Brain and Spinal Cord Lesions in Leprosy: A Magnetic Resonance Imaging–Based Study

Abstract

Neurotropism and infiltration by Mycobacterium leprae of peripheral nerves causing neuropathy are well established, but reports of central nervous system (CNS) damage are exceptional. We report CNS magnetic resonance imaging (MRI) abnormalities of the brain and spinal cord as well as lesions in nerve roots and plexus in leprosy patients. Eight patients aged between 17 and 41 years underwent detailed clinical, histopathological, and MRI evaluation. All had prominent sensory-motor deficits with hypopigmented and hypo/anesthetic skin patches and thickened peripheral nerves. All demonstrated M. Leprae DNA in affected peripheral nerve tissue. All received multidrug therapy (MDT). Two patients had brainstem lesions with enhancing facial nuclei and nerves, and one patient had a lesion in the nucleus ambiguus. Two patients had enhancing spinal cord lesions. Follow-up MRI performed in four cases showed resolution of brainstem and cord lesions after starting on MDT. Thickened brachial and lumbosacral plexus nerves were observed in six and two patients, respectively, which partially resolved on follow-up MRI in the two cases who had reimaging. The site and side of the MRI lesions corresponded with the location and side of neurological deficits. This precise clinico-radiological correlation of proximal lesions could be explained by an immune reaction in the gray matter corresponding to the involved peripheral nerves, retrograde axonal and gray matter changes, or infection of the CNS and plexus by lepra bacilli. Further study of the CNS in patients with leprous neuropathy is needed to establish the exact nature of these CNS MRI findings.

Comment on ‘Ichthyosiform sarcoidosis: a mimic of leprosy?’

“…Neurotropism and infiltration by M. leprae of peripheral nerves causing neuropathy are well established, but reports of central nervous system (CNS) damage are exceptional . In 1952, Mitsuda identified lepra bacilli in the neurons of the facial nucleus, cervical anterior horns and nucleus ambiguus in autopsy specimens, confirming infection of the brain and spinal cord by M. leprae…”

“…In a recent case series study, Polavarapu et al . described MRI brainstem and spinal cord lesions and brachial and lumbosacral plexus abnormalities in eight patients with leprosy.…”

“…MRI cannot differentiate between sarcoidosis and leprosy. Hence, the clinicoradiological correlation requires confirmation of the pathophysiological basis and needs further tissue‐specific studies in such cases …”

Uso de la resonancia magnética nuclear de plexo braquial en paciente con enfermedad de Hansen

“…La literatura sobre la EH incluye artículos de reportes de caso y series de caso que describen la caracterización de las lesiones de plexo braquial mediante RMN 4,5 . Uno de estos artículos es el de Polavarapu et al 4 , el cual presenta los casos de seis pacientes con diagnóstico de lepra con engrosamiento generalizado de los plexos lumbosacro (cuatro pacientes) y del plexo braquial (dos pacientes) y menciona que dichas lesiones se correlacionaban con el sitio de déficit neurológico; estos hallazgos coinciden con lo encontrado en el presente caso, donde la paciente también presentaba compromiso bilateral sensitivo de miembros superiores.…”

Ichthyosiform sarcoidosis: a mimic of leprosy? Reply from authors

“…Akin to sarcoidosis, leprosy can present with varied manifestations and organ involvement. In this regard, the recently published report by Polavarapu et al . on central nervous system (CNS) and proximal nerve involvement in leprosy makes an interesting read.…”