Posterior cerebellar vermal deficits in bipolar disorder

Abstract

Background Based on growing evidence of the crucial role of the cerebellum in emotional regulation, we sought to identify cerebellar structural deficits in a large sample of patients with bipolar disorder (BD). Methods Cerebellar gray matter density was examined in 49 BD patients (24 medication-naive and 25 medication-treated) and 50 carefully matched healthy individuals, using voxel-based morphometry with a high-resolution spatially unbiased atlas template of the human cerebellum. This recently developed methodology is specifically optimized for the assessment of cerebellar structures. We further explored whether antimanic treatment could attenuate cerebellar structural deficits. Results BD patients showed a greater reduction in gray matter density of the posterior cerebellar regions, including the bilateral vermi and the right crus relative to healthy individuals (corrected p < .05). A stepwise linear reduction in gray matter density was observed in bilateral vermal regions between healthy individuals, medication-treated, and medication-naive BD patients. Furthermore, positive correlations of longer duration of illness with bilateral vermal gray matter deficits were observed only in medication-naive BD patients, but not in patients with medication history. Limitations This study adopted a cross-sectional design. The automatic intensity-normalization method for the measurement of cerebellar gray matter density may have a limitation in providing detailed anatomical information at a cerebellar folia level. Conclusions The current findings suggest that BD-related deficits in the posterior cerebellar regions, which appear to progress over the course of illness, could potentially be ameliorated by proper treatment with mood stabilizers.

Potential Gender-Related Aging Processes Occur Earlier and Faster in the Vermis of Patients with Bipolar Disorder: An MRI Study

“…Our study showed no differences in GM volume in the vermis areas of BD patients and healthy controls, similar to in other previous MRI studies [23,25,32]. A possible explanation for our negative results could be related to cerebellar morphology, which exhibits subtle changes that might not be identified by conventional structural neuroimaging techniques [25].…”

“…Furthermore, in our study, earlier onset of the disease was associated with a greater reduction in the volume of the vermis and its subareas in males with BD. Therefore, it is plausible that chronicity, due to an earlier disease onset, may induce earlier and faster neurodegenerative processes, as reported by several [13,31,32,33,34] but not all studies [21]. It has to be noted that our findings are mainly driven by gender, being significant in male patients only.…”

“…These results seem to support the neurodegenerative hypothesis, by suggesting that the brain aging process in BD could be faster and possibly more extensive with respect to healthy controls. Previous evidence consistently suggested that age may be an important factor involved in the anatomical brain abnormalities found in BD patients, with potential relevance for the pathophysiology of the disorder [32,33,34]. This could be due to the impact of affective episodes, and may partially explain the earlier cognitive decline observed in this population [13,31].…”

“…Specifically, some studies reported an inverse correlation between age and vermis volumes [32,33,34] as well as subtle cerebellar sex differences, with men having a larger cerebellum than women [35]. Additionally, it has been shown that males seem to have a more rapid reduction in vermis volumes, partially due to sex hormones [20].…”

El procesamiento temporal en la esquizofrenia: Revisión

“…En el TB, las alteraciones del cerebelo incluyen reducciones de la sustancia gris (Kim et al, 2013) y blanca (Canales-Rodriguez et al, 2013), sugiriendo el posible rol de las anomalías del cerebelo en las alteraciones de la percepción temporal en este trastorno.…”