Neurosyphilis in an eight-year-old child: usefulness of the SPECT study

[SPECT and FDG-PET in diagnostics of neurolues]

Syphilis is a recurrent treponematosis of acute and chronic evolution. In general it is either sexually or congenitally transmitted. Primary syphilis appears as a single and painless lesion. Secondary syphilis may manifest years later, the secondary bacteremic stage is accompanied by generalized mucocutaneous lesions. Tertiary disease can be disseminated to bones and virtually any organ, involving principally the ascending aorta and the central nervous system. Nuclear medicine provides diagnostic methods in case of skeletal manifestations by bone scan - identifying periostitis and osteomyelitis. Hepatic gummas can be imaged by 99m-Tc-colloid liver scintigraphy. In neurosyphilis brain perfusion SPECT enables imaging of cerebral involvement by small vessel endarteritis resulting from syphilitic vascular disease. 18-FDG PET is also useful to evaluate neurosyphilis, a reduction of brain glucose consumption is observed. The technique adequately enables imaging of therapeutic response and might be superior to morphologic imaging. We present our experiences with these nuclear medicine methods in patients with neurolues. The incidence of neurolues is estimated at 2 per 100.000 inhabitants worldwide, migration processes might bring a re-emergence of this disease to Austria and other developed countries of the EU. Scintigraphic methods should be kept in mind for diagnostic evaluation of neurosyphilis.

Congenital syphilis: beta2-microglobulin in cerebrospinal fluid and diagnosis of neurosyphilis in an affected newborn

Meningoencephalitis in neonatal congenital syphilis (CS) is a difficult diagnosis because of the limitation of standard cerebrospinal fluid (CSF) tests. This limitation means that new markers in CSF tests are needed to establish whether meningitis is present in presumptive cases of CS. beta2-Microglobulin (beta2-m) is raised in CSF recovered from neonates with central nervous system (CNS) infections, but it does not correlate with cellular count or proteins in the CSF. We present a preterm newborn with symptomatic CS. First-day CSF showed 50 cells/mm3, protein of 220 mg/dL and a beta2-m concentration of 16.9 mg/dL (normal <2.25 mg/dL). Serial determinations of beta2-m showed a marked reduction (76%) after 10 days of appropriate treatment. At 30 days of life, beta2-m was already within the normal range (1.8 mg/dL). Cerebral ultrasonography showed ventricular dilatation, moderate periventricular echogenicity, subependimal hemorrhages, and linear hyperechoic areas in the thalamus and basal ganglia. We suggest that beta2-microglobulin is very useful in the diagnosis of CNS involvement and in monitoring the response to treatment. In addition, infants with CS may exhibit CNS imaging findings similar to those observed in other intrauterine CNS infections.