Comparisons in fluctuation of muscle strength and function in patients with immune-mediated neuropathy treated with intravenous versus subcutaneous immunoglobulin.

INTRODUCTION: Variations in muscle strength and function have not been studied in patients with chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy whose treatment regimen has been changed from intravenous to subcutaneous immunoglobulin (IVIg to SCIg).

METHODS: In a prospective, open-label study, patients were changed from monthly IVIg to weekly SCIg. The primary endpoint was variation in isokinetic muscle strength (cIKS). Secondary endpoints were variations in Medical Research Council (MRC) score, grip strength (GS), 9-hole-peg test (9-HPT), and 40-meter-walk test (40-MWT).

RESULTS: The coefficient of variance of cIKS during the IVIg and SCIg treatment periods was unchanged (mean ± SD: 6.97 ± 4.83% vs. 5.50 ± 3.13%, P = 0.21). The variations in the 9-HPT and 40-MWT were significantly lower in the SCIg group (P = 0.01 and P = 0.005, respectively).

DISCUSSION: When therapy was changed from IVIg to SCIg, fluctuation of muscle strength was unchanged, but performance fluctuations were diminished. Muscle Nerve 57: 610-614, 2018.