1620 - A Diagnostic Challenge: Hirayama Disease Mimicking Amyotrophic Lateral Sclerosis in a Young Adult Male

Friday, February 20, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

MD

Minh A. Doan, DO

Resident
Emory School of Medicine
smyrna, Georgia, United States

Co-Author(s)

MB

Monica S. Branch, MD

Assistant Professor
Emory University School of Medicine
Atlanta, Georgia, United States
PD

Peter Darling, MA

Medical student
Morehouse school of medicine
Decatur, Georgia, United States
JT

Justin Tu, MD

Assistant Professor
Emory Healthcare
Decatur, Georgia, United States

Submitter(s)

MD

MInh A. Doan, DO

Emory School of Medicine
smyrna, Georgia, United States

Case Diagnosis: Hirayama disease (HD) is a rare and benign condition that presents with cervical myelopathy. Electromyogram and nerve conduction studies closely mimic alpha motor neuron disease, particularly early amyotrophic lateral sclerosis (ALS). Misdiagnosis can lead to unnecessary anxiety, interventions, and prognostic implications and providers should be aware of this rare disease.

Case Description: We present a case of a 20-year-old male from Bangladesh with progressive, asymmetric distal left upper extremity weakness progressing over five years. Symptoms were limited to the hand and forearm, without lower extremity or bulbar involvement. Electrodiagnostic testing revealed chronic denervation and reinnervation changes in the C8-T1 distribution, with relative sparing of sensory nerves and lower limbs and possible tongue fasciculations on EMG. Cervical spine MRI obtained showed atrophy from C4-C6. These findings, in combination with the patient’s demographic profile and the absence of widespread progression, were consistent with Hirayama disease rather than ALS.

Discussions: This case emphasizes the importance of correlating EMG/NCS findings with clinical features and advanced imaging. Key distinguishing factors between HD and ALS include the confined regional presentation, plateauing course, absence of bulbar/lower limb involvement, and flexion-induced cervical cord changes. Genioglossus EMG, although valuable, has limitations due to technical application and high amount of artifact. Early recognition of HD, especially in young Asian males, can prevent diagnostic delay and inappropriate prognostication.

Conclusions: Hirayama disease is a benign yet potentially disabling motor neuronopathy often mistaken for ALS due to overlapping electrophysiologic features. A comprehensive approach that integrates clinical history, EMG/NCS interpretation, and cervical MRI is critical for accurate diagnosis. EMG of the genioglossus muscle is technically challenging with a high rate of false positives. Clinicians should maintain a high index of suspicion in young males presenting with unilateral distal upper extremity weakness and lower motor neuron signs.