BACKGROUND: Juvenile muscular atrophy of the distal upper extremity (Hirayama disease) is a sporadic disorder, but very rarely occurs in a familial pattern. OBJECTIVE: To describe the clinical features of Hirayama disease in 2 brothers, especially the look-alike anatomic physiques and magnetic resonance imaging (MRI) findings. DESIGN: Case report. PATIENTS: Two physically look-alike young brothers with Hirayama disease. RESULTS: Clinical symptoms of the present brothers were consistent with those of sporadic cases. Their lanky physique, clinical features, and MRI findings looked alike to each other. CONCLUSIONS: The pathogenesis of familial Hirayama disease is not well understood. The present brothers looked alike in terms of their physical frame and clinical symptoms. These findings suggest that similar mechanical damage against the cervical spinal cord by look-alike anatomic frame of the neck could be an important factor of familial Hirayama disease in the present brothers.
BACKGROUND:Juvenile muscular atrophy of the distal upper extremity (Hirayama disease) is a sporadic disorder, but very rarely occurs in a familial pattern. OBJECTIVE: To describe the clinical features of Hirayama disease in 2 brothers, especially the look-alike anatomic physiques and magnetic resonance imaging (MRI) findings. DESIGN: Case report. PATIENTS: Two physically look-alike young brothers with Hirayama disease. RESULTS: Clinical symptoms of the present brothers were consistent with those of sporadic cases. Their lanky physique, clinical features, and MRI findings looked alike to each other. CONCLUSIONS: The pathogenesis of familial Hirayama disease is not well understood. The present brothers looked alike in terms of their physical frame and clinical symptoms. These findings suggest that similar mechanical damage against the cervical spinal cord by look-alike anatomic frame of the neck could be an important factor of familial Hirayama disease in the present brothers.