[The subnuclei of the oculomotor nucleus in humans]

Examinations of eye movements offer an easy clinical method for the diagnosis of disturbances in the pathways for the generation of eye movements including the extraocular and inner eye muscles. A prerequisite is a good knowledge of the anatomy of the pathways for the generation of eye movements. The oculomotor nucleus represents an important relay station, which contains not only the motoneurons of four extraocular muscles and the levator palpebrae muscle, but also the preganglionic neurons of the ciliary ganglion for the mediation of the pupillary and accommodation response. Recent work about the special anatomy of the extraocular muscles and histochemical findings about the neurons in the Edinger-Westphal nucleus (EW), which indicated that this nucleus does not contain the preganglionic neurons of the ciliary ganglion, led to a new, modified map of the oculomotor nucleus complex. The most serious alteration refers to the location of the preganglionic neurons, which form a group of scattered neurons outside of the EW and now are termed EWpg. In contrast, the traditional cytoarchitectonically defined EW in the human eye contains peptidergic neurons with a completely different function, e.g., stress related, and is therefore termed EWcp (centrally projecting). A knowledge about the exact locations of extraocular motoneurons and preganglionic neurons is essential for the correct interpretation of clinico-anatomic findings.