Neurosyphilis, A True Chameleon of Neurology

BACKGROUND: Neurosyphilis (NS) is a rarely encountered scenario today. Manifestations are heterogeneous, and their characteristics have changed in the antibiotic era. A differential diagnosis of NS is not commonly thought of even with relevant clinical-radiological features, as it mimics many common neurological syndromes. OBJECTIVES: To study the manifestations of NS in the present era and the process of diagnosis. METHOD: The data of ten patients with NS was collected and analyzed. Their background data, clinical features, investigations, the process of reaching the diagnosis, management and outcomes were recorded. OBSERVATIONS AND RESULTS: The manifestations of NS in our cohort included six patients with cognitive decline/encephalopathy and one each with meningitis with cranial nerve palsies, cerebellar ataxia, myelitis and asymptomatic NS. The presence of Argyll Robertson pupil helped to clinch diagnosis in one patient. Treponemal tests were ordered in two patients only after alternative etiologies were looked at, to begin with, whereas in six patients treponemal test was requested as a part of standard workup for dementia/ataxia. CONCLUSIONS: NS dementia and behavior changes are mistaken for degenerative, vascular, nutritional causes, autoimmune encephalitis or prion disease. Meningitis has similarities with infective (tubercular), granulomatous (sarcoidosis, Wegener's), collagen vascular disease and neoplastic meningitis, and myelitis simulates demyelination or nutritional myelopathy (B(12) deficiency). Rarely, NS can also present with cerebellar ataxia. Contemplate NS as one of the rare causes for such syndromes, and its early treatment produces good outcomes.