THE OCULOMOTOR NUCLEAR-COMPLEX IN HUMANS - MICROANATOMY AND CLINICAL-SIGNIFICANCE

This study has been performed to define better the anatomical structur e of the oculomotor nuclear complex and its neuronal components. The o culomotor nuclear complex was examined in fixed and serially sectioned midbrains from 12 adult subjects free from neurological diseases. The complex included the somatic portion, (formed by multipolar motor neu rons), and the parasympathetic portion, (formed by oval or fusiform pr eganglionic cells), on each side of the median raphe. The somatic port ion consisted of the lateral somatic cell column and the caudal centra l nucleus. The somatic column measured from 0.2 x 0.1 mm to 3.4 x 1.4 mm (X = 2.4 x 1.2 mm) in transverse section. It was divided into the p rincipal, intrafascicular and extrafascicular parts. The principal par t was subdivided into the dorsal, intermediate and ventral portions. I solated multipolar neurons were also found in the periaqueductal gray matter, the interstitial nucleus of Cajal, the Edinger-Westphal nucleu s and the fibre bundles of the oculomotor nerve. These cells most like ly represent the displaced motor neurons of the oculomotor nerve. The caudal central nucleus was 0.8 x 0.6 mm in size. The Edinger-Westphal nucleus consisted of the rostral, ventral and dorsal parts; the longes t rostrocaudal diameter of this nucleus measured 7.1 mm. The anatomica l data of our study are relevant clinically and allow explanation of t he neurologic signs following complete or partial lesions of the oculo motor nuclear complex.