Avaliação comportamental e eletrofisiológica do Processamento Auditivo Central na detecção de alterações subclínicas e comprometimento cognitivo em indivíduos infectados pelo HTLV-1

Abstract

Introduction: Infection with human T-cell lymphotropic virus type 1 (HTLV -1) has a wide spectrum of clinical manifestations, among which the HTLV-1-associated myelopathy / spastic tropical paraparesis (HAM/TSP) stands out. New diagnostic perspectives, such as the assessment of central auditory processing (CAP) can assist in the early identification of subclinical changes and cognitive impairment in the course of HTLV-1 infection. Objective: To evaluate the behavioral and electrophysiological responses of CAP in HTLV-1 infection and correlate them with self-perceived everyday memory. Methods: Cross-sectional comparative study nested in a cohort of former blood donors infected with HTLV-1 and uninfected controls matched for age, sex, and education. Self-perception of memory for everyday life was obtained by scoring from zero to 10 on a visual scale. The CAP was evaluated by auditory behavioral tests with dichotic listening tasks, low redundancy monaural speech, temporal ordering, temporal resolution, and binaural interaction, and by the cognitive evoked potential (P300). Results: The sample comprised 15 infected individuals with HAM/TSP, 20 asymptomatic infected, and 35 healthy seronegative controls. P300 latency and memory self-perception score were progressively worse in the asymptomatic and HAM/TSP groups compared to controls. P300 latency above 395ms and memory self-perception score below 7 points showed adequate sensitivity and specificity for detecting cognitive impairment having the neurological assessment as the gold standard for comparison. The frequency of cognitive impairment was 40 times higher in the asymptomatic group and 103 times higher in the HAM / TSP group when compared to controls. A high prevalence of altered auditory abilities was observed even in individuals considered asymptomatic (92%). The dichotic digit tests (p = 0.031) and GIN (p = 0.046) were significantly more altered in the HAM/TSP group when compared to the asymptomatic group. The dichotic digit tests, SSI, PPS, GIN, and MLD were able to differentiate participants with and without cognitive impairment in the sample. Conclusion: The present study expanded the understanding of the existence of a broad spectrum of clinical and subclinical manifestations in HTLV-1 infection by aggregating normative data of subjective and objective measures of the CAP and the self-perception of memory difficulties among infected individuals at different stages of the disease. neurological. The use of the memory self-perception score for complaints of everyday memory in the medical consultation was a useful and easy method for screening asymptomatic patients with HTLV-1 regarding cognitive changes.