Objective: To describe two patients with mesencephalic midline clefts and associated eye movement disorders.
Design: Case reports.
Results: The first patient developed bilateral internuclear ophthalmoplegia with exotropia, reduced convergence, right ptosis, right fourth-nerve palsy, and right elevator palsy several years after meningitis with hydrocephalus. The second patient had bilateral internuclear ophthalmoplegia with exotropia, reduced convergence, bilateral ptosis, limited upward gaze, and right hypertropia since childhood. In both patients, magnetic resonance imaging showed a midline cleft extending from the cerebral aqueduct into the midbrain.
Conclusion: It is likely that the clefts affected the oculomotor nuclei and medial longitudinal fasciculi, accounting for the eye movement disorders.