Male Adolescent with Left-Sided Muscle Atrophy of the Hand—The Rare Entity of Cervical Flexion Myelopathy (Hirayama disease)
A 19-year-old male presented with painless atrophic paralysis of the left-hand muscles (grade of muscle strength, 3/5) with no sensory impairment and normal muscle stretch reflexes. Magnetic resonance imaging (MRI) of the cervical spine in the supine position showed segmental myelopathy with cervical spinal cord atrophy of cervical vertebrae C5–C6 in the absence of mechanical spinal cord compression (Figure a). Dynamic cervical spine MRI while the patient performed maximum head flexion revealed massive ventral displacement of the dorsal dura with subsequent high-grade spinal canal stenosis and congestion of the epidural veins in the corresponding spinal motion segment C5–C6. Based on this, cervical flexion myelopathy (Hirayama disease) was diagnosed (Figure b), an extremely rare differential diagnosis of both autoimmune inflammatory multifocal motor neuropathy (MMN) and monomelic-onset amyotrophic lateral sclerosis (ALS). This leads (usually in young males) to progressive degeneration of the motor anterior horn cells of the cervical spinal cord and atrophic hand muscle paralysis as a result of head flexion-related spinal canal stenosis and secondary venous congestion. Conservative treatment with a cervical collar in order to avoid continued spinal cord compression from head flexion resulted in long-term clinical stabilization.
Dr. med. Filipp Maximilian Filippopulos, Klinik und Poliklinik für Neurologie, Ludwig-Maximilians-Universität München
Dr. med. Maximilian Patzig, Institut für Diagnostische und Interventionelle Neuroradiologie, Ludwig-Maximilians-Universität München
Dr. med. Florian Schöberl, Klinik und Poliklinik für Neurologie, Ludwig-Maximilians-Universität München, Florian.Schoeberl@med.uni-muenchen.de
Conflict of interest statement: The authors declare that no conflict of interest exists.
Translated from the original German by Christine Rye.
Cite this as: Filippopulos FM, Patzig M, Schöberl F: Male adolescent with left-sided muscle atrophy of the hand—the rare entity of cervical flexion myelopathy (Hirayama disease). Dtsch Arztebl Int 2021; 118: 402. DOI: 10.3238/arztebl.m2021.0102