✓ The authors conducted an autopsy study of 50 jugular foramina and surrounding tissue, using the dissecting microscope. Anatomical findings from this study are presented.
Albert L. Rhoton Jr. and Robert Buza
Albert L. Rhoton Jr. and Manuel R. Gomez
✓ A patient with postinflammatory hydrocephalus had a multiloculated, lateral ventricular system that was treated by a routine shunting procedure after the multiloculated system had been converted into a uniloculated system by direct intraventricular surgery.
Kristin Gudmundsson, Albert L. Rhoton Jr. and Joseph G. Rushton
✓ Fifty trigeminal nerves were studied at autopsy under various magnifications. Two findings that could explain the preservation of sensation after rhizotomy of the main sensory root are: 1) anastomosis between the motor and sensory root in the majority of nerves, and 2) aberrant sensory rootlets that arose from the pons separately from the main sensory root in one half of the nerves. The motor root is composed of as many as 14 separately originating rootlets that usually join about 1 cm from the pons. At the pontine level, the first division fibers are usually dorsomedial and the third division fibers caudolateral within the main sensory root. However, the third division fibers may vary from being almost directly lateral to directly caudal to the first division fibers. This may explain the variability of sensory loss with partial section in the posterior fossa.
Experimental study in the monkey
W. Frank Emmons and Albert L. Rhoton Jr.
✓ In 16 rhesus monkeys, rhizotomy of the whole trigeminal nerve and selective rhizotomy of each division were carried out, and neural degeneration techniques used, to determine whether a trigeminal root component exists which projects only to the main sensory or spinal nucleus of the trigeminal nerve. Such a root component was not found. Section of the rostral trigeminal fibers resulted in degeneration in both the main sensory nucleus and the spinal trigeminal nucleus. Section of the caudal fibers of the root produced degeneration similar to third division transection, indicating that the caudal fibers are from that division. The first- and third-division fibers were found to project to the ventral and dorsal portions of the main sensory nucleus and spinal nucleus. Findings showed that the most rostral portion of the root immediately adjacent to the motor root is predominately from the ophthalmic division. Some proprioception from the trigeminal area appears to be mediated through the medial cuneate nucleus because all the trigeminal divisions send some fibers to this nucleus.