The value of high-dose intravenous immunoglobulin in the treatment of chronic inflammatory demyelinating polyneuropathy was studied in a double-blind, placebo controlled, crossover investigation at the Department of Neurology, University Hospital Rotterdam-Dijkzigt, the Department of Immunohematology and Bloodbank, University Hospital Leiden, and the Central Laboratory of the Netherlands, Red Cross Blood Transfusion Service, Amsterdam, The Netherlands. Of seven patients treated two were children aged 10 and 7 and five were adults. At initial diagnosis one child was severely disabled and the other moderately disabled (Rankin score 5 and 3, respectively). All patients had weakness of both legs, areflexia, slowed nerve conduction velocities, and elevated CSF protein level. All had responded to treatment with IVIg, 0.4 g/kg bodyweight/2 weeks. All patients showed deterioration after IVIg was discontinued. The patients were then randomized to IVIg or placebo (albumin treatment) in a double-blind crossover study. Those treated with IVIg improved by day eight after the onset of treatment whereas those treated with placebo showed no improvement. The time lapse between discontinuation of the IVIg treatment until deterioration was 6.4 weeks. After placebo the time lapse in weeks until clinical deterioration was 1.3 weeks. [1]