Dr. Dellon is the author of seven books, 92 book chapters, and more than 450 articles published in peer-reviewed journals. He is on the Editorial Boards of Journal of Reconstructive Microsurgery, The Journal of Hand Surgery, Annals of Plastic Surgery, and Microsurgery. He has been on the Editorial Boards of Plastic and Reconstructive Surgery, Peripheral Nerve Regeneration and Repair, Journal of Clinical and Experimental Plastic Surgery, Journal of Brachial Plexus and Peripheral Nerve Injury and Repair, Journal of Foot and Ankle Surgery, Journal of Hand Therapy, and Journal of the American Podiatric Medical Association.
We assessed functional recovery after peripheral nerve injury and repair using a battery of tasks (A). Grip strength was measured because inaccurate re-innervation of finger flexors produces poor grip. Fine paw control was tested using the staircase test, because skilled hand function is poor in humans after nerve repair due to mis-innervation of the many small muscles controlling the hand. Sensation was tested using a von Frey hair method and cold stimuli because fine touch and temperature sensation are often abnormal after nerve repair. In all cases the left side was injured and the right side used as a control.
Hypothesis of the mechanism by which injections of ChABC into the spinal cord improved functional recovery after peripheral nerve injury and repair. In the normal spinal cord, sensory afferents enter the spinal cord into the dorsal horn, connecting with motoneurons and other neurons via interneurons in the intermediate grey of the spinal cord. This reflex pathway is modified by descending motor pathways including the corticospinal tract (CST) and the rubrospinal tract (RuST). Motoneurons and many interneurons are surrounded by perineuronal nets (PNNs). After peripheral nerve injury and repair the inaccuracy of reinnervation results in misdirection of the regenerating axons. However, the ECM and PNNs in the grey matter prevent central reorganization, so functional recovery is poor. Digestion of the grey matter of the spinal cord with the enzyme ChABC allows sprouting and reorganization of connections leading to improved functional recovery.