Neuronal Intermediate Filament-Positive Paraneoplastic Neurological Syndrome in Cervical Squamous Cell Carcinoma

Paraneoplastic neurological syndromes (PNS) are a group of neurological manifestations of a variety of carcinomas that result from the generation of paraneoplastic antibodies (PAb) against the tumors that subsequently attack the central nervous system (CNS). The resultant damage from these onconeural antibodies leads to significant neurological manifestations and syndromes, which are sometimes seen with certain antibodies and tumors; however, the presentation of PNS is diverse. Diagnosis is often delayed due to a lack of clinical suspicion. Unfortunately, late recognition leads to worse clinical outcomes as PNS requires prompt treatment to prevent permanent neurological damage. Cases that are diagnosed early and receive immediate treatment have significantly improved outcomes and restoration of neurological function. Non-responders to treatment likely have irreversible neuronal damage at the time the syndrome was recognized. Surgical resection of the tumor is paramount in the treatment paradigm because this would eliminate the source of PAb generation. Immunomodulatory therapy further reduces ongoing damage to the nervous system. We present an intriguing and the first documented case of PNS resulting from neuronal intermediate filament (NIF) antibodies detected in association with invasive cervical squamous cell carcinoma (SCC). The patient initially manifested with nonspecific weakness and loss of sensation that rapidly progressed to near complete loss of all motor function. Given the diverse presentation of PNS cases, heightened awareness and a high index of clinical suspicion are crucial for early diagnosis and prevention of further neurological compromise.