Schizophrenia with prominent catatonic features ('catatonic schizophrenia') III. Latent class analysis of the catatonic syndrome

Motor actions across psychiatric disorders: A research domain criteria (RDoC) perspective

The motor system is critical for understanding the pathophysiology and treatment of mental illness. Abnormalities in the processes that allow us to plan and execute movement in a goal-directed, context-appropriate manner (i.e., motor actions) are especially central to clinical motor research. Within this context, the NIMH Research Domain Criteria (RDoC) framework now includes a Motor Actions construct within the recently incorporated Sensorimotor Systems Domain, providing a useful framework for conducting research on motor action processes. However, there is limited available resources for understanding or implementing this framework. We address this gap by providing a comprehensive critical review and conceptual integration of the current clinical literature on the subconstructs comprising the Motor Actions construct. This includes a detailed discussion of each Motor Action subconstruct (e.g., action planning/execution) and its measurement across different units of analysis (e.g., molecules to behavior), the temporal and conceptual relationships among the Motor Action subconstructs (and other relevant RDoC domain constructs), and how abnormalities in these Motor Action subconstructs manifest in mental illness. Together, the review illustrates how motor system dysfunction is implicated in the pathophysiology of many psychiatric conditions and demonstrates shared and distinct mechanisms that may account for similar manifestations of motor abnormalities across disorders.

The pathobiology of psychomotor slowing in psychosis: altered cortical excitability and connectivity

Psychomotor slowing is a frequent symptom of schizophrenia. Short-interval intracortical inhibition assessed by transcranial magnetic stimulation demonstrated inhibitory dysfunction in schizophrenia. The inhibitory deficit results from additional noise during information processing in the motor system in psychosis. Here, we tested whether cortical inhibitory dysfunction was linked to psychomotor slowing and motor network alterations. In this cross-sectional study, we included 60 patients with schizophrenia and psychomotor slowing determined by the Salpêtrière Retardation Rating Scale, 23 patients without slowing and 40 healthy control participants. We acquired single and double-pulse transcranial magnetic stimulation effects from the left primary motor cortex, resting-state functional connectivity and diffusion imaging on the same day. Groups were compared on resting motor threshold, amplitude of the motor evoked potentials, as well as short-interval intracortical inhibition. Regression analyses calculated the association between motor evoked potential amplitudes or cortical inhibition with seed-based resting-state functional connectivity from the left primary motor cortex and fractional anisotropy at whole brain level and within major motor tracts. In patients with schizophrenia and psychomotor slowing, we observed lower amplitudes of motor evoked potentials, while the short-interval intracortical inhibition/motor evoked potentials amplitude ratio was higher than in healthy controls, suggesting lower cortical inhibition in these patients. Patients without slowing also had lower amplitudes of motor evoked potentials. Across the combined patient sample, cortical inhibition deficits were linked to more motor coordination impairments. In patients with schizophrenia and psychomotor slowing, lower amplitudes of motor evoked potentials were associated with lower fractional anisotropy in motor tracts. Moreover, resting-state functional connectivity between the primary motor cortex, the anterior cingulate cortex and the cerebellum increased with stronger cortical inhibition. In contrast, in healthy controls and patients without slowing, stronger cortical inhibition was linked to lower resting-state functional connectivity between the left primary motor cortex and premotor or parietal cortices. Psychomotor slowing in psychosis is linked to less cortical inhibition and aberrant functional connectivity of the primary motor cortex. Higher neural noise in the motor system may drive psychomotor slowing and thus may become a treatment target.

Treatment of schizophrenia with catatonic symptoms: A narrative review

Catatonia is a neuropsychiatric syndrome consisting of psychomotor abnormalities caused by a broad range of disorders affecting brain function. While the nosological status of catatonia is no longer restricted to a subtype of schizophrenia in standardized diagnostic systems, the character, course, and clinical significance of catatonia in people with schizophrenia remain unclear. Evidence suggests that catatonia could be a nonspecific state-related phenomenon, a fundamental core symptom dimension of schizophrenia, or a subcortical variant of schizophrenia. Either way, the validity of catatonia in schizophrenia is clinically significant only insofar as it predicts prognosis and response to treatment. Most contemporary clinical trials of antipsychotics have targeted schizophrenia as an overly broad unitary psychosis neglecting any differential response defined by phenomenology or course. However, early naturalistic studies showed that catatonia predicted poor response to first-generation antipsychotics in chronic schizophrenia and case reports cautioned against the risk of triggering neuroleptic malignant syndrome. More recent studies suggest that second-generation antipsychotics, particularly clozapine, may be effective in schizophrenia with catatonic symptoms, while small randomized controlled trials have found that the short-term response to ECT may be faster and more significant. Based on available data, conclusions are limited as to whether antipsychotics are as effective and safe in acute and chronic schizophrenia with catatonic symptoms compared to other treatments and compared to schizophrenia without catatonia. Further studies of the pathophysiology, phenomenology, course and predictive value of catatonia in schizophrenia are worthwhile.

Schizophrenia with prominent catatonic features: A selective review

A widely accepted consensus holds that a variety of motor symptoms subsumed under the term 'catatonia' have been an integral part of the symptomatology of schizophrenia since 1896, when Kraepelin proposed the concept of dementia praecox (schizophrenia). Until recently, psychiatric classifications included catatonic schizophrenia mainly through tradition, without compelling evidence of its validity as a schizophrenia subtype. This selective review briefly summarizes the history, psychopathology, demographic and epidemiological data, and treatment options for schizophrenia with prominent catatonic features. Although most catatonic signs and symptoms are easy to observe and measure, the lack of conceptual clarity of catatonia and consensus about the threshold and criteria for its diagnosis have hampered our understanding of how catatonia contributes to the pathophysiology of schizophrenic psychoses. Diverse study samples and methodologies have further hindered research on schizophrenia with prominent catatonic features. A focus on the motor aspects of broadly defined schizophrenia using modern methods of detecting and quantifying catatonic signs and symptoms coupled with sophisticated neuroimaging techniques offers a new approach to research in this long-overlooked field.

Prevalence of Catatonia and Its Moderators in Clinical Samples: Results from a Meta-analysis and Meta-regression Analysis

Catatonia is an independent syndrome that co-occurs with several mental and medical conditions. We performed a systematic literature review in PubMed/Scopus until February 2017 and meta-analyzed studies reporting catatonia prevalence. Across 74 studies (cross-sectional = 32, longitudinal = 26, retrospective = 16) providing data collected from 1935 to 2017 across all continents, mean catatonia prevalence was 9.0% (k = 80, n = 110764; 95% CI = 6.9-11.7, I2 = 98%, publication bias P < .01), decreasing to 7.8% (k = 19, n = 7612, 95% CI = 7-8.7, I2 = 38.9%) in a subgroup with low heterogeneity. Catatonia prevalence was 23.9% (k = 8, n = 1168, 95% CI = 10-46.9, I2 = 96%) in patients undergoing ECT/having elevated creatinine phosphokinase. Excluding ECT samples, the catatonia prevalence was 8.1% (k = 72, n = 109606, 95% CI = 6.1-10.5, I2 = 98%, publication bias P < .01), with sensitivity analyses demonstrating that country of study origin (P < .001), treatment setting (P = .003), main underlying condition (P < .001), and sample size (P < .001)moderated catatonia prevalence, being highest in Uganda (48.5%, k = 1) and lowest in Mexico (1.9%, 95% CI = 0.4-8.8, I2 = 67%, k = 2), highest in nonpsychiatric out- or inpatient services (15.8%, 95% CI = 8.1-28.4, I2 = 97%, k = 15)and lowest in psychiatric outpatients services (3.2%, 95% CI = 1.7-6.1, I2 = 50%, k = 3), highest in presence of medical or neurological illness with no comorbid psychiatric condition (20.6%, 95% CI = 11.5-34.2, I2 = 95%, k = 10)and lowest in mixed psychiatric samples (5.7%, 95% CI = 4.2-7.7, I2 =98%, k = 43), highest in studies with sample sizes <100 (20.7%, 95% CI = 12.8-31.6, I2 = 90%, k = 17) and lowest in studies with sample sizes >1000 (2.3%, 95% CI = 1.3-3.9, I2 = 99%, k = 16). Meta-regression showed that smaller sample size (P < .01) and less major depressive disorder (P = .02) moderated higher catatonia prevalence. Year of data collection did not significantly moderate the results. Results from this first meta-analysis of catatonia frequencies across time and disorders suggest that catatonia is an epidemiologically and clinically relevant condition that occurs throughout several mental and medical conditions, whose prevalence has not decreased over time and does not seem to depend on different rating scales/criteria. However, results were highly heterogeneous, calling for a cautious interpretation.

The psychometric properties of the "Reading the Mind in the Eyes" Test: an item response theory (IRT) analysis

INTRODUCTION

The "Reading the Mind in the Eyes" Test (hereafter: Eyes Test) is considered an advanced task of the Theory of Mind aimed at assessing the performance of the participant in perspective-takingthat is, the ability to sense or understand other people's cognitive and emotional states. In this study, the item response theory analysis was applied to the adult version of the Eyes Test.

METHODS

The Italian version of the Eyes Test was administered to 200 undergraduate students of both genders (males = 46%). Modified parallel analysis (MPA) was used to test unidimensionality. Marginal maximum likelihood estimation was used to fit the 1-, 2-, and 3-parameter logistic (PL) model to the data. Differential Item Functioning (DIF) due to gender was explored with five independent methods.

RESULTS

MPA provided evidence in favour of unidimensionality. The Rasch model (1-PL) was superior to the other two models in explaining participants' responses to the Eyes Test. There was no robust evidence of gender-related DIF in the Eyes Test, although some differences may exist for some items as a reflection of real differences by group.

CONCLUSIONS

The study results support a one-factor model of the Eyes Test. Performance on the Eyes Test is defined by the participant's ability in perspective-taking. Researchers should cease using arbitrarily selected subscores in assessing the performance of participants to the Eyes Test. Lack of gender-related DIF favours the use of the Eyes Test in the investigation of gender differences concerning empathy and social cognition.

The catatonia conundrum: controversies and contradictions

Although catatonia is known to psychiatrists for more than a century, it is still poorly understood, often under recognized, have inspired debate and criticism about nosological status of the catatonic syndrome in recent times without reaching its conclusion. It can present with a number of psychiatric and medical illnesses and is easily treatable, though treatment response varies depending upon the underlying condition and can lead on to a multitude of complications, if not treated. Some issues are more than forty catatonic signs are available to scientific audience for diagnosis; threshold number for labelling varies according to the nosological system followed and the underlying condition; and mood stabilizers like carbamazepine and lithium are helpful in some cases of idiopathic periodic catatonia. Researchers have been asking for a separate diagnostic category for catatonia since long and the debate has gained pace over the last few years, with new editions of both DSM and ICD coming up. Therefore, this paper looks at the controversies associated with the diagnosis and classification of catatonia, the arguments and counter-arguments and future directions, in crisp.

Schizophrenia-like features in transgenic mice overexpressing human HO-1 in the astrocytic compartment

Delineation of key molecules that act epigenetically to transduce diverse stressors into established patterns of disease would facilitate the advent of preventive and disease-modifying therapeutics for a host of neurological disorders. Herein, we demonstrate that selective overexpression of the stress protein heme oxygenase-1 (HO-1) in astrocytes of novel GFAP.HMOX1 transgenic mice results in subcortical oxidative stress and mitochondrial damage/autophagy; diminished neuronal reelin content (males); induction of Nurr1 and Pitx3 with attendant suppression of their targeting miRNAs, 145 and 133b; increased tyrosine hydroxylase and α-synuclein expression with downregulation of the targeting miR-7b of the latter; augmented dopamine and serotonin levels in basal ganglia; reduced D1 receptor binding in nucleus accumbens; axodendritic pathology and altered hippocampal cytoarchitectonics; impaired neurovascular coupling; attenuated prepulse inhibition (males); and hyperkinetic behavior. The GFAP.HMOX1 neurophenotype bears resemblances to human schizophrenia and other neurodevelopmental conditions and implicates glial HO-1 as a prime transducer of inimical (endogenous and environmental) influences on the development of monoaminergic circuitry. Containment of the glial HO-1 response to noxious stimuli at strategic points of the life cycle may afford novel opportunities for the effective management of human neurodevelopmental and neurodegenerative conditions.

Parsing the components of the psychomotor syndrome in schizophrenia

OBJECTIVE

Catatonia, extrapyramidal signs, psychomotor slowing, and (motoric) neurological soft signs are well-known psychomotor symptoms in schizophrenia. This study aims at investigating the interrelations between these symptoms. In addition, associations between psychomotor symptoms, clinical symptoms, and cognitive functioning will be studied.

METHOD

An extensive test battery containing psychomotor (Bush Francis Catatonia Rating Scale; St Hans Rating Scale; Salpêtrière Retardation Rating Scale; Neurological Evaluation Scale) and clinical (Positive and Negative Syndrome Scale; Calgary Depression Scale) rating scales as well as instrumental psychomotor tests (Line Copying Task; Finger Tapping Task) and cognitive tasks (Symbol Digit Substitution Test; Stroop Colour Word Test; Continuous Performance Test; Letter Number Sequencing) was administered to a sample of 124 patients with schizophrenia or schizoaffective disorder.

RESULTS

Correlational analyses showed that two clusters emerge from our data: first, a psychomotor poverty cluster referring to the interrelations between catatonia, parkinsonism, psychomotor slowing, and negative symptoms; second, a cluster containing motoric neurological soft signs, which were found to be correlated with cognitive functioning.

CONCLUSION

Psychomotor abnormalities are highly prevalent phenomena in schizophrenia that have to be considered as a heterogeneous construct. However, longitudinal and neurobiological research is needed to further explore the precise nature of the interrelations found in this study.