Re-visiting the nature and relationships between neurological signs and neurocognitive functions in first-episode schizophrenia: An invariance model across time

Abstract

The present study examined different types of neurological signs in patients with first-episode schizophrenia and their relationships with neurocognitive functions. Both cross-sectional and longitudinal designs were adopted with the use of the abridged Cambridge Neurological Inventory which comprises items capturing motor coordination, sensory integration and disinhibition. A total of 157 patients with first-episode schizophrenia were assessed at baseline and 101 of them were re-assessed at six-month interval. A structural equation model (SEM) with invariance model across time was used for data analysis. The model fitted well with the data at baseline assessment, X^2(21) = 21.78, p = 0.413, NFI = 0.95, NNFI = 1.00, CFI = 1.00, IFI = 1.00, RMSEA = 0.015. Subsequent SEM analysis with invariance model at six-month interval also demonstrated the same stable pattern across time and showed strong measurement invariance and structure invariance across time. Our findings suggest that neurological signs capture more or less the same construct captured by conventional neurocognitive tests in patients with schizophrenia. The measurement and structure of these relationships appear to be stable over time.

Neurological soft signs (NSS) and cognitive impairment in chronic schizophrenia

“…Taken together the present study supported our hypothesis that NSS are associated with a broad range of neurocognitive impairments in patients with chronic schizophrenia as well as healthy controls. With Chan et al (2015) these findings underline the usability of NSS as a screening instrument for cognitive impairment. From a clinical perspective, these findings facilitate the use of NSS as a marker for severity of the disease and of poor prognosis (Bachmann et al, 2014; Bachmann and Schröder, 2018).…”

“…That NSS in chronic schizophrenia are associated with a wide range of neuropsychological impairments rather than specific changes in discrete domains is supported by a number of studies (for review see Table 1). Along with this, Chan et al (2015) suggested that “ neurological signs capture more or less the same construct captured by conventional neurocognitive tests in patients with schizophrenia ”. These significant associations of NSS scores with cognition performance facilitate the possibility to use NSS as a screening instrument for the assessment of neurocognitive impairments in patients with chronic schizophrenia.…”

From neurological soft signs to functional outcome in young individuals in treatment with secondary services for non-psychotic disorders: a path analysis

“…The association between NSS and neurocognition can be explained in the light of a growing body of evidence suggesting that NSS predict impairment of frontal-subcortical brain network connections (Dazzan, 2005;Zhao et al 2014), which have been proposed as fundamental pathophysiological substrates of cognitive dysfunctions across different psychiatric syndromes (Chan et al 2009). Of interest, a recent work by Mittal et al (2014) suggests that NSS may reflect an abnormal white matter tract development of cerebello-thalamic tracts in ARMS+ individuals; these abnormalities, that the authors suggest to be part of a wider network dysfunction (i.e.…”

“…Of interest, consistent with the research domain criteria (RDoC) initiative from the National Institute of Mental Health (Insel et al 2010), there is evidence suggesting that common early vulnerability markers, such as neurological (Dazzan & Murray, 2002; De la Fuente et al 2006), neurophysiological (Bedwell et al 2015) or brain structural (Hatton et al 2012; Mittal et al 2014) and functional abnormalities (Carrión et al 2013), may predict poor functional outcomes across different recent-onset psychiatric syndromes (Millan et al 2012; Bedwell et al 2015; Lee et al 2015). Among these markers, neurological soft signs (NSS): (i) have shown close ties to specific brain structural and functional connectivity changes, in particular the cerebello–thalamo–prefrontal network (Zhao et al 2014); (ii) precede the onset of cognitive dysfunctions and negative symptoms in young individuals with recent-onset psychiatric disorders (Arango et al 1999; Chan et al 2015); (iii) have not shown specific associations with the ARMS status (De la Fuente et al 2006).…”

Prediction of functional outcome in young patients with a recent-onset psychiatric disorder: Beyond the traditional diagnostic classification system

“…Studies of adults with chronic mental illness show that multiple factors are linked to functional decline across traditional diagnostic boundaries (Iosifescu, 2012). Baseline impairments in functioning (Carrión et al, 2013), cognition and theory of mind (Lee et al, 2015), as well as neurological, neurophysiological and brain structural abnormalities (Dazzan and Murray, 2002), have been associated with future poor functional outcomes in schizophrenia (Chan et al, 2015), mood , anxiety , and personality disorders (Plaisier et al, 2010;Dazzan and Murray, 2002).…”