Intravenous immunoglobulin treatment in patients with motor neuron syndromes associated with anti‐GM ₁ antibodies

TLDR

Motor neuron syndromes associated with anti‑GM1 antibodies frequently involve conduction blocks. A double‑blind, placebo‑controlled crossover trial administered 0.4 g/kg IVIg daily for 5 days to 12 patients, with assessments of muscle strength, disability, nerve conduction, and immunologic markers at baseline and 5, 28, 56 days post‑treatment. IVIg significantly increased muscle strength only in patients with conduction blocks compared to placebo.

Abstract

We studied the effects of intravenous immunoglobulin (IVIg) in 12 patients with motor neuron syndromes associated with high titers of anti-GM1 antibodies. Five of the patients had conduction blocks. The study design was a double-blind, placebo-controlled, crossover trial with IVIg (0.4 g/kg body weight per day injected for 5 consecutive days). We evaluated the patients before and 5, 28, and 56 days after drug administration using a computerized analyzer for muscle strength, the Norris scale for disability, motor nerve conduction velocities for patients with conduction blocks, and measurements of immunologic markers. Compared with placebo, IVIg induced a significant increase in muscle strength only in the patients with conduction blocks.