Delayed onset of late movement-related cortical potentials and abnormal response to lorazepam in catatonia

A systematic scoping review of rodent models of catatonia: Clinical correlations, translation and future approaches

Catatonia is a psychiatric disorder, which subsumes a plethora of affective, motor and behavioral symptoms. In the last two decades, the number of behavioral and neuroimaging studies on catatonia has steadily increased. The majority of behavioral and neuroimaging studies in psychiatric patients suggested aberrant higher-order frontoparietal networks which, on the biochemical level, are insufficiently modulated by gamma-aminobutyric acid (GABA)-ergic and glutamatergic transmission. However, the pathomechanisms of catatonic symptoms have rarely been studied using rodent models. Here, we performed a scoping review of literature available on PubMed for studies on rodent models of catatonia. We sought to identify what we could learn from pre-clinical animal models of catatonia-like symptoms, their underlying neuronal correlates, and the complex molecular (i.e. genes and neurotransmitter) mechanisms by which its modulation exerts its effects. What becomes evident is that although many transgenic models present catatonia-like symptoms, they have not been used to better understand the pathophysiological mechanisms underlying catatonia so far. However, the identified neuronal correlates of catatonia-like symptoms correlate to a great extent with findings from neuroscience research in psychiatric patients. This points us towards fundamental cortical-striatal-thalamocortical and associated networks modulated by white matter inflammation as well as aberrant dopaminergic, GABAergic, and glutamatergic neurotransmission that is involved in catatonia. Therefore, this scoping review opens up the possibility of finally using transgenic models to help with identifying novel target mechanisms for the development of new drugs for the treatment of catatonia.

Microstructural white matter biomarkers of symptom severity and therapy outcome in catatonia: Rationale, study design and preliminary clinical data of the whiteCAT study

The number of magnetic resonance imaging (MRI) studies on neuronal correlates of catatonia has dramatically increased in the last 10 years, but conclusive findings on white matter (WM) tracts alterations underlying catatonic symptoms are still lacking. Therefore, we conduct an interdisciplinary longitudinal MRI study (whiteCAT) with two main objectives: First, we aim to enroll 100 psychiatric patients with and 50 psychiatric patients without catatonia according to ICD-11 who will undergo a deep phenotyping approach with an extensive battery of demographic, psychopathological, psychometric, neuropsychological, instrumental and diffusion MRI assessments at baseline and 12 weeks follow-up. So far, 28 catatonia patients and 40 patients with schizophrenia or other primary psychotic disorders or mood disorders without catatonia have been studied cross-sectionally. 49 out of 68 patients have completed longitudinal assessment, so far. Second, we seek to develop and implement a new method for semi-automatic fiber tract delineation using active learning. By training supportive machine learning algorithms on the fly that are custom tailored to the respective analysis pipeline used to obtain the tractogram as well as the WM tract of interest, we plan to streamline and speed up this tedious and error-prone task while at the same time increasing reproducibility and robustness of the extraction process. The goal is to develop robust neuroimaging biomarkers of symptom severity and therapy outcome based on WM tracts underlying catatonia. If our MRI study is successful, it will be the largest longitudinal study to date that has investigated WM tracts in catatonia patients.

Non-invasive brain stimulation for treating catatonia: a systematic review

Background

Non-invasive brain stimulation (NIBS) techniques offer new therapeutic options for modifying pathological neuroplasticity and have been proven to be beneficial in the treatment of neuropsychiatric disorders.

Objective

This study aimed to investigate the role of NIBS in treating catatonia.

Materials and methods

We conducted a systematic search to identify meta-analyses or systematic reviews on electroconvulsive therapy (ECT) and studies on the effects of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) on patients with catatonia from the PubMed, Web of Science, Embase, China National Knowledge Internet, Wanfang, and China Science and Technology Journal databases from inception until 31 July 2022. The methodological quality of the included studies was assessed with the AMSTAR2 or Joanna Briggs Institute Critical Appraisal tools. Paired t-tests and Wilcoxon signed-rank tests were used to compare changes in catatonia symptom scores after rTMS or tDCS.

Results

A total of 13 systematic reviews and one meta-analysis on ECT, two systematic reviews and 12 case reports on rTMS, and seven studies of 14 cases applying tDCS were identified. Systematic reviews of ECT consistently described improvement in catatonia symptoms across catatonia types and patient age groups. After treatment with rTMS (t = 4.489, p = 0.006) and tDCS (z = -3.065, p = 0.002), patients exhibited significant improvement.

Conclusion

ECT, rTMS, and tDCS were effective in treating catatonia. Early intervention with NIBS techniques may help improve catatonia symptoms in patients with schizophrenia. It may be advantageous to use rTMS or tDCS to maintain this improvement. NIBS techniques may thus represent a promising treatment for catatonia, but additional high-quality randomized controlled trials are needed.

The role of the electroencephalogram (EEG) in determining the aetiology of catatonia: a systematic review and meta-analysis of diagnostic test accuracy

BACKGROUND

Catatonia is a psychomotor syndrome that has a wide range of aetiologies. Determining whether catatonia is due to a medical or psychiatric cause is important for directing treatment but is clinically challenging. We aimed to ascertain the performance of the electroencephalogram (EEG) in determining whether catatonia has a medical or psychiatric cause, conventionally defined.

METHODS

In this systematic review and meta-analysis of diagnostic test accuracy (PROSPERO CRD42021239027), Medline, EMBASE, PsycInfo, and AMED were searched from inception to May 11, 2022 for articles published in peer-reviewed journals that reported EEG findings in catatonia of a medical or psychiatric origin and were reported in English, French, or Italian. Eligible study types were clinical trials, cohort studies, case-control studies, cross-sectional studies, case series, and case reports. The reference standard was the final clinical diagnosis. Data extraction was conducted using individual patient-level data, where available, by two authors. We prespecified two types of studies to overcome the limitations anticipated in the data: larger studies (n ≥ 5), which were suitable for formal meta-analytic methods but generally lacked detailed information about participants, and smaller studies (n < 5), which were unsuitable for formal meta-analytic methods but had detailed individual patient level data, enabling additional sensitivity analyses. Risk of bias and applicability were assessed with the QUADAS-2 tool for larger studies, and with a published tool designed for case reports and series for smaller studies. The primary outcomes were sensitivity and specificity, which were derived using a bivariate mixed-effects regression model.

FINDINGS

355 studies were included, spanning 707 patients. Of the 12 larger studies (5 cohort studies and 7 case series), 308 patients were included with a mean age of 48.2 (SD = 8.9) years. 85 (52.8%) were reported as male and 99 had catatonia due to a general medical condition. In the larger studies, we found that an abnormal EEG predicted a medical cause of catatonia with a sensitivity of 0.82 (95% CI 0.67-0.91) and a specificity of 0.66 (95% CI 0.45-0.82) with an I ² of 74% (95% CI 42-100%). The area under the summary ROC curve offered excellent discrimination (AUC = 0.83). The positive likelihood ratio was 2.4 (95% CI 1.4-4.1) and the negative likelihood ratio was 0.28 (95% CI 0.15-0.51). Only 5 studies had low concerns in terms of risk of bias and applicability, but a sensitivity analysis limited to these studies was similar to the main analysis. Among the 343 smaller studies, 399 patients were included, resulting in a sensitivity of 0.76 (95% CI 0.71-0.81), specificity of 0.67 (0.57-0.76) and AUC = 0.71 (95% CI 0.67-0.76). In multiple sensitivity analyses, the results were robust to the exclusion of reports of studies and individuals considered at high risk of bias. Features of limbic encephalitis, epileptiform discharges, focal abnormality, or status epilepticus were highly specific to medical catatonia, but features of encephalopathy had only moderate specificity and occurred in 23% of the cases of psychiatric catatonia in smaller studies.

INTERPRETATION

In cases of diagnostic uncertainty, the EEG should be used alongside other investigations to ascertain whether the underlying cause of catatonia is medical. The main limitation of this review is the differing thresholds for considering an EEG abnormal between studies.

FUNDING

Wellcome Trust, NIHR Biomedical Research Centre at University College London Hospitals NHS Foundation Trust.

Revisiting lorazepam challenge test: Clinical response with dose variations and utility for catatonia in a psychiatric emergency setting

OBJECTIVE

Catatonia can be life-threatening unless timely identified and treated. Lorazepam's ubiquitous response has led to its universal acceptance as being the first-line management of catatonia and alludes to catatonia's neurobiological underpinnings. Lorazepam challenge test (LCT) is widely used to either confirm a catatonia diagnosis or determine lorazepam sensitivity. It has a proposed schedule for administering lorazepam. However, efficacy of recommended LCT doses lack systematic evidence, resulting in variable LCT doses used in clinical and research settings contributing to findings that are challenging to generalize or assist with developing standardized lorazepam treatment protocols for catatonia. Given the same, this study aimed to objectively compare the response between two groups receiving different LCT doses and factors influencing the same.

METHODS

The 6-month study in a psychiatric emergency setting at a tertiary neuropsychiatric center in India evaluated 57 catatonia patients, before and after administration of single 2 mg (n = 37; LCT-2) or 4 mg (n = 20; LCT-4) lorazepam dose, applying Bush Francis Catatonia Rating Scale (BFCRS), Mini International Neuropsychiatric Interview (MINI 5.0) and obtaining sociodemographic, clinical data.

RESULTS

No between-group differences (LCT-2 vs LCT-4) for sociodemographic, clinical profiles or BFCRS severity score changes to lorazepam on Mann-Whitney U test were noted. Applying Wilcoxon signed rank test comparing individual sign severity demonstrated response variability, with significant response noted to both doses (stupor, mutism, staring, posturing, withdrawal, ambitendency, automatic obedience) and others selectively to 2 mg (echolalia, rigidity, negativism, mitgehen). Notably, sign resolution (present/absent) only to 2 mg was significant for stupor, mutism, staring, posturing, echolalia, rigidity, negativism and mitgehen.

CONCLUSION

This study suggests 2 mg lorazepam may be an optimal LCT dose, given significant response to most catatonic signs thereby ensuring accurate detection and preventing misinterpretation of response. It offers future studies direction for standardizing lorazepam dosing schedules for catatonia management and exploring neurobiological underpinnings for individual catatonic signs that may be potentially different, given these findings.

Timing of the Sense of Volition in Patients With Schizophrenia

Schizophrenic patients often do not have the sense that they direct their own movements or author their own thoughts (passivity phenomena). As willing must precede movement to be causal and thus generate the sense of agency, it is possible that the timing between the senses of willing and movement is shortened in schizophrenia. We tested the subjective perception of this time interval in patients with schizophrenia using a method based on Libet’s paradigm, in which subjects specify a time W – the time of willing a movement – and a time M – the time that movement occurred. Patients with schizophrenia and healthy volunteers made voluntary movements at times of their own choice while looking at a fast-rotating clock on a computer screen and reported when their movements were willed and made. We recorded surface electromyography to determine the time of actual movement, and electroencephalography to record brain potentials associated with movement. Results showed a significantly reduced interval between the reported M and W in patients with respect to the healthy volunteers (p < 0.05). Specifically, patients did not report a significant difference in the timing of W at 19 ms prior to movement onset and M at 7.4 ms prior to movement onset (p > 0.05), while the control group experienced a time W at 100 ms prior to movement onset and this differed significantly from their time M at 19 ms prior to movement onset (p < 0.01). These results suggest that patients with schizophrenia do have an altered timing of awareness of action – or an impaired judgment of the sequence of events – and that this might be etiologic in the development of the abnormal sense of agency.

Catatonia in elderly psychiatric inpatients is not always associated with intense anxiety: Factor analysis and correlation with psychopathology

OBJECTIVE

Catatonic stupor has been linked to extreme fear. Whether the underlying phenomenology of every catatonic dimension is intense anxiety or fear remains unknown.

METHODS

One hundred and six patients aged ≥64 years were assessed for catatonia and clinical variables during the first 24 hours of admission. Two-sample t test were used to test for group differences. A principal component analysis was developed. Analysis of variance was performed to assess for differences in the diagnostic groups. Correlation coefficients were used to examine the association between catatonic dimensions and psychopathological variables.

RESULTS

There were statistically significant differences between catatonic and non-catatonic patients in the Hamilton and NPI scores. The three factor-model accounted for 52.23% of the variance. Factor 1 loaded on items concerned with "excitement," factor 2 on "inhibition" items, and factor 3 on "parakinetic" items. There was a significant effect for factor 1 (F [5.36] = 2.83, P = .02), and not significant for factor 2 and factor 3. Compared with patients with depression, patients with mania scored significantly higher on factor "excitement" (P < .05). Factor 2 showed a moderate correlation with Hamilton total score (r = .346, P = .031) and Hamilton psychic score (r = .380, P = .017).

CONCLUSIONS

Catatonic patients experienced more anxiety and hyperactivity. A three-factor solution provided best fit for catatonic symptoms. Patients with mania scored highest on Excitement, patients with depression on Inhibition, and patients with schizophrenia on Parakinetic. The main finding in this study was a positive moderate correlation between the Hamilton psychic score and the Inhibition factor score, meaning that not every catatonic dimension is associated to intense anxiety.

Higher Serum C-Reactive Protein Levels in Catatonic Patients: A Comparison to Non-catatonic Patients and Healthy Controls

Catatonia is a psychomotor syndrome defined by a constellation of predominantly motor symptoms. The aim of the present study was to determine whether recently admitted psychiatric patients with catatonia exhibited higher serum C-reactive protein (hs-CRP) levels compared to non-catatonic psychiatric patients and healthy controls (HCs). Recently admitted psychiatric patients were screened and evaluated for the catatonia syndrome using the Bush-Francis Catatonia Rating Scale and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). The study sample was formed by 150 individuals (39 male and 111 female), including 51 catatonic patients, 55 non-catatonic patients, and 44 HCs. Serum hs-CRP levels were processed with the enzyme-linked immunosorbent assay. Serum levels of creatine kinase (CK), adrenocorticotropic hormone (ACTH), immunoglobulin G (IgG), complement component 3 (C3), and complement component 4 (C4) were also determined. There was a significantly higher percentage of patients with high inflammatory levels (hs-CRP > 3000ng/ml) in the catatonic (43.1%) than in the non-catatonic (14.5%) or HCs group (9.1%) (χ 2 =18.9, P < .001). Logistic regression showed that catatonic patients had significantly higher hs-CRP levels compared to non-catatonic patients even after controlling for other clinical and laboratory variables (OR = 3.52, P = .015, 95% CI 1.28-9.79). Multiple linear regression analysis revealed that log-transformed hs-CRP was independently predicted by body mass index and log-transformed C4, ACTH, and Cortisol in catatonic patients. Findings of the present study suggest that catatonia is specifically linked to a higher level of systemic inflammation, not merely attributable to the overall psychopathology, or alterations in the stress level and complement system.

Movement disorder and sensorimotor abnormalities in schizophrenia and other psychoses - European consensus on assessment and perspectives

Over the last three decades, movement disorder as well as sensorimotor and psychomotor functioning in schizophrenia (SZ) and other psychoses has gained greater scientific and clinical relevance as an intrinsic component of the disease process of psychotic illness; this extends to early psychosis prediction, early detection of motor side effects of antipsychotic medication, clinical outcome monitoring, treatment of psychomotor syndromes (e.g. catatonia), and identification of new targets for non-invasive brain stimulation. In 2017, a systematic cooperation between working groups interested in movement disorder and sensorimotor/psychomotor functioning in psychoses was initiated across European universities. As a first step, the members of this group would like to introduce and define the theoretical aspects of the sensorimotor domain in SZ and other psychoses. This consensus paper is based on a synthesis of scientific evidence, good clinical practice and expert opinions that were discussed during recent conferences hosted by national and international psychiatric associations. While reviewing and discussing the recent theoretical and experimental work on neural mechanisms and clinical implications of sensorimotor behavior, we here seek to define the key principles and elements of research on movement disorder and sensorimotor/psychomotor functioning in psychotic illness. Finally, the members of this European group anticipate that this consensus paper will stimulate further multimodal and prospective studies on hypo- and hyperkinetic movement disorders and sensorimotor/psychomotor functioning in SZ and other psychotic disorders.

rTMS and tDCS for the treatment of catatonia: A systematic review

BACKGROUND

Catatonia is a potentially life threatening syndrome in various psychiatric disorders. As first line treatment, benzodiazepines and electroconvulsive therapy (ECT) are recommended. In some cases, benzodiazepines are ineffective and ECT is not available or contraindicated. Therefore, the search for new and alternative treatment strategies is of great importance.

OBJECTIVE

To review the evidence for alternative neurostimulation treatment strategies (rTMS and tDCS) for catatonia according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

METHOD

We performed a systematic literature search in several electronic databases. We also searched the WHO International Clinical Trials Registry Platform (ICTRP) and the ClinicalTrials.gov database to detect registered studies.

RESULTS

We identified nine publications on rTMS treatment and four publications on tDCS in catatonia. Most of the publications reported clinically relevant improvement of catatonic symptoms. Only two publications reported insufficient improvement. The available Bush-Francis Catatonia Rating Scale scores showed statistical significant improvement following rTMS and tDCS. We could not identify any finished clinical studies or case series, dedicated to this topic. We also could not identify any publications that compared first line treatment options with rTMS or tDCS.

CONCLUSIONS

Based on the case report literature, rTMS and tDCS might be promising alternative treatment strategies for patients who do not respond to benzodiazepines or in case ECT is not available or contraindicated. There are even hints that rTMS or tDCS might be an option in patients who respond to ECT but need long-term treatment to control catatonic symptoms. Further clinical trials are needed to allow for an evidence-based evaluation of potential risks and benefits of rTMS and tDCS for catatonia.

Structure and neural mechanisms of catatonia

Catatonia is a psychomotor syndrome associated with several psychiatric and medical conditions. Psychomotor signs range from stupor to agitation, and include pathognomonic features such as verbigeration and waxy flexibility. Disturbances of volition led to the classification of catatonia as a subtype of schizophrenia, but changes in nosology now recognise the high prevalence in mood disorders, overlap with delirium, and comorbidity with medical conditions. Initial psychometric studies have revealed three behavioural factors, but the structure of catatonia is still unknown. Evidence from brain imaging studies of patients with psychotic disorders indicates increased neural activity in premotor areas in patients with hypokinetic catatonia. However, whether this localised hyperactivity is due to corticocortical inhibition or excess activity of inhibitory corticobasal ganglia loops is unclear. Current treatment of catatonia relies on benzodiazepines and electroconvulsive therapy-both effective, yet unspecific in their modes of action. Longitudinal research and treatment studies, with neuroimaging and brain stimulation techniques, are needed to advance our understanding of catatonia.

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.

[German version of the Northoff catatonia rating scale (NCRS-dv) : A validated instrument for measuring catatonic symptoms]

The clinical picture of catatonia includes impressive motor phenomena, such as rigidity, dyskinesia, festination, negativism, posturing, catalepsy, stereotypies and mannerisms, along with affective (e. g. aggression, anxiety, anhedonism or emotional lability) and behavioral symptoms (e.g. mutism, autism, excitement, echolalia or echopraxia). In English speaking countries seven catatonia rating scales have been introduced, which are widely used in clinical and scientific practice. In contrast, only one validated catatonia rating scale is available in Germany so far. In this paper, we introduce the German version of the Northoff catatonia rating scale (NCRS-dv). The original English version of the NCRS consists of 40 items describing motor (13 items), affective (12 items) and behavioral (15 items) catatonic symptoms. The NCRS shows high internal reliability (Crombachs alpha = 0.87), high interrater (r = 0.80-0.96) and high intrarater (r = 0.80-0.95) reliability. Factor analysis of the NCRS revealed four domains: affective, hyperactive or excited, hypoactive or retarded and behavior with individual eigenvalues of 8.98, 3.61, 2.98 and 2.82, respectively, which explained 21.5 %, 9.3 %, 7.6 % and 7.2 % of variance, respectively. In conclusion, the NCRS-dv represents a second validated instrument which can be used by German clinicians and scientists for the assessment of catatonic symptoms.

Catatonia

One of the most exciting psychiatric conditions is the bizarre psychomotor syndrome called catatonia, which may present with a large number of different motor signs and even vegetative instability. Catatonia is potentially life threatening. The use of benzodiazepines and electroconvulsive therapy (ECT) has been efficient in the majority of patients. The rich clinical literature of the past has attempted to capture the nature of catatonia. But the lack of diagnostic clarity and operationalization has hampered research on catatonia for a long time. Within the last decades, it became clear that catatonia had to be separated from schizophrenia, which was finally accomplished in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). In DSM-5, catatonia syndrome may be diagnosed as a specifier to major mood disorders, psychotic disorders, general medical conditions, and as catatonia not otherwise specified. This allows diagnosing the syndrome in a large variety of psychiatric disorders. Currently, the pathobiology remains widely unknown. Suspected neurotransmitter systems include gamma-aminobutyric acid (GABA) and glutamate. Neuroimaging reports pointed to reduced resting state activity and reduced task activation in motor areas of the frontal and parietal cortex. The new classification of catatonia will foster more clinical research and neuroscientific approaches by testing catatonia in various populations and applying stringent criteria. The scarce number of prospective trials will hopefully increase, as more trials will be encouraged within a more precise concept of catatonia.

Motor dysfunction within the schizophrenia-spectrum: A dimensional step towards an underappreciated domain

At the beginning of the 20th century, genuine motor abnormalities (GMA) were considered to be intricately linked to schizophrenia. Subsequently, however, GMA have been increasingly regarded as unspecific transdiagnostic phenomena or related to side effects of antipsychotic treatment. Despite possible medication confounds, within the schizophrenia spectrum GMA have been categorized into three broad categories, i.e. neurological soft signs, abnormal involuntary movements and catatonia. Schizophrenia patients show a substantial overlap across a broad range of distinct motor signs and symptoms suggesting a prominent involvement of the motor system in disease pathophysiology. There have been several attempts to increase reliability and validity in diagnosing schizophrenia based on behavior and neurobiology, yet relatively little attention has been paid to the motor domain in the past. Nevertheless, accumulating neuroscientific evidence suggests the possibility of a motor endophenotype in schizophrenia, and that GMA could represent a specific dimension within the schizophrenia-spectrum. Here, we review current neuroimaging research on GMA in schizophrenia with an emphasis on distinct and common mechanisms of brain dysfunction. Based on a dimensional approach we show that multimodal neuroimaging combined with fine-grained clinical examination can result in a comprehensive characterization of structural and functional brain changes that are presumed to underlie core GMA in schizophrenia. We discuss the possibility of a distinct motor domain, together with its implications for future research. Investigating GMA by means of multimodal neuroimaging can essentially contribute at identifying novel and biologically reliable phenotypes in psychiatry.

Bereitschaftspotential in remitted paediatric bipolar disorder

Bereitschaftspotential (BP) is an anticipatory slow wave in the brain that typically precedes a voluntary motor act and its deficit reflects abnormal motor preparatory processes in the brain. Although BP deficits have been consistently noticed in schizophrenia, similar research in depression has yielded contradictory results; therefore, it is unclear if motor anticipatory processes are actually abnormal in mood disorder. We compared both early and late BP between thirty remitted paediatric bipolar patients (PBD) and thirty matched healthy control group subjects. We did not find any evidence of BP abnormality in PBD, indicating normal motor preparatory processes in this condition. This finding is in agreement with our previous research reporting normal anticipatory slow waves in bipolar subjects. Future research needs to address the specificity of normal anticipatory slow waves in bipolar disorder, compared to other major Psychoses.

Movement-related potentials point towards an impaired tuning of reafferent sensory feedback by preceding motor activation in schizophrenia

The link between focal motor system activation and reafferent sensory feedback is thought to be crucial for the perception that a movement is actively performed. In this article, we examine how schizophrenia affects the relationship between motor and somatosensory system activation. Movement-related potential source analysis allowed us to separate and compare motor activation deficits and reafferent feedback processing. We analyzed lateralized movement-related potentials during choice reaction movements in 16 subjects with schizophrenia/schizoaffective disorder. These subjects had partial remissions with predominantly negative symptoms and were compared to an age-matched healthy control group. In the schizophrenia/schizoaffective group, dipole source analysis indicated a significantly reduced lateralized sensorimotor activation immediately preceding movement execution. In contrast, activation by reafferent feedback was relatively unimpaired. Subjects with schizophrenia/schizoaffective disorder lacked a focal motor and reafferent sensory processing correlation, which can be identified through a significantly different regression slope from healthy controls. Reduced action-related motor system activation in subjects with schizophrenia/schizoaffective disorder was associated with preserved activation by reafferent sensory feedback. Most importantly, motor-sensory tuning, i.e. a specific enhancement of sensory information necessary to monitor movements, could not be found in subjects with schizophrenia/schizoaffective disorder. Our data provide further evidence for disturbed motor-sensory interactions in schizophrenia.

Lateralized movement-related potential amplitudes differentiate between schizophrenia/schizoaffective disorder and major depression

OBJECTIVE

To examine whether deficits in focal lateralized motor system activation would differentiate between subjects with schizophrenia/schizoaffective disorder and subjects with a major depressive episode. Reductions of Bereitschaftspotential amplitude have been described for both diagnostic groups.

METHODS

We analyzed multi-channel lateralized movement-related potentials (LMRP) during choice reaction movements in 16 schizophrenic/schizoaffective patients in partial remission with predominant negative symptoms, 18 patients with a non-psychotic major depression and two healthy control groups age-matched to the respective patient groups (20/23 subjects).

RESULTS

A significant reduction of lateralized potentials over the (pre-)motor areas immediately preceding and around movement execution was found only in subjects with schizophrenia/schizoaffective disorder but not with a major depressive episode. Reduced LMRP amplitudes correlated with negative symptoms (SANS score). Other movement stages (preceding response-locked 'contingent negative variation' during response selection and post-movement evaluation during motor postimperative negative variation) were not affected in the same way.

CONCLUSIONS

Deficits in focal motor cortex activation during movement execution may reflect rather schizophrenia-specific deficits in fronto-striatal circuits. A general lack of drive and depressed mood did not alter the degree of lateralization of motor activation during movement execution.

SIGNIFICANCE

Lateralization of movement-related potentials could differentiate psychotic from non-psychotic disorders on the group level.

A case of catatonia and neuroleptic malignant syndrome probably associated with antipsychotic in Korea

Several studies have reported on catatonia caused by the use of antipsychotic drugs and on the association between catatonia and neuroleptic malignant syndrome (NMS), but none has reported such a case in Korea. Here, we report the case of a 20-year-old woman whose catatonia and NMS appeared associated with the administration of an atypical antipsychotic drug. We discuss the association between NMS and catatonia due to neuroleptic use.

Catatonia - case report and review

Catatonia is a neuro-psychiatric disorder that can occur in medical, psychiatric and drug-induced conditions but is often unrecognised. A 64 year-old woman was admitted to hospital for assessment of a significant deterioration in her ability to communicate and function normally so that she had become completely dependent on others for all activities of daily living for nearly three years. Outpatient medical and psychiatric assessments failed to clarify diagnosis. On admission to a general hospital, the neurology team initially believed she had a Parkinson's-like syndrome but after further investigation and comprehensive multidisciplinary assessment, including neuro-psychiatric review, she was diagnosed with catatonia. She was subsequently admitted to a psychiatric hospital where she received electro-convulsive therapy and changes to her psychotropic medication regimen. She responded well to treatment and within a short period of time was able to function independently again.

Catatonia as a risk factor for the development of neuroleptic malignant syndrome: report of a case following treatment with clozapine

Catatonia is characterized by the predominance of psychomotor abnormalities and shares many clinical, biological and treatment response features with the neuroleptic malignant syndrome (NMS), a rare adverse reaction to psychoactive medications. It has been advocated that the two conditions should be placed along the same spectrum of disorders. A case of a 49-year-old woman, who developed NMS while on low dose clozapine soon after recovering from catatonia, is presented. The potential relationship between catatonia and NMS is discussed in the light of the existing literature, and attention is drawn to the risk for clozapine-induced NMS in catatonic patients.

Histamine H1 receptor blockade predominantly impairs sensory processes in human sensorimotor performance

BACKGROUND AND PURPOSE

Centrally active antihistamines impair cognitive performance, particularly sensorimotor performance. The aim of the present study was to further elucidate the scarcely studied subprocesses involved in sensorimotor performance, which may be affected by H1 receptor blockade. Better knowledge about the cognitive deficits associated with histamine dysfunction can contribute to better treatment of clinical disorders in which histamine hypofunction may be a contributing factor, such as in schizophrenia.

EXPERIMENTAL APPROACH

Interactions of dexchlorpheniramine with specific task manipulations in a choice reaction time task were studied. Task demands were increased at the level of sensory subprocesses by decreasing stimulus quality, and at the level of motor subprocesses by increasing response complexity. A total of 18 healthy volunteers (9 female) aged between 18 and 45 years participated in a three-way, double-blind, crossover design. Treatments were single oral doses of 4 mg dexchlorpheniramine, 1 mg lorazepam and placebo. Behavioural effects were assessed by measuring reaction times and effects on brain activity by event-related potentials.

KEY RESULTS

Dexchlorpheniramine significantly slowed reaction times, but did not significantly interact with task manipulations. However, it did significantly interact with stimulus quality, as measured by event-related potentials. Lorazepam slowed reaction times and interacted with perceptual manipulations, as shown by effects on reaction times.

CONCLUSIONS AND IMPLICATIONS

The results confirm that the histamine system is involved in sensory information processing and show that H1 blockade does not affect motoric information processing. Histamine hypofunction in clinical disorders may cause impaired sensory processing, which may be a drug target.

Which perspectives can endophenotypes and biological markers offer in the early recognition of schizophrenia?

The early recognition of schizophrenia seems crucial; various studies relate a longer duration-of-untreated-psychosis to a worse prognosis. We give an overview over common psychopathological early recognition instruments (BSABS, CAARMS, SIPS, IRAOS, ERIraos). However, many clinical symptoms of prodromal schizophrenia stages are not sufficiently specific. Thus we review recent contributions of neuroimaging and electrophysiological as well as genetic studies: which new diagnostic perspectives offer endophenotypes (such as P300, P50 sensory gating, MMN, smooth pursuit eye movements; indicating a specific genetic vulnerability) together with a better understanding of schizophrenic pathophysiology (state-dependent biological markers, e.g. aggravated motor neurological soft signs during psychosis) in prodromal schizophrenia when still ambiguous clinical symptoms are present. Several examples (e.g. from COMT polymorphisms to working memory deficits) illustrate more specific underlying neuronal mechanisms behind behavioural symptoms. This way, a characteristic pattern of disturbed cerebral maturation might be distinguished in order to complement clinical instruments of early schizophrenia detection.

Towards a valid nosography and psychopathology of catatonia in children and adolescents

Paraphrasing Taylor and Fink (2003), catatonia needs "a home of its own" in child and adolescent psychiatry. Limited but expanding literature supports that catatonia in children and adolescent can be identified reliably among other childhood conditions, is sufficiently common, treatable with the same specific treatments as adult catatonia (e.g., sedative drugs and electroconvulsive therapy), and can be worsened by other treatments (e.g., antipsychotics). Other findings in child and adolescent catatonia suggest that sex ratio and associated disorders may differ, and the proposed classification of Taylor and Fink (2003) needs modification. Adopting a broader diagnostic schedule may accommodate both child, adolescent, and adult catatonia. A psychomotor automatism variant should be included as a diagnosis, as well as specifiers for associated disorders such as acute nonpsychotic anxious state and pervasive developmental disorder. Duration of illness should be specified as acute or chronic. Regardless of associated psychiatric disorders, this chapter describes a new psychopathological model. Three main modalities of movement dysfunction in catatonic subjects are listed: (1) adherence to delusional ideas leading to a psychomotor automatism (De Clérambault, 1927); (2) resistance to delusional thinking or conviction; and finally (3) hyperanxious states. Case-vignettes illustrate the model, and future research directions are identified.

GABA-ergic modulation of prefrontal spatio-temporal activation pattern during emotional processing: a combined fMRI/MEG study with placebo and lorazepam

Various prefrontal cortical regions have been shown to be activated during emotional stimulation, whereas neurochemical mechanisms underlying emotional processing in the prefrontal cortex remain unclear. We therefore investigated the influence of the GABA-A potentiator lorazepam on prefrontal cortical emotional-motor spatio-temporal activation pattern in a combined functional magnetic resonance imaging/magnetoencephalography study. Lorazepam led to the reversal in orbito-frontal activation pattern, a shift of the early magnetic field dipole from the orbito-frontal to medial prefrontal cortex, and alterations in premotor/motor cortical function during negative and positive emotional stimulation. It is concluded that negative emotional processing in the orbito-frontal cortex may be modulated either directly or indirectly by GABA-A receptors. Such a modulation of orbito-frontal cortical emotional function by lorazepam has to be distinguished from its effects on cortical motor function as being independent from the kind of processing either emotional or nonemotional.

Cataleptic postures in thalamic hemorrhage: case report

We report a case of catalepsy associated with thalamic hemorrhage. A 72 year-old hypertensive woman had acute onset of right-sided weakness and speech disturbances. She was on anticoagulants because of aortic valve replacement. When postures were imposed, the patient maintained the left upper limb raised for several minutes, even in uncomfortable or bizarre positions. A CT scan of the head revealed a left thalamic hemorrhage. Cataleptic postures have been reported in few cases with acute stroke.