Aila Särkkä (Chalmers University of Technology, Gothenburg, Sweden): Spatial modelling of epidermal nerve fiber structure
 
Epidermal nerve fibers (ENFs) are thin sensory nerve fibers in the epidermis, the outermost cell layers in the skin. After they have entered the epidermis, they grow and branch and finally, terminate. Small fiber neuropathies, such as diabetic neuropathy, can cause damage to the ENF structure. For example, it has been established that the ENF density and summed length of ENFs per epidermal surface area are reduced, and ENFs may appear more clustered within the epidermis in subjects suffering from diabetic neuropathy compared to healthy subjects (Kennedy et al., 1996). In our data from healthy subjects and subjects suffering from mild diabetic neuropathy, we regard the nerve patterns as spatial point patterns consisting of entry points, branching points, and end points. We concentrate on 2D projections of the 3D data since the main interest is on how the skin is covered by the nerve endings that are responsible for transferring signals, such as heat and pain, to the central nervous system. We will present some multitype and marked point process models for the nerve patterns and compare the healthy and mild patterns in terms of some summary statistics and model parameters (Olsbo et al., 2013; Andersson et al., 2016; Ghorbanpour et al., 2021; Konstantinou and Särkkä, 2021). 
 
References
 
Andersson, C., Guttorp, P., and Särkkä, A. (2016). Discovering early diabetic neuropathy from epidermal nerve fiber patterns. Statistcs in Medicine 35(24), 4427-4442.
                             
Kennedy, W.R., Wendelschafer-Crabb, G., and Johnson, T. (1996). Quantitation of epidermal nerves in diabetic neuropathy. Neurology 47(4), 1042-1048.
 
Konstantinou, K. and Särkkä, A. (2021). Spatial modeling of epidermal nerve fiber patterns. Statistics in Medicine 40(29), 6479-6500.
 
Olsbo, V., Myllymäki, M., Waller, L.A., and Särkkä, A. (2013). Development and evaluation of spatial point process models for epidermal nerve fibers. Mathematical Biosciences 243, 178-189.
 
Ghorbanpour, F., Särkkä, A., and Pourtaheri, R. (2021). Marked point process analysis of epidermal nerve fibers. Journal of Microscopy 283(1), 41-50.