis of AD.

Clozapine (Clozaril) is a novel and unique prototype atypical, tricyclic, dibenzodiazepine-derivative, antipsychotic agent. It has been proven effective and significantly superior to placebo, as well as to conventional neuroleptics, in several placebo-controlled, double-blind studies in treatment-resistant schizophrenia. It has also been found to produce an incidence of extrapyramidal symptoms (EPS) as low as that found with placebo. Approximately 30-60% of all schizophrenic patients who fail to respond to typical antipsychotics may respond to clozapine. It was the first major advance that marked a turning point in the treatment of schizophrenia and other psychotic disorders since the introduction of the typical antipsychotic agents, i.e., chlorpromazine and haloperidol in the 1950s and 1960s, respectively. After its introduction in clinical studies in the United States in the early 1970s, it was withdrawn in 1974, and was not approved for clinical use in the United States until February 1990, because of the risk of agranulocytosis. Its novel pharmacological profile, lack of propensity to cause EPS in both short- and long-term uses, lack of effects on serum prolactin, and ameliorative effects on tardive dyskinesia have resulted in the expansion of its use from refractory schizophrenia to schizoaffective disorders, affective disorders, some neurological disorders, aggression, as well as psychosis in patients with dementia and parkinsonism. This review covers the history, pharmacology, management of side effects, and fetal and neonatal effects of clozapine.

Despite the advent of newer atypical antipsychotics, clozapine remains an important option, and sometimes the only option, in the treatment of patients with poor response to antipsychotics because of its unique property of being effective for treatment-refractory schizophrenia and its low propensity for extrapyramidal symptoms (EPS). 1 It is the only antipsychotic that has been ap-proved by the FDA for treatment-refractory schizophrenia-schizophrenia that has not responded to one typical and one atypical antipsychotic agent.Approximately 30-60% of all schizophrenic patients who fail to respond to typical antipsychotics respond well to clozapine. 2 Clozapine also demonstrated effectiveness in treating resistant psychosis and schizophrenia, tardive

Objectives Brain MRIs are considered essential in the evaluation of children diagnosed with growth hormone deficiency (GHD), but there is uncertainty about the appropriate cut-off for diagnosis of GHD and little data about the yield of significant abnormal findings in patients with peak growth hormone (GH) of 7–10 ng/mL. We aimed to assess the frequency of pathogenic MRIs and associated risk factors in relation to peak GH concentrations. Methods In this retrospective multicenter study, charts of patients diagnosed with GHD who subsequently had a brain MRI were reviewed. MRIs findings were categorized as normal, incidental, of uncertain significance, or pathogenic (pituitary hypoplasia, small stalk and/or ectopic posterior pituitary and tumors). Charges for brain MRIs and sedation were collected. Results In 499 patients, 68.1% had normal MRIs, 18.2% had incidental findings, 6.6% had uncertain findings, and 7.0% had pathogenic MRIs. Those with peak GH<3 ng/mL had the highest frequency of pathogenic MRIs (23%). Only three of 194 patients (1.5%) with peak GH 7–10 ng/mL had pathogenic MRIs, none of which altered management. Two patients (0.4%) with central hypothyroidism and peak GH<4 ng/mL had craniopharyngioma. Conclusions Pathogenic MRIs were uncommon in patients diagnosed with GHD except in the group with peak GH<3 ng/mL. There was a high frequency of incidental findings which often resulted in referrals to neurosurgery and repeat MRIs. Given the high cost of brain MRIs, their routine use in patients diagnosed with isolated GHD, especially patients with peak GH of 7–10 ng/mL, should be reconsidered.