CONGENITAL OCULAR MOTOR APRAXIA - IMAGING FINDINGS

PURPOSE: To determine the frequency of cerebellar and cerebral abnorma lities on brain imaging studies in children with congenital ocular mot or apraxia. METHODS: Brain imaging studies were performed in 19 childr en with typical congenital ocular motor apraxia who were in the care o f a Visual impairment program at a children's hospital. Independent cl inical review categorized the subjects as having partial (n = 10) or e xpanded (n = 9) congenital ocular motor apraxia on the basis of extent of associated speech or neurodevelopmental problems. Fifteen CT studi es and 13 MR examinations of the brain performed in these children wer e reviewed independently by two pediatric neuroradiologists. Radiologi c findings were agreed on by consensus. RESULTS: Cerebellar abnormalit ies were found in 12 of 19 cases. The cerebellar Vermis was small in 1 0 children. A small cerebellar vermis was the only abnormality in five of 10 children with partial congenital ocular motor apraxia and in tw o of nine children with expanded congenital ocular motor apraxia. Amon g seven children with a small vermis examined with high-resolution MR imaging, the inferior portion of the vermis was preferentially involve d in each case. Of these seven subjects, none of four with partial con genital ocular motor apraxia but two of three with expanded congenital ocular motor apraxia had an abnormality of the superior portion of th e vermis. Miscellaneous supratentorial lesions affecting both gray and white matter were found in six subjects. Five of the 19 children had normal imaging findings. CONCLUSION: Inferior vermian hypoplasia is th e most common abnormality in children with congenital ocular motor apr axia.