Anatomy
Neurapraxia occurs in the peripheral nervous system typically in the ulnar, median, and radial nerves of the upper body and in the sciatic and peroneal nerves of the lower body. Peripheral nerves are myelinated, relatively large, spatially complex cells whose size and connectivity typically make them more susceptible to damage and compromise their capacity to self-repair, although this is not the case in neurapraxia. Microscopic evidence has shown that there is damage to the myelin sheath, but not to the axon. Therefore, distal nerve fibers do not degenerate and the myelin damage can be repaired. Order of pathology
The order of pathology within the first 24 hours after injury follows a general pattern of nerve injury. The first physical manifestation of the injury is focal swelling adjacent to the site of the injury. In the cellular dimension, a fragmentation of neurotubules and neurofilaments occurs as a result of pressure exerted on the nerve. Axons swell at some sites and are compressed at others, leading to a beaded appearance. Mechanisms of injury
There are several mechanisms of nerve injury including mechanical lesions, ischemia, immunologic attack, metabolic disorder, toxic agents, and exposure to radiation. The most common mechanism of injury is nerve compression in which external pressure causes decreased blood flow to the nerve and deformation of the nerve fibers. Repeated or prolonged compression of the nerve results in ischemia and ultimately edema above and below the source of the pressure (I).
Cream vehicle
Clocortolone pivalate 0.1% is formulated in a cream that contains three ingredients which assist in stratum corneum permeability barrier integrity: white petrolatum (occlusive), mineral oil (humectant), and stearyl alcohol (long-chain fatty alcohol emollient). This cream does not contain lanolin, fragrance, nor propylene glycol, all of which have been known to be problematic for some patients. Clinical studies
In Phase III trials, Cloderm was found to be especially useful in treating eczema, atopic dermatitis, and psoriasis. Phase III trials also showed rapid action and relief for the majority of the patients involved. There is no age restriction on the use of clocortolone pivalate 0.1% cream. Clinical trials comparing clocortolone pivalate 0.1% topical cream with vehicle in atopic dermatitis/eczematous dermatitis, psoriasis, and contact dermatitis included pediatric patients (N=44). The mean age of pediatric subjects was 10 years (range 3–14 years). Clocortolone pivalate 0.1% cream was efficacious for the majority (75%) of the pediatric patients in these trials, with no serious adverse effects occurring in either group.In six parallel, double-blind, placebo-controlled trials, patients with atopic dermatitis/eczematous dermatitis were randomized to treatment with clocortolone pivalate 0.1% topical cream (total n=109) or vehicle (total n=100), applied three times daily over a duration of 14 days.