[Medical findings on the trochlear nerve].

The exit-zone, the intracisternal course, the course in the sidewall of the cavernous sinus and inside the orbit were measured at 91 head-halves. Included are measurements of the length of the area nervosa, its nerve fibers and its distance to the total extracerebral length of the IVth nerve is estimated. The results are discussed with earlier investigations and some clinical approaches and neurophysiological methods are given.