Use of QTRAC Technique to Measure Axonal Excitability in Anti-MAG Neuropathy

Axonal Excitability Measured by QTRAC Technique in Patients With Anti-MAG Neuropathy

Status

Terminated

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02468596

Acronym

EXCIMAG

Enrollment

Registered

2015-06-11

Start date

2014-11-30

Completion date

2022-02-28

Last updated

2023-02-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Peripheral Neuropathy Associated With Anti-myelin Associated Glycoprotein Antibodies (Anti-MAG Neuropathy)

Keywords

Axonal excitability, Neuropathy, QTRAC, anti-MAG, Electrophysiology

Brief summary

The QTRAC method is an electrophysiological technique that assesses peripheral nerve axonal excitability, using computerized analysis of the muscular response of musculus abductor pollicis brevis, to series of electrical stimulations of the median nerve. Because of its high sensitivity to small changes in axonal excitability, QTRAC may help improve the follow-up of patients suffering from peripheral neuropathy caused by anti-myelin-associated-glycoprotein antibodies (anti-MAG neuropathy), as axonal excitability is early affected in this disease. The main aim of the study is to compare QTRAC results in anti-MAG neuropathy patients, with QTRAC results in healthy persons (matched for sex and age). A secondary aim is to determine whether or not the disease's clinical severity (measured by quantitative clinical scores) is correlated with the results of the QTRAC and could be predicted by a model based on the several parameters measured in the QTRAC exploration. 100 anti-MAG neuropathy patients will undergo a QTRAC exploration and a thorough neurological examination with clinical scoring. The results will be compared with data (matched by sex and age) from the reference database on healthy subjects, that is provided with the QTRAC software. The investigators expect to prove that QTRAC results are modified in anti-MAG neuropathy patients, and that the clinical severity of the disease can be predicted by a combination of QTRAC-measured parameters.

Interventions

OTHERQTRAC assessment

Computerized analysis of the muscular response of musculus abductor pollicis brevis, to series of electrical stimulations of the median nerve

OTHERClinical assessment of peripheral nerve function

Clinometric assessment using RT-MRC, Martin vigirometer, RT-mISS, T25W, 9 hole peg test, and ataxia scale

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

DIAGNOSTIC

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 90 Years

Healthy volunteers

Inclusion criteria

* Anti-MAG neuropathy (peripheral neuropathy and IgM monoclonal gammopathy with anti-MAG activity superior to 1000 BTU)

Exclusion criteria

* current treatment with a medication that modifies peripheral nerve excitability (e.g. anticonvulsivants)

Design outcomes

Primary

Measure	Time frame	Description
QTRAC-measured refractority of the median nerve	Inclusion	the duration of the refractory period of the median nerve (expressed in milliseconds) is automatically measured by the QTRAC system, using a series of double electrical stimulations (the first being supra-maximal and the second, sub-maximal) and progressively increasing the time between the two stimuli.

Countries

France

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026