Cortico-cerebellar functional connectivity and sequencing of movements in schizophrenia

<p>Abstract</p> <p>Background</p> <p>Abnormal execution of several movements in a sequence is a frequent finding in schizophrenia. Successful performance of such motor acts requires correct integration of cortico-subcortical processes, particularly those related to cerebellar functions. Abnormal connectivity between cortical and cerebellar regions with resulting cognitive dysmetria has been proposed as the core dysfunction behind many signs and symptoms of schizophrenia. The aim of the present study was to assess if these proposed abnormalities in connectivity are a unifying feature of schizophrenia, or, rather, reflect a specific symptom domain of a heterogeneous disease. We predicted that abnormal functional connectivity between the motor cortex and cerebellum would be linked with abnormal performance of movement sequencing.</p> <p>Methods</p> <p>We examined 24 schizophrenia patients (SCH) and 24 age-, sex-, and handedness-matched healthy controls (HC) using fMRI during a modified finger-tapping task. The ability to perform movement sequencing was tested using the Neurological Evaluation Scale (NES). The subjects were categorized into two groups, with (SQ+) and without (SQ-) movement sequencing abnormalities, according to the NES-SQ score. The effects of diagnosis and movement sequencing abnormalities on the functional connectivity parameters between the motor cortex and cerebellum (MC-CRBL) and the supplementary motor cortex and cerebellum (SMA-CRBL) activated during the motor task were analyzed.</p> <p>Results</p> <p>We found no effect of diagnosis on the functional connectivity measures. There was, however, a significant effect on the SQ group: SQ + patients showed a lower level of MC-CRBL connectivity than SQ- patients and healthy controls. Moreover, the level of MC-CRBL and SMA-CRBL negatively correlated with the magnitude of NES-SQ abnormalities, but with no other NES domain.</p> <p>Conclusions</p> <p>Abnormal cortico-cerebellar functional connectivity during the execution of a motor task is linked with movement sequencing abnormalities in schizophrenia, but not with the diagnosis of schizophrenia per se. It seems that specific patterns of inter-regional connectivity are linked with corresponding signs and symptoms of clinically heterogeneous conditions such as schizophrenia.</p

Longitudinal association between motor and obsessive compulsive symptoms in patients with psychosis and their unaffected siblings

Little is known about the co-prevalence of obsessive compulsive symptoms (OCS) and motor symptoms in patients with psychotic disorders. Cross-sectional associations between OCS and motor symptoms were assessed at baseline and at 3years follow-up in patients (n=726) with psychotic disorders and in their unaffected siblings (n=761) from the Dutch Genetic Risk and Outcome of Psychosis (GROUP) study. Furthermore, longitudinal associations between changes in OCS and motor symptoms were evaluated. At baseline, OCS was not associated with any motor symptom (akathisia, dyskinesia, parkinsonism or dystonia) in patients. At follow-up, patients with OCS reported significantly more akathisia. Dividing the patients into four groupsno OCS, OCS remission with OCS only at baseline, OCS de novo with OCS only at follow-up and a persistent OCS grouprevealed that the OCS de novo group already reported more akathisia at baseline compared to the no-OCS group. At follow-up, both the OCS de novo and the persistent OCS group reported more akathisia. These results remained significant after correcting for relevant confounders clozapine, GAF score, PANSS-negative score and IQ. Motor symptoms at baseline were significantly associated with OCS at follow-up, but not the other way around. In siblings, OCS at baseline was associated with akathisia, but this association was lost at follow-up. Results suggest that motor symptoms might precede co-occurring OCS in patients with psychotic disorders. However, no inference can be made about causality, and further prospective research is needed to investigate this assumption

Choice, cost and community : the hidden complexities of the rural primary school market.

National rural policy places the local primary school as a key resource within the rural community, yet as a consequence of countywide financial constraints, some small schools are undergoing reorganization, involving amalgamation, federation and school closure. This article considers the complexities involved in the workings of the English rural primary school market for parents and for schools, the cost dilemma of providing primary education for local authorities and the perception that the local school provides a key service to the rural community. Using primary data collected through interviews and observations the article focuses on a small school operating under the threat of closure, and the ensuing campaign by the ‘education-insider’ parents to save their school from closure as the local authority attempts to balance school and community service delivery with cost effectiveness. The article argues that the previously hidden consequence of cost logic is an aspect largely overlooked both in the rhetoric of the school at the heart of the rural community and in the rhetoric of parental choice