Head-tilt test in unilateral and symmetric bilateral acquired trochlear nerve palsy

BACKGROUND: The head-tilt phenomenon (difference between the vertical deviations with an ipsilateral and contralateral head-tilt by 45 deg. each) occurring in patients with a superior oblique palsy has traditionally been explained by the lacking contraction of the superior oblique muscle within the synkinetic movement of ocular counterrolling. However, using a computer model, Robinson showed that the superior oblique palsy itself causes only a relatively small head-tilt phenomenon. Adaptive mechanisms amplifying the otolith reflex were suggested to explain the increase of the head-tilt phenomenon in the course of time. In order to reduce the abnormal head posture required for binocular vision, the otolith reflex would be amplified, accepting the greater vertical deviation when the head is tilted to the paretic side . QUESTION: If the head-tilt phenomenon were solely caused by the lacking contraction of the superior oblique muscle, it should be greater in bilateral than in unilateral superior oblique palsies. If an adaptive mechanism were acting to reduce the abnormal head posture, the head-tilt phenomenon should not be greater, and could even be smaller in bilateral than in unilateral superior oblique palsy, because in bilateral (symmetric) trochlear nerve palsies the vertical deviation at straight gaze is already small or absent without adaptation. PATIENTS AND METHODS: We have carried out a retrospective comparison of 10 patients with bilateral symmetric superior oblique palsies and 10 patients with unilateral superior oblique palsy. In all cases, the palsy was acquired and had been present for at least 1 year. RESULTS: The patients with bilateral superior oblique palsy had a head-tilt phenomenon ranging from 0 to 7 degrees (median, 2 deg.). The patients with unilateral superior oblique palsy had a head-tilt phenomenon between 2 and 13 degrees (median, 8 deg.). The difference was significant (p = 0.0117). CONCLUSIONS: The head-tilt phenomenon is smaller in long-standing bilateral symmetric superior oblique palsies than in long-standing unilateral superior oblique palsy. This finding supports the hypothesis that in unilateral superior oblique palsy, an adaptive mechanism augments the head-tilt phenomenon by an amplification of the otolith reflex. However, we presume that the amplification of the otolith reflex is only a side effect of the adaptive change of the vertical fusional vergence tonus and thus the price of the improved vertical fusion, rather than a compensatory mechanism.     

Understanding ocular torticollis in children

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.     

伴有面转代偿头位的先天性下直肌麻痹临床特征与手术治疗

目的：描述伴有面转代偿头位的先天性单纯下直肌麻痹患者的临床表现,并分析其手术治疗效果。

方法：回顾性分析2014-05/2018-07伴有明显面转代偿头位的先天性下直肌麻痹患者,手术前后患者面转程度的变化借助骨科量角器来检查,垂直、水平斜视度变化通过三棱镜交替遮盖试验来测量,旋转斜视度变化通过眼底对眼球客观旋转状态评估。下直肌缩短术是主要治疗方案。

结果：在15例研究对象中,有13例行下直肌缩短术或者联合上直肌后徙术术后疗效好,下直肌运动不足明显改善,眼球运动协调,以面转为主的代偿头位消失,垂直、水平、旋转斜视得到矫正; 并得出：每缩短1 mm下直肌可矫正1.54±0.93°内旋斜视。而行下斜肌断腱术治疗的垂直斜视度小的患者,面转改善不理想,仍遗留眼球运动不协调。

结论：先天性单纯的下直肌麻痹以面转代偿头位为主,下直肌缩短术治疗效果好,轻度的过矫及欠矫不影响手术疗效。     

Skew deviation and inferior oblique palsy.

PURPOSE: To describe ocular motility and neuro-ophthalmologic findings in six patients with an ocular tilt reaction (OTR) that mimicked an inferior oblique palsy (IOP). DESIGN: Observational Case Series. METHODS: Series of six patients presenting to tertiary care pediatric or neuro-ophthalmologist. RESULTS: Five patients had ocular motility and three-step test results suggesting an IOP; one patient had a suspected bilateral IOP. All six patients had excyclotorsion of the hypotropic eye, and four had incyclotorsion of the hypertropic eye. This is contrary to that expected with an IOP (incyclotorsion of the hypotropic eye). In addition, all six patients had other neurologic findings in the history or examination that were associated with neurologic insult rather than an isolated IOP. Two patients had surgery consisting of a superior rectus recession; this was successful in eliminating diplopia in both patients and in eliminating the vertical deviation and head posturing in one patient. CONCLUSION: While many vertical deviations that appear to be due to an inferior oblique palsy based on the results of the three-step test may be caused by inferior oblique weakness, skew deviation should also be considered in any patient with a history of head trauma, or other neurologic findings. The cyclotorsion observed in IOP is opposite that seen with OTR, and differentiates the two entities clinically. We postulate that these deviations are caused by damage to the otolithic projections that correspond to those from the ipsilateral posterior semicircular canal (on the side of the hypotropic eye).     

婴幼儿眼性斜颈的临床特征与早期手术效果

目的:探讨婴幼儿眼性斜颈的临床特征,评估眼性斜颈早期手术效果。方法:对70例患儿进行回顾性分析。通过获取歪头试验、九方位眼球运动检查及眼底照相的结果,分析眼球肌肉异常的类型,对眼性斜颈做出定性诊断。采用计算机辅助斜视诊断技术,精确测量出水平斜视度数。对眼性斜颈患者中,上斜肌麻痹、下斜肌功能亢进者,行下斜肌部分切除术。其它原因引起的眼性斜颈,根据眼球肌肉异常类型的不同,设计不同的手术方法。对合并水平斜视者以计算机辅助下斜视测量软件测量出的水平斜视角度为根据,定量设计手术。随访时间6～12mo。结果:本组病例中,均找到眼部病因,以单纯性单眼上斜肌麻痹最常见,54例(77%)。全部患儿均接受手术治疗。一次手术后,单纯性单眼上斜肌麻痹患儿,6mo内治愈或改善者53例(占所有单纯性单眼上斜肌麻痹患儿的98%)。所有患儿6mo内治愈或改善者64例(91%),手术失败者6例。其中3例接受第二次手术,术后3例均治愈或改善。合并水平斜视者11例(16%),一次手术后水平斜视全部矫正。结论:婴幼儿眼性斜颈是一组包含不同类型病因的斜视。明确病因后尽早手术可获得满意头位矫正效果。     

Treatment of Knapp Class V superior oblique palsy with contralateral inferior rectus muscle recession

Objective: To describe the clinical features of patients with Knapp Class V superior oblique palsy (hypertropia greatest across the lower fields of gaze) and to present the results of a contralateral, adjustable, inferior rectus muscle recession procedure performed on these patients.Design: Clinical, cohort study.Participants: We retrospectively reviewed a series of 4 cases of superior oblique palsy (Knapp Class V). The patients, seen between the years 1991 and 2000, were selected from the private practice of 1 of the authors (Michael Flanders).Methods: Clinical and surgical data were extracted from the patients' records. All patients had had complete ophthalmologic and orthoptic assessments. Those included in this series had difficulty reading and compensated by lowering their chins. They had a hypertropia, which increased in downgaze, decreased in upgaze, and increased on ipsilateral head tilt. Both the ipsilateral superior oblique and inferior rectus muscles were underactive. All 4 patients underwent contralateral, adjustable, inferior rectus muscle recession.Results: The mean vertical deviation of the paretic eye preoperatively was 8.25 prism D (PD) in primary position and 20 PD in downgaze. Postoperatively it was 2 PD in primary position and 5 PD in downgaze. All patients had improved head posture and a more comfortable reading position after surgery. Mean follow-up was 6.4 years (range 1-9 years).Conclusions: Contralateral inferior rectus muscle recession is an effective treatment for visual symptoms associated with Knapp Class V superior oblique palsy.     

Anterior and nasal transposition of the inferior oblique muscles.

BACKGROUND: When performing anterior transposition of the inferior oblique (IO) muscle, placement of the posterior suture close to the lateral border of insertion of the inferior rectus (IR) muscle decreases the incidence of antielevation syndrome (AES). We hypothesized that placement of the suture nasal to the IR muscle insertion will convert the IO muscle into an intorter and depressor. Here we present the first series of results obtained with a new procedure for the treatment of elevation in adduction with extorsion and abnormal head postures. METHODS: Twenty patients with IO muscle overaction, superior oblique (SO) muscle palsy, absent SO muscles, AES, or Duane syndrome were studied. Before surgery, each patient showed at least one, but often more, of the following signs: elevation in adduction, exotropia (XT) in up gaze, abnormal head posture, and extorsion. Each underwent anterior and nasal transposition (ANT) of the IO muscle, with the new insertion typically 2 mm nasal and 2 mm posterior to the nasal border of the IR muscle insertion. RESULTS: Large improvements in ocular alignment, extorsion, and head posture were found in most patients. However, a poor result was noted in a patient with Y-pattern XT, who developed a mild amount of comitant XT after an extreme degree of ANT (4 mm nasal and 3 mm anterior to the nasal border of the IR muscle insertion). In Duane syndrome, ANT corrects upshoot, but downshoot may get worse. Mersilene permanent sutures, rather than dissolving suture materials, are recommended to avoid postoperative retraction of muscle fibers. CONCLUSIONS: ANT converts the IO muscle into an intorter and tonic depressor and can significantly improve elevation in adduction. This procedure seems particularly useful in patients with severe or recurrent congenital and acquired SO palsies, particularly as a secondary procedure. Extreme ANT may induce exotropia in the primary position.     

上斜肌麻痹代偿头位观察

目的:临床上上斜肌麻痹最常见,本文分析上斜肌麻痹代偿头位的原因、机理和规律。方法:所有病例行常规眼科检查、眼肌检查,Bielschowsky头位倾斜试验以及同视机双眼视觉功能检查。结果:本文报告上斜肌麻痹代偿头位的发生率为40.7％,并且与发病的年龄及病程长短相关。有代偿头位者基本具有双眼视觉功能。无代偿头位者丧失双眼视觉功能。结论:上斜肌麻痹是否出现代偿头位取决于:(1)双眼视觉功能。(2)发病年龄。(3)病程长短。本文结果表明发病年龄较大(>3岁)且病程短、有Ⅰ度以上双眼视功能者容易出现代偿头位。发病年龄小(<3岁),无代偿头位者,均已丧失双眼视觉功能。因此应重视早期诊断,及时进行恢复双眼视觉功能的训练和治疗。眼科学报 1995;11:227—229。     

Is congenital superior oblique strabismus a paretic disorder?--A magnetic resonance tomographic study

BACKGROUND: Recent reports postulate that the concomitant vertical deviation found in congenital superior oblique palsy is due to mechanical abnormalities rather than a congenitally paretic muscle, and is overcome in most patients by fusion. On the basis of the clinical characteristics alone a primary paresis is indeed unlikely. Although intraoperatively a different elasticity of the superior oblique tendon exists in congenital versus acquired cases of superior oblique palsy, preoperatively performed MR imaging shows that the clinical findings in congenital superior oblique muscle malfunction could nevertheless be of paretic origin. MATERIALS AND METHODS: Seventeen consecutive patients (males: n = 13; females: n = 4) were examined. The vertical deviation in adduction was concomitant in vertical versions, the excyclotropia was small and concomitant in all directions of gaze and was less than 10 degrees even after diagnostic occlusion. All patients showed a positive Bielschowsky head tilt phenomenon and large fusional ability. We performed preoperative MR imaging of both orbits in high resolution 3 mm sections in coronal and axial orientations with and without contrast enhancement. RESULTS: In sixteen patients we found a significant reduction in muscle volume or even total aplasia of the superior oblique muscle of the affected side in comparison to the sound muscle on the other side. In contrast, two patients had a full blown clinical picture of a congenital superior oblique palsy but showed symmetrical muscle volumes on both sides in all coronal sections. CONCLUSIONS: Hypoplasia or aplasia of the superior oblique muscle on magnetic resonance imaging provides evidence for a primary paretic cause for the vertical squint found with congenital superior oblique dysfunction. It is not clear, however, whether this is caused by a primary hypoplasia or is of neurogenic origin. Our data together with the consistent difference in tendon morphology of the congenital and acquired forms of superior oblique palsy seem to exclude a purely neurogenic cause for the affection.     

Anterior and nasal transposition of the inferior oblique muscles in patients with missing superior oblique tendons.

INTRODUCTION: Patients with missing superior oblique (SO) tendons present with overelevation/underdepression in adduction. Unilateral cases often exhibit abnormal head postures, whereas in bilateral cases, there may be a marked V-pattern with upgaze exotropia. These patients may have craniosynostosis. METHODS: Nine children with unilateral (n = 2) or bilateral (n = 7) absent SO tendons underwent anterior and nasal transposition of the inferior oblique (IO) muscles, some in combination with horizontal rectus recession for horizontal strabismus. They were evaluated 6 to 46 months postoperatively for alignment and oculomotor examination. Cyclodeviations were not evaluated in most children. RESULTS: Postoperatively, all patients improved. Both unilateral cases were orthotropic with no abnormal head posture. In the bilateral cases, vertical deviation in adduction and exotropia in upgaze had largely cleared, although some symptoms remained, most notably vertical deviation in side gaze (3 patients) and V-pattern esotropia in downgaze (2 patients). A patient missing both SO tendons as well as the left superior rectus muscle, who had the anterior and nasal transposition on the right side only, remained with 25(Delta) left hypotropia. CONCLUSIONS: Anterior and nasal transposition of the IO muscle reduces overelevation in adduction and helps eliminate or reduce divergence of the eyes in upgaze, but esodeviation may persist in downgaze. This procedure was most effective in unilateral absence of the SO tendon. It is likely to benefit patients with severe congenital fourth nerve palsy in which standard IO muscle weakening procedures have been ineffective.     

Paralytic strabismus

In the last year, published works on paralytic strabismus have concerned many topics. New advances have been made in the knowledge of epidemiology of ocular nerve palsies in children, muscular causes of paralytic strabismus, and neuroimaging management of patients with third nerve palsy who are at risk of cerebral aneurysms. The author describes reports on rare associations of oculomotor imbalances and neurologic diseases as well as atypical orbital localizations of tumors. He also discuss new neuroimaging findings in congenital superior oblique muscle palsy and new acquisitions on cyclofusion deterioration in acquired trochlear palsy.     

Comparison of two surgical techniques for the treatment of superior oblique palsy

AIM: To compare two surgical techniques for the treatment of superior oblique palsy. PATIENTS AND METHODS: Retrospective study involving 32 patients operated on at the Rouen Teaching Hospital for superior oblique palsy. Group 1 patients were treated by surgical reinforcement of the superior oblique muscle and group 2 patients were treated by surgical loosening (or weakening) of the antagonist muscles. One-year follow-up explored head tilt, diplopia, vertical deviation and cyclotorsion. RESULTS: Functional results (presence of diplopia or stiff neck) were positive in both groups but better in group 1. Only 12.5% of patients required a second operation. Cyclotorsion amounted to less than 2% in group 1 and was still greater than 8% in group 2; on the other hand, vertical deviation had improved more in group 2, where it decreased to 2.1 diopters versus 3.1 in group 1. DISCUSSION: and conclusion: Only reinforcing the superior oblique adequately corrects cyclotorsion, which is the main cause of asthenopia and diplopia, despite an often insufficient height correction that is otherwise clinically well tolerated. We suggest reinforcing the superior oblique as a first intent rather than weakening hyperactive muscles, and in case of excessive postoperative height, we would carry out additional treatment of one of the hyperactive muscles later.     

Surgery for Bilateral Superior Oblique Palsy

Following head trauma, because the patient has no overt vertical or horizontal tropia to account for the complaint of diplopia, the symptoms are dismissed, when in fact cyclodiplopia resulting from the excyclotropic feature of bilateral superior oblique palsy is the cause. A prospective study of nine patients with bilateral superior oblique muscle palsy caused by head trauma and managed by an identical surgical regimen are presented. All patients had symptomatic cyclodiplopia that increased in downgaze. Cover testing performed in various gaze positions and in left and right head tilt positions plus the double Maddox rod tests confirmed the diagnosis. The four expected findings are left hypertropia (LHT) in right gaze and right hypertropia (RHT) in left gaze, RHT on right head tilt and LHT in left tilt, V pattern, and excyclodeviation. All patients received symmetrical bilateral superior oblique tendon surgery, using a modified technique originally described by Harada and Ito, which consisted of advancing the anterior tendon half along the equator of the globe toward the superior border of the lateral rectus muscle. Elimination of the cyclodiplopia symptom was achieved in all cases by reducing the quantity of excyclotropia.     

Large Bielschowsky head-tilt phenomenon and inconspicuous vertical deviation in the diagnostic positions in congenital superior oblique palsy

PURPOSE: To report a case of congenital superior oblique palsy with an unusually large Bielschowsky head-tilt phenomenon (BHP) and disproportional inconspicuous vertical deviation. METHODS: Case report. RESULTS: An 18-year-old woman presented with slight compensatory head tilting and a Bielschowsky head-tilt phenomenon of 50 Delta on left tilting. Magnetic resonance imaging revealed atrophy of the left superior oblique muscle. A Hess screen test showed a slight underaction of the left superior oblique muscle, but neither an obvious overaction of the ipsilateral inferior oblique muscle nor inhibitory palsy of the contralateral superior rectus muscle was found. With a 3-mm recession of the ipsilateral superior rectus muscle, Bielschowsky head-tilt phenomenon decreased to 25 Delta. CONCLUSION: A large Bielschowsky head-tilt phenomenon was possibly caused by an increased gain of the otolith-ocular reflex affecting the vertical rectus muscle.     

Congenital ocular motor apraxia

PURPOSE: Congenital ocular motor apraxia is a rare disease characterized by defective or absent voluntary and optically induced horizontal saccadic movements. Jerky head movements or thrusts on attempted lateral gaze are a compensatory sign. Most affected children have delayed motor and speech development. Cases associated with systemic diseases, neurologic maldevelopment, metabolic deficits, and chromosomal abnormalities have been described. METHODS: Case report and review of the scientific literature. RESULTS: The authors describe the ophthalmologic, pediatric, and neurologic evaluations and follow up of a child with impaired horizontal saccades, jerky head movements, and delayed motor and speech development. CONCLUSIONS: Congenital ocular motor apraxia is an uncommon disorder of ocular motility. Even so, ophthalmologists should be aware of the developmental delay and the other associated conditions, in order to grant the patients the multidisciplinary assistance they often require.     

Ocular myasthenia presenting as superior oblique weakness

We diagnosed ocular myasthenia in a 39-year-old man whose presenting symptom was vertical diplopia. Unrecognized weakness of the right superior oblique and secondary overaction of the right inferior oblique caused a right hypertropia, which was worse on left gaze. One week later left blepharoptosis, right medial rectus weakness, and bilateral obicularis oculi weakness were found on ocular examination. All findings were partially reversed by the injection of Tensilon. Superior oblique muscle palsy simulating a fourth cranial nerve palsy is infrequently reported in patients with ocular myasthenia. Pseudofourth nerve palsy is another sign of myasthenia gravis.     

先天性上斜肌麻痹52例临床分析

目的:探讨先天性上斜肌麻痹的临床特点和治疗方法。方法:回顾分析52例61眼伴有先天性上斜肌麻痹病例的资料。结果:先天性上斜肌麻痹在先天性垂直眼外肌麻痹中常见;年龄较小,有较好的双眼视觉;有典型的代偿头位;歪头试验阳性;一般无复视。结论:先天性上斜肌麻痹一经确诊应尽早行手术治疗。     

Depression in adduction syndrome

Three cases of depression in adduction syndrome are described. All occurred unilaterally, in the left eye, in boys and were characterized by depression and retraction of the involved eye with attempted adduction. This was accompanied by an inability to elevate the eye in adduction and a markedly abnormal head posture. Surgery, consisting of superior oblique tenotomy and recession of the lateral rectus muscle, did not allow the ocular rotation to improve but did allow the anomalous head posture to be corrected. The homogeneity of the clinical appearance and the lack of response to surgery suggests that this is a distinct clinical entity.     

Vertical abnormal retinal correspondence in three patients with congenital absence of the superior oblique muscle

Three patients with large vertical deviations diagnosed as palsy of the superior oblique muscle were found to have a congenital absence of the muscle during surgery. They also showed large, vertical abnormal retinal correspondence, which caused paradoxical vertical diplopia when the deviations were corrected with Fresnel membrane prisms or surgery. Each patient showed large, long-standing, vertical deviations for which head tilting could not have compensated.     

Treatment of inferior oblique paresis with superior oblique silicone tendon expander.

INTRODUCTION: Patients with inferior oblique eye muscle paresis may show hypotropia and apparent superior oblique muscle overaction on the side of the presumed weak inferior oblique (IO) muscle. We report 8 such patients successfully treated using unilateral silicone superior oblique (SO) tendon expanders. METHODS: Eight consecutive cases over the course of 6 years from the authors' private practice are described. None had a history of head trauma or a significant neurologic event. All patients showed IO paresis by 3-step test, with incyclotorsion and SO overacton of the hypotropic (paretic) eye. Forced ductions of the hypotropic eye were normal in all cases, and the vertical strabismus was treated with placement of a 7- mm silicone SO tendon expander in the hypotropic (paretic) eye. RESULTS: Mean preoperative primary position hypotropia was 6.5 prism diopters (PD); mean postoperative was 0.5 PD. Seven of 8 patients had resolution of primary position hypotropia, whereas the eighth was reduced. Mean preoperative SO overaction was 3+; all patients had postoperative resolution of SO overaction. Of 4 patients with preoperative ocular torticollis, mean preoperative head tilt was 9.3 degrees; mean postoperative tilt was 2.9 degrees. Two patients' head tilts had resolved, the other 2 showed improvement. All patients showed preoperative incylclotorsion of the hypotropic (paretic) eye; inclyclotorsion resolved in all patients after the placement of a SO tendon expander. CONCLUSION: The silicone SO tendon expander effectively restores ocular alignment in IO paresis with apparent SO overaction. Associated ocular torticollis can also be improved.