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Ocular neuromyotonia with spastic lid closure
Akihiko Oohira1, Tatsuyuki Furuya
1Department of Ophthalmology, Tokyo Women's Medical University, Tokyo, Japan. ohira@wakaba-hp.or.jp
Summary
Ocular neuromyotonia, a condition causing eye muscle spasms, can occur after radiation treatment for nerve tumors. This case highlights a new symptom: spastic eyelid closure, with synkinesis being a lasting effect.
Area of Science:
- Neuro-ophthalmology
- Neurology
Background:
- Ocular neuromyotonia involves tonic spasms of extraocular muscles, triggered by eccentric gaze, leading to temporary strabismus and diplopia.
- A 70-year-old woman with a history of fifth cranial nerve schwannoma treated with radiation presented with new neurological deficits.
Observation:
- The patient developed ocular neuromyotonia and synkinesis affecting the third cranial nerve ipsilaterally.
- A novel observation included spastic eyelid closure during neuromyotonia attacks.
- The ocular neuromyotonia resolved spontaneously over three years.
Findings:
- Ephaptic transmission in the damaged third cranial nerve is hypothesized as the cause of neuromyotonia and synkinesis.
- Synkinesis presented as a more persistent manifestation than neuromyotonia.
Implications:
- This case expands the understanding of ocular neuromyotonia presentation and its potential sequelae.
- It suggests that ephaptic transmission is a plausible mechanism for these post-radiation neurological phenomena.
- The findings underscore the importance of recognizing synkinesis as a potentially enduring complication.
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