Neurosyphilis: mighty imitator forays with benign presentation and unique neuroimaging findings

Background Common causes of temporal lobe hyper intensities are central nervous system infections like herpes simplex encephalitis, Lyme disease, limbic encephalitis and vascular pathology like Cerebral Autosomal Dominant Arteriopathy with Subcortical infarcts and Leukoencephalopathy.

Personal assessment, laboratory data analysis and neuroimaging for the patient who was admitted to a central Pennsylvania tertiary care referral centre were conducted.

A 52-year-old male presented with a 1-year history of diffuse dysesthesia in upper and lower extremities with associated intermittent headaches and neck stiffness. Evaluation with lumbar puncture revealed increased nucleated cells (50ul) with lymphocytic predominance (96%) and an elevated protein level of 109mg/dl. Magnetic resonance imaging (MRI) of the brain showed T2/FLAIR hyper intensity in bilateral subcortical temporal white matter, left-greater-than-right and associated volume loss in cerebral parenchyma. Additional abnormal work up included reactive serum reactive plasma regain and Treponema pallidum antibody particle agglutination. Diagnosis of neurosyphilis was made and the patient was treated with intramuscular (IM) penicillin for 3 weeks. At the time of discharge, his headache and neck stiffness resolved and dysesthesias were decreased in intensity.

The diagnosis of neurosyphilis is intricate, and no reference standard exists. Neuroimaging findings of neurosyphilis commonly are cerebral infarctions, leptomeningeal enhancement or non-specific white matter lesions. Less common features on fluid-attenuated inversion recovery (FLAIR) sequences are cortical atrophy and mesial temporal parenchymal signal changes. It is prudent to keep neurosyphilis in differential of mesial temporal lobe white matter changes, as early diagnosis and treatment results in better prognosis.