On the Nerve Supply of the Connective Tissue of Some Peripheral Nervous System Components

Concept of acute neuropathic pain. The role of nervi nervorum in the distinction between acute nociceptive and neuropathic pain

“…However, there might be microvascular ischemia in case of vasculitis, condition where there might be localized nervous injury. Nervous trunks are mechano-sensitive because their connective tissue has afferents normally participating in mechano-reception 22,23 . Peripheral nerves are innervated by neurovegetative fibers, the nervi vasorum, and by intrinsic nerves, the nervi nervorum, made up of unmyelinated or thin myelinated fibers composing a thin plexus layer of free nervous terminations in the epineurium, perineurium and endoneurium and some encapsulated Pacini terminations in the endoneurium 16,[22][23][24][25][26] .…”

“…Nervous trunks are mechano-sensitive because their connective tissue has afferents normally participating in mechano-reception 22,23 . Peripheral nerves are innervated by neurovegetative fibers, the nervi vasorum, and by intrinsic nerves, the nervi nervorum, made up of unmyelinated or thin myelinated fibers composing a thin plexus layer of free nervous terminations in the epineurium, perineurium and endoneurium and some encapsulated Pacini terminations in the endoneurium 16,[22][23][24][25][26] . In late 19 th century, John Marshall, mentioned by Powell 27 , and neurosurgeon Victor Horsley, mentioned by Sugar 28 , both English citizens, have evaluated histological features of peripheral nerves and have observed nervous ramifications in the epineurium coming from the nerve itself, the nervi nervorum.…”

“…Together with Horsley 28 he has shown that nervi nervorum were sensitive to pain, especially to pressure 29 . Hromada 22 has observed that nervi nervorum originated from vasa vasorum nervous plexus or from nervous trunks themselves where they reached their targets following blood vessels. He has evidenced four distinct regions of peri and non perivascular innervations in nervous trunks: perivascular innervation of extraneural arteries and veins; perivascular innervation of intraneural blood vessels (vasa nervorum); non-perivascular fibers (nervi nervorum) originated from the nervous trunk and perivascular plexus and distributed by epi, peri and endoneural connective tissues; and intrafascicular fibers with major adrenergic component, particularly in the sciatic nerve.…”

“…Adrenergic nervi nervorum and vasa vasorum innervation is modified in a non uniform way in nerves of experimental diabetes mellitus models 30 . Pia-arachnoid of cranial nerves and ventral roots have structure similar to the perineurium 31 and innervation patterns similar to nervi nervorum 22,32,33 . Unmyelinated axons 23 associated to specific glycoconjugated [34][35][36] with terminations distribution patterns different from sensory peptidergic axons innervate blood vessels [37][38][39] .…”

Epi-perineurial anatomy, innervation, and axonal nociceptive mechanisms

“…Although recognized as an entity for more than a century (Horsley 1884, Sappey 1867, an good anatomical description did not appear in the literature until 1963 (Hromada 1963). In the 1990s we performed a series of experiments that documented the functional properties of these neural elements.…”