Cranial Nerve Abnormalities in Oculo-Auriculo-Vertebral Spectrum

Abstract

Background and purpose: Cranial nerve abnormalities might be observed in hemifacial microsomia and microtia (oculo-auriculo-vertebral spectrum), but the rate, features, and relationship with functional impairment or phenotype severity have not yet been defined. This study aimed at investigating absence/asymmetry, abnormal origin, morphology and course of cranial nerves, and presence/asymmetry of the foramen ovale and inferior alveolar nerve canal in a cohort of oculo-auriculo-vertebral spectrum patients.

Materials and methods: Twenty-nine patients with oculo-auriculo-vertebral spectrum (mean age, 7 years; age range, 0.2-31 years; 12 females) underwent brain MR imaging, CT, and neurologic evaluation; 19 patients had a more severe phenotype (Goldenhar syndrome).

Results: Cranial nerve abnormalities were detected only in patients with Goldenhar syndrome (17/19, bilaterally in 8) and were involved the second (4/19), third (1/18), fifth (11/19), sixth (8/16), seventh (11/18), and eighth (8/18) cranial nerves. Multiple cranial nerve abnormalities were common (11/17). Eleven patients showed bone foramina abnormalities. Trigeminal and facial nerve dysfunctions were common (44% and 58%, respectively), especially in patients with Goldenhar syndrome. Trigeminal abnormalities showed a good correlation with ipsilateral dysfunction (P = .018), which further increased when bone foramina abnormalities were included. The facial nerve showed a trend toward correlation with ipsilateral dysfunction (P = .081). Diplopia was found only in patients with Goldenhar syndrome and was associated with third and sixth cranial nerve abnormalities (P = .006).

Conclusions: Among patients with oculo-auriculo-vertebral spectrum, cranial nerve morphologic abnormalities are common, correlate with phenotype severity, and often entail a functional impairment. The spectrum of cranial nerve abnormalities appears wider than simple hypo-/aplasia and includes an anomalous cisternal course and partial/complete fusion of diverse cranial nerves.

Fig 1.

A–C, Axial T2-weighted images of 3 different patients with Goldenhar syndrome. A, The absence of the right trigeminal nerve. B, The absence of the left trigeminal nerve. C, The relative hypoplasia of the left trigeminal nerve (arrowhead). D, Coronal multiplanar reconstruction image, obtained from the same patient as in C, shows the different diameters of the trigeminal nerves (arrow and arrowhead).

Fig 2.

Brain MR imaging. A, Contiguous T2-weighted axial images show the common origin of the left fifth and seventh/eighth cranial nerves from the anterior profile of the middle cerebellar peduncle (arrow). The common trunk runs in the cisternal space and subdivides into 2 nerves entering the Meckel cave (asterisk) and, slightly caudally, the internal acoustic meatus (arrowheads). B, Oblique multiplanar reconstruction shows the common nerve origin and the subsequent subdivision.