Injection of Peripheral Nerves from the Subarachnoid Space

Abstract

The injection mass used by Funaoka and Yamada 1 suggested such interesting possibilities that their work was repeated and extended. For the most part their mixture of ultramarine blue 2 parts, ether 15 parts, and turpentine 30 parts was satisfactory.

The principle of inlet and outlet cannulation was adopted in all of the work. In one group 2 laminectomies were done, one in the cervical region, the other in the sacral. The dura mater was opened and relatively large glass cannulae were introduced into the subarachnoid space. The cervical cannula served as the inlet, the sacral as the outlet. For another group the inlet cannula was placed in the lumbar segment, the severed optic nerves served as outlet cannulae. The pressure was usually from 3 to 5 pounds. Fifteen dogs were used. The injections were usually begun with the animal under an anesthetic. They died as soon as the injection mass reached the brain.

In no instance was a complete injection obtained and there were variations from animal to animal. Perhaps the most constant result was the injection of the cervical lymph nodes. At one time or another many of the peripheral nerves were injected. Specifically there may be mentioned the brachial plexus and its branches as far distally as the hand; the 2 sympathetic chains and their ganglia; the phrenic nerves including their ramifications on the diaphragm; the intercostal nerves and their branches. The position of the ligatures for the cannulae prevented the injection of the nerves of the caudal extremities.

Other injection masses have been found satisfactory. The important factor seems to be to select one that is not readily miscible with the body fluids.