Treatment of acute comitant esotropia in Chiari I malformation.

PURPOSE: To explore the appropriate treatment of acute comitant esotropia in patients with Chiari I malformation. DESIGN: Interventional case reports and literature review. PARTICIPANTS: Two patients with Chiari I malformation presenting with acute comitant esotropia are described. INTERVENTION: Strabismus surgery, then neurosurgical decompression of the Chiari I malformation was performed. MAIN OUTCOME MEASURE: Both patients were evaluated for resolution of esotropia and other ocular motility problems. RESULTS: After initially successful strabismus surgery, both patients developed recurrent esotropia with diplopia, which resolved on suboccipital decompression. CONCLUSION: Comitant esotropia may recur and other eye movement disorders may develop after initially successful strabismus surgery in patients with Chiari I malformation. The data suggest that the appropriate sequence of treatment should first be suboccipital decompression, then strabismus surgery if spontaneous realignment does not occur, but further studies are needed to confirm this impression.

Tonic ocular tilt reaction simulating a superior oblique palsy: diagnostic confusion with the 3-step test.

BACKGROUND: The tonic ocular tilt reaction (OTR) consists of vertical divergence of the eyes (skew deviation), bilateral conjugate ocular torsion, and paradoxical head tilt. The head and superior pole of both eyes are rotated toward the hypotropic eye. OBJECTIVE: To describe ocular motility and torsion findings in 5 patients with OTRs that mimicked superior oblique palsies (SOPs). RESULTS: In 5 patients, results of the 3-step test suggested an SOP (bilateral in 1 patient); however, no patient had the expected excyclotorsion of the hypertropic eye. Two patients had conjugate ocular torsion (intorsion of the hypertropic eye and extorsion of the hypotropic eye), and 2 patients had only intorsion of the hypertropic eye. All had other neurologic features consistent with more widespread brainstem disease. CONCLUSIONS: Vertical ocular deviations that 3-step to an SOP are not always caused by fourth nerve weakness. When a patient with an apparent fourth nerve palsy has ocular torsion that is inconsistent with an SOP, OTR should be suspected, especially if vestibular system or posterior fossa dysfunction coexists. The rules for the 3-step test for an SOP may be fulfilled by damaging the otolithic projections corresponding to projections of the contralateral anterior semicircular canal. Because results of the Bielschowsky head tilt test may be positive in patients with the OTR, the feature distinguishing OTR from an SOP is the direction of torsion. We advocate use of a fourth step-evaluation of ocular torsion-in addition to the standard 3 steps.

High prevalence of bihemispheric structural and functional defects in Sturge-Weber syndrome.

Abnormal cerebral venous drainage is associated with hypoxia and glucose deprivation, which can account for progressive neurologic deterioration in Sturge-Weber syndrome. Although developmental delay is common in Sturge-Weber syndrome, bihemispheric calcification is uncommon. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to study the neuroanatomy, while single photon emission computed tomography (SPECT) was used concurrently to evaluate perfusion and glucose metabolism using 99mTc hexamethylpropyleneamine oxime (HMPAO) and [18F] fluorodeoxyglucose (FDG), respectively. Ten patients (10 to 22 years of age) with previously diagnosed Sturge-Weber syndrome, port-wine nevi, and clinical evidence of seizures or stroke-like episodes were studied. Five children with onset of seizures in the first year of life had overall clinical severity comparable to that of children with later-onset seizures. Calcification was present in both hemispheres in one patient; six additional patients had other radiologic evidence of bihemispheric disease; SPECT studies detected bihemispheric disease in four cases. Our study is the first to concurrently evaluate structure, perfusion, and glucose metabolism in Sturge-Weber syndrome and to show a mismatch between functional and structural brain imaging in both cerebral hemispheres. Widespread abnormalities of cerebral perfusion and glucose metabolism might explain the high prevalence of developmental delay associated with Sturge-Weber syndrome. Longitudinal studies are needed to define better the natural history of neurologic deterioration and radiologic progression that relates to central nervous system circulatory dysfunction in Sturge-Weber syndrome.

Central nervous system structure and function in Sturge-Weber syndrome: evidence of neurologic and radiologic progression.

Sturge-Weber syndrome is characterized by the presence of a port-wine nevus, epilepsy, stroke-like episodes, headache, and developmental delay. We studied 20 cases to test the hypothesis that decreased cerebral blood flow alters neurologic function by affecting cellular glucose metabolism. Group A consisted of 10 patients with a mean age of 1.75 years and early seizure onset (6.8 months), whereas group B was composed of older patients (mean age, 15.3 years) with later onset of seizures (3.7 years). Neurologic disease was more severe in group A, but group B had more widespread structural brain defects - shown on computed tomographic scans and magnetic resonance imaging - and metabolic brain defects shown on hexamethylpropyleneamine oxime and [18F] fluorodeoxyglucose single photon emission computed tomographic scans. Six group A cases had hypoperfusion at baseline and five of nine had worsening of perfusion and glucose metabolism 1 year later. A total of 119 stroke-like episodes occurred in six group A cases and eight group B cases; there were 65% fewer strokes in children treated with aspirin. The data suggest that progressive hypoperfusion and glucose hypometabolism are associated with neurologic deterioration in Sturge-Weber syndrome. Longitudinal studies are needed to better define the natural history of disease and to evaluate the safety and efficacy of aspirin therapy.

"Joubert syndrome" revisited: key ocular motor signs with magnetic resonance imaging correlation.

Joubert syndrome is characterized by episodic hyperpnea and apnea, developmental delay, hypotonia, truncal ataxia, ophthalmologic abnormalities, and vermian dysgenesis. We studied 15 patients with the diagnosis of Joubert syndrome to (1) more fully define the syndrome's clinical features, and (2) correlate the clinical features with magnetic resonance imaging (MRI) findings. Eight of 15 patients had a history of episodic hyperpnea and apnea. All patients had developmental delay and hypotonia. Of the 13 patients receiving detailed neuro-ophthalmologic evaluations, three had optic nerve dysplasia, pendular nystagmus, and gaze-holding nystagmus. All 13 patients had a normal vestibulo-ocular reflex based on head thrust, but had absent to poor ability to cancel the vestibulo-ocular reflex horizontally and vertically. Twelve of 13 patients had impaired smooth pursuit. Twelve of 13 patients had defects in initiation of saccades and quick phases. Two of the most consistent radiologic features were absent or hypoplastic posterior cerebellar vermis, and deformed midbrain and pontomesencephalic junction, which based on ocular motor physiology correlate with the vestibulo-ocular reflex cancellation/ pursuit defect and saccade initiation defect, respectively. As a result of midbrain, vermian, and superior cerebellar peduncle abnormalities, axial neuroimaging showed a unique "molar tooth" appearance of these structures. These results indicate that Joubert syndrome results from maldevelopment of the midbrain and cerebellar vermis, producing a pathognomonic sign on MRI.

Neovascular glaucoma after carotid endarterectomy.

The authors examined a patient who had neovascular glaucoma (NVG) shortly after ipsilateral carotid endarterectomy and followed the patient's clinical course. The authors speculate that the sudden reperfusion after endarterectomy that occurs in patients with combined central retinal artery occlusion and carotid occlusive disease may enhance the circulation of preformed angiogenesis factors, leading to the development of neovascularization. The authors recommend frequent and careful surveillance of patients with central retinal artery occlusion associated with carotid occlusive disease if ipsilateral carotid endarterectomy is performed.

Intact binocular function and absent ocular torsion in children with alternating skew on lateral gaze.

BACKGROUND: A form of skew deviation, called alternating skew on lateral gaze, resembles bilateral superior oblique overaction. Oblique muscle overaction has been recently speculated to result from loss of fusion with subsequent "free-wheeling" of the torsional control mechanisms of the eyes, causing sensory intorsion or extorsion with attendant superior or inferior oblique muscle overaction, respectively. We wanted to investigate whether loss of fusion plays a role in the pathogenesis of alternating skew on lateral gaze. SUBJECTS AND METHODS: We examined seven consecutive patients with posterior fossa tumors, enrolled in a multi-disciplinary pediatric neuro-oncology program, who displayed alternating skew on lateral gaze. All patients underwent a thorough ophthalmologic evaluation. RESULTS: Visual acuities in the study patients ranged from 20/20 to 20/40. Five of the seven patients were orthotropic, and showed 40 sec of arc stereopsis. Three patients showed associated downbeat nystagmus. No ocular torsion was found in any of the five patients who showed normal stereopsis upon inspection of fundus landmarks on indirect ophthalmoscopy. CONCLUSION: Patients with alternating skew on lateral gaze often have normal binocular vision and stereopsis, and lack ocular intorsion so typical of superior oblique overaction. Alternating skew on lateral gaze is neurologically mediated, with no role for defective fusion in its pathogenesis.

Venous stasis orbitopathy: a clinical and echographic study.

AIMS: A variety of acute and chronic orbitopathies may be distinguished by standardised echography. Venous stasis orbitopathy (VSO) often presents with orbital signs when secondary to cavernous sinus and middle cranial fossa disorders. In this study, the aim was to assess whether differentiation between vascular and nonvascular causes of VSO could be made on the basis of clinical and echographic features at the time of presentation. METHODS: This study comprised 37 patients with echographic features of VSO (17 patients with arteriovenous fistulae, confirmed by computed tomography imaging or angiography, and 20 patients with non-vascular diseases). Excluded were patients with orbital mass lesions detected by echography and muscle enlargement due to other causes (for example, orbital myositis). Patients with a suspected mass involving the orbital apex and echographic features of VSO were included. After full neuro-ophthalmic and ocular examination, both orbits were examined to document maximal thickness and reflectivity of four recti muscles and compared with the normal contralateral orbit with standardised A-scan (Kretz-technik 7200MA or Ophthascan) and contact B-scan (Ultrascan or Ophthascan S). RESULTS: Cumulative ocular recti muscle thickness was significantly greater in patients with arteriovenous fistulae compared with the non-fistula group (23.3 (SD 3.7) and 17.8 (2) mm, p = 0.001). Clinically, the presence of a bruit and a uniocular rise in intraocular pressure were significantly greater in the fistula group of patients. CONCLUSIONS: Standardised echography is a safe and non-invasive method of diagnosing VSO in patients presenting with signs of proptosis, ophthalmoplegia, and inflammation of the conjunctiva. Furthermore, using these standard techniques the two major causes of VSO (arteriovenous fistulae and compressive mass lesions) could be differentiated.

Use of scheimpflug photography to study iris configuration in patients with pigment dispersion syndrome and pigmentary glaucoma.

PURPOSE: To evaluate the use of Scheimpflug photography in the examination of iris configuration and anterior chamber depth in eyes with pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). METHODS: The Nidek EAS 1000 Scheimpflug camera was used to photograph the anterior segment of 12 eyes with PDS/PG, as well as 12 age-matched controls and four eyes with primary open-angle glaucoma (POAG). Anterior chamber depth, iris insertion angle, and iris configuration were evaluated. Five eyes of three patients were serially photographed over 10 min while blinking was prevented. RESULTS: Patients with PDS/PG showed deeper anterior chambers than age-matched controls or patients with POAG. Nine of 12 PDS/PG eyes showed a concave iris configuration. There were no concave irides noted in control or POAG eyes. Preventing blinking resulted in significant anterior excursion of concave irides in three of the five eyes studied. CONCLUSIONS: Scheimpflug photography is a useful modality to study iris configuration. These photographs document the presence of a concave iris configuration in some patients with PDS/PG, and support the hypothesis that blinking may be significant in producing this configuration.

Fixation duress in the pathogenesis of upper eyelid retraction in thyroid orbitopathy. A prospective study.

BACKGROUND: Upper eyelid retraction in thyroid eye disease may be caused by proptosis, levator and Müller's muscle infiltration with fibrosis or individual fiber enlargement, excessive sympathetic innervation, abnormal adhesions between levator palpebrae muscle and surrounding tissues, or fixation duress. Fixation duress refers to upper eyelid retraction while fixating with an eye with inferior rectus muscle restriction due to excessive simultaneous firing of the ipsilateral superior rectus and levator palpebrae muscles. METHODS: The authors prospectively examined six patients with strabismus and thyroid eye disease associated with inferior rectus restriction and upper eyelid retraction in whom the eyelid retraction was suspected clinically to be a result of fixation duress. All six patients underwent recession of both inferior recti ranging from 3 to 6.5 mm (mean, 4.5 mm) to improve the ocular motility and alignment, reduce the diplopia, and mitigate the upper eyelid retraction. RESULTS: Reduction of upper eyelid retraction measured as the preoperative versus postoperative difference in corneal light reflex-upper eyelid margin measurements was achieved in all patients postoperatively, ranging from 1.5 to 5.5 mm (mean, 3.2 mm). Only one patient showed significant residual retraction to warrant consideration of upper eyelid surgery. CONCLUSION: Fixation duress plays a significant role in upper eyelid retraction of thyroid eye disease in a subset of patients with restriction of the inferior rectus muscle. In this selected group of patients, the upper eyelid retraction may be reduced or eliminated upon proper recession of the tight inferior rectus muscle(s).

Temporary blindness in the TUR syndrome.

The TUR syndrome is a clinical disorder consisting of circulatory, gastrointestinal, and neurologic signs that are infrequently seen in some patients undergoing endoscopic surgery of the prostate gland with the use of nonconductive irrigating fluids. Several theories of its pathogenesis have been proposed. The condition may occasionally be associated with bilateral profound loss of vision. We report a patient with the TUR syndrome who suffered bilateral temporary blindness and speculate on the etiology of the visual loss and localization of the dysfunction along the visual pathway.

Spontaneous orbital hemorrhage during general anesthesia and arthroplasty.

A 72-year-old woman who had a history of arthritis and cerebral vascular accident 4 years earlier underwent hand surgery. Because regional anesthesia was not successful, general anesthesia was administered. Shortly before extubation, proptosis developed in her left eye, and she was unable to open it. The condition was due to spontaneous orbital hemorrhage and resolved with conservative treatment.

Value of thallium-201 SPECT imaging in childhood brain tumors.

Thallium-201 chloride single photon emission computed tomography (201Tl SPECT) has been proposed as a diagnostic tool in the assessment of patients with brain tumors. We performed SPECT scans coupled with magnetic resonance imaging (MRI) in children with brain tumors to determine the sensitivity and potential value of SPECT in neuro-oncology. Each patient was injected with 2.5-3.0 mCi of thallium chloride, followed by technetium-99m HMPAO (5-15 mCi) to assess cerebral perfusion. 201Tl uptake was imaged with triple-headed SPECT in 20/24 (83%) histologically and anatomically diverse neoplasms with MRI-measurable residual disease, including 13/16 (80%) posterior fossa tumors. 201Tl SPECT demonstrated uptake in tumors with MRI volumes ranging from 0.03 to 60 cm3. 201Tl SPECT imaging was not correlated with the following MRI features: gadolinium enhancement, necrosis, exophytic, unicentric and multicentric. 201Tl uptake was not detectable in patients with tumors of maldevelopmental origin or radionecrosis. It is suggested that 201Tl SPECT is an important imaging adjunct in the assessment of children with brain tumors.

The prevalence of neurologic dysfunction in children with strabismus who have superior oblique overaction.

BACKGROUND: Children with certain neurologic diseases (hydrocephalus, meningomyelocele, or cerebral palsy) have been reported to manifest a high frequency of A-pattern strabismus and superior oblique overaction. However, it is not generally recognized whether children with strabismus who have superior oblique overaction are more likely to have concurrent neurologic diseases than those without superior oblique overaction. In this study, the authors examine this issue. METHODS: The authors retrospectively reviewed the medical records of all patients (n = 168) with overdepression of the downturned eye in adduction, who were examined between October 1989 and March 1992. A randomly selected population of children with strabismus who did not have overdepression of the eye on infraduction and adduction served as controls (n = 98). Patients with simulating or confounding conditions such as pseudo-superior oblique overaction, inferior rectus skew deviation (alternating skew on lateral gaze), and restrictive or paralytic strabismus, and who were older than 20 years of age, were excluded. RESULTS: One hundred twelve patients with true superior oblique overaction were analyzed. Of these 112 patients, 45 (40.2%) had concurrent neurologic abnormalities, compared with less than one fifth (17.3%) of control subjects (17 of 98) (P < or = 0.001). CONCLUSIONS: Children with strabismus who have superior oblique overaction were found to have higher prevalence of concurrent neurologic diseases than control subjects. Superior oblique overaction may represent a clinical marker for an associated neurologic dysfunction, possibly representing a form of skew deviation in some cases.

Bilateral isolated retrobulbar optic neuropathy in limited Wegener's granulomatosis.

Wegener's granulomatosis causes a variety of ophthalmologic disorders, some of which occasionally constitute the initial presentation of the disease. We describe a patient who presented with bilateral, isolated, consecutive, posterior optic neuropathy with light perception and no light perception vision. The patient had no other symptoms or signs of orbital disease. Investigations revealed cavitary lung lesions, positive antineutrophilic cytoplasmic antibody (ANCA) titers, subtle focal enhancement of the intracanalicular optic nerves on magnetic resonance imaging, and a confirmatory bronchial biopsy. This exceedingly rare ocular presentation of Wegener's granulomatosis may pose a diagnostic quandary.

Juvenile xanthogranuloma of the corneoscleral limbus.

A 10-year-old boy had a slowly enlarging left limbal mass, extending into the corneal stroma, but not into the anterior chamber. The lesion was excised by lamellar sclerokeratectomy and subsequently confirmed histopathologically as a juvenile xanthogranuloma. Though rare, juvenile xanthogranuloma of the corneoscleral limbus should be considered in the differential diagnosis of limbal mass lesions extending into the cornea. Total resection is usually curative.

Magnetic resonance angiography of vascular lesions causing neuro-ophthalmic deficits.

Magnetic resonance angiography (MRA) is a noninvasive, rapidly evolving technique for imaging the intra- and extracranial carotid and vertebrobasilar circulations. It may in some circumstances obviate conventional angiography and the accompanying risks associated with catheterization and contrast injection. MRA exploits the different physical properties between moving protons and stationary tissue to yield flow sensitive data in the form of anatomic images or velocity and flow measurements. Since patients with various vascular disorders may present exclusively with ophthalmologic signs and symptoms, it is expected that MRA will become more frequently utilized by ophthalmologists. The exact role of MRA in the workup of vascular disorders remains to be more precisely defined, pending the performance of additional well-controlled standardized studies. At present, MRA is utilized to complement the conventional spin-echo studies of patients with arterial and venous occlusion, vascular malformations, intracranial aneurysms, and neoplastic vascular invasion. With further refinements, it is expected that MRA will become a standard diagnostic tool for the evaluation of patients with vascular disorders.

Brainstem glioma: I. Pathology, clinical features, and therapy.

Gliomas that arise in the brain stem have been associated with a poor prognosis. Diagnostic neuroimaging readily identifies the tumor as it extends between normal brainstem structures. Histologic sampling of tumor with stereotactic methods is notoriously unreliable in establishing a definitive prognosis. Clinical trials that incorporate high-dose chemotherapy, autologous bone marrow rescue, and irradiation hold promise of better tumor control by overcoming the inaccessibility of the central nervous system to standard doses of chemotherapy. We review the pathology, clinical features, neuroimaging features, and current therapeutic concepts relative to brainstem glioma. The pediatric neurologist has a pivotal role in identifying and monitoring children with this malignancy.