Cerebellar ataxia in youths at risk for bipolar disorder.

Objective: Structural, biochemical, and functional cerebellar abnormalities occur in individuals with or at-risk for developing bipolar disorder (BD), but the clinical implications of these abnormalities are unknown. The present study examined cerebellar function in youths who were at familial risk for BD by comparing ataxia battery scores of youths with a bipolar parent to those of healthy youths.

Methods: Trained raters administered an ataxia battery, consisting of three tasks, to children (aged 8-12 years) with at least one parent with BD type I (BDI) who themselves did not have BDI (at-risk or AR group, n = 21) and healthy comparison children (aged 8-12 years) with parents free of DSM-IV Axis I psychopathology (HC group, n = 23).

Results: AR youths performed worse than HC youths on the Sharpened Romberg test (subjects standing heel-to-toe) and standing on one foot with eyes open (p < 0.02).

Conclusions: The results indicate that youths at familial risk for BD have more difficulty performing a Sharpened Romberg test than a HC group, suggesting that midline cerebellar dysfunction may be a biomarker for the future development of BD. Further studies examining the relationships among youths at risk for BD, coordination abnormalities, and cerebellar dysfunction are needed.