Cyclic oculomotor palsy.

This rare condition, an oculomotor palsy which is interrupted by spastic contractions of the levator muscle and the pupillary sphincter at fairly regular intervals, had been reported in 54 patients up to 1975. Two patients presented to the authors with apparently complete unilateral ptosis but abnormal pupillary reactions prompted closer examination. Once the diagnosis has been considered only 5 minutes of careful clinical examination are necessary to confirm or reject it. During the past 4 years the authors have found nine new cases of the condition and it is clear that the diagnosis must often be missed. Details of the patients are shown and discussed in the light of Loewenfeld and Thompson's theory of the pathology. The place of surgical treatment is considered.