Analysis of brain activity for speech stimuli and child development of an infant with neurosyphilis: case report

Neurosyphilis is an infection of the central nervous system caused by Treponema pallidum and may be symptomatic or asymptomatic in children with congenital syphilis. This study aims to describe the cortical activation pattern of a four-month-old infant with neurosyphilis using functional near-infrared spectroscopy (fNIRS). Born at term weighing 3,475 kg, she presented a Venereal Disease Research Laboratory (VDRL) test of 1:32 and changes in the cerebrospinal fluid test. She underwent treatment with crystalline penicillin for 10 days before discharge from the hospital. In the audiological evaluation, she presented normal tympanometry, otoacoustic emissions evoked by transient stimulus, brainstem auditory evoked potential with click stimulus at 80 and 30 dB nHL bilaterally. The Bayley III Scale was applied to assess language, cognition and motor development, showing delays in expressive language and broad motor skills. In the fNIRS acquisition, data were collected through 20 channels divided between the cerebral hemispheres. The /ba/ and /da/ stimuli were presented at 40 dB HL with the Psychopy software through a headphone. Data analysis used the MNE and MNE-NIRS toolboxes in the Spyder environment. The average by channel, ROI, and condition was exported for analysis. A similar theta coefficient was observed between the conditions and channels evaluated in both cerebral hemispheres, with a greater amplitude of oxyhemoglobin (HbO) being observed in the anterior position when compared to the posterior region of the temporal lobe. Therefore, this case report highlights the need to monitor the child development of babies with neurosyphilis.