Magnetic Resonance Imaging in 14 Patients with Congenital Oculomotor Nerve Palsy.

PURPOSE

To elucidate the imaging findings of congenital oculomotor nerve palsy by evaluating the oculomotor nerve and extraocular muscles on magnetic resonance (MR) imaging in a relatively large series of 14 patients with congenital oculomotor nerve palsy.

METHODS

Ophthalmologic examination of 14 consecutive patients diagnosed with congenital oculomotor nerve palsy, and MR imaging of the orbit and oculomotor nerves were performed.

RESULTS

Of the 14 patients with congenital oculomotor nerve palsy, 13 patients (93%) were unilateral and 12 patients (86%) had incomplete palsy. On MR imaging, 5 patients (36%) had hypoplasia or aplasia of the oculomotor nerve with variable degrees of extraocular muscle atrophy on the affected side. Of the 14 patients, nine (64%) had normal-sized oculomotor nerves with or without muscle atrophy. The most frequently involved muscles were the inferior rectus (64%) and medial rectus (50%), followed by the superior rectus (29%) and inferior oblique muscles (14%). None of the 14 patients showed an abnormal abducens nerve.

CONCLUSION

Congenital oculomotor nerve palsy was mostly incomplete and hypoplasia or aplasia of the oculomotor nerve was apparent in one third of patients showing variable degrees of extraocular muscle atrophy, mostly of the medial rectus and inferior rectus muscles.