Thalamus surface shape deformity in obsessive-compulsive disorder and schizophrenia

Area of Science:

• Neuroimaging
• Psychiatry
• Computational Anatomy

Background:

• Thalamic nuclei abnormalities are implicated in various psychiatric disorders.
• Obsessive-compulsive disorder (OCD) and schizophrenia are complex conditions with overlapping and distinct neurobiological features.
• Understanding specific patterns of thalamic deformation may elucidate disease mechanisms.

Purpose of the Study:

• To investigate and compare three-dimensional shape deformation patterns of specific thalamic nuclei in patients with OCD and schizophrenia versus healthy controls.
• To identify distinct neuroanatomical signatures associated with OCD and schizophrenia within the thalamus.
• To explore thalamic asymmetry differences across the groups.

Main Methods:

• Three-dimensional shape deformation analysis was applied to MRI data.
• Age- and sex-matched groups of 22 patients with OCD, 22 with schizophrenia, and 22 healthy controls were recruited.
• Statistical comparisons were performed to identify significant differences in thalamic shape and asymmetry.

Main Results:

• Patients with OCD showed significant anterior and lateral outward thalamic surface deformities compared to controls.
• Patients with schizophrenia exhibited prominent posterior and medial outward thalamic deformities.
• Both OCD and schizophrenia groups demonstrated a loss of the typical leftward pattern of thalamic asymmetry on the posterior, medial surface.

Conclusions:

• Distinct patterns of thalamic shape abnormality characterize obsessive-compulsive disorder and schizophrenia.
• Altered thalamic asymmetry is a shared feature in both OCD and schizophrenia.
• These findings suggest that specific thalamic nuclei abnormalities may correlate with the differing clinical presentations (phenomenology) of OCD and schizophrenia.