Since CB is the major physiologic phenomenon underlying MMN, understanding the cause of the block can lead to treatments directed at the specific target.
Progress: Initially the CB in MMN was thought to be caused by the stripping off of the insulation of the axon (myelin). This demyelination is known to cause CB in other diseases including the demyelinating form of GBS as well as CIDP. However, we know that the acute motor axonal form (AMAN) form of GBS has CB without demyelination. It has been shown in AMAN that the target of the antibodies in AMAN are directed at a region of the axon that produces the fast transmission of impulses down the nerve- the Node of Ranvier. AMAN has similar antibodies to those found in MMN and there is now increasing evidence that the CB in MMN is also due to an attack of the Node of Ranvier or its adjacent regions. This knowledge is likely to provide investigators the opportunity to develop treatments directed at specific targets in this region.
