The relationship between insight and neurological dysfunction in first-episode psychosis

How soft are neurological soft signs? Content overlap analysis of 71 symptoms among seven most commonly used neurological soft signs scales

INTRODUCTION

Neurological soft signs (NSS) are described as subtle, non-localizable neurological abnormalities that cannot be related to impairment of a specific brain region or are not believed to be typical for any specific neurological disease. Crucial issue concerning research on NSS are the instruments with which they are assessed, since the results and the conclusions of the studies are mediated by the characteristics of such instruments. There is common, silent and unverified assumption that NSS rating scales may be used as interchangeable measure of the same phenomenon.

AIM

To investigate the differences in item content and the interchangeability of commonly used NSS scales.

METHODS

A content analysis was carried out to determine symptom overlap among the chosen seven most often used scales using the Jaccard index (0 = no overlap, 1 = full overlap) according to the methodology of Fried 2017.

RESULTS

71 NSSs were distinguished from 167 items used in 7 above mentioned instruments. Mean overlap among all scales is low (0.27), overlap among specific scales ranges from 0.1 to 0.5.

CONCLUSIONS

The diversity of NSS in analyzed tools causes the low overlap between scales, leading to uncertainty as to whether they measure the same phenomena. This limits the reproducibility of studies and impedes the possibility of unifying the knowledge stemming from existing data. We argue that the non-localizable nature of NSS is yet to be examined.

Changes in insight over the first 24 months of treatment in schizophrenia spectrum disorders

BACKGROUND

While insight in schizophrenia improves with treatment, significant impairments often persist. The degree of persistence is not well characterised.

AIMS

We assessed patient and clinician-rated changes in insight in acutely ill, minimally treated first-episode schizophrenia spectrum disorder patients over 24 months of standardised treatment with a depot antipsychotic.

METHOD

This single arm open label longitudinal cohort study included 105 participants with first-episode schizophrenia, schizophreniform or schizoaffective disorder. Insight was assessed at months 0, 6, 12 and 24 using the patient-rated Birchwood Insight Scale (BIS) and clinician-rated global insight item of the Positive and Negative Syndrome Scale (PANSS). Changes in insight over time were assessed using linear mixed-effect models for continuous repeated measures. Relationships between insight and psychopathology, functionality, cognition and quality of life were assessed with regression models.

RESULTS

There was significant improvement over time for the PANSS insight item (p < 0.0001). However, the only significant improvement for the BIS was with the Need for Treatment subscale (p = 0.01). There were no significant improvements noted for the Symptom Attribution (p = 0.7) and Illness Awareness (p = 0.2) subscales, as well as the BIS Total score (p = 0.6). Apart from depressive symptoms at baseline, there were no significant predictors of patient-rated insight.

CONCLUSIONS

Clinicians should note that, even when treatment is assured and response is favourable, fundamental impairments in patient-rated insight persist.

Luria revisited: complex motor phenomena in first episode schizophrenia and schizophrenia spectrum disorders

Patients with schizophrenia frequently exhibit motor deficits. However, to date, there are no studies comparing motor performance in first episode patients with schizophrenia and schizophrenia spectrum disorders (SSD; e.g. schizoaffective and brief psychosis). Participants comprised 57 first episode patients with schizophrenia, 32 first episode patients with SSD, and 51 healthy controls who underwent neuropsychological testing based on Luria׳s systematic approach, including the following tests on complex motor sequencing: the Fist-Edge-Palm (FEP) test and the bimanual probe (BP). Schizophrenia patients performed worse than SSD patients in FEP and BP, and both patient groups showed decreased scores compared to healthy controls. Furthermore, we found that a higher proportion of schizophrenia cases failed to correct their motor performance and needed external error correction, while SSD cases exhibited a higher proportion of self-correction in FEP and in BP. Lack of insight and poor executive functioning correlated with motor performance in schizophrenia, while impulse control and difficulties in abstract thinking were related to motor performance in schizophrenia spectrum disorder. Thus, psychomotor impairments appear already in first episode patients with schizophrenia and differ from impairments in SSD. Especially the inability to self-correct errors may be characteristic of schizophrenia, suggesting that impairments in error monitoring are related to psychomotor dysfunction in schizophrenia.