Experimental Study on the Mechanism of Action of Nerve Root Infiltration for Lumbosacral Radicular Pain

While the usefulness of nerve root infiltration (NRI) for lumbosacral radicular pain has been eatablished clinically, the mechanism of action of NRI is not elucidated yet. In this study, NRI was performed on monkeys to elucidate the mechanism of action of NRI from the morphological point of view. At first the fine structure of the connective tissue of the lumbar spinal nerve root was evaluated histologically. Secondly the location of Pelican ink injected with a contrast medium was investigated. As a result, the structure of the connective tissue of the spinal nerve root of monkeys was quite similar to humans. In addition, arachnoid villi were found near the subarachnoid angle. Furthermore, some ink was found in the nerve root near the subarachnoid angle while most of it was in the epiradicular space around the nerve root sleeve. These findings strongly suggested that local anesthetics injected into the epiradicular sapce ascended in a tubular fashion through the epidural space, and then some entered the nerve root at the subarachnoid angle via arachnoid villi acting as a pathway from the subarachnoid space to the epidural space.

腰仙部神経根症状

神経根ブロック

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