The spectrum of central nervous system manifestations in leprosy: a systematic review of published case reports and case series.

BACKGROUND: This systematic review aimed to investigate central nervous system (CNS) involvement in leprosy by analysing multiple cohort studies, individual cases and case series. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PubMed, Scopus and Embase databases were searched up to 8 July 2023, using a predefined search strategy. Inclusion criteria included patients diagnosed with leprosy with evidence of CNS involvement. The quality of the included cases was evaluated using the Joanna Briggs Institute checklist. RESULTS: A total of 34 records were identified, including 18 cohort studies and 16 reports describing 27 isolated cases. Autopsies revealed macroscopic changes in the spinal cord, neurofibrillary tangles and senile plaques. Mycobacterium leprae was detected in neurons of the medulla oblongata and spinal cord using PCR and phenolic glycolipid 1 staining. Cerebrospinal fluid (CSF) analysis showed inflammatory changes, increased gamma globulins and detection of Mycobacterium leprae antigens and antibodies. In 21 patients (78%), spinal cord/brachial plexus abnormities were detected. In the majority, MRI revealed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity in the cervical cord. In patients with brainstem involvement, T2/FLAIR hyperintensity was noted in the cerebellar peduncles, facial nerve nuclei and/or other cranial nerve nuclei. Brain parenchymal involvement was noted in three patients. CONCLUSIONS: This systematic review provides evidence of CNS involvement in leprosy, based on autopsy findings, neuroimaging, CSF analysis and neurophysiological studies.

Central nervous system, spinal root ganglion and brachial plexus involvement in leprosy: A prospective study.

Background: Leprosy is primarily a disease of peripheral nerves. Some isolated case reports and case series have communicated imaging changes in the central nervous system (CNS) and brachial plexus in patients with leprosy. Objectives: To study the neuroimaging abnormalities in patients with lepra bacilli-positive neuropathy in the context of CNS, spinal root ganglion, and brachial plexus. Design: Prospective observational study. Methods: We screened newly-diagnosed patients with multibacillary leprosy presenting with neuropathy. Patients with bacilli-positive sural nerve biopsies were included in the study and subjected to magnetic resonance imaging (MRI) of the brain and spinal cord. Results: A total of 54 patients with bacteriologically confirmed multibacillary leprosy were screened; Mycobacterium leprae was demonstrated in the sural nerve biopsies of 29 patients. Five patients (5/29; 17.24%) had MRI abnormalities in CNS, spinal root ganglion, and/or brachial plexus. Three patients had MRI changes suggestive of either myelitis or ganglionitis. One patient had T2/FLAIR hyperintensity in the middle cerebellar peduncle while 1 had T2/FLAIR hyperintensity in the brachial plexus. Conclusion: CNS, spinal root ganglion, and brachial plexus are involved in patients with leprous neuropathy. Immunological reaction against M leprae antigen might be a plausible pathogenetic mechanism for brachial plexus and CNS imaging abnormalities.