Originally Posted by glenntaj

--that benign fasciculation syndrome and small fiber neuropathy are quite the same thing, as small-fiber neuropathy refers specifically to dysfunction of small, unmyelinated and thinly myelinated sensory nerves and fasciculation involves muscle, and even the smallest muscles are ennervated by more thickly myelinated nerve fibers.

There's nothing that says, though, that a similar originating process or etiology may be behind both in some cases. Moreover, it is common to have mixed types of neuropathy, in which both myelinated and unmyelinated fibers are involved. Often, a process that attacks the axon--the nerve fiber itself, instead of the myelin covering--will affect both small and larger fibers. (Small-fiber syndromes, be definition, are axonal; larger fiber syndromes can be axonal, myelin-based, or both.)