Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intramuscular injections of botulinum toxin type A (Oculinum) is used to treat strabismus and focal dystonias affecting orofacial muscles. However, the toxin-induced morphological changes that underlie the therapeutic alterations of tone in the muscles of mastication have not been described. In this study, paired intramuscular injections of botulinum toxin (10 units) were made in three adult monkeys (Macaca fascicularis) allowed to survive 14, 28 and 63 days. Another monkey received multiple injection-pairs over 84 days. Animals were killed by deep pentobarbital anaesthesia before transcardiac perfusion-fixation. Tissue sampled from comparable regions of the injected masseter, the uninjected masseter and an uninjected animal was processed for ultrastructural analysis. Few changes were found 14 days post-injection. However, muscle fibres showed myofibrillar dissolution, aberrations in the Z-line, and enlarged mitochondria in the region of the I-band by 28 days. In the 63-day and 84-day animals, the injected muscle was considerably smaller than the uninjected, contralateral muscle. Regions of the injected muscle contained fibres with markedly reduced cross-sectional area. Internalization of myonuclei, loss of myofibrillar organization, and helical complexes were common. Toxin-induced changes, though similar to those that follow denervation by axotomy, were not accompanied by degeneration of neuromuscular junctions. Instead, morphological evidence for axonal sprouting in the region of the neuromuscular junction, possibly contributing to functional recovery, was seen as early as 14 days in toxin-treated muscles.
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PMID:Ultrastructural changes in the masseter muscle of Macaca fascicularis resulting from intramuscular injections of botulinum toxin type A. 176 79

For a long time the problem of the functional recovery in convergent strabismus has been a hardly debated topic. For some authors, it is very rare; for others, on the other hand, the result is frequently achieved. Such disparities seem to be chiefly related to the tests used. The authors have selected 10 binocular tests and they carried out this scale in a prospective study in 100 cases of esotropias having normal moving performances following a medico-surgical management and in 20 normal cases. statistical correlations reveal that there is a very large disparity of "good answers" according to the tests; but there is no redundancy at all between them. Consequently for a relevant check up every single one is necessary. The total of "good scores" and differential values of ten tests allow to know the true state of binocular spatial adaptation. The statistical analysis shows that in secondary microtropias and orthotropias there is almost always an actual binocular spatial adaptation. Its level may be high, medium or low. The high margin is clearly different from the binocular scores in normal cases. Two events are very uncommon: a full recovery of binocular vision and the opposite condition of its complete suppression. The results of such a method give a clear explanation of conflicting opinions about the binocular evolution of convergent squints following medical and surgical management.
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PMID:[Spatial binocular adaptation in microtropia and orthotropia. Definition and method of measurement]. 377 30

Functional treatment of strabismus is no longer empirical, but has currently a scientific basis. To disperse the "doubts" surrounding functional treatment, it appeared necessary to situate it more clearly within its true framework, that of functional re-education in general. Indeed, although the terrain differs adults with a lesion and children whose binocular function is poorly or only partially developed - in both cases: - functional recovery is the result of changes within the central nervous system, changes which are possible due to the plasticity of the central nervous system. These modifications occur very slowly, sometimes over a period of years. - The crucial condition for success of treatment remains the same: the patient must participate actively, this being all the more essential in that recovery will take a long time. Although strabismus treatment must obviously consider physiological parameters (triad), psychological parameters are just as important, and as well as purely technical problems, other factors must also be taken into account: subject's motivation, length of treatment, communication with the doctor and medical team, attitude of the patient's family. This type of therapy is only justified as long as strabismus is considered to be a dysfunction of binocularity (this however, does not exclude surgery in some cases, and the operation is an integral part of the treatment). Functional treatment of strabismus is therefore difficult and disconcerting for the practising ophthalmologist. Disconcerting in that it differs radically from other types of eye therapy (medical or surgical); difficult in that the restraint it imposes is often in contradiction with the permissive society we live in. One of the main obstacles to be overcome is perhaps our own judgement as ophthalmologists; our opinion of the nature of strabismus, the possibility of a cure, to which must be added the application of the right technique, patient participation, etc. This study attempts to situate strabismus within the general framework of functional re-education, employing different authors' opinions of basic notions of neurophysiology relating to nervous plasticity and their application in cases of cortical lesions in adults. In Part II we shall outline why and how we have opted for functional re-education. The reasons why and the manner in which functional re-education was chosen are then outlined.
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PMID:[Functional treatment of strabismus: theoretical bases--practical rules]. 635 Apr 13

The paper enumerates the objectives of functional recovery in strabismus and the approaches to the achievement of these objectives. The goal in the treatment of the strabismus is obtaining a binocular sight with the remake of the divergence-convergence synergism. A three stage scheme for the treatment is made: 1st stage--the treatment of the amblyopia; 2nd stage--the correction of the strabismus deviation; 3rd stage--the recovery of the binocular sight. The conclusion is that the healing of the strabismus with "restitutio ad integrum" is a distant desire.
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PMID:[Functional recovery in strabismus]. 940 79

Several reports on monocular optokinetic nystagmus (OKN) in observers with strabismus have found that asymmetry of OKN tends to occur in both eyes of observers with an early onset of strabismus but only in the deviating eye of those with a later onset of strabismus. Our objective was to quantify and compare the magnitude of the OKN asymmetry in each eye as a function of observer's age at onset of strabismus. We studied monocular OKN in ten observers with early-onset (up to 24 months of age), seven observers with late-onset (after 24 months of age) unilateral strabismus, and 12 normally sighted control observers. In the deviating eye, observers with early-onset strabismus showed large OKN asymmetries in favour of nasalward motion while observers with late-onset strabismus showed smaller OKN asymmetries in that eye. The majority of early- and late-onset observers showed near normal OKN in the non-deviating eye although the early-onset observers showed bilateral asymmetries more often. These findings may be due to both age at onset of strabismus and chronological age and are discussed in terms of the issue of plasticity or recovery of function.
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PMID:Monocular horizontal OKN in observers with early- and late-onset strabismus. 1051 82

Several cases of acute necrotizing encephalopathy (ANE) with influenza A (H1N1) have been reported to date. The prognosis of ANE associated with H1N1 is variable; some cases resulted in severe neurologic complication, whereas other cases were fatal. Reports mostly focused on the diagnosis of ANE with H1N1 infection, rather than functional recovery. We report a case of ANE with H1N1 infection in a 4-year-old Korean girl who rapidly developed fever, seizure, and altered mentality, as well as had neurologic sequelae of ataxia, intentional tremor, strabismus, and dysarthria. Brain magnetic resonance imaging showed lesions in the bilateral thalami, pons, and left basal ganglia. To our knowledge, this is the first report of ANE caused by H1N1 infection and its long-term functional recovery in Korea.
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PMID:Novel Influenza A (H1N1)-Associated Acute Necrotizing Encephalopathy: A Case Report. 2370 27

Jensen procedures were performed on 29 eyes of 26 patients with lateral rectus palsy between January 1972 and July 1985. The cases were reviewed retrospectively to assess efficacy of the procedure and long-term stability. The patients were evaluated preoperatively with prism cover test, versions, forced auctions, saccadic velocities, and diplopia fields. All patients were observed preoperatively for at least 6 months and had no further recovery of function. Eighteen eyes had less than 20% of normal abduction saccadic velocity; nine eyes had 20% to 40%; two could not be assessed with saccadic velocities. The procedure was a Jensen's union combined with a medial rectus recession on adjustable suture. The average follow-up was 4 years. Twenty-four patients had good head positions and fusion with a functional area of single binocular vision, averaging 41 horizontally. All patients demonstrated improved saccadic velocities, with similar improvement for those beginning with less than 20% abduction saccadic velocity and those with 20%-40%. A single case of anterior segment ischemia is reported.
J Pediatr Ophthalmol Strabismus
PMID:Long-term follow-up of Jensen procedures. 2488 Jan 84

Botulinum toxin type A is a potent muscle relaxant that blocks the transmission and release of acetylcholine at the neuromuscular junction. Intramuscular injection of botulinum toxin type A has served as an effective and safe therapy for strabismus and focal dystonia. However, muscular weakness is temporary and after 3-4 months, muscle strength usually recovers because functional recovery is mediated by nerve sprouting and reconstruction of the neuromuscular junction. Acrylamide may produce neurotoxic substances that cause retrograde necrotizing neuropathy and inhibit nerve sprouting caused by botulinum toxin type A. This study investigated whether acrylamide inhibits nerve sprouting after intramuscular injection of botulinum toxin type A. A tibial nerve sprouting model was established through local injection of botulinum toxin type A into the right gastrocnemius muscle of Sprague-Dawley rats. Following intramuscular injection, rats were given intraperitoneal injection of 3% acrylamide every 3 days for 21 days. Nerve sprouting appeared 2 weeks after intramuscular injection of botulinum toxin type A and single-fiber electromyography revealed abnormal conduction at the neuromuscular junction 1 week after intramuscular injection of botulinum toxin type A. Following intraperitoneal injection of acrylamide, the peak muscle fiber density decreased. Electromyography jitter value were restored to normal levels 6 weeks after injection. This indicates that the maximal decrease in fiber density and the time at which functional conduction of neuromuscular junction was restored were delayed. Additionally, the increase in tibial nerve fibers was reduced. Acrylamide inhibits nerve sprouting caused by botulinum toxin type A and may be used to prolong the clinical dosage of botulinum toxin type A.
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PMID:Acrylamide inhibits nerve sprouting induced by botulinum toxin type A. 2531 70

Carcinoid tumors are rare, slow-growing, low-grade neuroendocrine tumors with a propensity for orbital metastatic spread. The typical treatment paradigm for localized orbital disease involves excision, adjuvant radiotherapy, and/or receptor-targeted chemotherapy, followed by delayed evaluation for reconstructive strabismus surgery. We present a 58-year-old female patient with carcinoid tumor metastatic to the right inferior rectus muscle who presented with worsening binocular diplopia. The patient underwent coordinated "tag-team" orbital and strabismus surgeries that included excision of the right inferior rectus muscle to the annulus of Zinn followed immediately by reconstructive strabismus surgery. The patient required 1 additional strabismus surgery 1 year later. Follow up revealed no tumor recurrence at 4 years, and excellent binocular vision with good function. Deep orbital and strabismus surgeries, when performed simultaneously in a "tag-team" approach, may offer superior functional outcomes and improved patient quality of life, with expedited functional recovery. This approach may become a new treatment paradigm for surgical disease processes localized to the extraocular muscles.
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PMID:"Tag-Team" Orbital and Strabismus Surgeries with Immediate Reconstruction After Tumor Excision Metastatic to the Inferior Rectus. 2565 Jul 97

Infantile strabismus impairs the perception of all attributes of the visual scene. High spatial frequency components are no longer visible, leading to amblyopia. Binocularity is altered, leading to the loss of stereopsis. Spatial perception is impaired as well as detection of vertical orientation, the fastest movements, directions of movement, the highest contrasts and colors. Infantile strabismus also affects other vision-dependent processes such as control of postural stability. But presently, rehabilitative therapies for infantile strabismus by ophthalmologists, orthoptists and optometrists are restricted to preventing or curing amblyopia of the deviated eye, aligning the eyes and, whenever possible, preserving or restoring binocular vision during the critical period of development, i.e., before ~10 years of age. All the other impairments are thus ignored; whether they may recover after strabismus treatment even remains unknown. We argue here that medical and paramedical professionals may extend their present treatments of the perceptual losses associated with infantile strabismus. This hypothesis is based on findings from fundamental research on visual system organization of higher mammals in particular at the cortical level. In strabismic subjects (as in normal-seeing ones), information about all of the visual attributes converge, interact and are thus inter-dependent at multiple levels of encoding ranging from the single neuron to neuronal assemblies in visual cortex. Thus if the perception of one attribute is restored this may help to rehabilitate the perception of other attributes. Concomitantly, vision-dependent processes may also improve. This could occur spontaneously, but still should be assessed and validated. If not, medical and paramedical staff, in collaboration with neuroscientists, will have to break new ground in the field of therapies to help reorganize brain circuitry and promote more comprehensive functional recovery. Findings from fundamental research studies in both young and adult patients already support our hypothesis and are reviewed here. For example, presenting different contrasts to each eye of a strabismic patient during training sessions facilitates recovery of acuity in the amblyopic eye as well as of 3D perception. Recent data also demonstrate that visual recoveries in strabismic subjects improve postural stability. These findings form the basis for a roadmap for future research and clinical development to extend presently applied rehabilitative therapies for infantile strabismus.
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PMID:Beyond Rehabilitation of Acuity, Ocular Alignment, and Binocularity in Infantile Strabismus. 3007 76


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