Hyperkalaemic paralysis, neuropathy and persistent motor neuron discharges at rest in Addison's disease

A 50 year old man with Addison's disease suffered two episodes of hyperkalaemic paralysis, with delayed muscular relaxation and persistent motor neuron discharges at rest resembling the Isaacs-Mertens syndrome. Sural nerve biopsy shows a demyelinating neuropathy. The symptoms ceased after corticosteroid therapy.