Objective: The authors studied mood disorder and neurobehavioral correlates of solitary focal cerebellar (CB) lesions.
Background: CB function has been correlated with cognitive, behavioral, and psychiatric conditions. Systematic study of uncomplicated CB pathology can further our understanding of these correlates.
Method: Magnetic Resonance Images were blindly selected from 20,000 scans for solitary focal CB lesions after excluding other pathology. “Secondary” conditions (developing after lesion onset) were determined using structured clinical interviews (DIS and SCID) for psychiatric diagnoses while blind to MRI findings. Clinical correlates of lesions and a priori hypotheses were examined in 13 participants while controlling for alternative attributions (atrophy, hyperintensities, ventriculomegaly, disability, etc.).
Results: Bipolar disorders after CB lesions were more common than expected in normal populations (OR 28.62, 95% CI 3.51 <->233.34, P=0.0001), replicating a previous finding. Secondary DSM-III and –IV depressive disorders correlated with posterolateral lesions of the right CB posterior lobe (P=0.0035); severity correlated with lesion size. Other lesion correlates included hypomania (anterolateral left CB posterior lobe), apathy (medial left anterior lobe, anterolateral right posterior lobe), disinhibition and dysexecution (medial left anterior lobe), agitation (central left and anterolateral right posterior lobe), and elation (anterolateral right posterior lobe). Although other structural cerebral and psychosocial variables did not explain the findings, much larger sample sizes will be needed to adequately control for these variables.
Conclusions: Review of the literature reveals support for these findings, suggesting CB control of mood, behavior, and frontal cognition.