Imaging Findings in Congenital Cranial Dysinnervation Disorders

Abstract

In 2002, the term congenital cranial dysinnervation disorders (CCDDs) was proposed to group heterogeneous syndromes with congenital abnormalities of ocular muscle and facial innervations. The concept of neurogenic etiology has been supported by discovery of genes that are essential to the normal development of brainstem, cranial nerves, and their axonal connections. The CCDDs include Duane retraction syndrome, congenital fibrosis of the extraocular muscles, Möbius syndrome, horizontal gaze palsy with progressive scoliosis, the human homeobox-related disorders, pontine cap tegmental dysplasia, and an expanding list. The purpose of this review was to update the imaging features, as well as clinical and genetic information, regarding cases of CCDDs.

Pontine tegmental cap dysplasia with a duplicated internal auditory canal

“…On MRI, the hindbrain malformation is described as a flattened, hypoplastic ventral pons with a tegmental cap, a curved protrusion of the dorsal pons from the middle third of the tegmentum into the fourth ventricle [17]. The protrusion has been characterized as cap-like or beaklike [14].…”

“…The protrusion has been characterized as cap-like or beaklike [14]. There is often absence or hypoplasia of the middle or inferior cerebellar peduncles which sets this apart from Moebius syndrome, another neurological disorder that may present similarly [9], [17]. Additional imaging findings include a molar tooth appearance of the pontomesencephalic junction, absent inferior olivary prominences, and variably absent CNs V, VI, VII, VIII, and IX [1], [17].…”

“…There is often absence or hypoplasia of the middle or inferior cerebellar peduncles which sets this apart from Moebius syndrome, another neurological disorder that may present similarly [9], [17]. Additional imaging findings include a molar tooth appearance of the pontomesencephalic junction, absent inferior olivary prominences, and variably absent CNs V, VI, VII, VIII, and IX [1], [17]. In a study by Nixon et al, 94% presented with duplication of at least 1 internal auditory canal, with vestibulocochlear nerve canal stenosis or atresia in the duplicated internal auditory canals and ipsilateral vestibulocochlear nerve aplasia [8].…”

“…In a study by Nixon et al, 94% presented with duplication of at least 1 internal auditory canal, with vestibulocochlear nerve canal stenosis or atresia in the duplicated internal auditory canals and ipsilateral vestibulocochlear nerve aplasia [8]. While many of these imaging findings are present in PTCD, the most specific characteristic is the tegmental cap [17].…”

Eyelid Retraction in Isolated Unilateral Congenital Blepharoptosis

“…The roles of several genes have been elucidated and found to have important or essential roles in the development of the brainstem, specific cranial nerve nuclei, or their axonal connections to their target, usually muscles (6). We refer the interested reader to several excellent reviews on the topic (6–8). …”