Trigeminal Hypoplasia
- Hypoplasia of the trigeminal nerve and ganglion has been described within the context of Goldenhar-Gorlin syndrome (oculoauriculovertebral dysplasia-hemifacial microsomia) where it is associated with distinctive phenotypic features.
- More rarely, congenital trigeminal neuropathy can occur in isolation. Patients often present in childhood with recurrent corneal abrasions secondary to corneal anaesthesia. There is also accompanying diminished sensation to the ipsilateral face. Muscles of mastication may be atrophic (note atrophy of masseter in this patient).
- This diagnosis needs to be considered when encountering patients with life-long unilateral facial numbness, especially children. Undiagnosed corneal anaesthesia should prompt consideration of isolated unilateral hypoplasia of the trigeminal nerve; MR is the imaging modality of choice.
- Management revolves around management of corneal anaesthesia. There are serious implications for eye function and visual acuity secondary to repeated corneal ulceration/scarring. Mechanical protection such as eye shields, eye lubricants and regular opthalmological review are mainstays of management.
