Memory impairment: an intermediate clinical syndrome symptom in HTLV-1-infected patients?

Abstract

Background Although classical human T-cell lymphocyte virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis syndrome is the most frequent HTLV-1-associated neurological disorder, some “minor” neurological disorders can be seen in “asymptomatic” carriers. These disorders, including cognitive alterations already described in clinical cases and studies, may constitute an intermediate syndrome (IMS) between the asymptomatic state and myelopathy. The aim of this study was to investigate the presence of cognitive deficits in patients with HTLV-1 virus, who usually are diagnosed as asymptomatic. Methods A total of 54 HTLV-1-infected patients were evaluated, 35 asymptomatic and 19 with minor neurological alterations (evaluated by a neurologist); 25 HTLV-1-seronegative individuals served as controls. The instruments used were: Beck’s Depression Inventory, Lawton’s Daily Life Activity Scale, and a complete neuropsychological battery. The application of these evaluation instruments was performed blindly, with the evaluator neuropsychologist not knowing the clinical condition of the patient. Results Most of the participants in this cohort, including seronegative controls, were female (n = 57, 72.21%), their mean age was 52.34 years (SD = 14.29) and their average schooling was 9.70 years (SD = 4.11). Discussion Participants classified with IMS had lower gross scores when compared with both the patients classified as asymptomatic and with the control group, and when tested for auditory episodic memory of immediate (p < 0.01), and late (p = 0.01), recall. Conclusion Patients with IMS presented with memory impairment when compared with asymptomatic patients and seronegative individuals; this is one of the symptoms that aids in the classification of the syndrome.

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

“…In fact, non-medullary symptoms have been neglected in the HTLV-1 infection [7].Recent evidences have showed that HTLV-1 is related to a complex of neurological manifestations that are not limited to the clinical spectrum of HAM/TSP, affecting all the segments of the central nervous system to a greater or lesser extent [3,[8][9][10][11][12][13][14][15][16][17][18]. In this context, cognitive impairment has been reported as one of the manifestations of the HTLV-1 infection [11,13,[19][20][21][22][23][24]. On the other hand, HAM/TSP remains as the most important neurological disease associated with 26].…”

“…Memory di culties are present in HTLV-1 infection at different stages of the neurological disease and the worsening in the performance of daily tasks, together with electrophysiological changes, can be an early sign of cognitive impairment when the individual is in the stage of asymptomatic infection [11,12,20,21,28,29].…”

“…It is important for everyday tasks, for everyday reasoning and decision-making processes [30]. The working memory di culties have been reported as a sign of cognitive impairment associated to HTLV-1 infection at different stages of this neurological disease [12,20,21,28,29]. Recently, it has been suggested, based on a complete neuropsychological exam battery, that memory dysfunction in the HTLV-1-neurological spectrum may occur between the asymptomatic and the HAM/TSP stages [21] and it could be related to a neurological impairment caused by subcortical and cortical white matter lesions [28,31].…”

“…The working memory di culties have been reported as a sign of cognitive impairment associated to HTLV-1 infection at different stages of this neurological disease [12,20,21,28,29]. Recently, it has been suggested, based on a complete neuropsychological exam battery, that memory dysfunction in the HTLV-1-neurological spectrum may occur between the asymptomatic and the HAM/TSP stages [21] and it could be related to a neurological impairment caused by subcortical and cortical white matter lesions [28,31]. The worsening in memory functioning, along with electrophysiological alterations, may be an early sign of cognitive impairment in HTLV-1 asymptomatic infection [11].…”

Cognitive Screening in HTLV-1 Infected People Using a Self-Perceived Memory Score and Auditory P300

“…In fact, non-medullary symptoms have been neglected in the HTLV-1 infection [7].Recent evidences have showed that HTLV-1 is related to a complex of neurological manifestations that are not limited to the clinical spectrum of HAM/TSP, affecting all the segments of the central nervous system to a greater or lesser extent [3,[8][9][10][11][12][13][14][15][16][17][18]. In this context, cognitive impairment has been reported as one of the manifestations of the HTLV-1 infection [11,13,[19][20][21][22][23][24]. On the other hand, HAM/TSP remains as the most important neurological disease associated with HTLV-1 [25, 26].…”