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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° 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° of vision. The horizontal meridian of the visual field is represented deep within the calcarine banks at the fissure base.

• Although the ophthalmologic manifestations of acute posterior multifocal placoid pigment epitheliopathy are well known to ophthalmologists, its possible CNS involvement has not come to the attention of neurologists. We treated the third reported case with cerebral vasculitis, the first with computed tomographic scan documentation of cerebral infarction.

Superior oblique myokymia is an unusual disorder of ocular motility characterized by rapid, small amplitude, rotary oscillations limited to one eye. Symptoms of monocular oscillopsia and torsional diplopia are experienced by the patient. Although symptomatically obtrusive, the syndrome is benign in our experience. While the cause remains obscure, we have found carbamazepine (Tegretol) to be effective in treating this condition.

• Recording of visual evoked potentials (VEPs) to pattern reversal is considered to be a reliable diagnostic procedure for examining patients with anterior visual pathway lesions (optic nerves and chiasm). Less consistent results have been reported in studies of more posterior lesions. The VEPs were recorded in 20 patients with occipital lobe lesions. A maximal VEP response (P 94 ) was recorded at the scalp electrodes situated over the involved occipital lobes and contralateral to the hemianoptic visual field defect, indicating a positive correlation of unilateral occipital lobe lesions, homonymous visual field loss, and the VEP abnormality.

• We report two elderly patients with normal erythrocyte sedimentation rate (ESR) and biopsy-confirmed giant cell arteritis. Because of the potentially disastrous consequences of undiagnosed giant cell arteritis, early treatment based on clinical diagnostic criteria is urged despite a normal ESR.

• The prognosis for vision in most patients with pseudotumor cerebri is excellent; however, visual loss, which is the only serious complication, may occur either early or late in the course of the disease. A group of 57 patients was followed up five to 41 years with visual fields, visual acuity, and fundus photographs. Blinding visual loss or severe visual impairment in one or both eyes occurred in 14 patients, and in seven patients, this occurred months to years after the initial symptoms. Systemic hypertension was a significant risk factor for visual loss in patients with pseudotumor cerebri, and blindness occurred in eight of 13 patients who were hypertensive. Despite suggestions that blind spot measurement is useful for following up patients with this condition, we believe that sequential quantitative perimetry gives more complete information and is essential to rational decision making in the treatment of pseudotumor cerebri.

Cavernous sinus thrombosis is an important but difficult clinical diagnosis to confirm by most imaging modalities. 1,2 Until the advent of highfield magnetic resonance imaging (MRI), the imaging method of choice for evaluating thrombus formation in the cavernous sinus was transarterial or intravenous digital subtraction angiography. This article discusses the MRI findings in the diagnosis of cavernous sinus thrombosis. REPORT OF A CASE A 73-year-old woman noticed pain around her left eye ten days before examination. Over the next four days, her left upper eyelid drooped, and she experienced double vision. She was hospitalized elsewhere, and computed tomography (CT) showed a mass in the left anterior cavernous sinus. A cerebral arteriogram was normal. The patient was treated with systemic corticosteroids (prednisone, 80 mg/d), with no resolution of the pain or ocular motility disturbance. Five years prior to admission, the patient had an episode of painful ophthalmoplegia that was described

To clarify the clinical syndrome of demyelinative chiasmal involvement, six case histories were analyzed and the literature was reviewed. This entitity is characterized by especial predilection for women in the third to fifth decades; visual deficites of a chiasmal pattern that may be modest to marked, with a generallly good prognosis for functional recovery; and other signs and symptoms, not necessarily severe, of scattered lesions of the neuraxis. Neuroradiological studies, especially laminography of the sellar area and computerized tomography, must be employed to rule out a suprasellar mass lesion. The efficacy of systemic corticosteroid therapy is moot, but it seems reasonable to use such agents during acute stages, especially where vision is severely reduced on both sides.

• We describe three newly diagnosed and untreated cases of pernicious anemia (PA) with clinical features suggestive of subacute combined degeneration. Visual evoked responses (VERs) were evaluated in all three patients. In each instance, delayed responses were obtained, suggesting that involvement of the visual pathways may be an early and perhaps not uncommon manifestation in PA, even in the absence of clinical stigmata of visual impairment. The need for excluding PA in cases of myelopathy with impaired VERs is stressed.

• Four patients exhibiting signs of partial aberrant oculomotor regeneration without a preceding acute third nerve palsy had meningiomas involving the cavernous sinus. Two of the patients had preceding sixth nerve palsies. We propose that slowly progressive primary aberrant oculomotor regeneration is diagnostic of intracavernous meningioma. The best diagnostic studies are orbital phlebography, carotid arteriography, and possibly computerized axial tomography.

• Congenital cavitary anomalies of the optic disc (optic pit and coloboma) are uncommon and frequently go unrecognized. Patients with these defects have a high incidence of visual loss and the abnormal appearance of the discs may be mistaken for atrophy due to acquired neurological disease. Occasionally, associated midline neurological developmental malformations will be found associated with pits, colobomas, or other dysplastic optic discs, as in one of our cases. A group of patients with optic pits and colobomas referred for neurological evaluation of visual loss are presented to remind the neurologist of the appearance of these congenital crater-like defects and of the causes of loss of vision.

Primary aberrant regeneration of the oculomotor nerve is a clinical syndrome involving eyelid, pupil, and extraocular movement abnormalities following damage to the peripheral portion of the oculomotor nerve. It has been described only with meningiomas and internal carotid artery aneurysms within the cavernous sinus.1-6We describe herein a patient with abetalipoproteinemia (Bassen-Kornzweig syndrome [BKS]) who has bilateral primary aberrant regeneration of the oculomotor nerve. REPORT OF A CASE A 31-year-old right-handed man was diagnosed as having BKS at age 9 years because of acanthocytosis and serum β lipoprotein levels less than 4% of normal7. Visual fields and funduscopic examination findings were normal, and visual acuity was 6/15 - 1 OD and 6/15 + 1 OS uncorrected. Extraocular movements and pupillary reaction were normal at that time, but he had moderate bilateral ptosis, greater on the right. He required assistance to walk, and his gait was broad based and ataxic. At age

• The distinction between early papilledema and drusen of the optic disk may be made more difficult by the presence of hemorrhages. We report five patients with drusen of the optic disk and associated hemorrhages. The distinguishing characteristics of both conditions are described.