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Query: UMLS:C0030552 (paresis)
 5,831 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients with long-standing unilateral strabismus, such as "sensory" exotropia in the absence of fusion, or esotropia with unilateral amblyopia, typically show bilateral deviations under anesthesia, often symmetric. Forced ductions usually show symmetric muscle tightness. Changes in extraocular muscle lengths thus appear to occur primarily bilaterally, whether fusion is present or not. With skeletal muscles responding to changes in stimulation by the gain or loss of sarcomeres, it is likely that abnormal or unguided vergence tonus, which changes the lengths of the extraocular muscles bilaterally, is largely responsible for changes in the angle of strabismus over time. This mechanism helps explain the development of [1] increasing "basic" deviations in accommodative esotropia; [2] torsional deviations with apparent oblique muscle "overaction/underaction" and A and V patterns; [3] recurrent esotropia with early presbyopia; [4] occasional divergence insufficiency in presbyopes; and [5] basic cyclovertical deviations that mimic superior oblique muscle paresis.
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PMID:The 10th Bielschowsky Lecture. Changes in strabismus over time: the roles of vergence tonus and muscle length adaptation. 1679 23

Botulinum toxin treatment was originally developed 25 years ago by Alan B. Scott to produce reversible weakening of extraocular eye muscles in humans (chemodenervation). The following uses are still helpful today in comparison with eye muscle surgery, prism applications etc.: Preoperative evaluation of possible postoperative diplopia in patients in whom this cannot be done by means of prisms or traction test, etc. Acute paretic loss of ocular muscle function when surgical treatment of the ocular muscles is not yet possible but the patient is obviously disturbed by diplopia or a forced head posture. This applies especially to VI cranial nerve paresis. Depending on the surgical approach in VI nerve palsies, Botulinum toxin may be injected in the medial rectus muscle before muscle transposition surgery to loosen contracture. Strabismus in acute Graves' disease. In strabismus in other conditions, Botulinum toxin is mostly inferior surgical treatment of the ocular muscles; this is the case, for example in congenital esotropia or horizontal strabismus in adults. While the reversibility of the Botulinum toxin A effect by fading out after 3-4 months is seen as an advantage, it does also mean that in these cases of constant strabismus it is necessary to keep repeating the injections.
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PMID:[Botulinum toxin injections for the treatment of strabismus. Which indications are still useful today?]. 1762 34

The congenital retinocephalic facial vascular malformation syndrome is characterized by unilateral, nonhereditary retinal and cerebral arteriovenous malformations (AVMs) and is occasionally associated with orbital vascular changes. Typical signs are facial and oral mucosal vascular changes, rarely with changes of the maxilla or mandible. An AVM causes high blood flow because of direct connection (shunting) of major vessels without interposition of capillaries. Ocular complications include retinal and vitreous hemorrhages, edema, venous occlusion (risk of rubeosis iridis and secondary glaucoma). Neuroophthalmological changes comprise optic atrophy, papilledema, proptosis, pupillary changes, hemianopia, gaze paresis, nystagmus, cranial nerve palsies, strabismus, and amblyopia. Neurological complications include headache, subarachnoid hemorrhage, convulsions, cerebral hemorrhages, increased intracranial pressure, hydrocephalus, and stroke with hemiparesis. Threatening oral hemorrhages or epistaxis may rarely occur.
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PMID:[Congenital retinocephalic facial vascular malformation syndrome. Bonnet-Dechaume-Blanc syndrome or Wyburn-Mason syndrome]. 1915 63

Worth's four dot test was first described one hundred years ago. Despite many technological advances in equipment and techniques during the last century, this simple test is still used routinely by many strabismus specialists. It is an invaluable test when used in the evaluation of longstanding and acquired strabismus in adults and in the management of complex diplopia. Techniques using the test include selecting an optimal prism, assessing the effect of a prescribed prism or compensatory head posture on the range of binocular single vision, identifying non-organic responses, diffe1rentiating monocular from binocular diplopia, especially when they co-exist, and blurred from double vision in older patients with divergence paresis. It also can be used with prisms preoperatively to determine the risks of postoperative diplopia and give clues to the presence of torsion or a visual field defect.
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PMID:The "worth" of the worth four dot test. 2114 94

A small esodeviation detected in an adult may represent an acquired event caused by a number of different mechanisms. These deviations may be comitant or incomitant, occur with or without diplopia and appear in association with other ocular or neurological findings or in isolation. The mechanisms include lateral rectus dysfunction, supranuclear gaze disturbances, anomalies in the vergence system, the influence of the near synkinesis and certain restrictive components. The presence of a small, acquired esodeviation may have neurological significance that may influence diagnosis and management decisions.1,2 Conditions such as divergence paralysis and convergence spasm are described in the classic literature with large esodeviations and obvious clinical features.3-7 They are not a common occurrence in most strabismus practices but are recognized readily when they occur. More subtle presentations of these entities are seen far more frequently and may be so small, or co-exist with other ocular findings, as to be overlooked. It is likely that with many clinical disorders like divergence paresis and convergence spasm that they present as a spectrum of dysfunction; it is the small end of that spectrum that will be discussed.
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PMID:Neurological significance of small esodeviations. 2114 81

We describe a report of a child with a horner's syndrome and sixth nerve paresis secondary to a petrous internal carotid artery (ICA) aneurysm. Management of this condition involved coiling of the aneurysm and the use of botulinum toxin to manage his strabismus and associated symptoms.
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PMID:Horner's syndrome and sixth nerve paresis secondary to a petrous internal carotid artery aneurysm. 2127

Force-length recordings were made from isolated human eye muscles during strabismus surgery in local, eye-drop anesthesia in 32 adult patients. From each muscle three recordings were made: (I) while the patient looked with the other eye into the field of action of the recorded muscle, (2) looked ahead, and (3) looked out of the field of action of the recorded muscle. Non-innervated eye muscles (state 3) had an approximately exponential relation between force and length. During contraction evoked by letting the patient look ahead or into the field of action of the muscle (states 1 or 2), the relation between force and length was grossly linear. The approximate spring constants of horizontal rectus muscles that had not been operated on before ranged from 2 to 4 g/mm. In palsies, the degree of muscle paresis could be quantified accurately using this method and, accordingly, cases of true superior oblique palsy could be well differentiated from strabismus sursoadductorius (= upshoot in adduction) that may mimic a superior oblique palsy. In seven patients with Graves' disease of recent onset, affected muscles were found to be very stiff when the other eye looked ahead. It was expected that these stiff muscles would be able to shorten to some extent but would not be able to lengthen, due to fibrosis of the muscle. We found, however, that the affected muscles lengthened considerably when the other eye looked out of the field of action of the muscle. This implies that, in these cases of Graves' disease of recent onset, the raised muscle tension and reduced elasticity of the affected muscles and, hence, the strabismus were primarily caused by active muscle contraction, not by fibrosis.
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PMID:Force-length recording of eye muscles during local-anesthesia surgery in 32 strabismus patients. 2131 97

Ocular abnormal head posture (AHP) or torticollis is a frequent sign in pediatric pathology The incidence is 5.6% in ophthalmological practice and 3.19% in pediatric ophthalmological practice. The abnormal head posture is adopted to improve visual acuity maintain binocular single vision, center residual visual field with the body or for cosmetic reasons. Face turn is the most frequent abnormal head posture in pediatric ophthalmology. The more common diseases causing face turn are Duane syndrome, congenital fibrosis of extraocular muscles, nystagmus, refractive errors, visual field defects. The most frequent ocular causes of head tilt in children are congenital nystagmus, superior oblique paresis, dissociated vertical deviation, Brown syndrome, refractive errors. Chin-up or chin-down abnormal head postures are most commonly caused by "A" and "V"-pattern strabismus, palpebral ptosis, nystagmus, refractive errors. Torticollis is not a diagnosis, but it is a sign of an underlying disease. There are ocular diseases which diagnosis is straightforward for general practitioner, pediatricians or pediatric surgeons (horizontal nystagmus, lateral rectus paralysis, ptosis, esotropia), but others less obvious (superior oblique paralysis, Duane syndrome, A and V-pattern strabismus, torsional nystagmus) because of the compensatory head posture, and these last disorders are predisposed to confusion with congenital AHP Interdisciplinary collaboration between ophthalmologist, pediatrician, pediatric surgeon, ENT specialist and neurologist is mandatory in establishing the etiology of AHP Every child with AHP must be examined by an ophthalmologist.
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PMID:Understanding ocular torticollis in children. 2177 81

Anterior plagiocephaly is a craniofacial anomaly related to premature uni-lateral synostosis. We present a case of anterior plagiocephaly with vertical strabismus, overaction of the contralateral superior oblique muscle and an A pattern. A detailed ophthalmic examination and radio-imaging were done. The patient underwent strabismus surgery and resolution of the strabismus was obtained. Plagiocephaly has been reported to simulate ipsilateral superior oblique muscle paresis. We report a rare occurrence of contralateral superior oblique muscle overaction in an adult with anterior plagiocephaly.
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PMID:A doubly paradoxical vertical eye deviation with an a pattern strabismus in plagiocephaly: management and a case report with outcome. 2199 59

Vertical strabismus can be associated with paretic or restrictive causes. Paretic causes may be due to a weak muscle or paresis, or to a total lack of muscle function caused by a third, fourth or sixth cranial nerve palsy. When examining a patient with vertical strabismus, it is paramount that we differentiate between a restricted cause and paretic cause. This paper discusses the nonsurgical techniques used in evaluating paretic vertical strabismus. There are no easy methods, and evaluation techniques can vary depending on the cooperation of the patient. It is essential to look at versions and ductions, pattern strabismus, measure in all positions of gaze and evaluate torsion. We know that measuring strabismus, especially in children can be challenging. Afew different tests and techniques are discussed. A review of the literature regarding the different evaluation techniques for vertical strabismus were collated and analyzed.
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PMID:Evaluation techniques for paretic vertical strabismus. 2206 43


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