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Biomedical subjects

S L Galetta

Publications and source records attributed to S L Galetta.

At least 73 records · Page 4Linked to original sources
PubMed1997

The central visual field in homonymous hemianopia. Evidence for unilateral foveal representation.

BACKGROUND: Controversy exists regarding the cortical representation of the foveal region in man. The most plausible explanation for foveal sparing in homonymous hemianopia is dual blood supply to the occipital pole. However, bilateral cortical representation has also been suggested. OBJECTIVE: To determine the representation of the foveal region in the primary human visual cortex. DESIGN: A case series correlating magnetic resonance imaging to the visual field defects of 6 patients with occipital lobe injuries. RESULTS: Four patients with foveal-sparing hemianopic defects demonstrated unilateral sparing of the posterior occipital cortex. In contrast, 2 patients with central homonymous defects showed isolated involvement of the posterior pole. One patient also demonstrated 5 degrees of field sparing along the horizontal meridian. CONCLUSIONS: On the basis of correlating the findings of magnetic resonance imaging and visual field defects in patients with occipital lobe injury, we conclude that the foveal region is unilaterally represented in the primary human visual cortex and that a major portion of the striate cortex is dedicated to the central 10 degrees of vision. The horizontal meridian of the visual field is represented deep within the calcarine banks at the fissure base.

Adult↗
PubMed1997

Pupil-involving third-nerve palsy and carotid stenosis: rapid recovery following endarterectomy.

We report a patient who presented with a painful pupil-involving third-nerve palsy. Cerebral angiography revealed a high-grade stenosis of the ipsilateral internal carotid artery with a 4-cm intraluminal thrombus. Following emergent carotid endarterectomy, the patient's partial third-nerve palsy resolved in 1 hour. A pupil-involving third-nerve palsy may be an unusual presentation of impending carotid occlusion.

Carotid Stenosis↗
PubMed1997

Magnetization transfer imaging in progressive multifocal leukoencephalopathy.

We report a patient with biopsy-proven progressive multifocal leukoencephalopathy (PML) who was serially imaged with MRI and magnetization transfer imaging. The magnetization transfer ratio (MTR) was profoundly and significantly diminished when compared with normal control subjects. The pattern of MTR was distinct from that of MS and periventricular ischemic white matter disease. Magnetization transfer imaging techniques may aid in the differential diagnosis of PML.

Aged↗
PubMed1997

Giant cell arteritis with unusual flow-related neuro-ophthalmologic manifestations.

We report two patients with giant cell arteritis and unusual neuro-ophthalmic findings. One patient developed a horizontal one and a half syndrome associated with upright posture. The responsible lesion was dorsal pontine infarction. The other patient had bright light-induced amaurosis fugax in the absence of extracranial carotid occlusive disease. Both patients continued to have symptoms despite the use of high-dose intravenous corticosteroids. The manifestations of both patients occurred early in the course of giant cell arteritis and were flow related.

Adrenal Cortex Hormones↗
PubMed1997

Refractory giant cell arteritis with spinal cord infarction.

We report an elderly patient with aggressive steroid-refractory giant cell arteritis manifesting as myelopathy and bilateral visual loss while on treatment. Pathologically, spinal cord infarction was observed and was due to extensive necrotizing granulomatous arteritis of spinal arteries. Spinal cord damage in giant cell arteritis is rare. One prior autopsy report of spinal cord infarction in giant cell arteritis did not identify vasculitic changes in the spinal arteries.

Aged↗
PubMed1997

Neuro-ophthalmic manifestations of Lyme disease.

Lyme disease is a multisystem disorder caused by infection with the Borrelia burgdorferi spirochete. The diagnosis of Lyme disease usually is based on several clinical criteria, with supportive data from laboratory testing. The presence of the bullseye skin lesion, erythema migrans, is the single pathognomonic criterion. In the 20 years since the initial description of Lyme disease in the United States, B. burgdorferi has been implicated as an etiologic agent in numerous ophthalmic and neuro-ophthalmic syndromes, involving most structures from the cornea to the cranial nerves. Neuro-ophthalmic and ocular manifestations of Lyme disease include meningitis with papilledema, cranial neuropathies, follicular conjunctivitis, nummular keratitis, and intraocular inflammation. Although an association with Lyme disease has been purported for numerous other syndromes, a definite causal relationship has not been proved in many cases. During a period of rapidly increasing awareness of Lyme disease, a high index of suspicion and poorly defined criteria for its presence have resulted in over-diagnosis of Lyme disease. In the authors' experience, the incorrect diagnosis of Lyme disease initially has been made in patients with allergic conjunctivitis, keratoconus, morning glory syndrome, craniopharyngioma, meningioma, CNS lymphoma, paraneoplastic syndrome, multiple sclerosis, sarcoid, syphilis, and functional illness. Nevertheless, this treatable infection must be an important consideration in the differential diagnosis of certain ocular or neurologic diseases.

Eye Diseases↗
PubMed1997

Neuro-ophthalmologic aspects of aneurysms.

The visual pathways and the ocular motor cranial nerves are frequently injured by expanding cerebral aneurysms. Neuro-ophthalmologic signs and symptoms may be the only indications of an aneurysm prior to rupture. Acute or chronic visual loss may herald an aneurysm prior to rupture. Acute or chronic visual loss may herald an aneurysm in the carotidophthalmic, supra clinoid carotid, internal carotid bifurcation, or anterior communicating artery distributions. Diplopia and retro-orbital pain may be warning signs that precede the discovery of a posterior communicating, basilar, or cavernous sinus aneurysm.

Acute Disease↗
PubMed1996

Severe sudden visual loss caused by pseudotumor cerebri and lumboperitoneal shunt failure.

PURPOSE: Severe vistral acuity loss associated with pseudotumor cerebri is usually caused by chronic optic disk edema or a retinal abnormality. METHODS: We treated a women, with known pseudotumor cerebri treated with a lumboperitoneal shunt, who developed acute pallied optic disk swelling and visual acuity of R.E.: no light perception and L.E.: 20/70 in association with lumboperitoneal shunt failure. There were no contributory retinal lesions. RESULTS: The patient underwent optic nerve sheath fenestration and lumboperitoneal shunt revision. Visual acuity improved to 20/20 in both eyes. The papilledema resolved. CONCLUSION: The severe sudden visual loss was attributed to axoplasmic stasis and optic nerve ischemia associated with a sudden rise in intracranial pressure.

Adult↗
PubMed1996

Localization of traumatic oculomotor nerve palsy to the midbrain exit site by magnetic resonance imaging.

PURPOSE: To present the magnetic resonance imaging findings for a patient with traumatic oculomotor nerve injury. METHODS: We examined a patient with a right pupil-involving oculomotor nerve palsy after severe closed head trauma. RESULTS: Magnetic resonance imaging of the brain demonstrated marked signal hypointensity on gradient-echo T2*-weighted images consistent with hemorrhage at the midbrain exit site of the right oculomotor nerve. CONCLUSIONS: Distal fascicular damage or partial rootlet avulsion is a mechanism of injury in some traumatic oculomotor nerve palsies. Gradient-echo T2*-weighted magnetic resonance imaging is the most sensitive method to detect hemorrhagic changes associated with shearing injury.

Accidents, Traffic↗
PubMed1996

Prominent proptosis in childhood thyroid eye disease.

BACKGROUND: Orbital signs and symptoms occur in approximately one half of children with Graves disease, but the symptoms are usually minor and limited to the eyelids. Prominent proptosis is uncommon in children with this disorder. METHODS: Review of eight children with prominent proptosis associated with thyroid eye disease. Four patients were treated at the Children's Hospital of Philadelphia, the other four at the Columbia Presbyterian Medical Center. RESULTS: At initial presentation, children ranged in age from 3 to 16 years. There were five girls and three boys. Seven of eight children had hyperthyroidism at ophthalmic presentation. Four patients had restrictive myopathy, and all of the seven patients who underwent neuroimaging had extraocular muscle enlargement. Five patients were treated with lubrication. Two underwent orbital fat decompression. One patient had thyroid eye disease and myasthenia gravis. CONCLUSIONS: Proptosis in childhood thyroid eye disease usually is associated with a hyperthyroid state. The proptosis may be dramatic, but corneal exposure and restrictive myopathy are seen in only some of the patients. Neuroimaging shows enlarged extraocular muscles. Most children with this complication can be treated conservatively with topical lubrication, but orbital fat decompression may be considered in patients with more advanced conditions.

Adolescent↗
PubMed1996

Diagnostic tests in neuro-ophthalmology.

This article reviews the diagnostic testing used in the evaluation of several common neuro-ophthalmologic entities including optic nerve disease, pseudotumor cerebri, anisocoria, ptosis, and ocular motor palsies. Emphasis is placed on these bedside tests that help to establish the diagnosis of these common clinical problems. The utility of the cocaine and Tensilon (edrophonium chloride) tests as well as the role of neuroimaging in these conditions are reviewed.

Brain Diseases↗