Atrophy, focal spinal cord lesions and alterations of diffusion tensor imaging (DTI) parameters in asymptomatic virus carriers and patients suffering from human T-lymphotrophic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Abstract

In tropical spastic paraparesis, spinal cord atrophy is a well-known finding in magnetic resonance imaging. But in contrast to histological reports, focal lesions of the spinal cord have only been described in imaging reports in exceptional acute cases. Here, we looked for such focal lesions and for alterations of diffusion tensor imaging parameters of the long fibre tracts in the usual case of a long-standing and slowly progressive disease. We examined 10 symptomatic patients, 11 seropositive, but asymptomatic human T-lymphotrophic virus type 1 carriers and 18 seronegative volunteers as controls. Sagittal and transversal T2-weighted images were visually assessed for atrophy and focal cord lesions. The spinal cord cross-sectional areas and the segmental cord volumes were measured at all levels. High-resolution diffusion tensor imaging was performed in sagittal planes from the bregma down to the cervical spine. For tractography and calculation of fractional anisotropy and mean diffusivity, we used manufacturer-provided software. Two-thirds of patients showed focal lesions affecting the antero-lateral columns and in two cases also the dorsal columns. Compared to carriers and volunteers, patients presented a significant spinal cord atrophy and a reduction of fractional anisotropy (p < 0.05), correlating more to duration of symptoms than to clinical impairment. Because our carriers did not show a significant atrophy, focal lesions or a change of diffusion tensor imaging parameters, we need further long-term studies to see if these parameters at some stage may be used as early indicators of spinal cord affection in virus carriers.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

“…A retrospective study from 1996 to 2007 from two sentinel hospitals from Havana and Matanzas Cuba that registered all lymphoid neoplasms, reported only five ATLL cases [220]. On the contrary, in spite of multiple reports about TSP/HAM in Dominican Republic and Puerto Rico [218,[221][222][223], we could not find a single ATLL case. Although it is not clear which is the most prevalent subtype, HTLV-1 is almost exclusively the one reported [216,220,224,225].…”

“…TSP/HAM was first described in the Southern Pacific of Colombia in 1981 as a chronic non-hereditary spastic paraparesis, initially termed Pacific spastic paraparesis [ 508 ], later also observed in the Caribbean islands of Martinique and Jamaica and in HTLV endemic regions of Japan. TSP/HAM seems to be highly prevalent in LA, particularly for Afro-descendants, but also for mestizo and Caucasian populations [ 223 , 249 , 351 , 448 , 449 , 452 , 453 , 454 , 455 , 461 , 464 , 472 , 509 ]. Likewise, infective dermatitis, strongyloidiasis and many other dermatological, oral, ocular and neurological complications are usually found co-presenting with ATLL or TSP/HAM, or independent of those diseases in HTLV endemic regions of Peru, Chile and Brazil.…”

Bladder dysfunction in human T cell lymphotropic virus infection: A prospective cohort study

“…Recent studies have shown that a large percentage of HTLV-1-infected subjects who do not meet the criteria for definite HAM/TSP suffer from symptoms or diseases related to this viral infection [8,9,[27][28][29]. Spinal cord injury is the main cause of bladder dysfunction in patients with definite HAM/TSP [30]. However, a high percentage of patients without definite HAM/ TSP also present urinary complaints characterized mainly by nocturia, urgency, incontinence and a feeling of incomplete bladder emptying [11].…”

Diffusion tensor imaging metrics in diagnosis of HTLV‐1‐associated myelopathy

“…In the spinal cord, inflammatory myelitis is characterized by decreased FA values in the region of T2‐weighted lesions, with increased FA values seen at lesion boundaries 15 . Vilchez et al., 11 in addition to conventional MRI of the cervical cord and thoracolumbar spine, investigated DTI parameters in the evaluation of patients with definite HAM and HTLV‐1 carriers. These authors identified significant correlations exclusively between reduced FA in dorsal fiber and neurological findings.…”