Neuromiotonía ocular: un infrecuente caso tras carcinoma nasofaríngeo tratado con radioterapia local / Ocular neuromyotonia: An unusual case after radiotheraphy for nasopharyngeal carcinoma

La neuromiotonía ocular es una patología poco frecuente caracterizada por episodios recurrentes de diplopía binocular ocasionada por una contracción paroxística mantenida de uno o más músculos extraoculares inervados por un mismo nervio craneal, espontáneamente o inducidos por una versión concreta mantenida en el tiempo, normalmente relacionado con un antecedente de radioterapia local intracraneal. Presentamos el caso de una mujer de 46 años que presenta episodios de diplopía binocular recurrentes, diagnosticada de neuromiotonía ocular del VI nervio craneal izquierdo a los 8 años de padecer un cáncer de cavum tratado mediante radioterapia local y en completa remisión. Aunque es poco frecuente, la radiación a nivel de cavum debe tenerse en cuenta como potencial causa de neuromiotonía ocular, por su proximidad a la base del cráneo y su estrecha relación con el trayecto de los nervios oculomotores, especialmente el VI par craneal, como el caso que se presenta en este artículo.(AU)

Ocular neuromyotonia is an infrequent disorder characterised by recurrent episodes of binocular diplopia caused by paroxysmal contraction of one or several extraocular muscles innervated by the same cranial nerve. It can be triggered spontaneously or caused by prolonged contraction of specific eye muscle(s) and is usually related to a local intracranial radiotherapy antecedent. We report the case of a 46-year-old woman who developed intermittent episodes of binocular diplopia 8 years after radiotherapy for a nasopharyngeal carcinoma. After a complete neuro-ophthalmic assessment we diagnosed the case as an abducens nerve neuromyotonia. Although it is infrequent, radiotherapy to the nasopharynx is a possible cause of ocular neuromyotonia, due to the proximity to the base of the skull and extraocular motor nerve pathways, especially that of the VI cranial nerve, as is the case presented in this article, about a patient whose history is a nasopharyngeal carcinoma treated with local radiotherapy.(AU)

Ocular neuromyotonia: an unusual case after radiotheraphy for nasopharyngeal carcinoma.

Ocular neuromyotonia (ONM) is an infrequent disorder characterised by recurrent episodes of binocular diplopia caused by paroxysmal contraction of one or several extraocular muscles innervated by the same cranial nerve. It can be triggered spontaneously or caused by prolonged contraction of specific eye muscle(s) and is usually related to a local intracranial radiotherapy antecedent. We report the case of a 46-year-old woman who developed intermittent episodes of binocular diplopia eight years after radiotherapy for a nasopharyngeal carcinoma. After a complete neuro-ophthalmic assessment we diagnosed the case as an abducens nerve neuromyotonia. Although it is infrequent, radiotherapy to the nasopharynx is a possible cause of ONM, due to the proximity to the base of the skull and extraocular motor nerve pathways, especially that of the VI cranial nerve, as is the case presented in this article, about a patient whose history is a nasopharyngeal carcinoma treated with local radiotherapy.