A neuropsychological and neuroimaging study of a patient before and after treatment for paretic neurosyphilis

A 41-year-old woman suffering from paretic neurosyphilis was treated successfully with high-dose penicillin. Detailed neuropsychological and neuroimaging studies were performed before and after treatment. The patient initially presented with presbyophrenia-like features of an amnesic-confabulatory state with a hypomanic mood. Pre-treatment neuropsychological examination revealed deficits in general intelligence, attention, memory, and frontal robe executive function. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated severe hippocampal/parahippocampal damage, in addition to fronto-temporal atrophy and ventricular dilatation. Immediately after treatment, she was no longer confabulatory or hypomanic, but remained densely amnesic. Neuropsychological examination at that time revealed a significant improvement in frontal lobe function, whereas her memory was still impaired. However, CT and MRI showed no interval change. Single-photon emission CT (SPECT) demonstrated a remarkable improvement in cerebral perfusion, but the increase in frontal perfusion was relatively small. Seven months after treatment, clinical and neuropsychological examination revealed no evidence of memory impairment. Cerebral perfusion on SPECT in the frontal areas by this time had improved to normal. Positron emission tomography (PET), however, still showed patchy areas of hypoperfusion/hypometabolism. This study demonstrates the patient's stepwise clinical recovery following early antibiotic therapy and shows the dissociation of neuropsychological recovery and changes on SPECT and PET.