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Background: Evidence suggests that cognitive subtypes exist in schizophrenia that may reflect different neurobiological trajectories. We aimed to identify whether IQ-derived cognitive subtypes are present in early-phase schizophrenia-spectrum disorder and examine their relationship with brain structure and markers of neuroinflammation. Method: 161 patients with recent-onset schizophrenia spectrum disorder (<5 years) were recruited. Estimated premorbid and current IQ were calculated using the Wechsler Test of Adult Reading and a 4-subtest WAIS-III. Cognitive subtypes were identified with k-means clustering. Freesurfer was used to analyse 3.0 T MRI. Blood samples were analysed for hs-CRP, IL-1RA, IL-6 and TNF- α. Results: Three subtypes were identified indicating preserved (PIQ), deteriorated (DIQ) and compromised (CIQ) IQ. Absolute total brain volume was significantly smaller in CIQ compared to PIQ and DIQ, and intracranial volume was smaller in CIQ than PIQ (F (2, 124) = 6.407, p = 0.002) indicative of premorbid smaller brain size in the CIQ group. CIQ had higher levels of hs-CRP than PIQ (F (2, 131) = 5.01, p = 0.008). PIQ showed differentially impaired processing speed and verbal learning compared to IQ-matched healthy controls. Conclusions: The findings add validity of a neurodevelopmental subtype of schizophrenia identified by comparing estimated premorbid and current IQ and characterised by smaller premorbid brain volume and higher measures of low-grade inflammation (CRP). [ABSTRACT FROM AUTHOR]

Minor neurological signs are subtle deficits in sensory integration, motor coordination, and sequencing of complex motor acts present in excess in the early stages of psychosis. Still, it remains unclear whether at least some of these signs represent trait or state markers for psychosis and whether they are markers of long-term disease outcome of clinical utility. We examined the relationship between neurological function at illness onset assessed with the Neurological Evaluation Scale and subsequent illness course in 233 patients from AESOP-10 (Aetiology and Ethnicity in Schizophrenia and Other Psychoses), a 10-year follow-up study of a population-based cohort of individuals recruited at the time of their first episode of psychosis in the United Kingdom. In 56 of these patients, we also explored changes in neurological function over time. We included a group of 172 individuals without psychosis as controls. After 10 years, 147 (63%) patients had developed a non-remitting course of illness, and 86 (37%) a remitting course. Already at first presentation, patients who developed a non-remitting course had significantly more primary, motor coordination, and total signs than both remitting patients and healthy controls. While Motor Coordination signs did not change over time, rates of Primary, Sensory Integration, and Total signs increased, independently of illness course type. These findings suggest that motor coordination problems could be a useful early, quick, and easily detectable marker of subsequent clinical outcome. With other motor abnormalities, a measure of motor incoordination could contribute to the identification of the most vulnerable individuals, who could benefit from targeted and more assertive treatment approaches. [ABSTRACT FROM AUTHOR]

Functional magnetic resonance (fMRI) has an important role in the study of the vulnerability to psychosis: it is an essential tool to search for endophenotypes that can let us to understand the pathophysiological mechanisms of schizophrenia and increase the ability to predict the onset of the illness. In this review are summarized results of the fMRI studies conducted on individuals at enhanced risk for developing psychosis, for clinical or genetic reasons. The cerebral activity in this kind of subjects appear in most cases more similar to that of individuals affected than to that of normal controls; this increases the possibility, in the future, for a diagnostic role of the cerebral activation. Nevertheless the technology is too young and the studies are too heterogeneous to reach conclusive results.

Obsessive-compulsive disorder is a disabling disorder. Genetic predisposing factors may have an important role in the onset of the symptoms, but is not been individualized any specific gene yet. In the last years it has been demonstrated that obsessive-compulsive disease and/or tic syndromes may be triggered by an antecedent infection especially with group A beta-hemolytic streptococci. On the basis of recent studies has been postulated that in genetically predisposed individuals, certain streptococcal antigens trigger antibodies which, through a process of molecular mimicry, cross-react with epitopes on the basal ganglia. According to such hypothesis, the acronym PANDAS has been used to describe a subset of children with abrupt onset or exacerbations of OCD or tics, or both, following streptococcal infections. Neuroimaging studies reveal increased basal ganglia volumes, and the proposed cause involves the cross-reaction of streptococcal antibodies with basal ganglia tissue. The hypothesis of a possible involvement of the immunitary system seems justified from quantitative alterations of TNF-alpha, IL-6 and IL-1 in the patients' serum with such syndrome. Echotomographic studies on cardiac valves have not yet demonstrated the parallels between PANDAS and Sydenham's chorea. The use of treatment strategies, such as therapeutic plasmapheresis or intravenous immunoglobulin, has been proposed to explain the autoimmune process responsible for the pathogenesis of PANDAS. Further research is still necessary in order to understand the role of streptococcal infection in the pathogenesis of PANDAS.