John E. Carter

Current management of amaurosis fugax

We present a consensus on the pathophysiology, etiology, diagnosis, and treatment of amaurosis fugax. The phenomenon is defined and described, and the roles that extracranial and ocular vascular diseases play are discussed. Nonvascular ophthalmic and neurologic disorders that can be confused with amaurosis fugax are listed, and an algorithm for evaluation (which includes ophthalmic examination, laboratory studies, and noninvasive carotid artery studies) is given. Treatment of atherosclerosis, carotid artery disease, and other causes of amaurosis fugax are also discussed.

Anterior ischemic optic neuropathy is not associated with carotid artery atherosclerosis.

Background and Purpose: The relation between anterior ischemic optic neuropathy and carotid artery atherosclerotic disease is unclear. We studied patients with anterior ischemic optic neuropathy to determine if they had an increased occurrence of carotid artery stenosis. Methods: Fifteen consecutive patients with anterior ischemic optic neuropathy were evaluated prospectively for cervical carotid artery stenosis and compared with 30 age‐ and sex‐matched asymptomatic patients and also with 11 age‐ and sex‐matched patients experiencing transient monocular blindness. Results: There was no difference in the mean stenosis of the internal carotid artery between patients with anterior ischemic optic neuropathy (mean carotid stenosis, 19%) and asymptomatic patients (mean carotid stenosis, 9%; p >0.05), whereas patients with transient monocular blindness had significantly more stenosis (mean, 77%) in the cervical carotid arteries than both control subjects (p < 0.0001) and patients with anterior ischemic optic neuropathy (p < 0.0001). There was also no difference in the percentage of patients with stenosis ≥30% in anterior ischemic optic neuropathy (two of 15) and asymptomatic patients (five of 30), whereas 10 of 11 patients with transient monocular blindness had stenoses ≥30%, significantly more than patients with anterior ischemic optic neuropathy (p < 0.0001) and asymptomatic patients (p < 0.0001). Conclusions: Anterior ischemic optic neuropathy is not a marker for atherosclerotic carotid artery stenosis. The pathogenesis of nonarteritic anterior ischemic optic neuropathy does not involve carotid artery stenosis in most patients. (Stroke 1993;24:539‐542)

Ollier's disease and Maffucci's syndrome: distinct entities or a continuum. Case report: enchondromatosis complicated by an intracranial glioma.

SummaryA patient with the diagnosis of enchondromatosis (Olliers disease) presented with seizures. CT examination showed an avascular right frontal lobe lesion. Surgery revealed a histologically verified grade II astrocytoma. This case is consistent with recent evidence that questions the distinction between the two forms of enchondromatosis (Olliers disease and Maffuccis syndrome). Maffuccis syndrome is associated with a high rate of malignancy, including intracranial gliomas. Ollivers disease has not been associated with malignant change, other than sarcomatous transformation of the enchondromas. However, Olliers disease and Maffuccis syndrome may be a spectrum of the same disease process, and therefore patients with diagnosed Olliers disease are at a higher risk for malignancy than has been previously recognized.

Congruous and incongruous sectoral visual field defects with lesions of the lateral geniculate nucleus

Quantitative perimetric studies in two women, each 52 years of age, with involvement of the lateral geniculate nucleus (caused by a small arteriovenous malformation in one and by an astrocytoma in the other) disclosed a striking wedge-shaped horizontal sectoranopia that was perfectly congruous in one case and incongruous in the other. Selective interruption of the dual blood supply to the lateral geniculate nucleus (with the anterior choroidal artery supplying the anterior hilus, together with the anterior and lateral nucleus and the lateral choroidal artery supplying the remainder of the nucleus) may result in a congruous visual field defect with steeply sloping borders because such a lesion must respect the anatomic boundaries produced by this vascular supply. Partial infiltration or involvement of the lateral geniculate nucleus (where uncrossed retinal projections terminate in one group of laminae, while crossed retinal projections terminate in another) provides a logical explanation for the occurrence of incongruous visual field defects. This unusual horizontal wedge-shaped defect should suggest lateral geniculate nucleus involvement, especially in the absence of trauma.

Anterior ischemic optic neuropathy and stroke with use of PDE-5 inhibitors for erectile dysfunction: Cause or coincidence?

The PDE-5 inhibitors sildenafil (Viagra) vardenafil (Levitra) and tadalafil (Cialis) have been taken by millions of men for erectile dysfunction. Transient visual symptoms are common but there also have been fourteen cases of nonarteritic anterior ischemic optic neuropathy (NAION) described in patients using these drugs as well as a few other vascular events. NAION is a common optic neuropathy in patients in the age group using these drugs and the question arises whether or not PDE-5 inhibitors are causing NAION. One case of NAION occurred after transient visual symptoms occurred with repeated use and one patient experienced a transient ischemic attack after taking a dose followed by a stroke on using the drug again later. Other than these two cases with strong dechallenge-rechallenge data, the evidence to support PDE-5 inhibitors as a cause of NAION or any vascular event is weak. PDE-5 inhibitors probably are a rare cause of a common ischemic disorder of the optic disc. They should be avoided in men who have already experienced NAION in one eye. Patients should be warned to seek medical attention if they have visual field or acuity loss after using PDE-5 inhibitors. Otherwise there is little basis for modifying the current guidelines for the use of these drugs.

Lesions of the optic radiations mimicking lateral geniculate nucleus visual field defects.

Three patients were found to have visual field defects which involved homonymous horizontal sectors of the visual fields, thus mimicking field defects associated with lesions of the lateral geniculate nucleus. Computed tomography provided anatomical evidence that the responsible lesion involved the optic radiations rather than the lateral geniculate nucleus.

The impossible aneurysm Canalicular and orbital apex aneurysms of the ophthalmic artery

Aneurysms of the intracanalicular and intraorbital ophthalmic artery are rare but present as a mass lesion compressing the optic nerve and are in the differential diagnosis of the progressive unilateral optic neuropathy of unknown cause. A 44-year-old female presented an 18-month history of progressively worsening visual hallucinations followed by the sudden onset of decreased vision with impaired color vision and optic disc edema with segmental atrophy. Arteriography revealed an aneurysm of the ophthalmic artery at the orbital exit of the optic canal. Visual symptoms and signs fluctuated for six months before stabilizing with a mild residual optic neuropathy.

A case of Jacobsen syndrome with multifocal white matter lesions

Jacobsen syndrome is a rare disorder caused by partial deletions of the long arm of chromosome 11. The phenotype is variable with involvement of multiple organ systems, resulting in congenital heart defects, blood dyscrasias, and impaired growth. We describe a case of a 30-year-old man with multiple ophthalmic manifestations and brain magnetic resonance imaging (MRI) that was remarkable for multiple T2-hyperintense subcortical white matter lesions. It is important to be aware that patients with Jacobsen syndrome may have nonspecific white changes seen on MRI.

Shrinkage of the pituitary gland following steroid therapy in a patient with Tolosa-Hunt syndrome.

A 33-year old woman presented with symptoms and signs of the Tolosa-Hunt syndrome [1]. All laboratory studies were normal except for an elevated erythrocyte sedimentation rate of 33 mm/h. The patient was treated initially with oral prednisone, 60 mg daily, the dose gradually reduced over 4 weeks and finally discontinued. MRI of the cavernous sinuses before treatment demonstrated no gross abnormality (Fig. 1). MRI 5 weeks after starting the prednisone showed apparent gross shrinkage of the pituitary gland (Fig. 2). No hypothalamic-pituitary-adrenocortical axis dysfunction was apparent. The patient was not cushingoid in appearance and was not immediately postpartum; as there were no signs of abnormal endocrine status, no laboratory determinations were made. Follow-up MRI was deemed unwarranted in the absence of a specific clinical indication. The patient continues without treatment or recurrent symptoms. Fig.1. Gadolinium-enhanced Tl-weighted (500/20/2:TR/TElexdtations) coronal image through the pituitary gland demonstrates a flat upper border