Risperidone in the treatment of patients with Alzheimer's disease with negative symptoms

INTRODUCTION

Negative symptoms such as diminished initiative, drive, motivation, and emotional reactivity have been described in patients with Alzheimer's disease (AD). The purpose of this study was to retrospectively analyze the efficacy and tolerability of risperidone for the treatment of clinically significant positive and negative symptoms in AD.

METHODS

We reviewed the charts of 50 community-residing AD patients who had been treated in a specialized university-based dementia management clinic. Clinical data comparing baseline and 12 weeks of treatment were obtained by reviewing a series of rating scales that were recorded as part of a comprehensive behavioral assessment.

RESULTS

Reviewed subjects had a mean age of 79.7 6 years and a mean of 12 +/- 3.6 years of school. Seventy percent of the subjects were female and the majority was White. The mean dose of risperidone prescribed was 1.3 +/- 0.6 mg per day (range from 0.5 mg to 3.0 mg). After 12 weeks of treatment, the severity of positive and negative symptoms was significantly reduced. Importantly, improvement in negative symptoms with the use of risperidone appeared to be independent of a positive treatment effect on positive symptoms. Risperidone had insignificant effects on both cognitive status and the emergence of extrapyramidal symptoms.

CONCLUSION

This retrospective study demonstrates that risperidone appears to be efficacious in the treatment of clinically significant positive and negative symptoms in patients with AD.

Risperidone in the treatment of elderly patients with psychotic disorders

The authors evaluated the safety, tolerability, and efficacy of risperidone in 103 elderly patients (mean age, 71 years) with schizophrenia (75%) or schizoaffective disorder (25%). Using the Extrapyramidal Symptoms Rating Scale (ESRS), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression (CGI) scale, they conducted a prospective, open-label, 12-week trial in 14 psychiatric centers in the United States. Patients' symptoms were assessed at baseline and over a 12-week period. At endpoint, ESRS scores were significantly reduced, as were PANSS total and subscale scores. There were no clinically significant changes in electrocardiograms, laboratory test results, or vital signs. Risperidone was well tolerated and efficacious in elderly patients with schizophrenia or schizoaffective disorder.

Psychiatric consultation in the nursing home. A survey of six states

The authors examined availability, characteristics, and perceived adequacy of psychiatric consultation in nursing homes, as reported by directors of nursing, who returned 899 questionnaires. Thirty-eight percent of nursing home residents were judged to need a psychiatric evaluation; current frequency of consultation was rated as adequate by half of nursing directors. Nearly two-thirds reported that psychiatrists adequately provided diagnostic and medication recommendations; however, advice on nonpharmacologic management techniques, staff support, and dealing with staff stress and family conflicts was largely viewed as inadequate. Findings suggest that perceived need for psychiatric services is far greater than the level actually provided. Overall, more attention must be directed to identifying incentives for psychiatrists to practice in nursing homes, determining clinical effectiveness of mental health services, and examining effects of alternative payment mechanisms on level of care.

Cognitive deficits and psychopathology in elderly schizophrenic patients

The authors investigated the syndromal and cognitive profiles of 25 DSM-III-R older schizophrenic inpatients with continuous acute psychotic symptoms and compared them with 20 younger schizophrenic patients by means of a multidimensional assessment battery. Subjects were medically well and without neurological comorbidity and were comparable in length of current hospitalization and medication regimens. There were no significant differences between the two groups on various symptom rating scores or on neurological variables. The older group's mean scores for various cognitive measures did not reach the value for senile dementia. They also scored significantly better on a memory test and on formal cognitive functions. These findings support the notion of a stable encephalopathy, rather than a dementia-like process, underlying the course of the illness. Authors discussed limitations and implications of these findings.

A naturalistic outcome study of risperidone treatment among hospital patients

Risperidone, an atypical antipsychotic, was introduced into clinical use in New York State facilities in April 1994. In this chart review study, records were reviewed for the first 63 patients started on risperidone at the Bronx Psychiatric Center during 1994. Sixty percent of patients treated with risperidone had a positive outcome, indicated by clinical improvement either at discharge or in the hospital. Twenty-two percent required termination of risperidone treatment within the initial three months. Risperidone appeared to be associated with favorable outcome among chronic state hospital patients, including those not discharged within the first three months of treatment.

Inhibition of high-affinity [3H]L-proline binding to rat brain membranes by 2-amino-7-phosphonoheptanoic acid

L-Glutamate and 2-amino-7-phosphonoheptanoic acid [corrected] (AP-7) (10(-9) to 10(-6) M), a competitive NMDA (N-methyl-D-aspartate) antagonist, inhibit approximately 60% of [3H]L-proline binding to rat membranes from midbrain. In hippocampal membranes, AP-7 inhibits proline binding by 80%, while in cerebellar membranes AP-7 had little effect. These results are indicative of the possible neuromodulatory role of proline in the central nervous system, possibly through the NMDA receptor(s).

GABAergic neurotransmission in the C57BL/10 sps/sps mouse mutant: a model of absence seizures

The C57BL/10 sps/sps mouse mutant displays generalized absence seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps/sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca(2+)-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the absence-like seizures in C57BL/10 sps/sps mice.

The C57BL/10Bg sps/sps mouse: a mutant with absence-like seizures; neurochemical and behavioral correlates

C57BL/10Bg sps/sps mice display behavioral arrest, similar to generalized absence seizures. Compared with the parent strain C57BL/10Bg SPS/SPS, the activities of glutamate decarboxylase (GAD, E. C. 2.6.1.15), GABA aminotransferase (GABA-T, E. C. 2.6.1.19), aspartate aminotransferase (ASP-T, E. C. 2.6.1.1), and glutamate dehydrogenase (GDH, E. C. 1.4.1.3) in whole brain crude supernatant were significantly reduced in the sps/sps mice. Alanine aminotransferase activity (ALA-T, E. C. 2.6.1.2), was not altered in any of the strains, and normalization of GAD, GABA-T and GDH activities by that of ALA-T, further revealed significant differences between the normal strain (SPS/SPS), the heterozygotes (SPS/sps), and behavioral arrest (sps/sps) mice. These results suggest the possible involvement of GABAergic and glutamatergic neurotransmission in the absence-like behavior displayed by sps/sps mice. Open field behavior of C57BL/10Bg sps/sps mice is characterized by periods of marked inactivity which easily distinguish affected homozygotes, from their heterozygotes littermates.

High-affinity binding of proline to mouse brain synaptic membranes

There is evidence suggestive of the possible neuromodulatory role for L-proline in the mammalian brain. The binding of proline to whole mouse brain synaptic membranes has been partially characterized. Several binding sites for this imino acid have been identified; one in the nanomolar range and at least two in the submicromolar range. The binding of proline is inhibited by NaCl. Pipecolic acid (40 microM), ornithine, aminooxyacetic acid (AOAA), glycine, GABA, and glutamate were capable of significantly inhibiting proline binding. Although detailed pharmacological and functional studies are needed, these results are consistent with a brain-specific function for this imino acid, as well as, with the presence of specific binding site(s) for proline.