Anatomical classification of septum pellucidum variations and analysis of the co-occurrence of the variations with psychiatric disorders

Abstract

This study sought to categorize anatomical variations of the septum pellucidum (SP), cavum vergae (CV), and cavum veli interpositi (CVI), as well as to examine potential correlations between these variations and psychiatric disorders. A total of 2949 patients were retrospectively analyzed utilizing brain MRIs. Variations were categorized into nine types according to the coexistence of CSP and CVI in either mild or moderate manifestations. The prevalence of CSP, CV, and CVI in the study population was 7.9%, 1.4%, and 9.0%, respectively, with an overall occurrence of variation at 13.8%. A chi-square test indicated a significant correlation between moderate CSP with mild CVI (Type VIII) and a reduced prevalence of psychiatric disorders (p = .007), implying a possible protective effect. Nevertheless, the majority of SP variations exhibited no statistically significant correlation with psychiatric diagnoses, including schizophrenia, OCD, or bipolar disorder. Logistic regression analysis revealed a significant interaction between gender and SP variations in predicting psychiatric disorders, with females exhibiting a higher overall prevalence. The interaction term was statistically significant (p < .001), suggesting that variations in SP and gender collectively affect the probability of psychiatric disorders. The findings offer valuable insights; however, limitations including the retrospective design, small subgroup sizes, and absence of genetic data necessitate caution in result interpretation. This study enhances comprehension of SP variations and their possible involvement in psychiatric disorders, emphasizing the necessity for additional research to clarify the underlying neurobiological mechanisms and clinical ramifications.

Keywords: Septum pellucidum; cerebrospinal fluid; magnetic resonance imaging; mental disorders; sex factors.

Figure 1.

Figure exhibits examples of SP variation subgroups determined in the current study. Green arrowheads indicate CSP, red arrowheads indicate CVI, yellow arrowheads indicate CV. (a): Mild CSP alone (Type I), (b): Moderate CSP alone (Type II), (c): Mild CVI (Type III) (d): Moderate CVI (Type IV), (e): CV (Type V), (f): Mild CSP with mild CVI (Type VI), (g): Mild CSP with moderate CVI (Type VII), (h): Moderate CSP to mild CVI (Type VIII), (i): Moderate CSP with moderate CVI (Type IX).