Resumo

DILUCA, P et al. Magnetic resonance of the cervical spine with sequence in flexion for the diagnosis of Hirayama disease. Rev. argent. radiol. [online]. 2017, vol.81, n.2, pp.105-109. ISSN 1852-9992.  http://dx.doi.org/10.1016/j.rard.2016.06.004.

Hirayama disease is a type of myelopathy related to neck flexion. It affects young male adults between 15 and 25 years, and is characterised by unilateral and asymmetric upper limb muscle weakness with atrophy. It usually presents insidiously, with a progressive course and self-limits in 3-4 years. It is believed that it could be produced by ischaemic disorders in the microcirculation of the anterior horns of the cervical spine segment C8 and T1 due to anterior displacement of the dura. There are several theories for the cause of this displacement, with the most accepted being the relationship between the lack of growth of the dura mater and the spine during puberty. This increases the tension of the posterior dura mater and consequently the anterior displacement during flexion. Due to its excellent tissue contrast and the possibility of acquisitions in different planes, magnetic resonance imaging is the study of choice. Images must be obtained in both neutral and cervical flexion to highlight the displacement of the dura mater. This increases the sensitivity and specificity of the test, giving greater confidence in the diagnosis, and reducing false positives compared to neutral as a single acquisition.

Palavras-chave : Atrophy; Spine; Hirayama disease; Magnetic resonance imaging.