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Biomedical subjects

Robert A Egan

Publications and source records attributed to Robert A Egan.

At least 19 recordsLinked to original sources
PubMed2006

Intermittent reversal of complete ptosis associated with sphenoid wing meningiomas.

CASE REPORT: Ptosis secondary to dense oculomotor pareses generally improves over several months, but intermittent elevation of the eyelid has not been reported. The authors describe two patients who demonstrated intermittent involuntary monocular eyelid elevation in an eye with complete ptosis caused by partial resection of sphenoid wing meningioma. Both patients had complete ophthalmoplegia and decreased corneal sensation. The involved eye was ipsilateral to a meningioma that had been debulked 11 to 12 months previously. Although the lids were devoid of volitional movement, each patient could elevate the lid for 10 to 20 seconds by either tickling the eyelashes or rubbing the eyelids. The lids occasionally rose spontaneously and there was no clinical evidence of aberrant regeneration or cyclic spasm. COMMENTS: Although the mechanism of action of this involuntary eyelid elevation is unknown, it is possible that some process of aberrant regeneration activated by sensory stimuli is responsible.

Adult↗
PubMed2006

Ischemic optic neuropathy following spine surgery in a 16-year-old patient and a ten-year-old patient.

Peri-operative ischemic optic neuropathy typically occurs in middle-aged or older patients. We report this condition in two patients aged 16 and 10 years. Only six other cases of peri-operative ischemic optic neuropathy have been reported in patients aged less than 30 years, all but one occurring after spinal surgery. Although the visual prognosis appears to be more favorable in younger patients, the pathogenesis of this rare complication of surgery is likely to be the same as that affecting older individuals.

Adolescent↗
PubMed2005

Clinical and electrophysiologic characterization of paraneoplastic and autoimmune retinopathies associated with antienolase antibodies.

PURPOSE: Paraneoplastic and autoimmune retinopathies are immunologically mediated retinal degenerations that are associated with antibodies directed against any of several retinal proteins, including alpha-enolase. We report the clinical and electrophysiological features of antienolase retinopathy in contrast to the features of antirecoverin retinopathy. DESIGN: Retrospective, observational case series. METHODS: Patients were referred for evaluation of unexplained acquired visual symptoms, including photopsias, and loss of visual acuity or field considered of possible retinal origin. Full-field and multifocal electroretinograms (ERGs) were performed. Sera from patients were examined for antiretinal antibodies by Western blot analysis using proteins extracted from human retinas and by immunohistochemistry; antienolase was confirmed by incubating patient sera with purified alpha-enolase. RESULTS: Of 87 patients with unexplained retinal visual symptoms associated with abnormal ERGs, 37 (43%) demonstrated autoantibodies to retinal antigens, including 12 against alpha-enolase, of whom 4 had cancer. Initial visual loss was typically central and often asymmetric. The ERGs demonstrated mostly normal rod responses but central cone abnormalities (evident on multifocal ERG) and, for many, global cone abnormalities. Seven patients developed optic disk pallor. Corticosteroid and immunosuppressive therapy, when attempted, was clinically ineffective. CONCLUSIONS: Antienolase retinopathy is a protean autoimmune retinopathy that characteristically presents with cone dysfunction. The visual impairment and course vary from relative stability for years to slow progression with loss of central vision. With time, optic disk pallor can evolve, presumably from attrition of ganglion cells.

Adult↗
PubMed2005

Neuro-ophthalmologic and electroretinographic findings in pantothenate kinase-associated neurodegeneration (formerly Hallervorden-Spatz syndrome).

PURPOSE: The onset of pantothenate kinase-associated neurodegeneration (PKAN) occurs in the first and second decade of life and a pigmentary retinal degeneration is a feature of the disorder. Since the neuro-ophthalmologic and electroretinographic (ERG) features have never been well delineated, we describe them in 16 patients with PKAN. DESIGN: Observational case series. METHODS: Sixteen patients with genetic and neuroimaging-confirmed PKAN were examined. Ten underwent neuro-ophthalmologic examination and all had ERGs. RESULTS: Of the 10 who underwent neuro-ophthalmologic examination, all showed saccadic pursuits and eight showed hypometric or slowed vertical saccades. Seven of eight had inability to suppress the vestibulo-ocular reflex; two patients could not cooperate. Two had square wave jerks and four had poor convergence. Vertical optokinetic responses were abnormal in five, and two patients had blepharospasm. Eight patients had sectoral iris paralysis and partial loss of the pupillary ruff consistent with Adie's pupils in both eyes. Only four of 10 examined patients showed a pigmentary retinopathy, but 11 of 16 had abnormal ERGs ranging from mild cone abnormalities to severe rod-cone dysfunction. No patient had optic atrophy. The PANK2 mutations of all of the patients were heterogeneous. CONCLUSIONS: Adie's-like pupils, abnormal vertical saccades, and saccadic pursuits were very common. These findings suggest that mid-brain degeneration occurs in PKAN more frequently than previously thought. ERG abnormalities were present in approximately 70% and no patient had optic atrophy. Although genotype-ocular phenotype correlations could not be established, allelic differences probably contributed to the variable clinical expression of retinopathy and other clinical characteristics in these patients.

Adolescent↗
PubMed2005

Treatment of corticosteroid dependent optic neuropathy with intravenous immunoglobulin.

PURPOSE: To report a patient with corticosteroid dependent optic neuropathy treated with intravenous immunoglobulin (IVIg). DESIGN: Interventional case report. METHODS: Records review. RESULTS: A 25-year-old woman developed bilateral vision loss with pain on eye movement in association with disk edema, dilated retinal veins, and hemorrhage. The vision improved markedly with prednisone, but she required a minimum of 20 mg/d despite concomitant therapy with methotrexate, cyclosporine, and/or mycophenolate mofetil. IVIg, 0.5 g/kg/d for 3 days each month with subsequent reduction in frequency, allowed discontinuation of all immunosuppression. CONCLUSIONS: Corticosteroid dependent optic neuropathy was successfully treated with IVIg.

Adult↗
PubMed2005

Idiopathic repetitive oculomotor nerve palsies in otherwise normal patients.

OBJECTIVE: To describe a unique idiopathic disorder characterized by transient repetitive unilateral oculomotor pareses. DESIGN: Retrospective observational case series. PARTICIPANTS: Three women presenting for tertiary neuro-ophthalmologic evaluation. METHODS: Review of patient records. MAIN OUTCOME MEASURES: Historical information, clinical examination, neuroimaging, and laboratory evaluation for myasthenia gravis. RESULTS: Three 44- to 69-year-old women had recurrent unilateral ptosis over the course of 2 to 4 years. Two had concurrent diplopia with ipsilateral limitation of adduction, and 2 also had a large poorly reactive pupil in the involved eye during the episodes. The attacks lasted between 30 seconds and 4 hours and occurred up to 6 times daily. None of the patients were migraineurs, nor had they received radiation therapy. Neuro-ophthalmologically normal between episodes, all patients had normal magnetic resonance imaging/angiography and testing for myasthenia gravis. CONCLUSION: Transient, recurrent, unilateral oculomotor nerve palsies may occur spontaneously in healthy individuals. The pathogenesis remains obscure, but the multiple recurrences without evident sequelae and the failure to develop any systemic or neurological disorder suggest that this phenomenon is not indicative of a serious underlying disorder.

Adult↗
PubMed2005

Frequency and amplitude of elevation of cerebrospinal fluid resting pressure by the Valsalva maneuver.

BACKGROUND: Patients are referred to ophthalmologists to evaluate for papilledema when they are found to have elevated cerebrospinal fluid (CSF) pressure. However, some of these patients have no clinical history consistent with intracranial hyper-tension. We aimed to determine how often and how high patients with normal opening pressure could artificially elevate their CSF pressure to a pseudo-pathologic level by performing a Valsalva maneuver. METHODS: We measured CSF pressure at rest and after a Valsalva maneuver in 15 consecutive normotensive patients referred for CSF analysis to determine the frequency and amplitude of elevation of pressure. Manometry was performed in the standard lateral decubitus position with legs and knees extended and abdomen relaxed and then again during a Valsalva maneuver with hip flexion and bearing down against a closed glottis. RESULTS: All 15 normotensive patients elevated their CSF pressure to levels greater than 25 cm water. One patient reached a maximum pressure of 47 cm water. INTERPRETATION: Artifactual elevation of CSF pressure may therefore occur frequently. Caution is advised before accepting a diagnosis of intracranial hypertension in those lacking this syndrome. These patients require repeat CSF pressure measurements to either verify or refute previous recordings.

Adolescent↗
PubMed2004

Functional visual loss.

Functional visual loss is a common problem encountered in practice. It must be recognized that this problem occurs in patients who have organic illness. Manual perimetry is the most effective method for evaluating functional visual loss, and the presence of a central scotoma in a functional visual field strongly suggests that organic pathology is present. Neuropsychological and psychiatric intervention can be useful in treating these patients.

Humans↗
PubMed2003

Retinal arterial wall plaques in Susac syndrome.

PURPOSE: To demonstrate retinal arterial wall plaques (RAWPs) in patients with Susac syndrome, a disorder that consists of the triad of branch retinal artery occlusion, encephalopathy, and hearing loss. The clinician may misinterpret these RAWPs as emboli. DESIGN: Observational case series. METHODS: Four patients (one man and three women, aged 21-38 years) were examined and followed. RESULTS: Four patients with Susac syndrome had RAWPs in association with branch retinal artery occlusions. They were present in six of eight eyes. The plaques were yellow to yellow-white and located usually away from retinal bifurcations. Retinal arterial wall plaques occur at the midarteriolar segments, whereas Hollenhorst plaques occur at vascular bifurcations. Four of six eyes had resolution of the plaques. CONCLUSIONS: Retinal arterial wall plaques may occur with branch retinal artery occlusions in Susac syndrome. This finding should help the clinician who is struggling to make a diagnosis in a patient with an enigmatic encephalopathy and/or hearing loss. These plaques may resolve over time.

Adult↗
PubMed2003

Prevalence of organic neuro-ophthalmologic disease in patients with functional visual loss.

PURPOSE: To determine the concurrence of various patterns of functional visual loss (FVL) and organic disease. DESIGN: A retrospective case series in a university neuro-ophthalmology practice. METHODS: A retrospective case series in which we reviewed the clinical histories and neuro-ophthalmologic examinations of 133 consecutive patients diagnosed with FVL between July 1999 and August 2001. Functional visual loss was defined as an apparent afferent or efferent dysfunction that was unassociated with or far out of proportion with an identifiable lesion of the visual pathways. RESULTS: A total of 133 patients were identified. Nineteen were pediatric, and 76 were female. Fifty-six had concurrent head or eye pain. Nineteen had a recent history of trauma, and 17 had a recent surgical procedure. The most common pattern of FVL was a normal visual field in the presence of reduced visual acuity. Seventy-one patients (53%) with FVL presented with abnormal neuro-ophthalmologic examinations. Thirteen patients had central scotomata, and all had concurrent retinal or optic nerve pathology. Only 18 patients had a known disability claim pending. CONCLUSION: Although FVL was found in patients with no pathology, it was more common to find objective abnormalities on examination. This concurrence rate underscores the clinical necessity for following patients closely despite the diagnosis of FVL. No pattern of visual field constriction was routinely predictive of ophthalmologic or neurologic pathology except the presence of a central scotoma. The presence of a central scotoma in a nonorganic visual field should alert the practitioner to search for organic pathology.

Adolescent↗
PubMed2003

Survey of genetic neuro-ophthalmic disorders.

This article provides an overview of the genetic aspects of neuro-ophthalmic disorders. Leber's hereditary optic neuropathy, optic nerve hypoplasia, Duane's retraction syndrome, congenital nystagmus, and other disorders of neuro-ophthalmic interest are discussed.

Afferent Pathways↗