Serkan KIRBAS, Ender ALKAN
Turkish Journal of Neurology - 2026;32(1):106-111
Hirayama disease (HD), historically recognized as monomelic amyotrophy or juvenile asymmetric segmental spinal muscular atrophy, is a rare neurological condition first described by Hirayama et al. in 1959. The disorder predominantly affects young males, with a peak onset typically occurring between adolescence and the early third decade of life. Pathophysiologically, HD is considered a focal cervical myelopathy precipitated by the anterior displacement of the posterior cervical dural sac during neck flexion. This displacement results in transient spinal cord compression and chronic venous congestion within the lower cervical segments. The clinical hallmark of HD is the insidious and progressive onset of symmetric or asymmetric muscular weakness and atrophy, primarily involving the distal upper extremities.
