Partial oculomotor nerve palsy in a 7-year-old child.

Oculomotor nerve palsy can be due to varied causes that include diabetic neuropathy, myasthenia gravis, brainstem infarction, demyelinating conditions, and cerebral aneurysms. Among the aneurysmal causes of oculomotor nerve palsy, aneurysm of the posterior communicating artery has been observed to be the most common. Pupillary dysfunction is considered to be an important feature of aneurysmal oculomotor nerve paresis. A case of a 7-year-old boy with partial oculomotor nerve palsy with pupillary sparing is being reported here, the etiology of which is tortuous and ectatic distal internal carotid artery. This is a rare cause of oculomotor nerve paresis and to the best of our knowledge has not yet been reported in children. Ischemia rather than compression seems to be the most plausible cause in this case.