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RESEARCH PRODUCT

Chapter 33 Experimental human models of neuropathic pain

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Publisher Summary This chapter reviews human surrogate models of neuropathic pain that focus on the mechanisms of symptom generation. A vast array of human surrogate models exists for ongoing symptoms, for positive sensory symptoms, and for sensory loss. The chapter discusses that by design, human surrogate models of neuropathic pain involve a reversible modulation of the properties of the nociceptive system such as its acute plasticity (phase 2). They usually do not create a long-lasting and potentially irreversible modification (phase 3). The denervation and ectopic activity of phase 3 can be modeled to a certain extent by transient nerve compression–ischemia and by topical capsaicin. By being models for phase 2 mechanisms, however, most human surrogate models mimic sensory symptoms that may occur in both neuropathic and nociceptive pain. The chapter reviews that each sensory finding is compatible with several neurobiological and neuropharmacological mechanisms, because of convergence in the generation of clinical manifestations. Thorough characterization of human surrogate models may in the future lead to a refinement of the proposed grouping scheme. Already at the present stage, human surrogate models of neuropathic pain are useful for the investigation of pharmacological mechanisms of action and therapeutic efficacy, because they are based on identical assessment techniques as in the actual patient studies.