<s>[INST] <<SYS>> This is a medical question of type : causes <</SYS>> What causes Multifocal motor neuropathy ? [/INST] What causes multifocal motor neuropathy? The exact underlying cause of multifocal motor neuropathy (MMN) is poorly understood. It is considered an immune-mediated disorder (due to an abnormal immune system response), both because IVIG therapy improves symptoms, and many patients have anti-GM1 antibodies. Research to further understand the cause of MMN is underway. </s>