Progressive Cyclic Oculomotor Nerve Palsy: An Update Focusing on Accommodation and Visual Acuity Changes

Cyclic oculomotor nerve palsy is a rare and typically congenital disorder.It is characterized by a unilateral third cranial nerve palsy with involuntary periodic spasms that cause one or more of the following: upper eyelid elevation, miosis, accommodation, and contraction of one or more of the extraocular muscles innervated by the third nerve.We provide an update on a previous case report of a female with this disorder and highlight how its features evolved over a 13-year follow-up period.Our patient presented in early infancy with a congenital partial right oculomotor nerve palsy without ptosis, which was later followed by cyclic spasms of the pupil.Cyclic accommodation was suspected at age five years because her visual acuity (VA) changed between the spastic and paralytic phases.At age 11 years, she developed cyclic ptosis.The periodicity of the spastic and paralytic phases varied over the years and from cycle to cycle.In addition, the spasms were usually not synchronous among the affected muscles within any single cycle.The pathogenesis remains unknown.Based on this single case report, we conclude that congenital cyclic oculomotor nerve palsy causes weakness in one or more muscles innervated by the oculomotor nerve, and this weakness may occur sequentially.The age of onset of spasms varies.The periodic spasms may affect one muscle at onset and may then involve additional muscles over subsequent years.The duration of the spasms varies across different muscles during any one cycle, across successive cycles in any one muscle, and over the years in any one muscle.