Hirayama Disease with Proximal Involvement.

Area of Science:

• Neurology
• Neuroscience
• Clinical Medicine

Background:

• Hirayama disease is typically a benign motor neuron disease affecting distal upper limbs.
• It is characterized by slow progression and often stabilizes over time.

Observation:

• A 29-year-old male presented with a year of left proximal upper limb weakness.
• He had a prior diagnosis of Hirayama disease 9 years earlier with no prior progression.
• Clinical examination revealed proximal upper limb muscle atrophy and weakness.

Findings:

• Diagnostic imaging, including MRI and somatosensory evoked potentials, yielded normal results.
• Needle electromyography demonstrated abnormalities in the proximal upper limb muscles.
• The patient's presentation indicated a secondary progression of Hirayama disease affecting proximal muscles.

Implications:

• This case illustrates a rare proximal progression pattern of Hirayama disease.
• Accurate clinical manifestation assessment and electromyography are crucial for diagnosing atypical presentations.
• Understanding such rare progression patterns offers valuable clinical insights for managing Hirayama disease.