Neuro-leishmaniasis with cauda equina syndrome and cranial nerve palsy: a rare manifestation of recurrent atypical visceral leishmaniasis.

Background: Visceral leishmaniasis (VL) is a neglected tropical disease primarily affecting Brazil, East Africa, and India, with India accounting for 18% of the global burden. While VL typically presents with systemic symptoms like fever, weight loss, and splenomegaly, it can occasionally manifest atypically, posing significant diagnostic challenges. Neurological presentations of VL are extremely rare, making them difficult to suspect and diagnose. Cases where VL predominantly presents with neurological symptoms are particularly novel, underscoring the need for heightened awareness of such atypical manifestations in endemic regions.

Clinical case: A 38-year-old man with history of recurrent atypical VL presented with diffuse lower back pain, progressive tingling, numbness, weakness in the lower extremities, and double vision for one month. Clinical and radiological evaluations suggested cauda equina syndrome and cranial nerve palsy, accompanied by generalized lymphadenopathy, subcutaneous nodules, and skin papules. The differential diagnosis initially included disseminated tuberculosis, histoplasmosis, and lymphoma. Cerebrospinal fluid (CSF) analysis revealed an inflammatory syndrome. Histopathology of lymph node and bone marrow revealed Leishmania amastigotes and subcutaneous nodule and skin biopsy revealed inflammatory cells with granulomas. Furthermore, the qPCR test on DNA from a subcutaneous nodule, lymph node, and CSF was positive for Leishmania kinetoplast DNA. The species was further confirmed as Leishmania donovani through ITS-based PCR amplification and sequencing. Finally, a diagnosis of relapse of VL with lymph node, cutaneous, and neurological involvement, including abducens nerve palsy and cauda equina syndrome, was established. He was treated with combination of liposomal amphotericin B and miltefosine, along with intrathecal hyaluronidase, resulting in significant improvement.

Conclusion: Unlike previously reported cases with both systemic and neurological symptoms, our patient predominantly presented with neurological manifestations, making this a unique and novel presentation of VL. This case highlights diagnostic challenges and management of atypical VL, emphasizing neurological involvement and successful therapeutic strategies.