For example, chronic pain-induced microglial neuroinflammation has been directly implicated in Alzheimer’s disease pathogenesis via production of amyloid beta plaques and neurofibrillary tangles [21]; persistent inflammation negatively affects neuroplasticity and synaptic performance via reduction in brain-derived neurotrophic factors [66,68,69]. This evidence concerns the gene BDNF and early-onset autosomal dominant Alzheimer disease.