Menu
Not yet recruiting NCT07725120

Single-Center Study Evaluating the Impact of Age on the Diagnostic Performance of the Sural-to-Radial Sensory Amplitude Ratio in Length-Dependent and Non-Length-Dependent Peripheral Polyneuropathies

— Observational Polyneuropathies Electromyography Diagnostic Techniques

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Retrospective Medical Record Review.
Who it may be relevant to
Registry conditions: Polyneuropathies, Electromyography, Diagnostic Techniques. Basic parameters: 18 years — 90 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
France
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Official title

Retrospective Single-Center Study Evaluating the Impact of Age on the Diagnostic Performance of the Sural-to-Radial Sensory Amplitude Ratio in Length-Dependent and Non-Length-Dependent Peripheral Polyneuropathies

Overview

This retrospective single-center observational study will evaluate the impact of age on the diagnostic performance of the sural-to-radial sensory nerve amplitude ratio (SRAR) in patients with length-dependent and non-length-dependent peripheral sensory polyneuropathies. Clinical and electrophysiological data collected during routine care between January 2013 and July 2026 will be analyzed. Diagnostic performance will be assessed using receiver operating characteristic (ROC) curve analysis across predefined age groups to determine whether age-adjusted SRAR thresholds improve the differentiation between the two polyneuropathy phenotypes.

Detailed description

Peripheral sensory polyneuropathies are commonly classified as length-dependent (LDN) or non-length-dependent (NLDN) based on their clinical and electrophysiological features. This distinction is clinically important because it guides etiological investigations and therapeutic management. The sural-to-radial sensory nerve amplitude ratio (SRAR) is an electrophysiological marker that has been proposed to improve the diagnosis of sensory polyneuropathies and to help differentiate LDN from NLDN. Although the SRAR has traditionally been considered independent of demographic characteristics, recent evidence suggests that it decreases with aging, raising concerns about the use of a single diagnostic threshold across all age groups. The impact of age on the diagnostic performance of the SRAR, particularly in patients with non-length-dependent polyneuropathies, remains poorly characterized. This retrospective single-center study will analyze clinical and electrophysiological data from patients evaluated at the Peripheral Neuromuscular Rare Disease Reference Center of Nice University Hospital between January 2013 and July 2026. The study aims to determine whether age-adjusted SRAR thresholds improve the diagnostic discrimination between length-dependent and non-length-dependent peripheral polyneuropathies.

Interventions

  • Other Retrospective Medical Record Review
    This observational study involves retrospective collection and analysis of routinely acquired clinical and electrophysiological data from approximately 180 patients with sensory polyneuropathy. Data extracted from medical records include demographic characteristics, clinical diagnosis, and nerve conduction study parameters, including sural and radial sensory nerve action potential amplitudes used to calculate the sural/radial amplitude ratio (SRAR). No additional diagnostic procedures, treatment

Primary outcome measures

  • Diagnostic performance of the sural-to-radial sensory nerve amplitude ratio (SRAR) [Time frame: Baseline (retrospective analysis of data collected between January 2013 and July 2026]
Secondary outcome measures (2)
  • Age-specific optimal SRAR diagnostic thresholds [Time frame: Baseline (retrospective analysis)]
  • Comparison of SRAR values between LDN and NLDN [Time frame: Baseline (retrospective analysis)]

Eligibility criteria

Inclusion criteria

  • Adults aged 18 years or older.
  • Diagnosis of peripheral sensory polyneuropathy.
  • Classification as length-dependent (LDN) or non-length-dependent (NLDN) based on clinical and electrophysiological findings.
  • Available nerve conduction study including sural and radial sensory nerve amplitudes allowing calculation of the SRAR.
  • Evaluated at the Peripheral Neuromuscular Rare Disease Reference Center, Nice University Hospital, between January 2013 and July 2026.

Exclusion criteria

  • Missing or incomplete clinical or electrophysiological data preventing SRAR calculation.
  • Unclassifiable neuropathy phenotype.
  • Technical factors affecting the reliability of nerve conduction studies.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model
Other

Study locations

France · 1 center
  • CHU de Nice — Nice

Identifiers

NCT: NCT07725120 · 26Neuro04

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗