Clinical Research Directory

Clinical Evaluation of Sensory Neuronopathies: the Neuronoscore Study

Sensory neuronopathies (SN) are a group of rare neuropathies characterized by selective destruction of sensory neurons located in the dorsal root ganglia. SN may result from a wide range of etiologies, particularly paraneoplastic, autoimmune, toxic, and genetic causes. The functional prognosis of patients with SN is generally poor: in a recent study, two-thirds of patients had a modified Rankin Scale (mRS) score ≥3 and nearly half had an mRS ≥4. The absence of reliable biomarkers in neuropathies justifies the use of clinical scales as indicators of disease severity, disability, and treatment response. However, none of the currently available "general neuropathy" scales have been specifically designed or validated for SN. The only scale developed specifically for SN is the SEARS (Sensory Ataxia Rating Scale), proposed in 2019, but it has not been widely used nor validated in large populations. As a result, the absence of a clinical scale specifically designed for patients with SN makes longitudinal follow-up more challenging, particularly when assessing the response to immunomodulatory or immunosuppressive treatments when these therapies are indicated.

Nerve Ultrasound in Acquired and Genetic Sensory Neuronopathies

Sensory neuronopathies (also called sensory ganglionopathies) are rare and heterogeneous disorders of genetic or acquired origin, caused by degeneration of the dorsal root ganglia. Their diagnosis currently relies on a combination of clinical evaluation and electrophysiological testing, as no specific biomarker is available. Early diagnosis is particularly important in acquired forms, where early treatment can significantly influence prognosis. Recent studies have reported a characteristic ultrasound pattern in several genetic sensory neuronopathies, showing abnormally small-caliber peripheral nerves in the upper limbs. However, these findings have only been described in genetic conditions. It is therefore unknown whether this ultrasound pattern is specific to genetic causes or may also occur in acquired sensory neuronopathies, especially those with long-standing evolution. This retrospective multicenter study will analyze data already collected as part of routine care in approximately 50 patients with sensory neuronopathy. The objective is to compare nerve ultrasound findings between genetic and acquired forms, and to evaluate their association with clinical severity and electrophysiological parameters. Determining whether nerve atrophy observed on ultrasound is specific to genetic etiologies could help integrate ultrasound into the diagnostic workup, guiding the choice of complementary tests such as genetic analyses or early treatment initiation in acquired cases.