Congenital Cranial Dysinnervation Disorders

Patients with congenital cranial dysinnervation disorders (CCDD) may present with complex strabismus secondary to dysinnervation of the extraocular muscles. (1-3) Among the CCDDs, congenital fibrosis of the extraocular muscles (CFEOM) is a group of strabismus disorders characterized by blepharoptosis and ophthalmoplegia. Animal models of CFEOM have revealed that the phenotype arises from dysinnervation of oculomotor and/or trochlear nerves (4-6). In humans, this dysinnervation manifests as incomitant strabismus with restriction of both vertical and also horizontal gaze. Historically, patients have been stratified into three phenotypes of CFEOM: 1, 2 and 3; since 2001, the genetic basis of these conditions has been identified.