RESUMO
The current review provides an overview of the existing literature on multimodal transcranial magnetic stimulation, and functional magnetic resonance imaging (TMS/fMRI) studies in individuals with schizophrenia and discusses potential future avenues related to the same. Multimodal studies investigating pathophysiology have explored the role of abnormal thalamic reactivity and have provided further evidence supporting the hypothesis of schizophrenia as a disorder of aberrant connectivity and cortical plasticity. Among studies examining treatment, low-frequency rTMS for the management of persistent auditory verbal hallucinations (AVH) was the most studied. While multimodal TMS/fMRI studies have provided evidence of involvement of local speech-related and distal networks on stimulation of the left temporoparietal cortex, current evidence does not suggest the superiority of fMRI based neuronavigation over conventional methods or of active rTMS over sham for treatment of AVH. Apart from these, preliminary findings suggest a role of rTMS in treating deficits in neurocognition, social cognition, and self-agency. However, most of these studies have only examined medication-resistant symptoms and have methodological concerns arising from small sample sizes and short treatment protocols. That being said, combining TMS with fMRI appears to be a promising approach toward elucidating the pathophysiology of schizophrenia and could also open up a possibility toward developing personalized treatment for its persistent and debilitating symptoms.
RESUMO
CONTEXT: Neurocognitive deficits are well documented in schizophrenia. Neurocognitive insight (NI), described as awareness of neurocognitive deficits, has not been evaluated in the Indian context. Its relation to clinical profile and social functioning also remains unexplored. AIMS: The aim of this study was to evaluate the subjective cognitive complaints (SCCs) and their relation to objective cognitive performance, clinical profile, clinical insight, and social functioning in patients of schizophrenia. SETTINGS AND DESIGN: This was a cross-sectional study at the outpatient department of a tertiary care teaching hospital. MATERIALS AND METHODS: One hundred individuals with schizophrenia were evaluated using Positive and Negative Syndrome Scale, Subjective Scale To Investigate Cognition in Schizophrenia, abbreviated version of Scale to Assess Unawareness in Mental Disorders, and Schizophrenia Research Foundation-Social Functioning Index. Cognitive performance was assessed using (1) Digit Span Test (attention) from Wechsler Adult Intelligence Scale, 3rd edition and (2) Passages Test (explicit memory), (3) Verbal n-back Test (working memory), and (4) Stroop Test (executive functioning) from the National Institute of Mental Health and Neuro Sciences Battery. STATISTICAL ANALYSIS: Statistical analysis was done using descriptive statistics, nonparametric tests, and Pearson's coefficient of correlation. RESULTS: Participants showed impairment in all cognitive domains. Except for working memory, there was no correlation between SCC and objective performance for other cognitive domains correspondingly, implying poor NI. Severity of psychosis and clinical insight did not have any correlation with SCC. Higher SCC correlated with poorer social functioning, especially in "occupational" and "other social roles" domains. CONCLUSIONS: Individuals with schizophrenia have poor NI. This is independent of severity of psychosis or clinical insight into illness. Socio-occupational functioning and depression should be actively enquired into when patients present with SCC.
