TEACHING POINTS
■ Neurosyphilis is present in 5% to 10% of all untreated syphilis patients and may or may not be symptomatic. While asymptomatic patients do not have neurologic signs and symptoms, they do have CSF abnormalities.
■ The criteria for diagnosis of neurosyphilis include CNS or ophthalmic signs or symptoms plus positive results on serologic nontreponemal and treponemal testing for syphilis infection. In addition, the patient must have at least one of the following CSF findings: (1) positive result on VDRL testing, (2) increased protein (>40 mg/dL), or (3) an elevated WBC count (>5 mononuclear cells/ l).
■ Penicillin G, administered as 3 to 4 million units IV every 4 hours or 18 to 24 million units continuous IV infusion per day for 10 to 14 days, remains the treatment of choice. Normalization of serum RPR test results is a strong indicator of successful treatment of neurosyphilis.
■ If the increase in CSF WBC count persists after 6 months or if the CSF is not entirely normal after 2 years, re-treatment should be considered.
■ Neurosyphilis should be considered in the diagnostic assessment of any adult with new-onset seizures and status epilepticus.
CASE
A 33-year-old male was brought to the emergency department (ED) by emergency medical services (EMS) after being involved in a motor vehicle collision. EMS personnel reported witnessing three episodes of seizure activity at the collision site and giving the patient a dose of lorazepam (Ativan) per protocol. After another three episodes of witnessed seizure activity in the ED, a lorazepam drip was started. CT of the head revealed no significant pathology. No drugs were detected on a toxicology screen of the urine. The patient was subsequently intubated for airway protection and transferred to the ICU. Empiric antibiotics were begun. The patient's family members reported that he had been in good health with no medical problems and that he did not use alcohol or illicit drugs. After the patient was extubated, he confirmed the report of family members and added that he had had unprotected sex with multiple partners. He was unaware of having any sexually transmitted diseases and denied any seizure disorder.
Physical examination was limited by intubation and sedation. Vital signs were normal. Findings on the head, ear, eye, and neck examinations were unremarkable. The lungs were clear. Heart and abdominal examinations were normal. A postextubation neurologic examination was unremarkable.
Results of serum chemistries and CBC were notable only for leukocytosis (WBC count, 37.5×103/µL). ECG and chest radiography findings were unremarkable. Results of HIV testing and a hepatitis panel were negative. A rapid plasma reagin (RPR) test yielded positive results (1:128 dilutions), as did an assay for fluorescent treponemal antibody absorbed (FTA-ABS). CSF analysis revealed a WBC count of 207/µL, protein of 89 mg/dL, positive results on VDRL testing, and negative results on herpes simplex virus (HSV) testing. An EEG demonstrated partial periodic lateralized epileptiform discharges (PLEDs). On MRI of the head, hyperintense signals were observed in the left frontotemporal region, the left frontal region (Figure 1), and the left as well as the right hippocampi. There was no evidence of acute stroke or hydrocephalus.
A definitive diagnosis of neurosyphilis was made. The patient was started on IV penicillin G procaine 4 million units every 4 hours. All other antibiotics as well as the lorazepam drip were discontinued. He was started on phenytoin (Dilantin) for the history of seizure activity. The patient's mental status subsequently improved, and he was discharged home with instructions to follow up in the infectious disease and neurology clinics.