Which type of local anesthetic nerve injury is primarily caused by direct injection of anesthetic?

The correct choice pertains to fascicular injury, which is primarily associated with the direct injection of local anesthetic. When an anesthetic agent is improperly injected directly into a nerve, it can cause damage to the nerve fibers that are grouped together in a bundle, known as fascicles. This type of injury occurs because the anesthetic can interrupt the normal function of these fibers, leading to localized nerve dysfunction.

Fascicular injuries are often characterized by effects that can result in transient symptoms, such as altered sensation or weakness in the area innervated by the affected nerve. In contrast, other types of nerve injuries, such as axonal or endoneurial injuries, might involve different mechanisms or levels of injury severity. Axonal damage typically refers to the injury to the axon itself, which can occur in more severe or prolonged compressive injuries. Endoneurial injury affects the endoneurium, the delicate connective tissue surrounding each nerve fiber, which is a more internal level of injury that does not primarily relate to direct injection.

By focusing on the fascicular injury as a direct consequence of local anesthetic injection, one can understand both the implications of the technique and the potential risks associated with direct nerve contact.