Hirayama disease in a patient with Loeys-Dietz syndrome: the first reported association

Abstract

Introduction: Hirayama disease (HD) is a rare, self-limiting cervical flexion myelopathy causing progressive, painless distal upper-limb weakness, typically in young Asian males. Loeys-Dietz syndrome (LDS) is a heritable connective tissue disorder due to TGF-β pathway variants, associated with dural ectasia. Their co-occurrence has not previously been reported. Case description: We describe a 23-year-old woman with genetically confirmed LDS type 2 who developed progressive, painless distal upper-limb weakness, initially unilateral and later bilateral. Examination and electrophysiology showed a C7–T1 polyradicular pattern. Dynamic flexion cervical magnetic resonance imaging (MRI) demonstrated anterior displacement of the posterior dural sac at C5–C7, fully reversible on extension, confirming HD. Conclusion: This presentation was atypical for HD (female sex, third-decade onset, bilateral course), yet electrophysiological and dynamic-MRI findings were unequivocal. HD should be considered in patients with heritable connective tissue disease presenting with progressive distal upper-limb weakness, irrespective of sex or age, and dynamic flexion MRI is essential for diagnosis.