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.

Ocular neuromyotonia caused by a recurrent sphenoidal ridge meningioma.

BACKGROUND: Ocular neuromyotonia (ONM) is a rare ocular motility disorder characterized by involuntary paroxysmal extraocular muscle contraction and is caused by radiation therapy, vascular compression, and inflammatory disease. This study includes a rare case of ONM caused by a recurrent meningioma. CASE DESCRIPTION: A 56-year-old man presented with diplopia due to the right oculomotor nerve palsy caused by a sphenoidal atypical meningioma, with improved symptoms after initial surgery. During the next 7 years, he underwent local radiation therapy, second surgery, and Gamma Knife radiosurgery to control the tumor's repetitive recurrence around the right anterior clinoid process. After these treatments, residual tumor was controlled for the next 3 years. However, 3 months after his last visit, he started to suffer from the right ONM and visual disturbance. The magnetic resonance imaging results revealed a rapid growth of the posterior part of the residual tumor, involving the right oculomotor nerve. The third tumor resection was performed to prevent further aggravation of the symptoms. Decompression of the right oculomotor nerve was achieved, and ONM disappeared immediately after surgery. CONCLUSION: If nerve compression by the tumor is clearly indicated with the neuroradiological assessment, surgical intervention is the treatment of choice to improve ONM.

Congenital Ocular Neuromyotonia with Partial Third Nerve Palsy.

PURPOSE: We report the first case of congenital ocular neuromyotonia (ONM) and the results of strabismus surgery for this patient's co-existing cranial nerve (CN) III palsy. PATIENTS AND METHOD: The patient presented at 18 months with strabismus that had reportedly been present since the time of birth. On exam, she had persistent exotropia (RXT) and hypertropia (RHT) with episodes of esotropia in the right eye that could be evoked by sustained left gaze. A diagnosis of ONM with partial CN III palsy was made. T1-weighted, T2-weighted, and fluid-attenuated inversion recovery magnetic resonance imaging failed to reveal intracranial pathology. RESULTS: Gaze induced intermittent esotropia resolved with carbamazepine. Surgery was performed to improve the patient's RXT and RHT. Post-operatively, the patient's RXT had improved from 12 to 15 prism diopters (∆) at near and 20∆ at a distance to 10∆ RXT at near with no horizontal deviation at distance. Her deviation has remained stable for 13 years, as has her neurological exam and good state of health. CONCLUSION: This case demonstrates that ONM may present congenitally and adds to the body of knowledge regarding surgical outcomes on concurrent CN palsies in these patients.

Shared Features of the Heimann-Bielshowsky Phenomenon and Ocular Neuromyotonia.

We describe a case of unusual ocular movement with features of both the Heimann-Bielshowsky Phenomenon and Ocular Neuromyotonia that might suggest that they share some common pathophysiology or be on a spectrum of abnormal firing of ocular motor cranial nerves. We are the first to propose such a relationship.

Bilateral oculomotor ocular neuromyotonia: a case report.

BACKGROUND: Ocular neuromyotonia (ONM) is characterized by episodic diplopia, which is usually triggered by prolonged eccentric gaze of the affected extraocular muscles. The spell is characterized by involuntary, occasionally painful, sustained contraction of one or more extraocular muscles innervated by the oculomotor, trochlear, or abducens nerve. ONM usually occurs as a late consequence of radiotherapy around the parasellar area, although idiopathic cases have been reported. Most cases are unilateral; however, bilateral ONM has occasionally been described. CASE PRESENTATION: A 60-year-old woman presented with a 4-month history of episodic, painful, horizontal binocular diplopia. She underwent external beam radiotherapy to the skull base for treatment of nasopharyngeal carcinoma. The tumor was well controlled. General neurological examination findings were unremarkable. Neuro-ophthalmic examination revealed normal visual acuity, visual fields, pupils, and fundi. Ocular alignment showed orthotropia with normal ocular motility. Myasthenic eyelid signs were absent. However, she developed episodes of involuntary sustained contraction of the medial rectus muscle following prolonged eccentric gaze toward the affected medial rectus muscle, which resulted in esotropia upon returning to the primary position. The esotropic episodes spontaneously resolved after approximately 2 min. These spells affected both medial rectus muscles. Both pupils remained normal throughout the examination. Magnetic resonance imaging revealed neither brain parenchyma/brain stem lesions nor tumor recurrence. Her symptoms were successfully treated with carbamazepine. CONCLUSIONS: Episodic esotropia in the adducting eye following prolonged horizontal eccentric gaze is a significant characteristic of ONM affecting the bilateral medial rectus muscles (i.e., bilateral oculomotor ONM). In spite of its extreme rarity, ONM should be considered as a differential diagnosis of episodic diplopia, especially in patients with a history of radiotherapy around the parasellar area. Careful examination with prolonged eccentric gaze should be performed to achieve a correct diagnosis and avoid an extensive unnecessary workup.

A Puzzling Ocular Motility Disorder: Apparent Up-Gaze Fatigability in a Patient With Oculomotor Nerve Compression.

We report the case of a woman who developed right third nerve dysfunction with synkinesis and ocular neuromyotonia secondary to a compressive arterial aneurysm. Surprisingly, our examination showed a downward drift of the right eye in sustained up-gaze resulting in transient hypotropia, suggesting either fatigability of the superior rectus or contraction of the inferior rectus. We believe this ocular motility pattern is secondary to a co-contraction of the inferior rectus in up-gaze caused by synkinesis (explaining the downward drift), followed by failure of the inferior rectus to relax upon return to primary position caused by ocular neuromyotonia (explaining the hypotropia).

Ocular Neuromyotonia: Case Reports and Literature Review.

Ocular neuromyotonia (ONM) is a rare eye movement disorder, presenting as a paroxysmal involuntary spasm of one or more extra-ocular muscles, that can persist for a few seconds up to several minutes. The phenomenon is caused by the contraction of an extra-ocular muscle, excited by a damaged nerve, which leads to delayed muscle relaxation. We present eight patients with this rare condition together with an overview of the literature on all published ONM cases. One of the presented cases is possibly secondary to hypovitaminosis D. This association has not been reported previously in the literature. A possible underlying mechanism is given.

Ocular neuromyotonia.

Ocular neuromyotonia is a rare, albeit treatable, ocular motor disorder, characterised by recurrent brief episodes of diplopia due to tonic extraocular muscle contraction. Ephaptic transmission in a chronically damaged ocular motor nerve is the possible underlying mechanism. It usually improves with carbamazepine. A 53-year-old woman presented with a 4-month history of recurrent episodes of binocular vertical diplopia (up to 40/day), either spontaneously or after sustained downward gaze. Between episodes she had a mild left fourth nerve palsy. Sustained downward gaze consistently triggered downward left eye tonic deviation, lasting around 1 min. MR scan of the brain was normal. She improved on starting carbamazepine but developed a rash that necessitated stopping the drug. Switching to lacosamide controlled her symptoms.

Metastatic Papillary Thyroid Carcinoma Presenting as Abducens Palsy Complicated by Ocular Neuromyotonia.

Papillary thyroid carcinoma (PTC) is a type of well-differentiated thyroid cancer that accounts for the majority of thyroid malignancies. The prognosis of PTC is very good and distant metastases are rare, especially to the skull base. The authors report the case of a 47-year-old woman with biopsy-proven PTC treated with surgery and radiation therapy who presented with headache and diplopia after 5 years and was found to have clivus and cavernous sinus metastasis. Following radiation therapy for her skull base and cavernous sinus lesion, she subsequently developed sixth nerve ocular neuromyotonia. Possible causes and treatments are reviewed.

Abducens ocular neuromyotonia as a delayed complication of oropharyngeal carcinoma treated with radiation.

BACKGROUND: Ocular neuromyotonia (ONM) is a disorder characterized by periodic involuntary extraocular muscle contraction that occurs almost exclusively in the setting of prior radiation to the sella or skull base. We present the first case of abducens neuromyotonia associated with oropharyngeal carcinoma. METHODS AND RESULTS: We report a case of a 63-year-old patient with abducens ONM occurring 16 years after radiation treatment for oropharyngeal squamous cell carcinoma. A literature review was performed using Medline and PubMed databases to search for all documented cases of abducens neuromyotonia. Our review found 20 cases of abducens neuromyotonia but none after radiotherapy (RT) to the oropharynx. CONCLUSION: Abducens ONM can occur because of disease at anatomic locations remote from the course of the sixth cranial nerve, most likely because of the irradiated area exceeding the intended field. Our case also supports the fact that RT can significantly precede symptom onset. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2428-E2431, 2016.

Ocular Neuromyotonia Noted after Recent Botulinum Toxin Injection for Sixth Nerve Palsy Following Resection of a Posterior Fossa Skull Base Meningioma.

A 56-year-old female complained of diplopia immediately after surgical excision of a recurrent left skull base tuberculum meningioma. She was found to have a left sixth nerve palsy, which was subsequently treated with botulinum toxin injection to the medial rectus muscle. Three months post injection, the patient had partial recovery of the sixth nerve palsy and new-onset ocular neuromyotonia.

Ocular Neuromyotonia Associated with Chronic Inflammatory Demyelinating Polyneuropathy.

Ocular neuromyotonia (ONM) is a neuro-ophthalmic disorder characterized by episodic diplopia caused by contraction of one or more ocular muscles due to spontaneous excitation of the respective ocular motor nerve. We report a patient whose ocular neuromyotonia arose in the setting of a subacute demyelinating polyneuropathy consistent with chronic inflammatory demyelinating polyneuropathy (CIDP) and subsequently resolved following the initiation of intravenous immunoglobulin (IVIg) for her neuropathy. Our patient provides additional evidence towards the role of demyelination and ephaptic neurotransmission in ocular neuromyotonia and also represents the first reported case of ocular neuromyotonia associated with a systemic neurological condition.

Acquired nonparalytic causes of superior oblique dysfunction.

BACKGROUND AND PURPOSE: To conduct a retrospective study to investigate the causes of acquired superior oblique dysfunction, excluding paralysis, in a consecutive series of adult patients and to compare presenting symptoms and clinical findings. METHODS: A retrospective review of all adult patients with superior oblique dysfunction between the ages of 18 and 80 who met the study profile was conducted at Saint Louis University Medical Center between January 2000 and April 2012. The presenting symptoms, clinical findings, and treatment course for each patient was recorded. The study was approved by the Institutional Review Board of our institution. RESULTS: Acquired forms of nonparalytic superior oblique dysfunction were identified in forty-eight patients. These included superior oblique myokymia (twenty-three patients), superior oblique click syndrome or variable Brown syndrome (nine), canine tooth syndrome (five), spontaneous acquired Brown syndrome (four), iatrogenic or traumatic Brown syndrome (four), and ocular neuromyotonia affecting the superior oblique (three). CONCLUSIONS: Several nonparalytic entities were identified that caused superior oblique dysfunction. Clinical findings may be similar despite entirely different mechanisms. Subjective symptoms may be difficult for the patient to describe or for the examiner to elicit on the day of the examination. Specific techniques can be used in eliciting, differentiating, and documenting the conditions. These included trochlear palpation, modified head tilt technique, interpretation of torsion, and Hess charts.

A novel association of ocular neuromyotonia with brainstem demyelination: two case reports.

Ocular neuromyotonia (ONM) is a rare disorder of ocular mal-alignment in which painless, transient spontaneous or gaze-induced abnormal deviation of the eye manifests as episodic diplopia. With only a few cases reported in the literature, ONM mostly follows months to years after cranial irradiation for sellar or suprasellar lesions. Here we present two patients with this rare ocular condition, secondary to brainstem demyelination, the association of which is hitherto unreported in the literature. Both patients were 15-year-old girls who presented to us with episodic forced-eye deviation with diplopia. Examination during these attacks revealed ONM involving the superior rectus and medial rectus in the first and second patient, respectively. There was clinical evidence of intrinsic brainstem involvement with downbeat nystagmus and skew deviation in one patient without any other cerebellar or long tract signs. MRI showed evidence of demyelination involving the brainstem in both, with CSF showing positive immunological markers and with positive aquaporin-4 antibody in one patient. Both patients responded remarkably to immunomodulatory therapy and are asymptomatic at follow-up. That ONM can occur with brainstem demyelination has not been reported in the literature. This association may help in explaining the pathophysiology of ONM as secondary to segmental demyelination.

A Case of Idiopathic Ocular Neuromyotonia

Ocular neuromyotonia (ONM) is an episodic involuntary contraction of one or more extraocular muscles, resulting from spontaneous neural discharges of ocular motor nerves. Previous radiation therapy to pituitary or other juxtasellar tumor and vascular compressions are the most common reported causes of ONM. We report one unique case of ONM involving the abducens nerve without any other organic brain lesion and prior radiation therapy.

The Spectrum of Ocular Neutomyotonia / 国际眼科杂志(Guoji Yanke Zazhi)

Objective To probe into the causes, clinical features, diagnosis and treatment of ocular neuromyotonia (ONM). Methods To deeply analyze and discuss the causes, clinical features, diagnosis an treatment of this disease by reporting 4 cases of ONM and refor a pituitary tumor. The spasms occurred in the primary position of gaze and were induced by eccentric gaze. A 72 year-old man had chronic arachnoiditis after myelography with radioactive thorium dioxide many years ago. Spasms of muscles innervated by a third nerve and a sixth nerve were produced by eccentric gaze. Treatment with carbamazepine stopped the ONM in both patients. A 47 year-old man had ONM of a lateral rectus muscle when he looked in eccentric gaze several years after irradiation for a cerebellar medulloblastoma. The spasms occurred when treatment for seizures with carbamazepine was decreased, and resolved with the dosage was increased.A 21 year-old man had recurrence of a congenital hemangioma of the neck, face and brain that caused ONM of a superior oblique muscle many years after it had been partially excised. Downward gaze cau sed the spasms, and they resolved spontaneously. Conclusion ONM begins months to years following treatment for intracranial lesions. Typically, the treatment is radiation for an intracranial tumor, but other eauses of damage to the cranial nerves can produce the syndrome. Spasm of extraocular muscles innervated by the third, fourth or sixth cranial nerves produce strabismus and diplopia, lasting from a few seconds to a few minutes. The spasms are spontaneous or induced by ecceutric gaze that stimulates the affected cranial nerve. Neuroradiologic tests might show abnormalities in or near the cavernous sinus, but usually do not show recurrence of the original tumor. The syndrome rarely resolves spontaneously, but responds well to treatment with carbamazepine.