The equation comes from "A model of Postural Control in Quiet Standing: Robust Compensation of Delay-Induced Instability Using Intermittent Activation of Feedback Control" (Asai et al. 2009). The authors call this SDE, with additive (not multiplicative) noise and say that the integration should be performed in terms of Ito integral.
I hope my equation is not too confusing, for example in the article the time delay d is actually '\Delta' and the dt is '\Deltat'.
I'm still studying these creatures, but does anyone have any idea how to implement stochastic (delay) differential equations with Matlab? I can do this in Simulink without the noise part, but not with it. If(!) I have understood correctly I cannot just include noise to my simulation and be happy.