HTLV-1-associated myelopathy (aka tropical spastic paraparesis) is
This condition has been independently described in Japan (HTLV-1 associated myelopathy) and in the Caribbean (tropical spastic paraparesis), and it is now often referred to by both terms, i.e. HTLV-1-associated myelopathy/tropical spastic paraparesis) 1.
HTLV-1 is only present in some parts of the world, endemic in Japan, and also found in the Caribbean, some parts of Africa and Melanesia 1. It is transmitted by blood (transfusion, IVDU) and other bodily fluids (breast feeding, sexual intercourse) 1.
The most common neurological manifestation of HTLV-1 associated myelopathy is a slowly progressing chronic spastic paraparesis, although a preceding episode of acute deterioration is reported in a minority of patients 1.
In addition of myelopathy, HTLV-1 can result in adult T-cell leukemia, uveitis and arthropathy 1.
MRI is the modality of choice to evaluate both cranial and spinal cord manifestations.
The most common imaging feature of HTLV-1 associated myelopathy is cord atrophy and increased signal, seen in three quarters of affected individuals 2. During the acute exacerbation, reported in a minority of patients, the cord is swollen and of high T2 signal with peripheral contrast enhancement 1.
Although the cord manifestations are the best known features of over half of affected individuals will also demonstrate high T2 signal in the cerebral white matter 2.