Abstract
Background
Schizophrenia is a common and severe mental disorder. The actual treatment is neuroleptic. Clozapine (CLZ), the atypical antipsychotic leader, is the best treatment of the resistant schizophrenia. Neuroimaging studies are important to understand better the neurological effects of CLZ. The main goal of this study is to analyze actual data of anatomic imaging studies (MRI, DTI, fMRI, PET and SPECT), evaluate CLZ anatomical and functional brain effect on patients suffering resistant schizophrenia (SZ) in order to characterize the mode of action of CLZ, identify the neural bases of the CLZ treatment response and establish the link between the mode of action and CLZ and the treatment response on patients suffering resistant SZ.
Methods
We have analyzed literature using PUBMED database with the following keywords: « clozapine », « neuroimaging », »MRI », « DTI », « VBM », « functional magnetic resonnance imaging », « PET », « fMRI », « SPECT ».
Results
51 studies were included. 10 on anatomical imagery and 41 on functional imagery. From an anatomic point of view, studies suggest best cerebral integrity on patients with CLZ treatment compared to other antipsychotics, on grey nuclei, prefrontal cortex and on white matter beams belonging to the fronto sub cortical network. LEROUX et col, OCZELIK et col. From the functional point of view, studies show a functional connectivity modulation and an action on the cerebral metabolism MOLINA et col, especially in the frontal cortex of patients that respond to CLZ treatment compared to patients who have received another antipsychotic treatment. The PET and SPECT studies show the CLZ action mechanism especially on the glutamatergic system FUKUYAMA et col. Concerning CLZ-treated patients’ response, many studies have shown a larger perfusion on the frontal cortex and thalamic region on patient responding to CLZ compared non-responders. MOLINA et col, ERTUGUL et col. About clinical evolution, the longitudinal studies show an amelioration of the psychotic symptoms (positive symptoms, negative symptoms, suicidal risk and cognitive alteration) on CLZ-treated patients compared than the ones who have been treated with another antispychotic. ARANGO et col, MOLINA et col. CLZ treatment allows a decrease of craving on patients who suffer cannabis usage disorders compared with patients who are treated with risperidone. MACHIELSEN et col.
Discussion
These results bring a new light on SZ psychopathological, on CLZ cerebral mechanism and open the debate of actual prescription recommendations. However, we won’t conclude with certainly due heterogeneity of the experimental design, as other studies are necessary to complete knowledge of this subject.
Acute effects of treatment for prodromal symptoms for people
putatively in a late initial prodromal state of psychosis
