Brainstem alterations contribute to catatonia in schizophrenia spectrum disorders

Catatonia is a severe psychomotor syndrome that frequently occurs in patients with schizophrenia spectrum disorders (SSD). Accumulating neuroimaging evidence suggests orbitofrontal, frontoparietal and cerebellar network dysfunction in catatonia. Very little is known about contributions of brainstem regions (as part of the dopaminergic-based subcortical-cortical motor circuit) to catatonia in SSD patients. Here, we used structural magnetic resonance imaging (MRI) at 3 T to examine volumes of brainstem regions in catatonic SSD patients compared to non-catatonic SSD patients. Catatonia severity was measured with the Northoff Catatonia Rating Scale (NCRS). The segmentation of the brainstem in order to investigate the volumes of medulla oblongata, pons, superior cerebellar pedunculus, and midbrain was carried out using FreeSurfer vers. 6.0. Catatonic patients (NCRS total score ≥ 3; at least 1 point in the three different symptom categories; i.e., motor, behavioral, and affective; n = 30) had significantly smaller midbrain volumes (p = 0.004, Bonferroni corr.) when compared to non-catatonic patients (NCRS total score = 0; n = 29). In catatonic patients, significant correlations were detected between NCRS motor scores and whole brainstem (p = 0.015, Bonferroni corr.) volumes. These results support a neuromechanistically important role of brainstem structures in catatonia in SSD, particularly in motor symptom expression.