Motor unit integrity in multifocal motor neuropathy: A systematic evaluation with CMAP scans.

ABSTRACT:

Introduction/aims

Progressive axonal loss in multifocal motor neuropathy (MMN) is often assessed with nerve conduction studies (NCS), by recording maximum compound muscle action potentials (CMAPs). However, reinnervation maintains the CMAP amplitude until a significant portion of the motor unit (MU) pool is lost. Therefore, we performed more informative CMAP scans to study MU characteristics in a large cohort of patients with MMN.

Methods

We derived the maximum CMAP amplitude (CMAP_max ), an MU number estimate (MUNE), and the largest MU amplitude stimulus current required to elicit 5%, 50%, and 95% of CMAP_max (S5, S50, S95) and relative ranges ([S95 - S5] × 100 / S50) from the scans. These metrics were compared with clinical, laboratory, and NCS results.

SUBMITTER: Stikvoort Garcia DJL 

PROVIDER: S-EPMC9300115 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature