Prevalence and Significance of Cranial Nerve Imaging Abnormalities in Patients With Hereditary Neuropathies

Abstract

Objective: To estimate the prevalence and significance of cranial nerve (CN) imaging findings in patients with hereditary neuropathy. Methods: We retrospectively analyzed data from patients at four tertiary academic medical centers with hereditary neuropathy diagnoses who had undergone gadolinium enhanced magnetic resonance imaging (MRI) of the brain between 2004 and 2018. MRI scans, as well as computed tomography (CT) imaging when available, were reviewed and bivariable analysis was performed to identify predictors of CN abnormalities on imaging. Results: Among 39 patients, 11 had CN deficits (28.2%). Out of the 8 patients who had CN abnormalities on imaging (20.5%), 4 had CN deficits with only 2 of these patients having imaging abnormalities in the CNs associated with the deficits. Imaging abnormalities were found in varied CNs and included CN thickening and enhancement on MRI and CN foramina enlargement on CT. MRIs obtained for evaluation of CN deficits found on exam had a statistically significant increased likelihood of imaging abnormalities. However, CN deficits themselves were not predictive of imaging abnormalities. Conclusions: Thickening and enhancement of CNs on MRI may be found in 1/5 of patients with hereditary neuropathies and are inconsistently associated with clinical deficits. These imaging findings, which can mimic certain neoplastic processes, are unlikely to require surgical management in these patients and instead may be manifestations of the underlying genetic neuropathy.