Laís Ferreira1, Maria Clara da Silva Valadão2, Piotr H Skarzynski3, Milaine Dominici Sanfins4, Eliara Pinto Vieira Biaggio5. 1. Speech Therapy Department, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: laaisferreira@hotmail.com. 2. Medical Pediatric Infectologist, University Hospital of Santa Maria, Brazil. 3. Institute of Physiology and Pathology of Hearing, Warsaw, Poland; Department of Heart Failure and Cardiac Rehabilitation, Warsaw, Poland; Institute of Sensory Organs, Warsaw, Poland. 4. State University of Campinas, Campinas, Brazil; Centro de Eletrofisiologia e Neuroaudiologia Avançada, São Paulo, Brazil. 5. Speech Therapy Department, Federal University of Santa Maria, Santa Maria, Brazil.
Abstract
OBJECTIVE: To investigate the effect of congenital toxoplasmosis (CTP) on the Frequency-Following Response (FFR) in infants. STUDY DESIGN: 11 infants diagnosed with CTP and 12 healthy infants with no risk indicators for hearing impairment, aged 29-90 days old. All infants underwent an FFR neurophysiological assessment. The test stimulus was the syllable [da], 40 ms in duration, which was monaurally presented to the right ear at an intensity of 80 dBnHL. Absolute latencies and amplitudes of the V, A, C, D, E, F, and O waves, the slope (μV/ms) and measure between onset (A) and offset (O), were compared between the two groups. RESULTS: Infants with CTP had increased latency of FFR waves V, A, E, F, and O, and decreased amplitude for waves A and F. They also showed a reduction in A-O slope and a higher latency difference between onset (A) and offset (O). CONCLUSION: The neurophysiological responses of Frequency-Following Response can be influenced by congenital toxoplasmosis. Since, the CTP showed prolongation of the V, A, E, F and O waves and decrease of the amplitude for waves A and F.
OBJECTIVE: To investigate the effect of congenital toxoplasmosis (CTP) on the Frequency-Following Response (FFR) in infants. STUDY DESIGN: 11 infants diagnosed with CTP and 12 healthy infants with no risk indicators for hearing impairment, aged 29-90 days old. All infants underwent an FFR neurophysiological assessment. The test stimulus was the syllable [da], 40 ms in duration, which was monaurally presented to the right ear at an intensity of 80 dBnHL. Absolute latencies and amplitudes of the V, A, C, D, E, F, and O waves, the slope (μV/ms) and measure between onset (A) and offset (O), were compared between the two groups. RESULTS:Infants with CTP had increased latency of FFR waves V, A, E, F, and O, and decreased amplitude for waves A and F. They also showed a reduction in A-O slope and a higher latency difference between onset (A) and offset (O). CONCLUSION: The neurophysiological responses of Frequency-Following Response can be influenced by congenital toxoplasmosis. Since, the CTP showed prolongation of the V, A, E, F and O waves and decrease of the amplitude for waves A and F.