CONGENITAL CEREBELLAR DYSMORPHOLOGY - MOTOR FUNCTION AND MRI-BASED MORPHOMETRIC ANALYSES

We explored the relation between motor function and congenital cerebel lar dysmorphologies in two 14-year-old girls with cerebellar dysmorpho logy as part of a history of shunted hydrocephalus. MRI-based morphome tric analyses demonstrated reduced cerebellar volume in both subjects. The cerebellum of the subject with an Arnold-Chiari II malformation w as 19% smaller than that of the subject with the Dandy Walker Syndrome ; however, the Dandy Walker subject's medial cerebellum was 26% smalle r than that of the Arnold-Chiari II subject. Functional deficits confo rmed with morphometric findings. The Arnold-Chiari II subject showed s igns of bilateral cerebellar dysfunction (e.g., limb dysmetria, dysdia dokokinesia) as well as bimanual and visuomotor impairments, while the Dandy-Walker subject showed only subtle signs of medial cerebellar dy sfunction in gait and balance.