Juvenile Cervical Flexion Myelopathy (Hirayama Disease): A Case Report

Hirayama disease, a rare form of cervical flexion myelopathy characterized by selective lower motor neuron involvement, typically presents in adolescence, which may increase the risk of misdiagnosing the condition as a progressive neurodegenerative disorder in adult patients. To identify key differential diagnostic features of an atypical disease course, a retrospective analysis of 6 years of clinical, neurophysiological, and neuroimaging data was performed in a patient with disease onset at the age of 38 years. In the early stages, nonspecific MRI finding and electroneuromyography results were incorrectly interpreted as indicative of motor neuron disease. findings: anterior displacement of the dural sac and the “snake-eye” sign on MRI and focal denervation in the C5–C7 myotomes with preservation of the lower cervical segments. Timely recognition of this condition is crucial, as it can prevent misdiagnosis of a fatal neurodegenerative disorder and avoid unnecessary treatment.