Hyperexcitability As A Potential Cause For Diffuse Lower Motor Neuron Loss In Isaacs' Syndrome

We present a patient who initially developed diffuse painful muscle cramps who had elevated antibodies against voltage-gated potassium channel (VGKC) complex. Despite the initial improvement after immunomodulatory therapy, she later developed progressive atrophy and weakness of the limb muscles whose electrophysiological finding mimicked that in lower motor neuron disease. A potential causal relationship between anti-VGKC complex antibody-associated hyperexcitability and lower motor axon loss is discussed.