[Hirayama disease in paediatrics: a clinical case report and review of the literature].

Introduction: Hirayama disease is a rare children's muscular atrophy that affects young Asian males, with muscular atrophy usually in one of the upper limbs that progresses slowly and later stabilises. It is diagnosed by means of electromyographic/electroneurographic with conduction speed studies (EMG/ENG-CS) and by magnetic resonance imaging (MRI) of the spinal cord in a neutral position and with cervical flexion. Treatment is based on the cervical collar and surgery (severe cases). Very few studies have been conducted on patients at the paediatric age.

Case Report: We report the case of a 7-year-old girl with atrophy of the muscles of the left hand and forearm, and a disease history of two years. The EMG/ENG-CS scans presented signs of very severe chronic denervation in the myotomes of C7, C8 and T1 on the left side, with conservation of the amplitudes of sensory evoked potentials, consistent with cervical myelopathy. Results of an MRI scan of the cervical spinal cord in a neutral position were normal at that level. Later, owing to suspicions pointing towards Hirayama disease, a new MRI scan of the cervical spinal cord was performed in a neutral position and in flexion. This second scan showed asymmetry in the size and morphology of the anterior funiculi of the spinal cord at C6/C7, hypersignal in the homolateral anterior horn and ingurgitation of the posterior epidural venous plexus. With a diagnosis of Hirayama disease, treatment is started with a cervical collar in order to prevent the damage from getting worse.

Conclusions: This case of Hirayama disease is peculiar due to its epidemiological characteristics and is presented here with the aim of making this entity more widely known in our milieu. If diagnosed at an early stage, treatment is effective, and the studies conducted on children at the paediatric age are reviewed.