Sensory neuronopathies (SNN), also known as sensory ganglionopathies, primarily involve the sensory neurons in the dorsal root ganglia (DRG) and result in irreversible degeneration of the cell body [1], [2], [3]. The concept of SNN was first introduced by Dereck Denny Brown in 1948 when he described the first pathologically confirmed cases of SNN, which were associated with cancer [4].

SNN can have various causes, including genetic, toxic, metabolic, infectious, and dysimmune mechanisms. However, a significant number of cases remain idiopathic despite extensive investigations [5], [6]. It is important to identify cases involving inflammation because they may respond to immunomodulatory or immunosuppressant treatments. However, for these treatments to be effective, they need to be administered before irreversible neuron damage occurs [7]. The challenge lies in diagnosing these disorders early since the therapeutic window is often narrow before definitive neuron degeneration. Therefore, efforts should be made to achieve an early diagnosis, and biomarkers play a crucial role, particularly in cases where there are no specific indications of an immune-mediated disorder. This is particularly crucial since in a given patient, diagnostic criteria of SNN and particularly items concerning the electroneuromyography, are probably reached at a time when sensory neurons have already degenerated. This review will focus on these different aspects and is based on our personal research in the field completed by a systematic search in PubMed.