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Dropped head sign as the only symptom of myasthenia gravis

Hiroaki Yaguchi1, Asako Takei, Sanae Honma

  • 1Neurology, Kushiro Rousai Hospital. yaguchi@xa2.so-net.ne.jp

Internal Medicine (Tokyo, Japan)
|June 2, 2007
PubMed

Insights

Neck extensor weakness, or dropped head sign, is uncommon in myasthenia gravis (MG). This case highlights a patient whose primary symptom was dropped head, diagnosed and treated successfully for MG.

Area of Science:

  • Neurology
  • Clinical Medicine

Background:

  • Neck extensor muscle weakness and dropped head sign are recognized symptoms in various neuromuscular disorders.
  • These clinical signs are considered relatively rare presentations of myasthenia gravis (MG).

Observation:

  • A 55-year-old male presented with subacute neck extensor muscle weakness, manifesting as a prominent dropped head sign.
  • The patient exhibited no other neurological symptoms during the entire clinical course.

Findings:

  • Diagnosis of myasthenia gravis (MG) was confirmed through a positive edrophonium test, abnormal voluntary single-fiber electromyography (vSFEMG), and elevated serum anti-acetylcholine receptor antibody levels.
  • The patient showed significant improvement in neurological symptoms following treatment with pyridostigmine.

Implications:

  • This case underscores that dropped head sign can be the sole presenting symptom of myasthenia gravis (MG).
  • It emphasizes the importance of considering MG in the differential diagnosis of isolated neck extensor weakness, even in the absence of other myasthenic signs.

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