Isolated Bilateral Abducens Nerve Palsies Due to Metastasis to the Clivus from Adenocarcinoma in the Lung

Objective: The term one-and-a-half syndrome, type II, was recently coined and has been applied to two somewhat different eye movement disorders: the loss of voluntary horizontal eye movements except for adduction in one eye (one patient with two lesions, one in the cerebral hemisphere and the other in the cavernous sinus) and the loss of all voluntary horizontal eye movements with adduction nystagmus in the right eye on attempted gaze to the left and preserved abduction in both eyes with the doll’s head maneuver (one patient with infarction of the midbrain). The justification of the term ‘one-and-a-half syndrome, type II’ is questioned. Design: Retrospective analysis of 9000 consecutive electro-oculographic recordings (EOG) with respect to combined abnormalities of conjugated horizontal eye movements to one side and abduction to the other. Results: Only one patient had loss of horizontal eye movements sparing adduction in one eye on clinical examination. In eight patients with clinically unilateral abduction paresis, EOG disclosed slowing of contraversive saccades. Another eight patients with clinically unrestricted horizontal eye movements had EOG-documented unilaterally slowed abduction saccades and slowing of contraversive saccades. Masseter reflex was abnormal in five patients and blink reflex in three. MRI performed in eight and CT in three of these patients failed to disclose acute lesions. Conclusions: The combination of a horizontal gaze paresis to one side and abduction paresis to the other is very rare, even if partial and subclinical forms are included. It occurs with single pontine or mesencephalic lesions or with two lesions at different sites, and can be caused by different mechanisms. Such an eye movement disorder does not constitute a new syndrome, as it entails neither a constellation of clinical findings due to an anatomically well-localized lesion, nor a consistent constellation of signs and symptoms due to a disease process.     

Afferent and efferent connections of the cat abducens nucleus: a study by injection of wheat germ agglutinin conjugated with horseradish peroxidase

The ascending projection of the abducens internuclear neurons and the afferent pathway to the abducens nucleus were examined after injection of wheat germ agglutinin conjugated with horseradish peroxidase (HRP) into the abducens nucleus of the cat. Orthograde neural terminations of the internuclear neurons of the abducens nucleus were found in the contralateral medial rectus subdivision of the oculomotor complex and the medial longitudinal fasciculus (MLF). Furthermore, HRP-positive cells were also found in the ipsilateral pontine reticular formation. These findings indicate that the axons of the neurons within the pontine reticular formation project to the ipsilateral abducens nucleus, and that the internuclear neurons of the abducens nucleus project to the contralateral medial rectus subdivision of the oculomotor complex and the MLF. Clinically, the pontine reticular formation is thought to be a center for the horizontal eye movements which generates impulses to the ipsilateral abducens motor neurons and excites the internuclear neurons of the abducens nucleus projecting to the contralateral MLF as well as to the oculomotor complex. These pathways are essential for conjugate horizontal eye movements.     

High-resolution magnetic resonance imaging demonstrates abnormalities of motor nerves and extraocular muscles in patients with neuropathic strabismus.

INTRODUCTION: Although the ocular motility examination has been used traditionally in the diagnosis of strabismus that is a result of cranial nerve (CN) abnormalities, magnetic resonance imaging (MRI) now permits the direct imaging of lesions in CN palsies. METHODS: Prospectively, nerves to extraocular muscles (EOMs) were imaged with T1 weighting in orbits of 83 orthotropic volunteers and 96 strabismic patients in quasicoronal planes using surface coils. Intraorbital resolution was 234-312 microns within 1.5- to 2.0-mm thick planes. CNs were imaged at the brainstem using head coils and T2 weighting, yielding 195 micron resolution in planes 1.0-mm thick in 6 normal volunteers and 22 patients who had oculomotor (CN3), trochlear (CN4), or abducens (CN6) palsies and Duane syndrome. RESULTS: Oculomotor (CN3) and abducens (CN6) but not trochlear (CN4) nerves were demonstrable in the orbit and skull base in all normal subjects. Patients with congenital CN3 palsies had hypoplastic CN3s both in orbit and skull base, with hypoplasia of involved EOMs. Patients with chronic CN6 and CN4 palsies exhibited atrophy of involved EOMs. Patients with Duane syndrome exhibited absence or hypoplasia of CN6 in both orbit and brainstem regions, often with mild hypoplasia and apparent misdirection of CN3 to the lateral rectus muscle. Unlike CN6 palsy, patients with Duane syndrome exhibited no EOM hypoplasia. Patients with congenital fibrosis exhibited severe hypoplasia of CN3, moderate hypoplasia of CN6, and EOM hypoplasia, particularly severe for the superior rectus and levator muscles. CONCLUSION: High-resolution MRI can directly demonstrate pathology of CN3 and CN6 and affected EOM atrophy in strabismus caused by CN palsies. Direct imaging of CNs and EOMs by MRI is feasible and useful in differential diagnosis of complex strabismus.     

Posttraumatic abducens to oculomotor nerve misdirection.

INTRODUCTION: Paradoxical patterns of extraocular muscle, eyelid, or pupillary movements can occur following injury between divisions of the oculomotor nerve, trigeminal and abducens nerves, and trigeminal and oculomotor nerves. We report three cases of unusual ocular motility and eyelid movements that are a result of aberrant connections between the abducens and oculomotor nerves. METHODS: Three patients with unusual eye movement abnormalities after trauma were studied. A complete ophthalmic examination plus neuroradiologic evaluation were performed. RESULTS: Each patient manifested an aberrant connection between the 6th and 3rd cranial nerves resulting in third nerve function during sixth nerve stimulation. Two patients demonstrated complete third nerve palsies except for adduction on attempted abduction. The third showed improved bilateral ptosis on abduction. CONCLUSIONS: The neuroanatomical abnormalities involve intraorbital structures in one patient and central nervous system pathways in the others. Explanations such as retrograde regeneration, ephaptic transmission, or denervation supersensitivity do not appear to explain these unusual eye movements. The most likely mechanism involves some form of peripheral neuronal misdirection. These rare sixth to third nerve misdirection cases add support to the "neuronal misdirection hypothesis" of aberrant eye movements after trauma.     

Visualization of the oculomotor cranial nerves by magnetic resonance imaging

MRI is the imaging method of choice in patients with cranial nerve palsies. However, the nerves are often not seen on MR images and smaller lesions may not be diagnosed on routine brain MRI. The purpose of this study is to show that the oculomotor cranial nerves can be visualized by standard MR sequences and to present an update on clinical applications of cranial nerve imaging. In MR images of normal subjects, it is demonstrated that the oculomotor nerve, the trochlear nerve and the abducens nerve can be identified not only in the subarachnoid space and cavernous sinus, but also in the orbit. However, a precondition is the use of appropriate imaging sequences and planes (e.g., subarachnoid cisterns: T2-weighted fast spin-echo or T2*-weighted three-dimensional sequences in oblique-axial and sagittal planes; cavernous sinus: contrast-enhanced T1-weighted coronal images; orbit: T1-weighted images without contrast agent in the coronal plane obtained using surface coils). The capability of imaging cranial nerves is clinically important not only for diagnostic purposes in eye muscle palsies but also for planning surgical procedures at the cranio-orbital junction.     

Spinocerebellar degeneration with slow eye movements and abducens nerve palsy.

A 51-year-old woman with spinocerebellar degeneration manifested an unusual disorder of eye movements. She presented with bilateral abducens palsy and slow eye movements in the horizontal plane. Slow eye movements typically are seen with supranuclear lesions, whereas abducens palsies are of nuclear or infranuclear origin. This unique combination of eye movement disorders is discussed, as well as other features of ophthalmoplegias associated with spinocerebellar degeneration.     

Pituitary Adenoma Manifesting as an Isolated Abducens Palsy

Ocular motor nerve palsies are rare complications of pituitary adenoma. We treated a patient who presented with an isolated abducens palsy and was subsequently found to have a pituitary adenoma. A 62-year-old woman was referred to us for an evaluation of her diplopia. She had an esotropia, which was larger on right gaze, and a limited abduction OD. Visual fields were normal. CT and MRI revealed a sellar region tumor invading the right cavernous sinus without compressing the optic chiasm. A diagnosis of macroprolactinoma was made endocrinologically. Her diplopia and right abducens palsy were quickly resolved and MRI showed significant shrinkage of the tumor after she was treated with cabergoline. A sixth nerve palsy can be the sole presenting feature of pituitary adenoma and can be treated effectively with medication.     

Brainstem diseases causing isolated ocular motor nerve palsies

There is a significant number of individual patients with ocular motor nerve palsies as the only clinical sign of MRI- and, less frequently, CT-documented small brainstem lesions with a predominance of infarctions and hemorrhages in the 3 rd and 4 th nerves and demyelinating lesions in the 6 th nerve. The 3 rd nerve is most commonly and the 6 th and 4 th nerves less frequently involved. An intra-axial basis for isolated ocular motor nerve palsies may be underestimated if based on MRI-documented lesions only, as electrophysiologic abnormalities indicating brainstem lesions may be independent of MRI-documented lesions.This paper reviews neuroimaging and electrophysiological data on brainstem diseases manifesting as isolated ocular motor nerve palsies. It supports the concept that small pontine and mesencephalic lesions are an underestimated cause of isolated ocular motor nerve palsies and the main cause of nontraumatic 3 rd and 6 th nerve palsies in the middle-aged and elderly population.     

Headaches in ophthamology

PURPOSE: To determine the frequency of ocular abnormalities in patients with headache seen for an ocular examination. METHODS: All 944 consecutive new patients with headache examined during a 3-year period (1984-1986) at the Department of Ophthalmology, University of Kinshasa, Democratic Republic of the Congo, were enrolled in this retrospective study. All patients received an ocular examination which included measurement of visual acuity, refraction, slit lamp examination, and fundoscopy. Other examinations such as measurement of intraocular pressure, neuro-ophthalmological examination, visual field and fluoangiography were performed when needed. RESULTS: The frequency of patients with headache examined during this period was 15.6% (944 out of 6,066 patients) or one patient out of 16 new patients. Their average age was 30+/-13.5 years. Females (60%) complained more frequently of headache than males (40%) (p<0.05). Migraine was found in 3.9% of patients. Ocular abnormalities were found in 505 (64%) patients and included refractive disorders (44%), lesions of the posterior segment (17%), abnormalities of the conjunctiva (12%), abnormalities of the anterior segment (12%), presbyopia (11%), and ocular motor palsies, heterophoria, convergence insufficiency and other ocular abnormalities (4%). Of 224 patients with ametropia, 154 (69%) were myopic with or without astigmatism. When specified, headache was most often fronto-occipital. Headache was most frequently associated with decreased vision, eye pain, epiphora, foreign body sensation, itching, and photophobia. CONCLUSION: Ocular examination could be necessary in cases of patients who complain of headache.     

Functional and Motor Outcomes of Strabismus Surgery for Chronic Isolated Adult Sixth Nerve Palsy

Abstract

Abducens nerve palsy is the most common acquired ocular motor nerve palsy in adults. Chronic cases of abducens palsy often require surgical intervention to relieve disabling diplopia. The goal of this study was to identify factors associated with surgical outcomes in isolated abducens palsy. Medical records of all adult patients from 1988 to 2012 with abducens palsies who underwent strabismus procedures were retrospectively reviewed. Motor alignment, extraocular motility, and sensory outcomes were recorded. Success was defined as absence of diplopia without prisms or face turn, vertical deviation ≤2 prism dioptres (PD), and horizontal deviation ≤10 PD. Eighty-one patients (age range: 20–86 years) met inclusion criteria. Success was achieved in 58% of patients. Final success rates for abducens palsy were 50% for neoplastic, 59% traumatic, 57% for microvascular/unknown, and 67% for other central nervous system causes (p?>?0.05). Patients with an underlying neoplastic or traumatic aetiology required more than one strabismus procedure more often than those with microvascular/idiopathic or other central nervous system causes (48% vs. 24%; p?=?0.03). For complete abducens palsies, patients who underwent Hummelsheim-type procedures had a higher success rate than those who underwent a full-tendon vertical rectus muscle transposition. (78% versus 35%; p?=?0.049). Success rates for strabismus procedures in patients with abducens palsies are similar across all aetiologies. Frequency of re-operation is higher among those patients with neoplastic or traumatic aetiologies for their abducens palsies. Hummelsheim-type procedures have a higher success rate for complete abducens palsies than full-tendon vertical rectus transpositions.     

Three cases of abducens nerve palsy accompanied by Horner syndrome

PURPOSE: To report three cases of nasopharyngeal carcinoma, exhibiting abducens nerve palsy and Horner syndrome during the medical treatment of the tumor, whose invasive cavernous sinus lesions could be detected. SUBJECTS: The patients were two men and one woman who were referred to our department with complaints of diplopia during the clinical course of nasopharyngeal carcinoma. RESULTS: Right abducens nerve palsy, Horner syndrome, and impairment of the 1st division of the trigeminal nerve were recognized in all patients. Magnetic resonance imaging (MRI) revealed invasive lesions in the right cavernous sinus in all three patients, with iso-intensity on T1-weighted images, which were enhanced by gadolinium. CONCLUSIONS: The abducens and sympathetic nerves run closely together in the cavernous sinus. Nasopharyngeal carcinoma is apt to invade the cavernous sinus and often impairs the abducens nerve. Therefore the presence of Horner syndrome and trigeminal palsy in combination with abducens nerve palsy should be cautiously investigated to confirm the existence of the cavernous sinus lesions.     

Acute VIth cranial nerve dysfunction in multiple sclerosis. Evaluation by magnetic resonance imaging.

VIth nerve palsy is not frequently considered a presenting sign of multiple sclerosis (MS); however, MS has been documented as a fairly common cause of VIth nerve dysfunction. In the present study we have evaluated the clinical features and magnetic resonance imaging (MRI) findings in four MS patients with acute VIth nerve palsy. Diplopia as a result of acute VIth nerve palsy was the prominent symptom leading to the diagnosis of MS in all of the individuals. Other signs specifically localizing to the ipsilateral brainstem were absent in these patients. Cranial MRI revealed multiple white matter lesions with a periventricular predominance in all four patients and pontine white matter lesions in three of the patients. These lesions were either adjacent to the VIth nerve nucleus or involved the fasciculus of the VIth nerve or both.     

Diagnostic yield for neuroimaging in patients with unilateral eye or facial pain

BACKGROUND: The neuroimaging evaluation of isolated pain in or around the eye has not been studied previously. We report the low diagnostic yield of neuroimaging in patients who have a normal ocular examination and unilateral eye pain or facial pain predominantly affecting the eye. METHODS: Retrospective review of patients referred to 3 neuro-ophthalmology practices for unexplained pain in or around the eye. Inclusion criteria were adults with isolated unilateral eye/facial pain, neuroimaging, and a normal eye exam. Ex-clusion criteria were symptoms typical of a defined pain syndrome (e.g., trigeminal neuralgia or giant cell arteritis), and exam findings that would account for the pain. RESULTS: One hundred and twenty-seven (127) of the 760 reviewed patients met study criteria, and underwent MRI (75) or CT (34) scans, or both (18). Imaging was normal in 106 (83%). Abnormalities (n = 21) on imaging (17%) included nonspecific T2-weighted hyperintensities (10), sinusitis (5), superior ophthalmic vein enlargement (1), pontine lacunar infarct (1), Chiari malformation (1), thalamic mass (1), old occipital stroke (1), and focal enlargement of the third cranial nerve (1). INTERPRETATION: Although imaging showed abnormalities in 17% of cases of isolated pain in or around the eye, only 2 abnormalities were believed to be possibly related to the pain and only 1 case was probably related. The diagnostic yield of neuroimaging in patients with a normal examination and isolated, unilateral eye/facial pain referred to a neuro-ophthalmologist is low.     

Functional and Motor Outcomes of Strabismus Surgery for Chronic Isolated Adult Sixth Nerve Palsy

Abducens nerve palsy is the most common acquired ocular motor nerve palsy in adults. Chronic cases of abducens palsy often require surgical intervention to relieve disabling diplopia. The goal of this study was to identify factors associated with surgical outcomes in isolated abducens palsy. Medical records of all adult patients from 1988 to 2012 with abducens palsies who underwent strabismus procedures were retrospectively reviewed. Motor alignment, extraocular motility, and sensory outcomes were recorded. Success was defined as absence of diplopia without prisms or face turn, vertical deviation ≤2 prism dioptres (PD), and horizontal deviation ≤10 PD. Eighty-one patients (age range: 20–86 years) met inclusion criteria. Success was achieved in 58% of patients. Final success rates for abducens palsy were 50% for neoplastic, 59% traumatic, 57% for microvascular/unknown, and 67% for other central nervous system causes (p > 0.05). Patients with an underlying neoplastic or traumatic aetiology required more than one strabismus procedure more often than those with microvascular/idiopathic or other central nervous system causes (48% vs. 24%; p = 0.03). For complete abducens palsies, patients who underwent Hummelsheim-type procedures had a higher success rate than those who underwent a full-tendon vertical rectus muscle transposition. (78% versus 35%; p = 0.049). Success rates for strabismus procedures in patients with abducens palsies are similar across all aetiologies. Frequency of re-operation is higher among those patients with neoplastic or traumatic aetiologies for their abducens palsies. Hummelsheim-type procedures have a higher success rate for complete abducens palsies than full-tendon vertical rectus transpositions.     

Internuclear ophthalmoplegia in 14 patients: Clinical and topographic correlation using magnetic resonance imaging

In a clinicotopographic study of 14 patients with internuclear ophthalmoplegia (INO) confirmed by electrooculography (EOG), the pattern of visual dysfunction was compared to the location and severity of lesions of the medial longitudinal fasciculus (MLF) visualized by magnetic resonance imaging (MRI). Of the 12 patients with classically-defined 'anterior' INO, nine were classed as having definite multiple sclerosis (MS), and three as probable or possible. Five of the 12 had MR-imaged MLF lesions, and five including one with MLF lesions, had cerebellum-associated lesions. Of the two patients with so-called 'posterior' INO, one presented a heredodegenerative disease and cerebellum-related lesions, and in the other, a non-visual neurological condition was not diagnosed. The finding that MR-imaged MLF lesions do not always occur simultaneously with INO may indicate that INO could be the expression of a functional disorder in the posterior fossa, preceding MLF lesion development.     

Neurological Imaging in Acquired Cranial Nerve Palsy: Ophthalmologists vs. Neurologists

ABSTRACT

Purpose: Cranial nerve palsies often require neurological imaging by MRI. Guidelines on whether or not to utilize MRI have been absent or lack clarity. In daily practice, both neurologists and ophthalmologists treat patients with cranial nerve palsy and determine whether neuro-imaging is required. There appear to be differences in policy with respect to neuro-imaging. The question, which will be answered in this study, is the following: to what extent do differences in policy exist between ophthalmologists and neurologists regarding imaging by MRI of patients with acquired ocular cranial nerve palsy?

Method: PubMed database was searched for literature on acquired cranial nerve palsy and MRI scanning performed by ophthalmologists and neurologists. Case series published between 2000 and 2015 were included. The first author screened the literature on eligibility, profession of the authors, and conducted data abstraction.

Result: Ten case series were found eligible for analysis. A total of 889 cranial nerve palsies were described, 770 by ophthalmologists and 119 by neurologists. The age range of patients in all case series was 2 to 96 years of age. The oculomotor nerve was investigated in 162 patients, the trochlear nerve in 131 patients, and the abducens nerve in 486 patients. All neurologists (n=3) and 2 out of 7 investigated ophthalmologists recommended performing MRI scanning in every patient who presented with an ocular cranial nerve palsy, while 5 ophthalmologists (5/7) opted to triage patients for risk factors associated with cranial nerve palsies prior to ordering MRI imaging. When different groups of patients were viewed separately, it became apparent that almost all specialists agreed that every patient with a third nerve palsy and patients under 50 years of age should undergo MRI scanning. In patients with fourth nerve palsy, MRI scanning was not indicated.

Conclusion: The neurologists in this study were more likely to perform MRI scanning in every patient presenting with ocular cranial nerve palsy. Ophthalmologists were more likely to determine risk factors associated with cranial nerve palsy, which they took into account when deciding whether or not to perform neurological imaging in patients aged more than 50 years or presenting with abducens nerve palsy.     

Abducens nerve palsy and Horner's syndrome revisited

Sympathetic fibers destined for the eye join the abducens nerve for a short distance within the cavernous sinus; thus, a unilateral sixth nerve palsy with an ipsilateral Horner's syndrome is of significant localizing value. We report two cases of cavernous sinus lesions producing an ipsilateral abducens palsy and Horner's syndrome: one case due to an intrinsic and the other to an extrinsic lesion of the sinus region.     

Pupillary Abnormalities Induced by Argon Laser Photocoagulation

Twenty-two patients who underwent panretinal argon laser ablation for proliferative diabetic retinopathy were studied for post-laser pupillary abnormalities. All 22 patients developed sector palsies of the iris sphincter. Fifteen demonstrated supersensitivity to 0.125% pilocarpine in the treated eye. Four of 12 patients developed accommodative paresis in the treated eye. Six showed light near dissociation in the treated eye. The sector palsies and associated cholinergic supersensitivity of the iris sphincter, the accommodative paresis, and light near dissociation imply that the laser treatment damaged the ocular parasympathetic innervation.     

后天性外展神经麻痹的MRI病因学分析

 目的 探讨后天性外展神经麻痹的MRI表现,分析外展神经麻痹原因,为临床诊断、治疗提供依据。设计 回顾性病例系列。研究对象 42例后天性外展神经麻痹患者。方法 回顾性分析42例临床诊断证实的后天性外展神经麻痹患者的MRI表现,包括病变部位、范围、信号和强化特征,结合外展神经的解剖特点,分析神经麻痹的原因。主要指标 MRI表现。结果 缺血性外展神经麻痹16例,患者均有糖尿病、高血压或高脂血症等病史,MRI表现为颅内多发缺血灶、软化灶,老年性脑萎缩等。占位性病变15例,病变位于桥前池、岩尖和海绵窦,累及展神经脑池段、Dorello小管段和海绵窦段。外伤性外展神经麻痹5例,1例有右侧颅骨多发骨折,出现左侧外展神经麻痹症状,其余4例均无明确颅骨和眼眶骨折证据。非特异性炎症4例,3例表现为海绵窦偏前部增厚、强化。其他原因包括重症肌无力1例,桥小脑角区胆脂瘤术后1例。结论 MRI检查有助于明确外展神经麻痹的病因及发病部位,进而指导针对性治疗。（眼科,2013, 22： 305-308）     

"Salt and pepper" in the eye and face: a prelude to brainstem ischemia

PURPOSE: To report the "salt and pepper"(SP) eye pain as a herald symptom of pontine ischemia. DESIGN: Observational case series. METHODS: We reviewed clinical and neuroimaging findings of four patients who presented initially with the sensation of SP in the eyes and then developed paramedian pontine infarcts confirmed by neuroimaging. RESULTS: All of the patients developed other neurologic symptoms or signs, either in association with the sensation of SP in the eyes, from hours to days later. Magnetic resonance imaging (MRI) showed paramedian pontine infarcts in all of the patients and angiography showed basilar artery occlusive disease in three of them. CONCLUSION: Impending pontine ischemia is an important differential diagnosis in patients with acute ocular pain. Prompt neurovascular evaluation and treatment may avoid devastating brainstem infarcts that cause death or long-term disability, particularly in patients with basilar artery occlusive disease.