NMOSD-like and longitudinal extensive HTLV1-associated myelitis are extremes that flank an overlooked continuum

Mickael Bonnan; Stéphane Olindo; Aissatou Signate; Quentin Lobjois; Maeva Stephant; Dalia Dimitri Boulos; Philippe Cabre

doi:10.1177/20552173211037361

NMOSD-like and longitudinal extensive HTLV1-associated myelitis are extremes that flank an overlooked continuum

Mult Scler J Exp Transl Clin. 2021 Jul 31;7(3):20552173211037361. doi: 10.1177/20552173211037361. eCollection 2021 Jul-Sep.

Authors

Mickael Bonnan¹, Stéphane Olindo², Aissatou Signate³, Quentin Lobjois³, Maeva Stephant³, Dalia Dimitri Boulos⁴, Philippe Cabre³

Affiliations

¹ Service de Neurologie, Centre Hospitalier, Pau, France.
² Service de Neurologie et Unité Neuro-Vasculaire, Hôpital Pellegrin, Bordeaux, France.
³ Service de Neurologie, Hôpital Zobda Quitman, Fort-de-France, French West Indies, France.
⁴ Service de Neurologie, hôpitaux universitaires Paris-Sud, Assistance publique des hôpitaux de Paris, Le-Kremlin-Bicêtre, France.

Abstract

Background: HTLV1-associated myelitis (HAM) is a slowly progressive myelopathy in which spinal cord MRI demonstrates no lesion or atrophy.

Objective: We examined the overlap between NMOSD features and HTLV1 infection.

Methods: We included all HTLV1-infected patients recruited in French West Indies (FWI) or referred from different centers, and suffering from at least one NMOSD feature. Literature connecting HTLV1-infection and NMOSD was reviewed.

Results: We included six NMOSD-like HAM with acute onset, seronegative against AQP4 and MOG-Abs. All displayed extensive longitudinal myelitis, and the optic nerve was involved in three. We gathered 39 cases of NMOSD-like HAM patients from the literature. Atypical signs of HAM were relapses (15.4%), sensory level (50%), upper limb symptoms (35.9%), optic neuritis (10.2%). Typical lesions involved lateral funiculi and featured a double rope sign (56.3%).

Conclusion: We propose that acute onset of NMOSD-like HAM could be more frequent than expected and should be evoked in high-risk patients. Extensive but often transient cord lesions could be the hallmark of an excessive inflammation of the funiculi targeted by HTLV1 infection. Although usually minor, a few HAM cases demonstrate specific MRI lesions, and the most severe cases may mimic NMOSD attacks.

Keywords: HTLV-1-associated myelopathy; Neuromyelitis optica spectrum disorder; human t-lymphotropic virus 1 infection; myelitis; optic neuritis.