Nerve Ultrasound in Acquired and Genetic Sensory Neuronopathies

Sensory neuronopathies (also known as sensory ganglionopathies) constitute a rare and heterogeneous group of acquired and genetic disorders related to degeneration of the dorsal root ganglia. Diagnosis relies on clinical and electrophysiological features demonstrating a pure, non-length-dependent sensory involvement. At present, no specific biomarker exists, and diagnosis is based on a combination of clinical and electrophysiological criteria. Because sensory neuronopathies are disabling conditions, early diagnosis is crucial, particularly in acquired forms for which early treatment is an important prognostic factor.

Recently, several studies have reported a unique nerve ultrasound pattern in genetic sensory neuronopathies, showing reduced caliber of mixed peripheral nerves in the upper limbs. A recent literature review suggested that sufficient evidence exists to consider ultrasound as a potential marker of genetic sensory neuronopathies. However, these studies included only patients with genetic etiologies, and no data are currently available regarding ultrasound findings in acquired sensory neuronopathies. Distinguishing between acquired and genetic causes is nevertheless essential, as the prognoses are very different and treatment must be initiated rapidly in acquired forms. Clinical evaluation alone is often insufficient to differentiate these etiologies due to substantial overlap between presentations.

The objective of this study is to compare nerve ultrasound findings in a retrospective, multicenter cohort of patients with sensory neuronopathies of either genetic or acquired origin. The study also aims to analyze correlations between nerve caliber, clinical severity, disease duration, and electrophysiological parameters. Ultimately, this research seeks to determine whether the pattern of nerve atrophy observed on ultrasound is specific to genetic causes or may also be present in acquired forms.

Inclusion criteria

• Sensory ganglionopathy diagnosed according to the criteria of Camdessanché et al.
• Nerve ultrasound performed as part of routine clinical care.
• Age > 18 years.

Exclusion criteria

• Comorbid conditions that may interfere with the interpretation of sensory ganglionopathy.
• Lack of consent (patient opposition to the use of clinical data for research).