Objective:

To describe an atypical case of Kikuchi-Fujimoto disease (KFD) with widespread central nervous system (CNS) involvement.

Background:

KFD is a rare, typically self-limiting lymphoproliferative disease with unknown etiology, predominant among Asian populations. It has autoimmune associations and is characterized by fever, rashes, and cervical lymphadenopathy. Neurological involvement is infrequent, including aseptic meningitis, cerebellar ataxia, and retinopathy. We present an unusual case of vasculitis with multifocal CNS symptoms in a patient with biopsy-proven Kikuchi-Fujimoto disease.

Design/Methods:

A 43-year-old Indian male presented to us with a complex history of gait imbalance, bradykinesia, dysarthria, dysphagia, and hypersomnia, all of which had progressively worsened over the past 12 months. He held a prior diagnosis of steroid-responsive KFD in 2014, manifesting as fever and lymphadenopathy, demonstrating histiocytic necrotizing lymphadenitis on biopsy. He was also diagnosed with seronegative ocular myasthenia gravis in 2019. In January 2022, he developed an ischemic stroke and, seven months later, began displaying increased falls, cognitive impairment, and behavioral apathy.

Results:

On examination, he exhibited retained primitive reflexes, dysarthria, vertical gaze restriction, spasticity, and gait abnormalities. Magnetic resonance imaging (MRI) revealed diffuse cortical and brainstem atrophy with multiple T2 fluid-attenuated inversion recovery (FLAIR) hyperintensities. Cerebrospinal fluid (CSF) analysis showed isolated protein elevation. Subsequent workups, including extensive imaging, genetic testing, comprehensive autoantibody, infectious, and paraneoplastic panels, returned negative. Ultimately, a diagnosis of CNS vasculitis secondary to KFD was established. The patient was treated with rituximab, a B-cell therapy, with significant clinical improvement.

Conclusions:

Neurological sequelae of KFD may appear years after the initial diagnosis, present as obscure manifestations, and persist chronically. Since KFD is a rare entity with non-specific CSF and imaging findings, a thorough assessment to rule out alternative causes and histopathology are crucial for a definitive diagnosis. While KFD is generally self-resolving, clinicians must recognize its complications as severe cases may require aggressive immunosuppressive treatment.