Cyclic Oculomotor Palsy.

THERE have been described about thirty cases of this interesting phenomenon. Axenfeld and Schuirenberg (1901) have their names attached to the condition in the Continental literature; they called it " Cyclic Congenital Oculomotor Disease". Fuchs, however, described a case much earlier (1893). The clinical picture is quite different from recurrent oculomotor palsy. The cause is still a matter of conjecture as no case has been examined post-mortem. Essentially the clinical picture is a rhythmic, or cyclic palsy of the muscles moving the eye and usually also of the levator muscle of the upper lid associated with dilatation of the pupil during the stage of full paresis and ptosis, and contraction of the pupil as the lid rises and the muscles of the globe recover part of their power. The condition is unilateral and may be acquired, or congenital. The movements are quite involuntary and the rhythmic alteration of tone in the paralysed muscles goes on during sleep and waking. When there is intermittent ptosis the condition is quite striking. The fourth and sixth nerves are much less commonly paralysed than the third, or part of the third, nerve. When the ptosis is absent and the extraocular muscle palsy is slight the pupil only may show the rhythmic movement. The mild cases of cyclic oculomotor palsy without ptosis may therefore be readily overlooked.