Two-years of home based functional electrical stimulation recovers epidermis from atrophy and flattening after years of complete Conus-Cauda Syndrome

Abstract

To evaluate progression of skin atrophy during 8 years of complete Conus-Cauda Syndrome and its recovery after 2 years of surface Functional Electrical Stimulation a cohort study was organized and implemented.Functional assessments, tissue biopsies, and follow-up were performed at the Wilhelminenspital, Vienna, Austria; skin histology and immunohistochemistry at the University of Padova, Italy on 13 spinal cord injury persons suffering up to 10 years of complete conus/cauda syndrome. Skin biopsies (n. 52) of both legs were analyzed before and after 2 years of home-based Functional Electrical Stimulation delivered by large anatomically shaped surface electrodes placed on the skin of the anterior thigh. Using quantitative histology we analyzed: 1. Epidermis atrophy by thickness and by area; 2. Skin flattening by computing papillae per mm and Interdigitation Index of dermal-epidermal junctions; 3. Presence of Langerhans cells.Linear regression analyses show that epidermal atrophy and flattening worsen with increasing years post-spinal cord injury and that 2 years of skin electrostimulation by large anatomically shaped electrodes reverses skin changes (pre-functional Electrical Stimulation vs post-functional Electrical Stimulation: thickness 39%, P < .0001; area 41%, P < .0001; papillae n/mm 35%, P < 0.0014; Interdigitation index 11%, P < 0.018), producing a significant recovery to almost normal levels of epidermis thickness and of dermal papillae, with minor changes of Langerhans cells, despite 2 additional years of complete Conus-Cauda Syndrome.In complete Conus-Cauda Syndrome patients, the well documented beneficial effects of 2 years of surface h-b Functional Electrical Stimulation on strength, bulk, and muscle fiber size of thigh muscles are extended to skin, suggesting that electrical stimulation by anatomically shaped electrodes fixed to the skin is also clinically relevant to counteract atrophy and flattening of the stimulated skin. Mechanisms, pros and cons are discussed.

Home-Based Functional Electrical Stimulation of Human Permanent Denervated Muscles: A Narrative Review on Diagnostics, Managements, Results and Byproducts Revisited 2020

“…Skin biopsies fixed in formalin were embedded in paraffin at the Wilhelminenspital, Vienna, Austria. Histological sections of 5 µm thickness were collected and stained by Hematoxilin–Eosin [ 24 , 25 ] or by immuno-histochemistry to analyze CD1a, a biomarker of Langerhans cells [ 26 ], at the Section of Human Anatomy of the Neuroscience Department of Padova University, Italy.…”

“…Here we add that the purpose-developed electrical fields delivered to ventral aspects of the thigh muscles by anatomically shaped large surface electrodes [ 22 ] produce clinically relevant recovery of the hamstring muscles [ 23 ] and of the thigh skin [ 24 , 25 , 26 ]. A believed drawback, co-activation of non-targeted muscles, is indeed responsible for a positive clinical result.…”

Functional electrical stimulation of permanently denervated muscles, updated 2020

“…Furthermore, because we harvested muscle tissue through a skin biopsy, we had the opportunity to extend our analyses to skin. Excitingly, we found that the home-based Functional Electrical Stimulation-sustained improvements in muscle structure are extended to skin, whose thickness and flattening worsen in accordance with the extent of years of SCI, but are substantially recovered after 2-years of homebased Functional Electrical Stimulation [20][21][22]. the improvement of tissue trophism will be even more clinically relevant if patients add home-based functional electrical stimulation of Gluteal muscles to their training workout, as the Vienna Strategy for denervated degenerated muscles SCI strongly recommends.…”

“…Home-based Functional Electrical Stimulation-induced recovery of skin thickness from SCI-induced skin atrophy It is certainly worth noting, that we recently demonstrated, using skin biopsies harvested from the same series of RISE patients, that the skin also became atrophic and flattened (i.e., there were decreased numbers of papillae-like structures per mm of skin and a decreased interdigitation index of dermalepidermal junctions) after several years of SCI [30], but that these issues recovered from atrophy and flattening after 2-years of home-based Functional Electrical Stimulation applied to treat denervated degenerated muscles [20][21][22].…”

“…Nonetheless, in previous studies we have shown that, in SCI patients suffering with permanent and complete conus and cauda equina syndrome, denervated leg muscles were rescued by 2-years of home-based Functional Electrical Stimulation, when a specific-purpose developed electrical stimulator (now commercially available: "Stimulette den2x" of the Schuhfried Medizintechnik GmbH, Vienna, Austria) provided the needed high currents to large surface electrodes covering the Quadriceps muscles [7,18,19]. Interestingly, we recently further demonstrated in these patients that skin, when exposed to 2 years of surface electrical stimulation, exhibits an improvement in epidermal thickness [20][21][22]. Here we add that the afore-described electrical fields also produced clinically relevant recovery in atrophic Hamstring muscles which were not in direct contact with the very large electrodes which are part of the Vienna Protocol of home-based Functional Electrical Stimulation for denervated degenerated muscles, validated by the EU Program: RISE [Use of electrical stimulation to restore standing in paraplegics with long-term denervated degenerated muscles (QLG5-Ct-2001-02191)].…”