Neuro-ophthalmic features of cerebral venous obstruction.

OBJECTIVE: To characterize the neuro-ophthalmologic manifestations of impaired cranial venous outflow. DESIGN: A retrospective study of 20 patients who developed increased intracranial pressure as the result of impaired cerebral drainage. SETTING: Three neuro-ophthalmologic referral centers. PATIENTS: Ten patients had noncompressive thrombosis of sagittal or lateral sinuses (noncompressive group), four had compression of the sagittal sinus or jugular veins (compressive group), and six had transient sinus thrombosis following surgical procedures (iatrogenic group). INTERVENTIONS: Medical and/or surgical treatment of increased intracranial pressure and of underlying conditions predisposing to venous obstruction. MAIN OUTCOME MEASURES: Symptoms (headache and esodeviation) and signs (visual acuity, visual fields, and optic disc appearance) of increased intracranial pressure. RESULTS: Headache was more severe, esodeviation was more prevalent, and onset was more abrupt in the noncompressive group than in the compressive and iatrogenic groups. Among the 10 patients with noncompressive thrombosis, factors predisposing to thrombosis were present in seven patients but sometimes overlooked. Following treatment, visual outcome was generally favorable in all three groups. All patients had 20/30 or better visual acuity in at least one eye, and substantial visual field loss was present in both eyes of only two patients. CONCLUSIONS: The clinical manifestation of impaired cerebral venous outflow vary depending on the underlying mechanism. Although most patients maintain good vision, more aggressive treatment is sometimes indicated in patients with thrombosis or compression. The abrupt onset and marked severity of symptoms in patients with thrombosis should help to differentiate these patients from those with idiopathic intracranial hypertension.

Upgaze paralysis caused by lesion of the periaqueductal gray matter.

A 61-year-old man with upgaze paralysis was found on postmortem examination to have had a single lesion of the brain stem confined to the periaqueductal gray matter between the levels of the superior and inferior colliculi. Most previous neuropathologic cases reported in human beings have consisted of much larger lesions with common involvement of the posterior commissure and pretectum. We suggest that the lesion in this case caused upgaze paralysis either by interrupting descending fibers from the interstitial nucleus of Cajal or by destroying neurons located within the periaqueductal gray matter.

Crashes and violations among drivers with Alzheimer disease.

BACKGROUND: Several small studies have found a high automobile crash rate for drivers with Alzheimer disease (AD) compared with unaffected elderly drivers, prompting the suggestion that the diagnosis of AD mandate cessation of driving. OBJECTIVES: To compare automobile crash and violation rates of a large number of patients with AD with appropriately matched elderly subjects. To determine if neuropsychological test scores predict these adverse driving events. To determine if intervention by physicians or family members influences driving cessation. DESIGN: Review of crashes and violations from 1986 to 1993 in police-filed Michigan State driving records of 143 licensed patients with AD and 715 licensed comparison subjects matched 5 to 1 in age (+/- 6 years), sex, and county of residence. We correlated crashes and violations with neuropsychological test scores. A questionnaire-based inquiry on the influence of physician, family, and state interventions on driving cessation was administered. RESULTS: The crash and violation rates of patients with AD were not significantly different from those of comparison subjects. However, patients with AD probably drove fewer kilometers than did comparison subjects. Neuropsychological test scores did not predict future crashes or violations. CONCLUSIONS: This study, the largest to our knowledge involving state driving records of patients with AD, does not confirm the previously reported excessive crash rate among drivers with AD relative to an appropriate comparison population. Reduced driving exposure of patients with AD probably kept their crash adverse equal to that of comparison subjects. Intervention by physicians and family members was major factor in reducing driving exposure. These findings affirm that the mere diagnosis of AD does not justify license revocation.

Nystagmus of Pelizaeus-Merzbacher disease. A magnetic search-coil study.

Magnetic search-coil oculography of three brothers with clinically diagnosed Pelizaeus-Merzbacher disease disclosed the presence of binocular elliptical pendular nystagmus in two patients in whom the waveform of the nystagmus was not obvious on inspection. This study, the first reported application of high-resolution oculography to Pelizaeus-Merzbacher disease, also demonstrated primary position upbeat nystagmus in all three patients. The importance of finding this combination of elliptical pendular and upbeat nystagmus is that it is not described in any other childhood neurodegenerative states and, in combination with supportive clinical history and magnetic resonance imaging, may be so characteristic of Pelizaeus-Merzbacher disease that a strong presumptive diagnosis can be made.

Visual loss in tuberous sclerosis.

Of 11 patients with tuberous sclerosis complex (TSC) treated from 1980 to 1990 for obstructive hydrocephalus secondary to subependymal giant-cell astrocytoma, four had adequate documentation to determine visual outcome. Despite surgical relief of elevated intracranial pressure in all cases, two patients sustained further visual loss. In one patient, visual loss was arrested, and in one patient, it was prevented. Although hydrocephalus is uncommon in TSC, its effects on the optic nerves are serious and eventually irreversible. Because TSC patients may not be able to express early symptoms of increased intracranial pressure, periodic ophthalmologic examination and brain imaging may be advisable when a subependymal lesion has been identified.

Brain biopsy in primary angiitis of the central nervous system.

To determine the yield of brain biopsy and the predictive value of clinical features and ancillary studies, we retrospectively analyzed hospital chart data from 61 consecutive patients suspected of having primary angiitis of the CNS (PACNS). Biopsies disclosed PACNS in 22 (36%), alternative diagnoses in 24 (39%), and no diagnosis in 15 (25%). Clinical indicators and angiography were not useful predictors of PACNS. Brain biopsy should be the primary diagnostic tool in this setting because of the poor reliability of other indicators and because of the high yield of alternative diagnoses requiring different management.

Cyclodeviation in acquired vertical strabismus.

The prevalence and pattern of cyclodeviation can differentiate among superior oblique palsy, dysthyroid ophthalmopathy, myasthenia gravis, and skew deviation. Excyclodeviation was detected in 30 of 33 patients with superior oblique palsy, eight of 15 patients with dysthyroid ophthalmopathy, three of six patients with nondysthyroid restrictive ophthalmopathy, and one of 13 patients with myasthenia. No cyclodeviation was found in cases of skew. Incyclodeviation was found in two patients with dysthyroid ophthalmopathy, two with nondysthyroid restrictive ophthalmopathy, and three with myasthenia. The amount of cyclodeviation did not vary between head-tilt positions, but did vary between primary and eccentric gaze positions, usually in the same direction as the amount of hyperdeviation. The patient's awareness of the presence of cyclodeviation varied with the degree of cyclodeviation, being 100% (4/4) for 15 degrees, 86% (12/14) for 10 degrees, and only 55% (11/21) for 5 degrees.

A screening test for integrative visual dysfunction in Alzheimer's disease.

OBJECTIVE: To develop a screening test to help ophthalmologists detect visually symptomatic patients with as yet undiagnosed Alzheimer's disease. DESIGN: Administration of a battery of tests consisting of items modified from existing psychometric materials to decrease examination time and increase ease of scoring. PARTICIPANTS: Fourteen patients with Alzheimer's disease and prominent visual symptoms; 53 control subjects matched to the patients with Alzheimer's disease for age, sex, and educational level; and 22 patients with subnormal visual acuity or visual fields who did not have Alzheimer's disease. RESULTS: The novel battery of tests distinguished all 14 visually symptomatic patients with Alzheimer's disease from patients without Alzheimer's disease and control subjects. CONCLUSION: This battery of tests should enhance the ophthalmologic detection of Alzheimer's disease.

The effectiveness initiative. I. Medical practice guidelines.

We examined the impact of the "effectiveness initiative" and medical practice guidelines on the practice of ophthalmology. The effectiveness initiative asserts that much of current medical practice is unnecessary or harmful, too costly, and unresponsive to patient desires. It promotes more critical review of the medical literature, research on outcomes, and stringent practice guidelines. Whereas current practice guidelines are helpful in codifying accepted procedures, they tend to sanction interventions of unproved value. Future guidelines will probably reject unproved interventions, especially if they are expensive. Although such guidelines may limit physicians' freedom of choice, they may protect them against capricious malpractice claims and unreasonable patient expectations.

Quantitative perimetry in compressive optic neuropathy and optic neuritis.

The Goldmann perimetric defects in 20 cases of compressive optic neuropathy and 54 cases of optic neuritis were analyzed. While defects involving the papillomacular bundle were the rule in both compressive and neuritis cases, sparing of the fixational area occurred in 24% of neuritis eyes but in none of the eyes with compressive neuropathy. The most reliable differential perimetric sign was the presence of a hemianopic defect; at least one eye of 15 (75%) cases of compression showed such a defect, which was not found in any neuritis cases. The I2e was the largest kinetic isopter to demonstrate the hemianopic defect in a substantial proportion of cases. These defects were corroborated with sequential static presentation of the I2e to I4e stimuli to either side of the vertical meridan, and with similar techniques using 18/1,000 red test objects at the tangent screen.

Future requirements for and supply of ophthalmologists. What do the forecasts show?

Forecasts of the requirements for and supply of ophthalmologists in 1990 have produced conflicting results because of varying assumptions about the future utilization of eye care services, incidence and prevalence of ophthalmic disease, physician productivity, and availability of residency training positions. A typical "utilization-based" models, founded on present consumer behavior, predicts a substantial 1990 surplus of ophthalmologists at current rates of residency training. Two "need-based" models, founded on ideal rather than actual use, reach different conclusions because of varying use of a fragile data base and the need to rely heavily on the subjective judgment of experts with regard to norms of care. The 1980 Graduate Medical Educational National Advisory Committee forecasted a surplus, while the 1978 American Academy of Ophthalmology predicted a deficit. Utilization-based models may slightly underestimate future ophthalmologist requirements. However, analysis of the factors that will influence future use suggests that need-based models are likely to overestimate the requirements. It is risky to accept the need-based model projections because of the high cost of a surplus, which include not only the expenses of training unneeded ophthalmologists but also the cost of their decreased exposure to disease and of declining physician morale, acumen, and thresholds for surgical procedures. Because free market mechanisms are ineffective in governing the supply of health providers, it will be necessary for the profession itself to review the current and projected supply and to set limits on the number of persons in training.

Dysthyroid optic neuropathy. Clinical profile and rationale for management.

Dysthyroid optic neuropathy (DON) was diagnosed in 36 eyes of 21 patients with progressive visual loss and congestive ophthalmopathy. Systemic features in the patients with DON did not differ from those reported for Graves' disease patients except that patients with DON were older (mean age, 61 years) and did not show female preponderance. Congestive symptoms always preceded visual loss, which was gradual in onset and bilateral in most patients but acute and asymmetrical in several. Presenting acuities were poorer than 20/60 in 50% of cases; central scotomas, sometimes combined with inferior depression, were the predominant field defects. Congestive signs were of moderate intensity without severe proptosis or exposure keratopathy. Bilateral and symmetrical ductional restriction was the most common motility disturbance. Oral corticosteroids were effective in restoring visual function in ten of 21 eyes treated. Many steroid-unresponsive eyes were improved promptly by supervoltage orbital irradiation or surgical decompression. In general, therapeutic intervention appeared to hasten recovery and improve visual outcome.

The effectiveness initiative. II: The spectrum of effectiveness research.

Effectiveness research aims to base medical decision making more on rigorous evidence than on intuition and anecdote. The methods used to generate new data include, in order of decreasing rigor, clinical trials, observational studies, claims data analysis, and anecdotal studies. The methods that synthesize existing data include unstructured literature reviews, consensus development, meta-analysis, and decision modeling. Cost minimization, cost-effectiveness, and cost-benefit analyses are formal methods of incorporating the economic impact of alternative medical interventions.

Optic atrophy. Differential diagnosis by fundus observation alone.

In order to assess the contribution of fundus examination to the differential diagnosis of acuqired optic neuropathy, five ophthalmologists viewed 163 fundus stereophotographs of nine disease entities as "unknowns." Glaucoma, central retinal artery occlusion (CRAO), and ischemic optic neuropathy (ION) were diagnosed by at least one observer with an accuracy above 80%. The remaining conditions (optic neuritis; compressive, traumatic, and hereditary optic neuropathies) were correctly identified with less than 50% accuracy. Retinal arteriolar attenuation and sheathing were most helpful in differentiating CRAO and ION. Although pathologic disc cupping often identified glaucoma, it was also seen in 20% of eyes with optic atrophy not associated with glaucoma. Excavation was more profound in glaucoma than in nonglaucomatous optic atrophy, the latter demonstrating relatively greater neuroretinal rim pallor. In 6% of nonglaucomatous optic atrophy eyes, however, disc cupping was misdiagnosed as "glaucomatous." Only 11% of eyes with previously documented papillitis or ION left clues that allowed observers to identify preexisting disc swelling.

Isolated oculomotor paralysis. The product of saccular and fusiform aneurysms of the basilar artery.

Isolated oculomotor paralysis was produced by an unsuspected saccular basilar aneurysm in one case and fusiform basilar aneurysm in another. The chronicity of symptoms and lack of pain were misleading features. The saccular basilar aneurysm, which has an untreated mortality of 50% to 80%, was visualized best with selective angiography and successfully clipped intracranially. The fusiform basilar aneurysm, part of a diffuse atherosclerotic ectasia of all basal intracranial arteries, indented and displaced the upper brain stem. A common ophthalmologic sign of posterior communicating aneurysms, oculomotor paralysis has not been documented frequently with basilar aneurysms.

Meningiomas and aneurysms of the cavernous sinus. Neuro-ophthalmologic features.

A series of 16 patients with unilateral ophthalmoplegia due to mass lesions of the cavernous sinus was analyzed; there were six cavernous meninglomas and nine intracavernous aneurysms. All meningiomas were characterized by painless, insidiously progressive partial nerve palsies, as were half of the aneurysms; the remaining aneurysm patients experienced acute painful episodes. Pharmacologic pupillary tests failed to confirm a coexisting Horner syndrome in the majority of cases with anisocoria. Although plain skull films were unremarkable or misinterpreted as normal, bone tomograms, computerized axial tomograms, radionuclide scans, and cerebral angiograms established the diagnosis in all cases. Because cavernous meningiomas show slow progression and are surgically inaccessible, craniotomy is advised only if the visual pathways or brain stem is compromised. Intractable pain appears to be the only distinct indication for intervention with cavernous aneurysms.

A screening method for chiasmal visual-field defects.

A strategy that selectively explores the vertical fixational meridian of the visual field was as sensitive as conventional quantitative Goldmann perimetry in detecting chiasmal hemianopic field defects, although it required only one quarter of the usual testing time. A trained but "masked" perimetrist, applying this abbreviated method to the examination of 28 eyes with hemianopic defects, 17 eyes with nerve-fiber defects, and 14 normal eyes, detected 100% of the hemianopias when using the Goldmann perimeter, 92% when using the conventional tangent screen, and 87% when using the projection tangent screen. False-positive diagnoses of hemianopic defects were 16%, 11%, and 14% on the respective instruments. While this strategy did not define the field defects fully, it accurately identified the features of diagnostic importance. By its efficiency, this approach may encourage greater use of visual fields as a determinant in managing the conditions of patients with unexplained visual loss.

Septic cavernous sinus thrombosis associated with gingivitis and parapharyngeal abscess.

A 29-year-old previously healthy man died of spread of infection from gingivitis to both parapharyngeal (pharyngomaxillary) spaces and to the cavernous sinus. The diagnosis was delayed because gingival and parapharyngeal sources of cavernous sinus thrombosis were not initially considered, and the ophthalmic congestion was believed at first to represent orbital cellulitis rather than cavernous sinus thrombosis.

Pupillary and electroretinographic abnormalities in a family with neuronal intranuclear hyaline inclusion disease.

Abnormal pupillary function and a severely depressed electroretinogram were found in four members of a family with neuronal intranuclear hyaline inclusion disease, an idiopathic degenerative disorder that involves the central and peripheral nervous systems. Symptoms were limited to the gastrointestinal system and consisted principally of abdominal pain, constipation, and severe weight loss. The discovery of light-fixed pupils in the propositus led to the first antemortem diagnosis by rectal biopsy in two generations of this family. Abnormalities of gastrointestinal motility and pupillary reactions constituted the only objective evidence of autonomic dysfunction; the abnormal electroretinogram was the only evidence of central nervous system dysfunction.

Painful oculomotor palsy caused by posterior-draining dural carotid cavernous fistulas.

BACKGROUND: Carotid cavernous fistulas cause conjunctival hyperemia and orbital soft-tissue swelling because of increased flow directed anteriorly in ophthalmic veins. Less well recognized is that when fistular flow is directed posteriorly, these congestive features will be absent and the diagnosis of the "white-eyed shunt" will be missed unless angiography is performed. METHODS: Two patients who had oculomotor nerve palsies caused by posteriorly draining dural carotid cavernous fistulas were studied, and the 28 previously described cases were reviewed. RESULTS: One patient had a chronic painful palsy of the sixth cranial nerve, and the other, a palsy of the third cranial nerve. Cerebral angiography disclosed the fistulas. The clinical and imaging features of these cases conform to those of the 28 previously reported white-eyed shunts. Angiographic features do not explain why some posterior-draining fistulas cause sixth-nerve palsies and others cause third- (or rarely, fourth-) nerve palsies. CONCLUSIONS: Dural carotid cavernous fistulas that drain primarily into the inferior petrosal sinus may cause painful oculomotor palsies that elude diagnosis because they lack congestive orbito-ocular features. Treatment by embolization leads to more rapid resolution of manifestations.