Neurosyphilis with oral‑facial‑lingual dyskinesia: A case report.

The present study describes the case of a 52-year-old male patient who presented with subacute onset dysarthria and oral-facial-lingual dyskinesia, with normal blood glucose and acanthocyte levels, and no history of drug use. The patient tested negative for autoimmune encephalitis-related antibodies and paraneoplastic-related antibodies. The level of cerebrospinal fluid (CSF) protein was slightly elevated, and the Treponema pallidum hemagglutination assay and rapid plasma reagin test were positive in both serum and CSF samples. After 1 month of treatment with doxycycline, the patient's oral-facial-lingual dyskinesia was significantly improved, suggesting the diagnosis of neurosyphilis.