Movement sequencing abilities and basal ganglia morphology in first-episode schizophrenia

Studies of brain morphology suggest a link between movement sequencing ability and basal ganglia dysfunction. Unfortunately, relevant studies have provided inconsistent data, which may be the result of differences in the methods of brain morphology assessment, statistical analysis or heterogeneity of the populations studied.

To test the hypothesis of a link between the dysfunction of movement sequencing and basal ganglia morphology in a homogenous sample of first-episode schizophrenia patients.

Thirty-seven first-episode schizophrenia patients underwent an assessment of movement sequencing abilities using the NES scale and basal ganglia morphology from MR images. The data were compared with a group of 19 age- and sex-matched healthy controls.

The group of first-episode patients had a higher concentration of gray matter than healthy controls in the putamen and pallidum in both hemispheres. Patients with abnormal sequencing of movements had lower gray matter concentration than patients without such abnormalities in the left putamen, and no differences were found between the symptomatic group and healthy controls.

Our study suggests the involvement of the left putamen in the movement sequencing abnormalities in schizophrenia. Because of the potential confounding effect of medication, the lack of support from external evidence and the low power to perform the whole-brain analysis the results should be considered as preliminary. Further studies, especially with antipsychotic-naive first-episode schizophrenia patients are needed to solve these issues.