Imaging spectrum and diagnostic insights in Hirayama disease: A case series.

Hirayama disease is a rare, self-limiting juvenile motor neuron disease predominantly affecting young males, characterized by progressive muscular atrophy and weakness in the distal upper extremities due to dynamic compression of the cervical spinal cord during neck flexion. This case series of 10 patients emphasizes the critical role of dynamic flexion MRI in diagnosis and management. All patients underwent clinical evaluation and detailed MRI imaging including dynamic flexion studies. Anterior displacement of the dural sac was observed in all 10 patients on flexion MRI, with engorgement of the posterior epidural venous plexus in 9 cases. Conservative treatment with cervical collar and physiotherapy was successful in 8 patients, while 2 with progressive disease underwent surgical fusion. Dynamic flexion MRI proved essential for establishing diagnosis and guiding treatment decisions, particularly in cases with normal or equivocal neutral imaging.