Cranial nerve palsies in leprosy: a systematic review of published case reports and case series

In leprosy, peripheral nerve involvement is well-documented, cranial nerve impairment in leprosy is less frequently reported, often through isolated case reports. This review aims to elucidate the pattern and spectrum of cranial nerve involvement in leprosy patients, enhancing understanding about pathogenesis and management.

Adhering to PRISMA guidelines, we conducted a systematic review of case reports and series documenting cranial nerve involvement in leprosy. Searches were performed across PubMed, Scopus, Embase, and Google Scholar up to February 2, 2024, without language restrictions.

We identified 40 documents reporting on 49 patients, with a mean age of 41.3 years and a predominance of male patients (87.6%). Cranial nerve involvement included the trigeminal nerve (28.6%), facial nerve (38.8%), and instances of multiple cranial nerve palsies (10.2%). Magnetic resonance imaging findings indicated nerve T2/FLAIR hyperintensity/enhancements. Neuroimaging abnormalities extended up to brain stem. Approximately 30% of patients experienced lepra reactions, with 51% showing improvement following treatment. Following mutidrug therapy (MDT), neuroimaging abnormalities were vanished.

Cranial nerve involvement in leprosy primarily affects the trigeminal and facial nerves, with multiple cranial nerves also being implicated. Exaggerated inflammation during lepra reaction involve nerve trunks and/or brainstem nuclei.