clozapine and Cerebrovascular-Disorders

The term "frontal lobe syndrome" comprises a variety of different clinical syndromes produced by focal lesions involving the prefrontal cortex. However, similar syndromes can be observed after lesions involving subcortical structures connected with the prefrontal cortex in neuronal networks. With respect to the different clinical pictures and underlying brain lesions, prefrontal lobe dysfunction may be divided into a disorganized type, caused by lesion of the dorsolateral prefrontal lobe and its connections, a disinhibited type that can be observed following lesions of the orbitofrontal cortex, and an apathetic type following lesions affecting the functional balance between the cingulum and the supplementary motor area. As intracerebral lesions are rarely limited to the brain regions described, in the majority of patients various degrees of behavioural dysfunction can be observed. The case reports of four patients illustrating the three major prefrontal syndromes following severe head injury (n = 2) or cerebrovascular disease (n = 2) are presented and diagnostic implications as well as possible treatment strategies are discussed.

Topics: Aged; Brain Concussion; Cerebral Arterial Diseases; Cerebrovascular Disorders; Clozapine; Craniocerebral Trauma; Female; Frontal Lobe; Humans; Male; Middle Aged; Nerve Net; Neurocognitive Disorders; Prefrontal Cortex; Syndrome

Previous reports show different cerebral activity patterns during treatment with clozapine and typical neuroleptics. However, to date no study has directly compared the brain activity patterns while subjects are undergoing treatment with clozapine and other atypical antipsychotics. This comparison is of interest, given the probably different mechanism of action of clozapine in comparison with other atypicals.. To assess the effect of clozapine on perfusion deviations still evident during treatment with risperidone.. Here we used hexamethylene-propylenaminoxime single photon emission computed tomography to compare the perfusion patterns observed during the performance of a Stroop test in 10 patients sequentially treated with risperidone and clozapine, owing to a lack of response to the former, and in 10 healthy controls.. Patients on risperidone showed decreased perfusion as compared to controls in the medial prefrontal, middle cingulate and insular regions, as well as increased activities in brain stem and the posterior hippocampus. After receiving clozapine, the same patients showed an even wider prefrontal perfusion deficit and the brain stem was still hyperactive, but the abnormalities in the cingulate cortex, insula and hippocampus had disappeared. Clinical improvement was directly related to an increase in thalamic perfusion.. Clozapine may alleviate hyperactivity in the limbic system in schizophrenia and may facilitate activation of the regions involved in cognitive tasks to a greater degree than risperidone, as well as eliciting greater inhibition of the PF region.

Topics: Adult; Antipsychotic Agents; Brain; Cerebrovascular Disorders; Clozapine; Cognition; Drug Resistance; Female; Haloperidol; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Psychiatric Status Rating Scales; Retrospective Studies; Risperidone; Schizophrenia; Tomography, Emission-Computed, Single-Photon; Treatment Failure

Concern exists about a possible increased risk of cerebrovascular events (CVEs) among elderly patients receiving risperidone or olanzapine. We estimated the effect of atypical and conventional antipsychotics on the risk of CVEs among elderly nursing home patients with dementia.. We conducted a case-control study on residents of nursing homes in 6 U.S. states by using the Systematic Assessment of Geriatric drug use via Epidemiology database, which includes data from the Minimum Data Set linked to Medicare inpatient claims. Participants were diagnosed with Alzheimer's disease or other forms of dementia on the basis of clinical criteria and medical history (including medical records and neuroradiologic documentation). Cases included patients hospitalized for stroke or transient ischemic attack between June 30, 1998, and December 27, 1999. For each case, we identified up to 5 controls hospitalized for septicemia or urinary tract infection residing in the same facility during the same time period. The sample consisted of 1130 cases and 3658 controls.. After controlling for potential confounders, the odds ratio of being hospitalized for CVEs was 0.87 (95% CI = 0.67 to 1.12) for risperidone users, 1.32 (95% CI = 0.83 to 2.11) for olanzapine users, 1.57 (95% CI = 0.65 to 3.82) for users of other atypical agents, and 1.24 (95% CI = 0.95 to 1.63) for conventional antipsychotic users compared to nonusers of antipsychotics. A history of CVEs appeared to modify the effect of atypical antipsychotics other than risperidone on the risk of new events.. Overall, no increased risk of CVEs seems to be conferred by atypical or conventional antipsychotics. Preexisting cerebrovascular risk factors might interact with some atypical antipsychotics to increase the risk of events. These results should be interpreted in light of the limitations of the study and need to be confirmed.

Topics: Aged; Aged, 80 and over; Antipsychotic Agents; Benzodiazepines; Case-Control Studies; Cerebrovascular Disorders; Clozapine; Comorbidity; Dementia; Female; Geriatric Assessment; Hospitalization; Humans; Ischemic Attack, Transient; Male; Medical Records Systems, Computerized; Nursing Homes; Odds Ratio; Olanzapine; Risk Factors; Stroke; United States