RESUMEN
Hirayama disease (HD) is a rare, benign, self-limiting condition that typically affects individuals in their 20s. Although the disease is self-limiting, it can result in functional impairment in those affected. The most common presentation is an asymmetrical, unilateral, or bilateral upper limb weakness with wasting. With an interesting pathogenesis and lack of definitive treatment, HD is an interesting neurological conundrum. Mild symptoms in patients often lead to underreporting of the disease, as individuals may not seek medical attention or may not recognize their symptoms. Most case reports in the literature are from Asia and the Middle East. We report a case of HD in a male patient in his 20s with gradual bilateral upper limb weakness and wasting, confirmed by imaging and nerve conduction studies.
RESUMEN
Juvenile monomelic amyotrophy (JMA), also known as Hirayama's disease, is a rare cervical myelopathy that predominantly affects young Asian males. It is characterized by degeneration of anterior horn cells due to compression by the redundant dural sac. This study presents an atypical case of a 23-year-old Indian male who exhibited uncommon symptoms of JMA. The patient displayed progressive weakness and atrophy in the left forearm, including the usually spared brachioradialis muscle. Electrophysiological tests and MRI scans solidified the diagnosis of Hirayama's disease. After wearing a cervical collar for one year, the patient's condition stabilized, reinforcing the diagnosis. Unlike most JMA cases, this instance highlights the involvement of the brachioradialis muscle, underlining the variability in JMA presentations. A precise diagnosis is contingent upon clinical criteria, dynamic MRI, and electrophysiological findings. Recognizing these variations is crucial for early detection and appropriate management of the disease.
RESUMEN
Hirayama disease (HD) is juvenile monomelic amyotrophy of the distal upper limb first described by Hirayama in 1959 AD. HD is a benign condition with chronic microcirculatory changes. The hallmark of HD is necrosis of the anterior horns of the distal cervical spine. Materials and Methods: Eighteen patients were assessed for clinical and radiological Hirayama disease. Clinical criteria included insidious onset nonprogressive chronic upper limb weakness and atrophy in teens or early twenties without sensory deficits and coarse tremors. MRI was done in a neutral position followed by neck flexion to evaluate cord atrophy and flattening, abnormal cervical curvature, loss of attachment between the posterior dural sac and subjacent lamina, anterior shifting of the posterior wall of the cervical dural canal, posterior epidural flow voids, and an enhancing epidural component with its dorsal extension. Results: The mean age was 20.33 years, and the majority, 17 (94.4%), were male. Neutral-position MRI revealed loss of cervical lordosis in 5 (27.8%) patients, cord flattening in all patients with asymmetry in 10 (55.5%), and cord atrophy was observed in 13 (72.2%) patients with localized cervical cord atrophy in only 2 (11.1%) and extension of atrophy to dorsal cord in 11 (61.1%) patients. Intramedullary cord signal change was seen in 7 (38.9%) patients. Loss of attachment of posterior dura and subjacent lamina and anterior displacement of dorsal dura was seen in all patients. A crescent-shaped epidural intense enhancement was noted along the posterior aspect of the distal cervical canal in all patients, with dorsal level extension in 16 (88.89%) patients. The mean thickness of this epidural space was 4.38±2.26 (mean±2SD), and the mean extension was 5.5±4.6 vertebral levels (mean±2SD). Conclusion: The high degree of clinical suspicion can guide additional contrast studies in flexion as a set MRI protocol for early detection and avoiding false negative diagnoses of HD.