Mononeuropathy multiplex as the initial manifestation of neurofibromatosis type 2

Abstract
The authors report a patient with neurofibromatosis type 2 (NF2) presenting with an axonal mononeuropathy multiplex. Sural nerve biopsy showed small scattered groups of Schwann cells transformed into irregular branching cells with abnormal cell—cell contacts. The authors hypothesize that defective Schwann cell function, due to inactivation of the NF2 gene product merlin, leads to changes in morphology, cell–cell contact, and growth, and finally to degeneration of axons.