Superior Oblique Myokymia Research Articles

Conversion of Superior Oblique Myokymia to Superior Oblique Neuromyotonia in a Patient With History of Superior Oblique Palsy.

Conversion of Superior Oblique Myokymia to Superior Oblique Neuromyotonia in a Patient With History of Superior Oblique Palsy.

Treatment of superior oblique myokymia with pregabalin. Review of a clinical case

Superior oblique myokymia is a rare idiopathic disease, characterized by sudden, spontaneous, unilateral, rhythmic contractions of the superior oblique muscle and typically presents with monocular oscillopsia and diplopia. This pathological condition most often affects middle‑aged patients without concomitant systemic diseases. The aim of the article was to study the features of the clinical course, diagnosis and methods of treatment of superior oblique myokymia based on a clinical case. A review of a clinical case of superior oblique myokymia in a patient born in 1983 is presented. The diagnosis was established on the basis of clinical manifestations in the form of sudden episodes of vertical oscillopsia and diplopia in the field of vision of the right eye, which occurred both spontaneously during prolonged work at the computer, driving a vehicle, and in response to light stimulation. A 38‑year‑old patient described the disease as the presence of periodic attacks, during which blurred vision, doubling and movement of objects in the field of vision of the right eye occurred for 2 — 3 seconds, after which the vision returned to normal. The number of attacks was up to 100 per day and significantly worsened the patient’s quality of life. During the neurological examination, an episode of vertical oscillopsia with diplopia was revealed when light was directed at the right eye. No other pathological changes were observed in the nervous system, eyes and other systems and organs, which was confirmed by laboratory and instrumental examination methods, examinations and consultations of different specialists. The patient had a positive therapeutic effect in the treatment of superior oblique myokymia with pregabalin at a dose of 150 mg per day. Recommendations to reduce the time spent working at the computer and to adopt a healthy lifestyle were important.
 Thus, superior oblique myokymia is a rare pathological condition manifested by sudden episodes of monocular vertical oscillopsia and diplopia. Pregabalin can be considered as the medication of choice in the treatment of this disease. Further research is needed to establish unified treatment guideline.

Lateral Supracerebellar Infratentorial Approach for Superior Oblique Myokymia: A Case Series.

Few reports have shown that superior oblique myokymia (SOM) may result from vascular compression of the trochlear nerve and may be curable using microvascular decompression (MVD). To report the clinical characteristics and surgical treatment of 2 cases of SOM and provide a review of the related literature. Two patients with SOM were treated using MVD with the lateral supracerebellar infratentorial approach. The patients underwent diagnostic magnetic resonance imaging and three-dimensional fusion imaging preoperatively. A lateral suboccipital craniotomy was performed in the park-bench position. The trochlear nerve and branches of the superior cerebellar artery were confirmed after opening the cerebellomesencephalic fissure over the tentorial surface of the cerebellum. The vessel, which compressed the root exit zone of the trochlear nerve, was transposed far from the nerve and attached to the surface of the midbrain using Teflon felt and fibrin glue. The first case showed compression on both the ventral and rostral sides of the trochlear nerve root exit zone, and the second showed compression only on the ventral side. Large bridging veins on the tentorial surface of the cerebellum complicated the approach in the second case. Postoperatively, both patients had immediate and complete resolution of symptoms without recurrence at the 24-mo and 17-mo follow-ups, respectively. Five previous reports described the complete resolution of SOM after MVD. A presentation of an intermittent fluttering ocular sensation should prompt magnetic resonance imaging for ipsilateral trochlear nerve compression. The lateral supracerebellar infratentorial approach allows safe and efficacious MVD for SOM.

Disorders of the Fourth Cranial Nerve.

This review of disorders of the fourth cranial nerve includes discussion on anatomy, examination techniques, congenital and acquired etiologies, differential diagnosis, and management options. The findings of the superior oblique muscle on orbital MRI in patients with fourth nerve palsy have had a major impact on our understanding of this cranial neuropathy. In addition, briefly reviewed are rare disorders of the fourth nerve: superior oblique myokymia, Brown syndrome, and ocular neuromyotonia. It behooves the clinician to have a clear understanding of the role that the fourth cranial nerve plays in a variety of neuro-ophthalmic conditions.

William F. Hoyt and the Neuro-Ophthalmology of Superior Oblique Myokymia and Ocular Neuromyotonia

The contributions of William F. Hoyt, MD, to the field of neuro-ophthalmology are immense. His precision in history-taking and examination skills provided the foundation to fully understand a clinical disorder-determining its underlying pathophysiology, prognosis, and management. We describe two unusual eye movement disorders, superior oblique myokymia and ocular neuromyotonia, and how Dr. Hoyt's contributions shaped our understanding of these clinical entities.

Superior Oblique Myokymia Presumed Due to Large Posterior Fossa Arteriovenous Malformation

A 26-year-old female presented with a complaint of intermittent oscillopsia and binocular vertical diplopia for the past 5 years. Over the past several months, she had noticed intermittent pulsatile tinnitus. She was otherwise healthy with no previous history of trauma and had no other visual or neurologic complaints. In Neuro-ophthalmology clinic, she was found to have 20/15 vision in both eyes with full ocular motility. There was a small exophoria in primary position and small esophoria in downgaze. Her slit lamp and fundus examinations were normal. During the assessment, the left eye was noted to undergo high-frequency, small amplitude incyclotorsional oscillations for a few seconds at a time (Video 1 in the supplementary material), which she was able to provoke by looking down. The diagnosis of superior oblique myokymia was made, and an MRI/MRA of the brain was requested.

Superior oblique myokymia, a review.

Superior oblique myokymia is a rare, monocular condition that typically presents in healthy adults. In this article, we review the proposed pathophysiology, describe the typical clinical presentation, and discuss the recommended work up and various treatment options. Treatment for this condition ranges from observation and reassurance to various topical and systemic medications. Both strabismus surgery and neurosurgery are reserved for patients who fail medical therapy or are intolerant to medication secondary to side effects. Due to its episodic nature, SOM is often under-diagnosed. We highlight key features in a patient's clinical history and the examination findings that suggest and support the diagnosis, with review of available treatment options.

Novel surgical approach to superior oblique myokymia

Superior oblique myokymia (SOM) is a rare eye movement disorder that produces debilitating oscillopsia and diplopia. Various medical and surgical techniques have been reported to attempt to alleviate oscillopsia including superior oblique (SO) tenectomy with inferior oblique (IO) myectomy, SO nasal tendon displacement, and intracranial neurovascular decompression. These techniques have inherent risks of iatrogenic vertical strabismus or carry high risk for morbidity. We report a novel surgical approach that alleviates oscillopsia and avoids creating vertical strabismus.

Superior Oblique Myokymia Associated with Neurovascular Cross Compression

Superior oblique myokymia (SOM) is a rare disorder characterized by unilateral paroxysmal oscillopsia or diplopia. Recent studies revealed that SOM can be associated with neuro-vascular cross compression (NVCC) of the trunk of the trochlear nerve. Although it frequently occurs without any underlying systemic disease or concurrent neurologic sign, we need to consider this NVCC especially in cases with persistent disturbing symptoms. Hereby, we present two cases of SOM whose neuroimaging studies suggest NVCCs and, discuss recent update of the pathomechanism of SOM. Key Words: Superior oblique myokymia, Nerve compression syndromes

Superior oblique myokymia treated with levobunolol

Superior oblique myokymia (SOM) is an uncommon condition of unclear etiology that results in episodes of oscillopsia and diplopia. There is no established treatment protocol for SOM. We present 2 cases of SOM successfully managed with topical levobunolol 0.5%; both patients responded to a short course of medication administration and required minimal ongoing therapy. Case 1 was a 69-year-old woman with left SOM who had previously undergone a left Harada-Ito procedure. Her SOM improved immediately on administration of levobunolol and was maintained at follow-up 1year later. Case 2 was a 49-year-old man with right SOM that affected his ability to work. After 2days of topical levobunolol 0.5% nightly in the right eye, SOM episodes ceased; he continues to use drops intermittently for occasional recurrences.

A Sheep in Wolves' Clothing? Nystagmoid Eye Movements

ABSTRACTNystagmoid eye movements are involuntary eye movements that are not pure forms of nystagmus. Nystagmus, by definition, is involuntary eye movements off of fixation that are initiated by a slow phase. By contrast, nystagmoid movements are often saccades that interrupt fixation or have a fast phase followed by a slow phase. Types of nystagmoid eye movements include saccadic intrusions, such as square wave jerks and ocular flutter/opsoclonus, voluntary nystagmus, superior oblique myokymia, as well as the Heimann-Bielschowsky phenomenon. In addition, sensory intermittent exotropia is a clinical entity that should be on the differential when considering patients with involuntary eye movements, many of whom will also have a history of decreased visual acuity. Other ocular comorbidities in these patients include optic nerve and retinal pathology, as well possible neurological findings such as head trauma or demyelinating disease.

Therapy of Vestibular Paroxysmia, Superior Oblique Myokymia, and Ocular Neuromyotonia.

Neurovascular compression syndromes are characterized by recurrent attacks of neurological symptoms and clinical signs depending on the cranial nerve affected. It is assumed that pulsatile compression of the nerve is caused mainly by an artery. The result is segmental demyelination of the transition zone or the central part of the cranial nerve, which is covered by oligodendrocytes, and subsequent ephaptic axonal transmission. Compression of the vestibular nerve can cause attacks of spinning or non-spinning vertigo: vestibular paroxysmia. Compression of the trochlear nerve is characterized by attacks of monocular oscillopsia: superior oblique myokymia. Damage to ocular motor nerves due to local radiation or rarely neurovascular compression can also lead to oscillopsia and double vision precipitated by sustained excentric gaze: ocular neuromyotonia. It is important to note that controlled trials have so far not been performed for any of these three syndromes, mainly because of their low prevalence. Therefore, treatment recommendations are based on single cases or small case series and thus have the lowest level of evidence. The sodium channel blockers carbamazepine (50 to 200mg tid) or oxcarbazepine (100 to 300mg tid) are evidently effective in most of the patients who have these three syndromes. However, one should always keep in mind the contraindications, side effects, and interactions with other drugs of carbamazepine ( http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682237.html ) All patients require regular laboratory examinations. Alternatives are other sodium channel blockers such as phenytoin (100 to 300mg tid), gabapentin (100 to 600mg tid), or valproic acid (100 to 300mg tid). Furthermore, there are also few reports on the effects of beta blockers, which may be explained by their reduction of the amplitude of blood pressure. Patients who do not respond to pharmacotherapy require further diagnostics to determine the possibility of other etiologies. Some of these patients benefit from surgical decompression of the affected nerve.

What is the best treatment for superior oblique myokymia?

Evidence-Based Answer There is no single best treatment for superior oblique myokymia (SOM), but all of the following therapies were reported to be a least somewhat effective: carbamazepine, phenytoin, propranolol, topical timolol, memantine, gabapentin, prism lenses, and microvascular decompression of the trochlear nerve (SOR: C, case series and case reports). Mirtazapine, onabotulinumtoxinA, and baclofen were ineffective long-term; mild symptoms may self-resolve (SOR: C, case studies).

Use of Video-oculography in the Diagnosis of Superior Oblique Myokymia

Use of Video-oculography in the Diagnosis of Superior Oblique Myokymia

Variable relations of the trochlear nerve with the pontomesencephalic segment of the superior cerebellar artery.

The superior cerebellar artery (SCA) is, perhaps, the most anatomically constant cerebellar artery which, in its lateral pontomesencephalic course, is crossed above by the trochlear nerve (CNIV). The SCA may determine, as an offending vessel, CNIV compression and superior oblique myokymia and thus surgical decompression may be indicated. In this regard an accurate knowledge of the variational possibilities of the SCA-CNIV is needed. Such rare neurovascular variants are reported here. The variables are determined by the length of the SCA, and the course of the CNIV as referred to the rostral (RT) and caudal (CT) trunks of the SCA. The CNIV may be pinched between the origins of the RT and CT, may pass above the RT or the SCA main trunk, and even between the primary branches of the RT. The CNIV was found compressed between the RT and the brainstem. Perhaps the most spectacular variation was a CNIV coursing through an arterial ring formed by the RT and CT which were anastomosed distally to the CNIV. The possibilities of neurovascular relations between the CNIV and the SCA should be considered when CNIV palsy, or surgical decompression, are estimated.

Acquired Nonparalytic Causes of Superior Oblique Dysfunction

Background and PurposeTo 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.MethodsA 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.ResultsAcquired 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).ConclusionsSeveral 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.

Topical timolol in the treatment of monocular oscillopsia secondary to superior oblique myokymia: a review

Some reports have outlined many different treatment strategies for superior oblique myokymia (SOM) that attempt to reduce or eliminate patients’ symptoms of monocular oscillopsia and/or diplopia. Most treatment strategies have focused solely on oral medications or invasive surgery. The following is a current and critical review of SOM along with its clinical findings/symptoms, demographics, theories of its pathogenesis, management/treatment options, new observations in SOM, as well as a case report to highlight a relatively novel idea for the treatment of SOM: topical timolol eye drops. It also highlights evidence of a new “localized theory” regarding topical β-blockers’ mechanism of action in SOM compared to the previous systemic hypothesis proposed in 1994.The case report shows a 29-year-old female patient who suffered with SOM symptoms for 8–10 years and then experienced a worsening of her symptoms shortly postpartum. The patient was prescribed topical timolol eye drops by the author in the affected eye based on one case report12 from 1994, which completely eliminated her symptoms within 1–2 days of starting the treatment with any recurrence with the daily use of the drop at the time of this article. Given the robust effect in this case, topical timolol may be a potentially useful drug in the management of SOM given its affordability and safer side effect profile in comparison to the oral medications traditionally used in SOM.

Ocular neuromyotonia: differential diagnosis and treatment

Ocular neuromyotonia (ONM) is a rare but distinctive clinical entity characterized by involuntary episodic contraction of one or more muscles supplied by the ocular motor nerves. A retrospective review was conducted on all patients with ONM seen by the neuroophthalmology service in the past 20 years. Ten patients were identified with ONM; six affecting vertical muscles (superior oblique; inferior rectus; superior rectus) and four affecting lateral rectus muscles. Case 1 has been reported previously. Most episodes occurred every 10–40 min, lasted a few seconds to several minutes, and were repeated throughout the day. Only two patients had previously undergone cranial radiation. Two had thyroid eye disease. One patient presented with superior oblique myokymia and subsequently developed ONM. Membrane stabilizing medications were prescribed in 7 of the 10 patients with varied success. ONM episodes ceased after extraocular muscle surgery in one patient with thyroid eye disease.

Treatment of superior oblique myokymia with oxcarbazepine

A 33-year-old male patient with ipsilateral intermittent oscillopsia and blurry vision for 18 months was found to have intorsional nystagmus of the right eye, especially when gazing at the nasal lower field. The oscillations improved with exercise and were aggravated by rest. An abnormal head posture, with a tilt towards the left, and mild right superior oblique muscle paresis were noted by the prism cover test and motility examination. Neurovascular compression was not confirmed by 0.9-mm thick, high-resolution magnetic resonance imaging with fast imaging employing steady state acquisition sequence. After treatment with oxcarbazepine (600 mg/day), the oscillations resolved and there have been no complications during the 1-year follow-up period. Superior oblique myokymia is a rare form of nystagmus that may cause oscillopsia and blurry vision. Oxcarbazepine, a structural derivative of carbamazepine, can be used to successfully eliminate oscillopsia without serious adverse reaction.

How to deal with diplopia

Diplopia is a frequent neuro-ophthalmologic symptom with diverse etiologies. This article describes elementary diagnostic tests and frequent causes of diplopia. Monocular diplopia persists when the other eye is closed and usually disappears when the patient looks through a pinhole. It is usually caused by errors in the optical media of the eye and has to be differentiated from spectacle-induced side effect and non-organic disorders. A sign of non-organic etiology is absence of change in image position when the head is tilted. Binocular diplopia disappears regardless of which eye is closed. Binocular diplopia occurs when the images of both eyes cannot be fused. The most frequent direct cause of diplopia is acquired strabismus. Knowledge of several specific types of strabismus enables efficient patient management. Congenital and decompensating strabismus like accommodative esotropia, pathophoria, strabismus surso- and deorsoadductorius, retraction syndrome, Brown's syndrome and esotropia in high myopia only need ophthalmologic treatment. Orbital injury, orbital tumor, ocular myositis, Graves orbitopathy and vascular disease usually require multidisciplinary management. Neurogenic paresis, superior oblique myokymia, ocular neuromyotonia, myasthenia, chronic progressive external ophthalmoplegia (CPEO), internuclear ophthalmoplegia (INO) and skew deviation require specific neurologic examination. Treatment of diplopia includes treatment of the fundamental disorder, monocular occlusion, prisms and strabismus surgery.