Treatment of acute comitant esotropia in Chiari I malformation

Advances in the diagnosis and treatment of acute acquired comitant esotropia

Acute acquired comitant esotropia (AACE) is mainly characterized by sudden onset, accompanied by diplopia, without extraocular muscles paralysis or ocular motility disorders. In recent years, the incidence of AACE has been increasing, researchers have found that this phenomenon may be related to the widespread use of electronic devices and the increase in the number of people working from home during the COVID-19 pandemic. However, its neural mechanisms have not been fully elucidated. This article primarily reviews the latest developments in the diagnosis and treatment of AACE from the perspectives of etiology and treatment methods, aiming to provide direction for future in-depth exploration of the pathogenesis and treatment approaches of this disease.

Clinical features and change in incidence of acute acquired comitant esotropia: a 15-year single-centre study in South Korea

BACKGROUND/OBJECTIVES

We investigated the clinical features and change in incidence of AACE in South Korea.

SUBJECTS/METHODS

We reviewed the medical records of AACE patients who visited the Strabismus Clinic of at a tertiary referral hospital from 2007 to 2021. Clinical features were retrieved, including age at onset, angle of deviation, refractive errors, neuroimaging findings, and treatment outcomes. For each year, the proportion of new AACE patients among all new patients who visited the clinic, and the ratio of new AACE patients to new intermittent exotropia (IXT) patients, were analysed to estimate the incidence of AACE.

RESULTS

Overall, 59 patients were included in the study. The mean age of the patients was 24.7 ± 9.3 years; the incidence of AACE was highest in teenagers and young adults. No patients had a history of visual occlusion, recent physical or psychological stress, or uncorrected myopia, unlike to classic AACE; moreover, no patients exhibited abnormalities in neuroimaging. There was a significantly increasing trend in the proportion of new AACE patients among all new patients (linear regression analysis, R2 = 0.778, p < 0.001). There was also a significantly increasing trend in the ratio of new AACE patients to new IXT patients (R2 = 0.803, p < 0.001).

CONCLUSIONS

A new type of AACE, distinct from the classic types, is increasingly common in South Korea; this increasing incidence also appears to be a global phenomenon. Large-scale investigations are needed to define the exact clinical features, incidence, and pathophysiology of this new type of AACE.

Effect of the base-out recovery point as the surgical target for acute acquired comitant esotropia

PURPOSE

To evaluate the treatment efficacy of the preoperative base-out recovery point as the surgical target angle for acute acquired comitant esotropia.

METHODS

Prospective study. Twenty-two patients with acute acquired comitant esotropia (AACE) underwent strabismus surgery based on the target angle of the preoperative base-out recovery point. The postoperative deviation, positive fusional vergence, and negative fusional vergence were evaluated and compared with those of 23 normal individuals.

RESULTS

The mean follow-up period was 18.68 ± 19.48 months. At the last follow-up, 19 (86.4%) of 22 subjects had orthophoria, whereas 3 (13.6%) had minimal esophoria. The postoperative angle of deviation was significantly smaller than the preoperative angle of deviation at near (P < 0.001) and distance (P < 0.001). Postoperative sensory fusion was significantly better than preoperative fusion at near (P < 0.001) and distance (P < 0.001). The postoperative stereoacuity improved significantly after the surgery at near (P < 0.001) and distance (P < 0.001). Compared with the controls, the convergence and divergence amplitudes in the AACE patients were similar at distance (P > 0.05) but were still narrower at near (P < 0.001).

CONCLUSION

Good alignment and binocular balance were obtained with the surgical target angle of the base-out recovery point in AACE.

Acute presentation of Chiari 1 malformation in children

PURPOSE

To review the literature about the acute presentation of Chiari 1 malformation in children, with a focus on acute cervical cord syndromes with impairment of the cortico-spinal tract. To analyze the possible precipitating factors and the pathophysiology of the acute onset.

METHOD

Illustrative case presentation with literature review.

RESULTS

The literature includes just a few dozens of children with acute presentation of Chiari 1 malformation. The more frequent presentations consist of oropharyngeal dysfunction, cranial nerve impairment, high intracranial pressure, peripheral motor deficit. Acute impairment of cervical long tracts is very rare and we could find only 16 previously reported cases of cervical cord impairment with quadriparesis or hemiparesis.

CONCLUSIONS

Nowadays, a lot of asymptomatic Chiari 1 malformations are frequently observed owing to the wide diffusion of magnetic resonance imaging. This raised the question about the management of these patients. Despite severe and even lethal manifestations being reported in previously asymptomatic patients, the absolute rarity of acute deterioration does not justify prophylactic surgery. The diagnosis of Chiari malformation may be initially difficult in patients with isolated, acute, and unusual presentations but physicians should bear in mind its possibility, because prompt cranio-cervical decompression may be decisive.

Acquired, Comitant, Non-Accommodative Esotropia (ANAET): Evaluation, Treatment, and Prognosis

Children presenting in later childhood with isolated, acquired, comitant non-accommodative esotropia (ANAET) form an unusual clinical group whose evaluation, treatment, and prognosis are unclear. We identified 9 such patients with no evidence of intracranial pathology whose outcomes following standard bilateral medial rectus recessions were excellent.

Divergence insufficiency alleviated by posterior fossa decompression with duraplasty in a patient with Chiari type 1.5 malformation

The authors present a case of Chiari type 1.5 malformation with the uncommon presenting symptoms of esotropia and diplopia due to divergence insufficiency in a 12-year-old girl. Imaging at initial diagnosis revealed cerebellar herniation with extension of the tonsils to the C2 vertebral body, a retroflexed odontoid, and a small cervical syrinx. The patient was initially treated with an uncomplicated Chiari malformation decompression without dural opening. Repeat imaging revealed an adequate decompression. Three months postoperatively the patient's diplopia recurred and she underwent repeat posterior fossa decompression with dural opening and duraplasty. Following repeat decompression with dural opening and duraplasty, the patient's diplopia had not recurred by the 2-year follow-up.https://thejns.org/doi/abs/10.3171/2018.5.PEDS1886.

Decompensated Esophoria as a Benign Cause of Acquired Esotropia

PURPOSE

To determine informative clinical and magnetic resonance imaging (MRI) characteristics of patients with symptomatic adult acquired, comitant esotropia due to decompensated esophoria.

DESIGN

Retrospective, interventional case series.

METHODS

Setting: Institutional.

STUDY POPULATION

Patients with decompensated esophoria who developed acute acquired comitant esotropia.

OBSERVATION PROCEDURES

Ophthalmic examination, stereopsis, and strabismus measurements at distance and near using prism cover tests in diagnostic gaze positions were performed. Patients underwent high-resolution surface coil MRI of extraocular muscles with target fixation, and MRI of the brain. Strabismus surgery was performed under topical anesthesia with adjustable sutures wherever possible. Paired t testing was used to evaluate postoperative changes with 0.05 considered significant.

MAIN OUTCOME MEASURE

Clinical and MRI characteristics, and surgical outcome of patients with decompensated esophoria.

RESULTS

Eight cases were identified involving subjects of mean age 29 ± 9.4 (range: 20-48) years having gradually progressive intermittent horizontal, binocular diplopia for 10 months to 3 years. Mean preoperative esotropia was 31 ± 12 Δ at distance and 29 ± 12 Δ at near, although this was intermittent in 5 patients who exhibited enhanced fusional divergence. Neurologic evaluation and MRI of brain, orbits, and extraocular muscles were unremarkable in all cases. Orthotropia was successfully restored in all by standard or enhanced doses of bimedial rectus muscle recession surgery, improving mean stereoacuity from 535 to 68 arc seconds, although 5 patients exhibited 2-14 Δ asymptomatic residual esophoria.

CONCLUSION

Decompensated esophoria is a benign clinical entity causing acute, acquired, comitant esotropia treatable with enhanced medial rectus recession.

Sudden onset of Chiari malformation Type I in previously asymptomatic patients

Chiari malformation Type I (CM-I) is usually suspected in patients with slowly progressing neurological symptoms. However, in some instances, especially if syringomyelia is associated, an abrupt clinical onset is reported and is accompanied by an acknowledged risk of potentially severe clinical signs or even sudden death. Little is known about such a critical course in CM-I/syringomyelia complex. The authors describe 3 challenging cases of the abrupt onset of CM-I/syringomyelia to reveal more information on the clinical presentation and pathogenetic mechanisms of this sudden and potentially severe clinical phenomenon: a 38-year-old man experienced acute respiratory failure requiring intubation following acute decompensation of hydrocephalus associated with Noonan syndrome, a 1-year-old boy had sudden hemiparesis and Horner syndrome after a minor head/neck injury, and a 2.5-year-old boy presented with quickly progressing tetraplegia and dyspnea after a mild flexion and extension neck injury a few hours before. All 3 patients showed a CM-I/syringomyelia complex at diagnosis, and all of them had a good neurological outcome after surgery despite the ominous clinical presentation.

Patients with Chiari malformation Type I presenting with acute neurological deficits: case series

OBJECT

A subset of patients with Chiari malformation Type I (CM-I) presented with acute onset of a neurological deficit. In this study the authors summarize their experience with these patients' clinical presentation, imaging results, timing of surgery, and outcome following decompression.

METHODS

The authors reviewed clinical records, imaging studies, and operative notes from all patients undergoing posterior fossa decompression for CM-I at St. Louis Children's Hospital from 1990 to 2008. Of the 189 patients who underwent surgery, 6 were identified with the acute onset of a neurological deficit at presentation.

RESULTS

All 6 children (age range 3-14 years, 3 boys and 3 girls) had either syringomyelia (5 patients) or T2 signal changes in the spinal cord (1 patient) and CM-I on initial MR imaging. Three patients presented after minor trauma (1 with paraparesis, 2 with sensory deficits). Three patients presented without a clear history of trauma (1 with abrupt onset of spontaneous dysphagia and ataxia, 2 with sensory deficits). Decompression was performed at a mean 7.7 ± 4.9 days after symptom onset (7.0 ± 1.6 days after neurosurgical evaluation). In 1 patient, symptoms had resolved by the time of surgery; in the remainder of the patients, clear improvements were noted within 2 weeks of surgery, with complete resolution of symptoms by 12 months postoperatively. Follow-up MR images were obtained in 4 patients, demonstrating improvement in the extent of the syrinx in each patient.

CONCLUSIONS

Children with CM-I and syringomyelia can develop acute spinal cord or bulbar deficits with relatively minor head or neck injuries. The prognosis for symptomatic improvement in the observed deficit is good, with each patient in our series showing resolution of deficits over time. However, based on this relatively limited experience, the authors suggest that patients who present with an acute neurological deficit and are found to have CM-I be managed with early posterior fossa decompression. Patients with CM-I and syringomyelia may be at higher risk of acute neurological deficit than those without a syrinx.

Nonsurgical treatment for esotropia secondary to Arnold-Chiari I malformation: A case report

A 14-year-old girl with diplopia and esotropia secondary to Arnold-Chiari I malformation was surgically treated with Arnold-Chiari I malformation decompression (suboccipital craniectomy), C1 and partial C2 laminectomy, and duraplasty. The residual esotropia was treated with compensatory prisms and vision therapy more than 1 year after Arnold-Chiari malformation surgery. The esotropia was resolved after approximately 3.5 months of treatment. Five years later, the patient continued to maintain fusion without compensatory prism.

Why do the eyes cross? A review and discussion of the nature and origin of essential infantile esotropia, microstrabismus, accommodative esotropia, and acute comitant esotropia

PURPOSE

To try to explain the long-term stability of bilateral medial rectus botulinum toxin (botox) chemo-denervation in essential infantile esotropia; to evaluate divergent fusion amplitude in accommodative esotropia and acute comitant esotropia of emmetropes; to look for accommodation anomalies in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes; and to discuss characteristics of microstrabismus.

METHODS

Retrospective analysis of 61 essential infantile esotropia patients with early treatment with one botox injection in both medial rectus; measurement of divergent fusion amplitude in accommodative esotropia and acute comitant esotropia; measurement of Near point of accommodation in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes.

RESULTS

Stable results were found in 85.24% of essential infantile esotropia treated patients; reduced divergent fusion amplitude was detected in accommodative esotropia and acute comitant esotropia; hypo-accommodation was found in some patients with high AC/A ratio accommodative esotropia and a convergence spasm in acute comitant esotropia of myopes.

CONCLUSIONS

Very early botox treatment probably eradicates the effect of an excessive convergence tonus in essential infantile esotropia. A prevention of accommodative esotropia with full retinoscopic correction is only mandatory with a significantly reduced amplitude of fusional divergence. A deficit in accommodation should be looked for in high AC/A ratio accommodative esotropia, before bifocal lenses prescription. Early diagnosed acute comitant esotropia of myopic patients can be treated as a convergence spasm. Only surgery treats acute comitant esotropia, in patients with emmetropia or moderate hypermetropia.

Bilateral abducens palsies and facial weakness as initial manifestations of a Chiari 1 malformation

PURPOSE

Chiari I malformations are rare, congenital anomalies involving the caudal herniation of the cerebellar tonsils into the upper cervical spinal canal. Osseous abnormalities of the skull permit the extension of the hindbrain below the foramen magnum and engender syringohydromyelia formation. Neuroophthalmic manifestations are not uncommon; nevertheless, this is the first report of concomitant bilateral abducens palsies and facial nerve impairment as presenting manifestations of a Chiari I malformation.

CASE REPORT

A 30-year-old black female presented with a recent history of blurred vision and binocular diplopia in both left and right gazes. Headaches, dizziness, and orofacial sensorimotor impairments were noted in conjunction with the onset of her diplopia. No history of surgery, trauma, or systemic illness was elicited. Extraocular motility testing confirmed a complete bilateral abduction deficit. Additional cranial nerve testing revealed bilateral facial nerve weakness and tactile hypesthesia in the perioral region. No taste disturbances were reported. Nuclear magnetic resonance imaging studies revealed a Chiari I malformation with a syringohydromyelia formation in the vicinity of the patient's sixth cervical vertebrae. Foramen magnum decompression surgery was performed. Two months after surgery, abduction capacity was restored along with resolution of symptoms of perioral numbness and signs of facial weakness.

CONCLUSION

Bilateral sixth nerve palsies are rare clinical commodities especially when they do not occur in isolation. Intracranial neoplams, trauma, subarachnoid hemorrhaging, demyelinating disease, and meningeal infarcts have all been shown to induce mixed cranial neuropathies. The concomitant bilateral abducens palsy and concomitant facial nerve weakness reported in this case represents an atypical and previously unreported presentation of a Chiari I malformation.

Divergence insufficiency

INTRODUCTION AND PURPOSE

To compare the clinical characteristics of a population of patients with divergence insufficiency in the absence of associated neurologic disease to those patients with divergence insufficiency and an associated neurologic disorder.

PATIENTS AND METHOD

A retrospective review of 251 patients diagnosed with divergence insufficiency and/or divergence paralysis. Clinical features include the age at onset, fusional divergence amplitudes, the size of the esodeviation, treatment offered, and the presence or absence of associated neurologic conditions. Classification into primary and secondary divergence insufficiency solely depended on the absence or presence of neurologic disorders, respectively.

RESULTS

The incidence of neurologic disease associated with divergence insufficiency was 17%. The average age at onset was 62 years for primary and 51 years for secondary divergence insufficiency. Nystagmus was noted in 43% of secondary divergence insufficiency patients and 0.01% of primary divergence insufficiency patients. Both groups exhibited decreased fusional divergence at distance fixation while retaining normal fusional divergence at near.

CONCLUSIONS

The majority of patients were classified as primary divergence insufficiency. Though this form of divergence insufficiency is neurologically benign, it may easily mask a more severe neurologic condition for which the presenting symptom is also diplopia for distance viewing only. These results show the importance of obtaining a detailed history regarding the symptoms, as well as documenting neurologic signs, particularly nystagmus, when investigating divergence insufficiency.

Progressive cerebellar tonsillar herniation with recurrent divergence insufficiency esotropia

The Chiari malformations are characterized by herniation of posterior fossa contents through the foramen magnum. Chiari I malformation is currently defined as ectopia of the cerebellar tonsils more than 5 mm below the foramen magnum. Extension of the cerebellar tonsils up to 3 mm may be found in the normal population. Although Chiari malformations are congenital, symptoms often do not manifest until the third and fourth decades of life, or even later. Patients usually present with headache, lower cranial nerve palsies, downbeat nystagmus, ataxia, or dissociated anesthesia of the trunk and extremities. Definitive diagnosis is made by magnetic resonance imaging (MRI), which shows the compressed tonsils extending through the foramen magnum into the cervical subarachnoid space. One of the rare presenting signs of Chiari I malformations is acquired esotropia with a divergence insufficiency pattern. We report such a case in which the initial neuroimaging showed tonsillar herniation, but of insufficient magnitude to meet diagnostic criteria for Chiari I malformation. When the strabismus recurred after initially successful eye muscle surgery, follow-up scan showed progressive tonsillar herniation.

Resolution of papilledema after neurosurgical decompression for primary Chiari I malformation

PURPOSE

To report a causal relationship between Chiari I malformation and its rare, but recognized manifestation of bilateral papilledema.

DESIGN

Interventional case series.

METHODS

Four adult female patients (mean age, 48, age range 25-59 years) with bilateral papilledema, signs and symptoms of increased intracranial pressure, and cranial magnetic resonance imaging (MRI) evidence of a Chiari I malformation ranging from 7 to 22 mm of tonsillar herniation underwent suboccipital decompression.

RESULTS

In all four patients, suboccipital decompression was followed by resolution of bilateral papilledema and signs and symptoms of increased intracranial pressure.

CONCLUSION

Patients with bilateral papilledema and presumed pseudotumor cerebri require a cranial MRI to determine if they have a Chiari I malformation, because patients with increased intracranial pressure and papilledema from a Chiari I malformation may benefit from suboccipital decompression.

Resolution of acute acquired comitant esotropia after suboccipital decompression for Chiari I malformation

PURPOSE

To report a case of acute comitant esotropia successfully treated with suboccipital decompression in a 9-year-old male patient with Chiari I malformation.

DESIGN

Interventional case report.

METHODS

A 9-year-old male with Chiari I malformation had acute onset of diplopia, headache, and comitant esotropia.

RESULTS

About 9 months after suboccipital decompression, diplopia resolved and there was near orthophoria on examination 15 months after surgery.

CONCLUSION

In view of our case and after a review of literature, we advocate primary suboccipital decompression to treat acute comitant esotropia in patients with Chiari I malformation. A follow-up period of at least 1 year rather than 6 months seems necessary to assess surgery effects.

Strabismus surgery in the treatment of paralytic strabismus

Strabismus surgery may restore limited binocular function and improve cosmesis in patients with paralytic strabismus. Evaluation of the amount of residual function of the affected extraocular muscles is essential to determine which surgical procedure will yield the best results. Standard muscle resection techniques are effective for patients who have paretic extraocular muscles with residual function. Muscle transposition procedures are indicated for patients with total paralysis of an extraocular muscle. Autogenous and alloplastic materials may be required to fix the eye in primary position in patients with total paralysis of multiple extraocular muscles. This article discusses the recent literature regarding the evaluation and management of patients with paralytic strabismus. Current concepts regarding extraocular muscle transposition and the use of autogenous materials are emphasized.

Heroin withdrawal as a possible cause of acute concomitant esotropia in adults

PURPOSE

To report the possible effects of heroin withdrawal on binocular vision.

METHODS

A case series of patients is presented in whom esotropia developed on cessation of heroin use.

RESULTS

In each case the esotropia was concomitant and prismatic correction restored binocular single vision. Intermittent spontaneous control occurred in one patient, the deviation resolved in one and one patient was lost to follow-up.

CONCLUSIONS

Heroin withdrawal should be considered as a cause of acute concomitant esotropia. However, an accurate history of other medication is needed to ensure that this is not the cause of decompensation.

Isolated comitant esotropia and Chiari I malformation

PURPOSE

To report four patients with isolated comitant esotropia and Chiari I malformation and discuss the most appropriate management.

METHODS

Case reports and literature review.

RESULTS

All four patients (5, 14, 16, and 37 years of age) presented with an isolated comitant esotropia that led to the diagnosis of Chiari I malformation. The first two patients underwent uncomplicated neurosurgical decompression of their malformation, followed by complete resolution of their esotropia. The third patient underwent strabismus surgery and experienced initial resolution of the esotropia, but eventual recurrence resulted in the strabismus surgery being repeated 5 years later. The fourth patient had strabismus surgery with resolution of the esotropia but only 2 months of follow-up.

CONCLUSION

Although management of patients with Chiari I malformation and severe neurologic findings typically includes surgical decompression, management is less straightforward in cases with subtle findings or in which ocular findings are isolated. The decision to perform neurosurgical decompression or strabismus surgery should still be made on a case-by-case basis, with the understanding that strabismus surgery may provide only temporary ocular alignment.