Expanding the clinical spectrum of Hirayama disease: a rare case of Hirayama disease with ulnar nerve palsy

Abstract

Hirayama disease, also known as monomelic amyotrophy, is a rare, self-limiting condition that primarily affects young males. It leads to muscle atrophy and weakness, especially in the hands and forearms, which is often due to cervical spinal cord compression during neck flexion. Here, we report a case of a 41-year-old female from rural India who presented with progressive weakness in her left hand, resulting from ulnar nerve compression. The patient was unable to actively extend the metacarpophalangeal joint of her left hand, thus substantially impairing her hand function. Notably, she did not exhibit autonomic symptoms, which are commonly present in cervical myelopathy. This case highlights the importance of considering Hirayama disease in females, despite its male predominance, as well as the need for early diagnosis and targeted rehabilitation. Timely intervention is essential for managing functional impairments and improving patient outcomes.