Cognitive screening in HTLV-1–infected people using a self-perceived memory score and auditory P300

Background: The HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is the most common neurological manifestation associated with Human T-cell Lymphotropic Virus type-1 (HTLV-1) infection. Although cognitive impairment has been highlighted in the spectrum of HTLV-1 neurological manifestations, it may go unnoticed in those who do not spontaneously report it. We aimed at evaluating the applicability of a self-perceived memory score (SMS) and the cognitive event-related potential (P300) for the early detection of cognitive impairment in HTLV-1-infected people. Methods: The SMS was measured by a 0-10 visual analog scale combined with a sad-happy faces rating scale. The higher the number, the better was the SMS. The P300 was obtained through an oddball paradigm with a mental counting task. The participants were 15(21,4%) individuals with HAM/TSP, 20(28,6%) HTLV-1-asymptomatic carriers, and 35(50%) seronegative controls. Results: SMS (p369.0 milliseconds were considered as altered result and indicated cognitive impairment. The HAM/TSP group showed the highest prevalence of altered P300 (80%) and SMS (87%). Interestingly, the asymptomatic group also presented significant higher prevalence of altered SMS (60%) and P300 (35%) when compared to controls (Conclusion: The use of SMS in the medical consultation was a useful and easy-to-apply method to screen HTLV-1 infected subjects for everyday memory complaints.