Altered subcortical emotional salience processing differentiates Parkinson's patients with and without psychotic symptoms

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Emotional salience processing differentiates PD patients with and without psychosis.

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Enhanced striatal, hippocampal and midbrain responses in PD patients with psychosis.

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Indication for ‘jumping to conclusions’ bias in the same PD patients with psychosis.

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Aberrant top-down and salience processing associated with PD psychosis.

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Similar deficits as proposed in ‘aberrant salience hypothesis’ of schizophrenia.

Objective

Current research does not provide a clear explanation for why some patients with Parkinson’s Disease (PD) develop psychotic symptoms. The ‘aberrant salience hypothesis’ of psychosis has been influential and proposes that dopaminergic dysregulation leads to inappropriate attribution of salience to irrelevant/non-informative stimuli, facilitating the formation of hallucinations and delusions. The aim of this study is to investigate whether non-motivational salience is altered in PD patients and possibly linked to the development of psychotic symptoms.

Methods

We investigated salience processing in 14 PD patients with psychotic symptoms, 23 PD patients without psychotic symptoms and 19 healthy controls. All patients were on dopaminergic medication for their PD. We examined emotional salience using a visual oddball fMRI paradigm that has been used to investigate early stages of schizophrenia spectrum psychosis, controlling for resting cerebral blood flow as assessed with arterial spin labelling fMRI.

Results

We found significant differences between patient groups in brain responses to emotional salience. PD patients with psychotic symptoms had enhanced brain responses in the striatum, dopaminergic midbrain, hippocampus and amygdala compared to patients without psychotic symptoms. PD patients with psychotic symptoms showed significant correlations between the levels of dopaminergic drugs they were taking and BOLD signalling, as well as psychotic symptom scores.

Conclusion

Our study suggests that enhanced signalling in the striatum, dopaminergic midbrain, the hippocampus and amygdala is associated with the development of psychotic symptoms in PD, in line with that proposed in the ‘aberrant salience hypothesis’ of psychosis in schizophrenia.

Does Viral Co-Infection Influence the Severity of Acute Respiratory Infection in Children?

Background

Multiple viruses are often detected in children with respiratory infection but the significance of co-infection in pathogenesis, severity and outcome is unclear.

Objectives

To correlate the presence of viral co-infection with clinical phenotype in children admitted with acute respiratory infections (ARI).

Methods

We collected detailed clinical information on severity for children admitted with ARI as part of a Spanish prospective multicenter study (GENDRES network) between 2011–2013. A nested polymerase chain reaction (PCR) approach was used to detect respiratory viruses in respiratory secretions. Findings were compared to an independent cohort collected in the UK.

Results

204 children were recruited in the main cohort and 97 in the replication cohort. The number of detected viruses did not correlate with any markers of severity. However, bacterial superinfection was associated with increased severity (OR: 4.356; P-value = 0.005), PICU admission (OR: 3.342; P-value = 0.006), higher clinical score (1.988; P-value = 0.002) respiratory support requirement (OR: 7.484; P-value < 0.001) and longer hospital length of stay (OR: 1.468; P-value < 0.001). In addition, pneumococcal vaccination was found to be a protective factor in terms of degree of respiratory distress (OR: 2.917; P-value = 0.035), PICU admission (OR: 0.301; P-value = 0.011), lower clinical score (-1.499; P-value = 0.021) respiratory support requirement (OR: 0.324; P-value = 0.016) and oxygen necessity (OR: 0.328; P-value = 0.001). All these findings were replicated in the UK cohort.

Conclusion

The presence of more than one virus in hospitalized children with ARI is very frequent but it does not seem to have a major clinical impact in terms of severity. However bacterial superinfection increases the severity of the disease course. On the contrary, pneumococcal vaccination plays a protective role.

Successful port-a-cath salvage using linezolid in children with acute leukemia

Central venous catheter (CVC) removal is indicated when persistent catheter-related bloodstream infection (CRBSI) occurs. This is a retrospective study to analyze the use of linezolid as a salvage therapy for CRBSIs due to coagulase-negative Staphylococci in children diagnosed with acute leukemia. Seven treatment courses of linezolid were administrated to six patients with port-type-CRBSI after non-effective intravenous vancomycin or teicoplanin treatment. Simultaneous lock and systemic therapy with linezolid avoided the removal of port-type-CVC in all cases. Treatment with linezolid was an alternative to catheter removal in these patients. Prospective studies are needed to confirm linezolid effectiveness as a salvage treatment in CRBSI.

Spanish validation of the Brief Assessment in Cognition in Schizophrenia (BACS) in patients with schizophrenia and healthy controls

Neurocognitive impairment is a core feature of schizophrenia and is closely associated with functional outcome. The importance of cognitive assessment is broadly accepted today, and an easy-to-use, internationality validated cognitive assessment tool is needed by researchers and in daily clinical practice. The Brief Assessment of Cognition in Schizophrenia (BACS) has been validated in English, French, Japanese and Italian. It is as sensitive to cognitive dysfunction as a standard test battery, with the advantage of requiring less than 35minutes to complete. In our study, we tested the psychometric characteristics of a Spanish version of the BACS in 117 patients with schizophrenia-spectrum disorders and 36 healthy controls. All BACS cognitive subtests discriminated between patients and controls (P<.001), and the concurrent validity between the BACS and a traditional neuropsychological test battery was similar to that reported in other languages. We conclude that the BACS can facilitate the comparison of the cognitive performance of patients with schizophrenia in many different countries.