Konasale M. Prasad

Neuroprotective Effects of Cognitive Enhancement Therapy Against Gray Matter Loss in Early Schizophrenia Results From a 2-Year Randomized Controlled Trial

CONTEXT Cognitive rehabilitation has shown efficacy in improving cognition in patients with schizophrenia but the underlying neurobiologic changes that occur during these treatments and support cognitive improvement are not well known. OBJECTIVE To examine differential changes in brain morphology in early course schizophrenia during cognitive rehabilitation vs supportive therapy. DESIGN Randomized controlled trial. SETTING An outpatient research clinic at a university-based medical center that provides comprehensive care services for patients with severe mental illness. PATIENTS A total of 53 symptomatically stable but cognitively disabled outpatients in the early course of schizophrenia or schizoaffective disorder. INTERVENTIONS A 2-year trial with annual structural magnetic resonance imaging and cognitive assessments. Cognitive enhancement therapy is an integrated approach to the remediation of cognitive impairment in schizophrenia that uses computer-assisted neurocognitive training and group-based social-cognitive exercises. Enriched supportive therapy is an illness management approach that provides psychoeducation and teaches applied coping strategies. MAIN OUTCOME MEASURES Broad areas of frontal and temporal gray matter change were analyzed with longitudinal, voxel-based morphometry methods using mixed-effects models followed by volumetric analyses of regions that demonstrated significant differential changes between treatment groups. RESULTS Patients who received cognitive enhancement therapy demonstrated significantly greater preservation of gray matter volume over 2 years in the left hippocampus, parahippocampal gyrus, and fusiform gyrus, and significantly greater gray matter increases in the left amygdala (all corrected P < .04) compared with those who received enriched supportive therapy. Less gray matter loss in the left parahippocampal and fusiform gyrus and greater gray matter increases in the left amygdala were significantly related to improved cognition and mediated the beneficial cognitive effects of cognitive enhancement therapy. CONCLUSION Cognitive enhancement therapy may offer neurobiologic protective and enhancing effects in early schizophrenia that are associated with improved long-term cognitive outcomes.

Insight and prefrontal cortex in first-episode Schizophrenia

Few studies have investigated the neurobiological basis of impaired insight in antipsychotic-naive schizophrenia. However, the relationship between insight and specific prefrontally mediated cognitive functions suggests that insight deficits may be an expression of prefrontal cortical dysfunction. This study was designed to examine the relationship among insight, neurocognition, and dorsolateral prefrontal cortex (DLPFC) volumes in first-episode antipsychotic-naive schizophrenia subjects. DLPFC volumes were compared between 35 first-episode schizophrenia subjects with good (n = 17) and poor insight (n = 18). Morphometric measurements were based on MRI scans by trained raters blind to clinical information. First-episode schizophrenia subjects with poor insight showed decreased right DLPFC volumes relative to those with good insight. In addition, those with poor insight had higher levels of perseverative errors (PEs) on the Wisconsin Card Sort Test (WCST). No differences in other neuropsychological measures were found between the good and poor insight groups. Similarly, no differences were found between schizophrenia subjects with good versus poor insight on any of the psychopathological measures employed in this study. These findings suggest that poor insight in schizophrenia may be a function of specific prefrontally mediated neurocognitive deficits rather than a global impairment in neuropsychological functioning or different profiles of psychopathology.

Genetic polymorphisms of the RGS4 and dorsolateral prefrontal cortex morphometry among first episode schizophrenia patients

Polymorphisms of the gene encoding the regulator of G-protein signaling subtype 4 (RGS4) may confer risk for schizophrenia.1 DNA microarray studies of postmortem brain samples have shown RGS4 underexpression in the dorsolateral prefrontal cortex (DLPFC, area 9), motor and visual cortices in schizophrenia patients relative to control subjects.2 Underexpression of RGS4 in DLPFC is pathophysiologically significant because DLPFC pathology in schizophrenia has been supported by neurocognitive,3,4 structural5 and functional6,7 imaging, postmortem,8 cellular9,10 and molecular11 pathological studies. For these reasons, we examined the association of DLPFC gray matter volume with RGS4 polymorphisms in a series of antipsychotic-naïve first-episode schizophrenia patients and control subjects. We hypothesized that volumetric alterations of the DLPFC would be associated with RGS4 polymorphisms and that these differences would be more pronounced in patients than in controls. We observed robust volumetric differences across the genotypes in the pooled sample of patients and control subjects; when separately analyzed, we observed differences within the patient group (n=30) but not in control subject (n=27) group. The findings suggest that RGS4 polymorphisms may contribute to structural alterations in the DLPFC.

Cannabis use and brain structural alterations in first episode schizophrenia — A region of interest, voxel based morphometric study

Structural alterations of the brain in schizophrenia have been associated with genetic and environmental factors. Among the environmental factors, cannabis use has been associated with increased risk for patients with schizophrenia, but the effect of cannabis on their brain structure is unclear. We examined gray matter alterations in first episode schizophrenia patients (FES) with cannabis use (FES+C; n=15) compared to FES without cannabis use (FES-C; n=24) and 42 healthy controls who did not use cannabis. We conducted a voxel based morphometric analysis of a priori determined regions of interest consisting of the CB1 receptor rich brain regions. We observed a decrease in gray matter density in the right posterior cingulate cortex (PCC) in FES+C when compared with FES-C. The results suggest that cannabis use may be associated with altered brain structure, in particular regions rich in CB1 receptors. These findings need to be confirmed by larger, prospective studies.

Psychopathology among offspring of parents with schizophrenia: Relationship to premorbid impairments

INTRODUCTION A broad range of psychopathology, including externalizing disorders is seen in offspring at genetic risk for schizophrenia. However, it is unclear whether such psychopathology may underlie a higher predisposition to the premorbid antecedents of schizophrenia. We examined the prevalence and correlates of psychopathology in an ongoing study of offspring genetically at risk for schizophrenia. METHODS Seventy five consenting high risk offspring (HR: offspring, age 15.68+/-3.27 years; male/female 34/41) and 82 matched comparison subjects (40 males and 42 females; age 15.92+/-3.0 years) participated in this study. Diagnoses were ascertained using structured psychiatric interviews and consensus meetings, including all available clinical information. RESULTS Sixty (60%) of the HR offspring had one or more lifetime diagnosis of axis I psychiatric disorder. HR subjects with axis I psychopathology had significantly more soft neurological signs, poorer premorbid adjustment, and higher schizotypy scores as measured by Chapman psychosis proneness scales. Among those with psychopathology, HR subjects with externalizing disorders showed the most abnormal scores in schizotypy. DISCUSSION A substantial proportion of HR offspring of parents with schizophrenia manifest a broad range of childhood psychiatric disorders. Psychopathology, especially externalizing disorders such as attention deficit hyperactivity disorder (ADHD) may represent a subgroup with an increased risk for schizophrenia spectrum disorders. This possibility needs to be examined by prospective follow-up studies, and would be of considerable importance to early diagnosis and intervention efforts in schizophrenia.

Cerebellar volume in offspring from multiplex alcohol dependence families.

BACKGROUND Increased susceptibility for developing alcohol dependence (AD) might be related to structural differences in brain circuits that influence the salience of rewards and/or modify the efficiency of information processing. The role of the cerebellum in regulating cognitive functions is being increasingly recognized along with its well-known influence on motor performance. Additionally, developmental changes in cerebellar volume during adolescence have been reported. METHODS Magnetic resonance imaging was used to measure the cerebellum in 17 high-risk adolescent and young adult offspring from multiplex alcohol dependence families and 16 control subjects matched for gender, age, and IQ. RESULTS High-risk (HR) adolescents/young adults showed increased total cerebellum volume and total grey in comparison with control subjects. Age-related decreases in total grey volume were seen with age, a pattern that was not seen in HR offspring. CONCLUSIONS Offspring from multiplex families for AD manifest genetic susceptibility by having larger cerebellar volume, which seems to be related to lesser grey matter pruning for age. Larger cerebellar volumes in adult obsessive compulsive disorder (OCD) patients have been reported. This suggests a possible similarity in structural underpinnings for alcohol dependence and OCD.

Antibodies to Cytomegalovirus and Herpes Simplex Virus 1 Associated with Cognitive Function in Schizophrenia

BACKGROUND Cognitive impairment in the form of decreased working memory and executive functions has been recognized as a key deficit in schizophrenia. Neurotropic viruses have been associated with focal gray matter deficits in patients with schizophrenia. We evaluated whether such agents alter cognitive function in schizophrenia. METHODS The sample consisted of 329 patients diagnosed with schizophrenia or schizoaffective disorder. We evaluated associations between exposure to selected agents (Herpes Simplex Viruses 1 and 2 (HSV1, HSV2 respectively) cytomegalovirus (CMV) and Toxoplasma gondii) and scores on the Trail Making Test (TMT), controlling for relevant variables. RESULTS Serological evidence of exposure to CMV was associated with impaired performance on TMT part A time to completion (p=0.044), a measure of visual search, working memory, and psychomotor speed. Both CMV and HSV1 were significantly associated with increased errors on TMT part B (p<0.001 for both viruses). HSV2 and T. gondii exposure measures were not associated with any of the cognitive functions evaluated using TMT. CONCLUSIONS Both CMV and HSV1 are associated with impaired cognitive function in schizophrenia as measured by the TMT. Further analyses to evaluate the impact of other illness related variables including genetic variants are warranted.

Morphology of the orbitofrontal cortex in first-episode schizophrenia: Relationship with negative symptomatology

Different studies have documented OFC abnormalities in schizophrenia, but it is unclear if they are present at disease onset or are a consequence of disease process and/or drug exposure. The evaluation of first-episode, drug-naïve subjects allows us to clarify this issue. Magnetic resonance imaging was performed on 43 first-episode, antipsychotic-naïve schizophrenia patients and 53 healthy comparison subjects matched for age, gender, race, and handedness. Gray matter OFC volumes were measured blind to the diagnoses. As compared to controls, patients had greater volumes in left total OFC (p=0.048) and left lateral OFC (p=0.037). Severity of negative symptoms (anhedonia, flattened affect, and alogia) positively correlated with both the left lateral (Spearmans, rho=0.37, p=0.019; rho=0.317, p=0.041; r=0.307, p=0.048, respectively) and the left total OFC (Spearmans, rho=0.384, p=0.014; rho=0.349, p=0.023; rho=0.309, p=0.047, respectively). The present results suggest that first-episode, antipsychotic-naïve schizophrenia subjects exhibit increased OFC volumes that correlate with negative symptoms severity. The OFC, through extensive and complex interconnections with several brain structures with putative role in pathophysiology of schizophrenia including amygdala, hippocampus, thalamus, DLPFC, and superior temporal lobe, may mediate schizophrenia symptoms such as blunting of emotional affect and impaired social functioning. Although the specific neuropathological mechanisms underlying structural abnormalities of the OFC remain unclear, increased OFC volumes might be related to deviations in neuronal migration and/or pruning. Future follow-up studies examining high-risk individuals who subsequently develop schizophrenia at different stages of disease could be especially instructive.

Brain morphological changes associated with exposure to HSV1 in first-episode schizophrenia

Infectious agents have been proposed as one of the risk factors for schizophrenia. However, the data on the association of infectious agents with in vivo brain changes are scant. We evaluated the association of serological evidence of exposure to herpes simplex virus 1 (HSV1) with in vivo brain structural variations among first-episode antipsychotic-naive schizophrenia/schizoaffective disorder patients and control subjects. We assayed HSV1 immunoglobulin G (IgG) antibody in serum samples from 30 patients and 44 healthy subjects and obtained structural magnetic resonance imaging scans from the same individuals. There were proportionately more patients with elevated HSV1 antibody ratios than healthy comparison subjects (χ2=3.98, 1 df, P=0.046) and patients had significantly higher HSV1 IgG antibody ratios compared with healthy subjects. Using optimized voxel-based morphometry, we examined diagnosis by HSV1 serological status interaction followed by within- and between-group comparison across the serological status. We observed a diagnosis by HSV1 serological status interaction and a significant main effect of HSV1 serological status in the prefrontal gray matter. Patients exposed to HSV1 had decreased gray matter in Brodmann area 9 (dorsolateral prefrontal cortex) and 32 (anterior cingulate cortex) compared with patients without serological evidence of exposure to HSV1. HSV1-associated differences in brain structure were not detected among healthy subjects. These findings suggest that HSV1 exposure in schizophrenia is associated with specific regional gray matter differences that may not be attributable to medications, illness chronicity or comorbid substance use. This study provides suggestive evidence for a link between HSV1 exposure and some of the cerebral morphological changes often reported in schizophrenia.

Exposure to Herpes Simplex Virus Type 1 and Cognitive Impairments in Individuals With Schizophrenia

Latent infection with neurotropic herpes viruses, such as herpes simplex virus, type 1 (HSV1), has been generally considered benign in most immunocompetent individuals except for rare cases of encephalitis. However, several recent studies have shown impaired cognitive functions among individuals with schizophrenia exposed to HSV1 compared with schizophrenia patients not exposed to HSV1. Such impairments are robust and are prominently observed in working memory, verbal memory, and executive functions. Brain regions that play a key role in the regulation of these domains have shown smaller volumes, along with correlation between these morphometric changes and cognitive impairments in schizophrenia. One study noted temporal decline in executive function and gray matter loss among HSV1-exposed first-episode antipsychotic-naïve schizophrenia patients. Furthermore, a proof-of-concept double-blind placebo-controlled trial indicated improvement in cognitive performance following supplemental anti-herpes-specific medication among HSV1 seropositive schizophrenia patients. Cross-sectional studies have also identified an association between HSV1 exposure and lesser degrees of cognitive impairment among healthy control individuals and patients with bipolar disorder. These studies fulfill several Bradford-Hill criteria, suggesting etiological links between HSV1 exposure and cognitive impairment. Exposure to other human herpes viruses such as cytomegalovirus and herpes simplex virus type 2 (HSV2) may also be associated with cognitive impairment, but the data are less consistent. These studies are reviewed critically and further lines of enquiry recommended. The results are important from a public health perspective, as HSV1 exposure is highly prevalent in many populations.