The confirmatory factor structure of neurological soft signs in Nigerians with first episode schizophrenia

The expression of neurological soft signs in two African populations with first-episode schizophrenia

Information about patterns of expression of neurological soft signs (NSS) in schizophrenia among individuals belonging to the same genetic ancestry may provide new insight for the understanding of the disease's genetic functions. This study aimed to investigate whether patterns of NSS expression in first episode schizophrenia are comparable in populations with dissimilar genetic ancestry. A sample of 207 patients with first episode schizophrenia were examined using the Neurological Evaluation Scale before they were exposed to anti-psychotics. They were allocated to two African ancestry groups: Black (81 Yoruba Nigerians, and 18 Xhosa South Africans), and non-Black (98 Coloured, and 10 White South Africans). Assessments were carried out using validated measures of clinical characteristics of schizophrenia. We determined the frequency, severity, factor structure, and association of NSS with clinical characteristics. Factor derived categories were compared using the Pearson's ( r) and Tucker's congruence methods. The associations between factor derived categories and clinical characteristics of schizophrenia were determined using Pearson's correlations and multiple regression analyses. Neurological soft signs were more frequent and more severe in the Black African ancestry group. Also, the factor structure and presentation of NSS in the two ancestry groups were significantly different. Neurological soft signs, especially motor sequencing and cognitive-perceptual abnormalities, were independently associated with disorganization psychopathologies in all the participant groups. Differences in the profile of NSS in Black compared with non-Black African ancestry patients with first episode schizophrenia may suggest differing patterns of expression of NSS in schizophrenia according to genetic ancestry.

Motor Abnormalities: From Neurodevelopmental to Neurodegenerative Through "Functional" (Neuro)Psychiatric Disorders

Background

Motor abnormalities (MAs) of severe mental disorders have been traditionally neglected both in clinical practice and research, although they are an increasing focus of attention because of their clinical and neurobiological relevance. For historical reasons, most of the literature on MAs has been focused to a great extent on schizophrenia, and as a consequence their prevalence and featural properties in other psychiatric or neuropsychiatric disorders are poorly known. In this article, we evaluated the extent to which catatonic, extrapyramidal and neurological soft signs, and their associated clinical features, are present transdiagnostically.

Methods

We examined motor-related features in neurodevelopmental (schizophrenia, obsessive compulsive disorder, autism spectrum disorders), "functional" (nonschizophrenic nonaffective psychoses, mood disorders) and neurodegenerative (Alzheimer's disease) disorders. Examination of the literature revealed that there have been very few comparisons of motor-related features across diagnoses and we had to rely mainly in disorder-specific studies to compare it transdiagnostically.

Results

One or more motor domains had a substantial prevalence in all the diagnoses examined. In "functional" disorders, MAs, and particularly catatonic signs, appear to be markers of episode severity; in chronic disorders, although with different degree of strength or evidence, all motor domains are indicators of both disorder severity and poor outcome; lastly, in Alzheimer's disease they are also indicators of disorder progression.

Conclusions

MAs appear to represent a true transdiagnostic domain putatively sharing neurobiological mechanisms of neurodevelopmental, functional or neurodegenerative origin.

Proposing the short Neurological Evaluation Scale

OBJECTIVES

The time required in completing the 26 items of neurological examinations in the standard Neurological Evaluation Scale (NES) may limit its utility in pragmatic clinical situations. We propose the Short Neurological Evaluation Scale (S-NES) for use in busy clinical settings, and in research.

METHODS

Using confirmatory factor analyses, we identified 12 items of neurological examination showing significant overlap with previously reported theoretical and empirical categories of neurological soft signs (NSS) in schizophrenia. This provided justification for the development of a shorter version of the NES based on the empirically identified NSS. In the present study, we relied on existing data to present an initial validation of the S-NES against the referent standard 26-item NES. We determined sensitivity, specificity, and likelihood ratios. Posterior-test probability was estimated using a Bayesian nomogram plot.

RESULTS

Using data derived from 84 unmedicated or minimally treated patients with first-episode schizophrenia, 12 empirically determined items of neurological examinations showed high agreement with the 26 items in the standard NES battery (sensitivity=96.3%, specificity=100%, and posterior-test probability=100%).

CONCLUSIONS

Within limitations of validity estimates derived from existing data, the present results suggest that the design of the S-NES based on empirically identified 12 items of neurological examination is a logical step. If successful, the S-NES will be useful for rapid screening of NSS in busy clinical settings, and also in research.

Quantitative exploration of factors influencing psychotic disorder ailments in Nigeria

In this data article, records on demographic data, family problem issues, as well as results of medical tests from five major classes of psychotic disorder namely: bipolar; vascular dementia, minimal brain dysfunction; insomnia; and schizophrenia, were collected on 500 psychotic patients carefully selected from the pool of medical records of Yaba Psychiatric Hospital, Lagos, Nigeria, for the period of 5 years, between January 2010 and December 2014, were examined. X-squared Statistic was used to examine each of psychotic disorders to identify demographic (age, gender, religion, marital status, and occupation) and family issues (loss of parent, history of such ailment in the family (family status), divorce, head injury, and heredity of such ailment (genetic) factors that influence them. A clear description on each of these psychotic disorders (bipolar; vascular dementia, minimal brain dysfunction (MBD), insomnia and Schizophrenia) was considered separately using tables and bar diagrams. Data analysis results are as follows: firstly, 40.2%, of the 500 psychotic patients tested positive to bipolar, 40.6% to insomnia, 75.0% to schizophrenia, 43.6% to MBD and 69.2% to vascular dementia. Secondly, female patients were more prone to all the psychotic indicators than their male counterpart except in MBD. Thirdly, the oldest age group (> 60 years) is more prone to bipolar and insomnia ailments, while the mid age group (30 - 60 years) is prone to schizophrenia and vascular dementia, and the youngest group (< 30 years) is prone to MBD. Lastly, the factors that influence the ailments are listed: bipolar (age, occupation, marital status, divorce, and spiritual consultation); insomnia (age, occupation, marital status, divorce, and spiritual consultation); schizophrenia (age, occupation, religion, marital status, hereditary, and divorce); MBD (gender, age, occupation, and marital status); and vascular dementia (history of the ailment and spiritual consultation). Bipolar and insomnia are influenced by the same set of factors, which implies that any patient having one is most likely to be at risk of having the other.

Exploratory factor structure of the neurological evaluation scale in black africans with first episode schizophrenia

While the organization of neurological soft signs (NSS) in schizophrenia into Sensory integration, Motor coordination, and Motor sequencing, is functionally ‘meaningful’, it has not been confirmed by empirical methods such as factor analysis. Data on the exploratory factor analysis of the Neurological Evaluation scale in Black Africans with first episode schizophrenia are presented in this report. Data on the confirmatory factor structure of NSS in this population as well as their interpretation can be found in the work by Ojagbemi et al. (2015) [7].