Ophthalmoparesis, Ophthalmoplegia

Ophthalmoparesis, Ophthalmoplegia

Ophthalmoparesis is a weakness or limitation, ophthalmoplegia a paralysis, of eye movements. Causes may be central (CNS pathways), or peripheral (cranial nerve nuclei, cranial nerves, neuromuscular junction, extraocular muscles).
A distinction is sometimes drawn between:

1. External ophthalmoplegia:

weakness of the extraocular muscles of central, neuromuscular, or myopathic origin (e.g., chronic progressive external ophthalmoplegia [CPEO], a mitochondrial disorder); and

1. Internal ophthalmoplegia:

fixity of the pupil with loss of all pupillary reflexes (iridoplegia) and ciliary apparatus.

Hence in an oculomotor (III) nerve palsy there may be both internal and external ophthalmoplegia.
If structural disease and myasthenia gravis are excluded, then mitochondrial disorder (CPEO) may be responsible for ophthalmoplegia, even if this is not evident on quadriceps muscle biopsy.

 

References
Schaefer AM, Blakely EL, Barron MJ, Griffiths PG, Taylor RW, Turnbull DM. Ophthalmoplegia: when all the tests are negative. Journalof Neurology, Neurosurgery and Psychiatry 2004; 75: 519 (abstract 020)

 

Cross References

Diplopia; Internuclear ophthalmoplegia (INO); Miosis; Mydriasis; Oculomotor (III) nerve palsy; Pupillary reflexes; Pupil sparing