Threshold tracking transcranial magnetic stimulation and neurofilament light chain as diagnostic aids in ALS.

Objective: There is a need for sensitive biomarkers in amyotrophic lateral sclerosis (ALS), to enable earlier diagnosis and to help assess potential treatments. The main objective of this study was to compare two potential biomarkers, threshold-tracking short-interval cortical inhibition (T-SICI), which has shown promise as a diagnostic aid, and neurofilament light chains (NfL).

Methods: Ninety-seven patients with ALS (mean age 67.

Estimating motor unit numbers from a CMAP scan: Repeatability study on three muscles at 15 centres.

Objective: To assess the repeatability and suitability for multicentre studies of MScanFit motor unit number estimation (MUNE), which involves modelling compound muscle action potential (CMAP) scans.

Methods: Fifteen groups in 9 countries recorded CMAP scans twice, 1-2 weeks apart in healthy subjects from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. The original MScanFit program (MScanFit-1) was compared with a revised version (MScanFit-2), designed to accommodate different muscles and recording conditions by setting the minimal motor unit size as a function of maximum CMAP.

Muscle velocity recovery cycles in myopathy.

Objective: To understand the pathophysiology of myopathies by using muscle velocity recovery cycles (MVRC) and frequency ramp (RAMP) methodologies.

Methods: 42 patients with quantitative electromyography (qEMG) and biopsy or genetic verified myopathy and 42 healthy controls were examined with qEMG, MVRC and RAMP, all recorded from the anterior tibial muscle.

Results: There were significant differences in the motor unit potential (MUP) duration, the early and late supernormalities of the MVRC and the RAMP latencies in myopathy patients compared to controls (p < 0.

Three different short-interval intracortical inhibition methods in early diagnosis of amyotrophic lateral sclerosis.

To compare the utility of conventional amplitude measurements of short-interval intracortical inhibition (A-SICI) with two threshold-tracking (T-SICI) methods, as aids to early diagnosis of amyotrophic lateral sclerosis (ALS). The new parallel threshold-tracking method (T-SICIp) was compared with the previously used serial tracking method (T-SICIs). 112 consecutive patients referred with the suspicion of ALS and 40 healthy controls were prospectively included.

Assessing inter-rater reproducibility in MScanFit MUNE in a 6-subject, 12-rater "Round Robin" setup.

Objective: To assess the inter-rater reliability of MScanFit MUNE using a "Round Robin" research design.

Methods: Twelve raters from different centres examined six healthy study participants over two days. Median, ulnar and common peroneal nerves were stimulated, and compound muscle action potential (CMAP)-scans were recorded from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and anterior tibial (TA) muscles respectively.