Eye Disease and Visual Disturbances

Question 1

361. A 36-year-old woman has tunnel vision in which she reports the same size area of perception regardless of how far from the testing screen the examination is performed. This history often indicates which of the following?
     a. Retinitis pigmentosa
     b. Neurosyphilis
     c. Sarcoidosis
     d. Chorioretinitis
     e. Conversion disorder

Answer 1

E

(Victor, pp 265–266.) Tunnel vision must be distinguished from concentric constriction. In the latter, the area perceived enlarges as the test screen is moved farther away from the patient, but the overall visual field is always smaller than the normal visual field. Concentric constriction associated with optic atrophy may develop with neurosyphilis. Tunnel vision, on the other hand, is characterized by the patient reporting the same size field even as the test screen is removed further away. Tunnel vision is not a physiologic pattern of visual loss, and should suggest either conversion disorder or malingering. Significant spiraling of the visual field, in which repeat testing of the same part of the visual field during the same examination leads to a successively smaller field each time, similarly may reflect conversion or malingering, although stress or panic may lead to mild effects of this sort.

Question 2

362. The most common form of retinal degeneration is
     a. Serous retinitis
     b. Retinitis pigmentosa
     c. Confluent drusen
     d. Drug-induced retinopathy
     e. Paraneoplastic retinal degeneration

Answer 2

B

(Victor, pp 1165–1166.) Retinitis pigmentosa is a hereditary degenerative disease involving the retinal receptors and adjacent pigment cells. As this degeneration progresses, small accumulations of pigment appear about the periphery of the retina. Optic disc pallor is evident later in the disease. Retinitis pigmentosa develops along with Bassen-Kornzweig disease (abetalipoproteinemia), Refsum’s disease, and other metabolic disorders that produce extensive nervous system damage.

Question 3

363. A newborn child is being examined. During ophthalmologic evaluation, it is noticed that the red reflex is absent. Which of the following could this indicate?
     a. Congenital cataracts
     b. Chorioretinitis
     c. Retinitis pigmentosa
     d. Optic atrophy
     e. Holoprosencephaly

Answer 3

A

(Victor, p 249. Swaiman, pp 66–67.) On shining a light through the pupil of the normal newborn, the normal color of the retina is perceived as an orange-red reflection of the light. Failure to perceive that reflection usually indicates opacification of the pathway of light transmission. Several types of intrauterine infections, including rubella and CMV infection, may produce congenital cataracts and impair light transmission in this way. The presence of a distinctive white reflex usually indicates disease behind the lens, such as a scar from retinopathy of prematurity or a retinoblastoma.

Question 4

364. Glaucoma develops in nearly one-third of children with
     a. Type 1 neurofibromatosis
     b. Type 2 neurofibromatosis
     c. Sturge-Weber syndrome (encephalotrigeminal angiomatosis)
     d. Tuberous sclerosis
     e. Arnold-Chiari malformation

Answer 4

C

(Rowland, pp 371–372.) Children with Sturge-Weber syndrome have large port-wine spots on their faces, contralateral hemiparesis, retardation, and seizures, as well as glaucoma. Skull radiographs reveal intracranial calcifications that are associated with leptomeningeal angiomatosis. This syndrome results from a defect on chromosome 3.

Question 5

365. A 23-year-old HIV-infected woman presents with visual loss. After testing, the diagnosis of retinitis caused by cytomegalovirus (CMV) is made. Which of the following should be used to treat this patient?
     a. Cytarabine
     b. Vidarabine
     c. Ribavirin
     d. Interferon
     e. Ganciclovir

Answer 5

E

(Bradley, p 1361.) All the drugs listed have anti-viral activity with effects on CMV in vitro. Ganciclovir is the only one with demonstrable clinical effects on CMV infection. This drug is a 2-deoxyguanosine analogue and has been used for CMV pneumonia and gastroenteritis as well as chorioretinitis.

Question 6

366. A 52-year-old woman is being evaluated for the acute appearance of a large central scotoma. Which of the following most likely preceded her presentation?
     a. Pseudotumor cerebri
     b. Chronic ethanolism
     c. Chlorpromazine ingestion
     d. Methyl alcohol intoxication
     e. Isoniazid use

Answer 6

D

(Victor, p 264.) Persons who ingest methyl alcohol will usually be very ill if they survive. Acidosis is a life-threatening complication of exposure to this toxin. Isoniazid, ethambutol, streptomycin, and other drugs may produce similar field cuts, but the blind spots developing with these toxins usually appear subacutely or chronically rather than abruptly.

Question 7

367. A 28-year-old man presents with right eye pain and blurry vision developing over 3 days. After examination and further history, a diagnosis of papillitis is made. How can papillitis be distinguished from the papilledema of increased intracranial pressure?
     a. Degree of swelling of the optic disc
     b. Associated homonymous hemianopsia
     c. Characteristic visual loss
     d. Associated limitation of eye movement
     e. Loss of red reflex

Answer 7

C

(Victor, pp 261–262.) Visual loss is usually substantial with papillitis, an inflammation of the optic nerve head, and inconsequential with papilledema. Patients with papillitis usually also complain of pain on moving the globe and sensitivity to light pressure on the globe. About 1 in 10 patients have both eyes involved simultaneously. Papillitis is often an early sign of multiple sclerosis.

Question 8

A 19-year-old woman with complaints of headaches and visual blurring has prominent bulging of both optic nerve heads with obscuration of all margins of both optic discs. Her physician is reluctant to pursue neurologic studies because the patient is 8 months pregnant and had similar complaints during the last month of another pregnancy. Her physical and neurologic examination are otherwise unrevealing.

368. If neuroimaging studies were to be performed on this woman, they probably would reveal
     a. A subfrontal meningioma
     b. Intraventricular blood
     c. Slitlike ventricles
     d. Transtentorial herniation
     e. Metastatic breast carcinoma

Answer 8

C

(Bradley, pp 1552–1554.) Although papilledema must be considered evidence of a potentially life-threatening intracranial process, optic nerve bulging in this young woman is most likely from pseudotumor cerebri. This is a relatively benign condition that occasionally develops in obese or pregnant women. Cerebrospinal fluid pressure is markedly elevated in these patients, but they are not at risk of herniation. The condition is presumed to arise from hormonal problems. Without treatment, the increased intracranial pressure will produce optic nerve damage with loss of visual acuity.

Question 9

A 19-year-old woman with complaints of headaches and visual blurring has prominent bulging of both optic nerve heads with obscuration of all margins of both optic discs. Her physician is reluctant to pursue neurologic studies because the patient is 8 months pregnant and had similar complaints during the last month of another pregnancy. Her physical and neurologic examination are otherwise unrevealing.

369. The treatment of choice for this young woman is
     a. Lumbar puncture
     b. Cesarean section
     c. Induction of labor
     d. Vitamin A supplements
     e. Acetazolamide

Answer 9

A

(Bradley, pp 1552–1554.) With pseudotumor cerebri, removal of some of the CSF produces a protracted lowering of the intracranial pressure. This pressure reduction is desirable because persistent pressure elevations will damage the optic nerve. Pseudotumor cerebri in the pregnant woman usually abates soon after the fetus leaves its mother, but this condition is not serious enough to justify termination or acceleration of a pregnancy. Vitamin excess may cause pseudotumor in some persons. Diuretics are sometimes used to manage patients who are not pregnant, but they are usually less effective than repeated lumbar puncture when that is practical.

Question 10

370. A young man with multiple sclerosis (MS) exhibits paradoxical dilation of the right pupil when a flashlight is redirected from the left eye into the right eye. Swinging the flashlight back to the left eye produces constriction of the right pupil. This patient apparently has
     a. Early cataract formation in the right eye
     b. Occipital lobe damage on the left
     c. Oscillopsia
     d. Hippus
     e. Optic atrophy

Answer 10

E

(Bradley, p 1439.) The test performed is usually called the swinging flashlight test, and the pupillary finding is a Marcus Gunn, or afferent pupillary, defect. It commonly develops in persons with MS as a sequela of optic neuritis. Damage to the optic nerve reduces the light perceived with the affected eye. If the other eye has less or no optic atrophy, the consensual response of the pupil to light perceived by the better eye will constrict the pupil in the atrophic eye, even though direct light to the injured eye does not elicit a strong pupillary constriction.

Question 11

371. A 23-year-old woman complains of 2 days of visual loss associated with discomfort in the right eye. She appears otherwise healthy, but her family reports recurrent problems with bladder control over the prior 2 years, which the patient is reluctant to discuss. On neurologic examination, this young woman exhibits dysmetria in her right arm, a plantar extensor response of the left foot, and slurred speech. The most informative ancillary test would be
     a. Visual evoked response (VER) testing
     b. Sural nerve biopsy
     c. Electroencephalography (EEG)
     d. Magnetic resonance imaging (MRI)
     e. Computed tomography (CT)

Answer 11

D

(Bradley, pp 1438–1439.) This young woman almost certainly has MS. Her visual loss can be explained by optic neuritis, and her bladder problems may be due to demyelination of corticospinal tract fibers. Many patients are reluctant to discuss minor problems with bladder, bowel, or sexual function with a physician of the opposite sex. The positive Babinski sign, focal dysmetria, and apparent dysarthria all support the diagnosis of a multifocal CNS lesion. Multiple lesions disseminated in time and space are typical of MS. With MRI, the multifocal areas of demyelination should be apparent. Many more lesions may be evident on MRI than are suggested by the physical examination.

Question 12

372. Injuries to the macula or fovea centralis typically affect vision by producing
     a. Bitemporal hemianopsia
     b. Nyctalopia (night blindness)
     c. Scintillating scotomas
     d. Mild loss of visual acuity
     e. Severe loss of visual acuity

Answer 12

E

(Victor, p 266.) The cones of the retina are packed into the macula, and the primary focus of the lens is at the macula. The macula is therefore responsible for visual acuity. Therefore, injury to the macula results in significant loss of acuity, often with preservation of peripheral vision. The macula is usually evident on ophthalmologic examination because it normally reflects a point of light that can be seen through the ophthalmoscope. It is located 3 to 4 mm temporally from the optic disc. Bitemporal hemianopsia is seen in injury to the optic chiasm, as from pituitary tumors. Nyctalopia (night blindness) is seen in retinal degeneration (e.g., retinitis pigmentosa), vitamin A deficiency, and color blindness. Scintillating scotomas are the classic signature of the migraine aura.

Question 13

373. A 64-year-old man who has had hypertension for over 30 years is being examined. The most obvious changes seen during retinal exam would include which of the following?
     a. Retinal tears
     b. Optic atrophy
     c. Segmental narrowing of arterioles
     d. Drusen
     e. Telangiectasias

Answer 13

C

(Victor, pp 253–255.) The vessels apparent on funduscopic examination of the retina are arterioles and venules. In addition to segmental narrowing of arterioles, the retina may exhibit arteriolar straightening and arteriolar-venular compression. The thickened arteriolar wall compresses the venule at the point where they cross, a pattern often referred to as nicking.

Question 14

374. Routine funduscopic examination of a 52-year-old man reveals small, discrete red dots located in largest numbers in the paracentral region. Such retinal microaneurysms most often occur with which of the following?
     a. Sarcoidosis
     b. Chronic hypertension
     c. Diabetes mellitus
     d. Anterior communicating aneurysms
     e. Chorioretinitis

Answer 14

C

(Victor, p 255.) These aneurysms appear as small red dots on the surface of the retina. They may appear as one of the first manifestations of diabetes mellitus and are rarely larger than 90 µm across. They may be more obvious in green light. A proliferative retinopathy may occur along with these microaneurysms in the patient with diabetes mellitus.

Question 15

375. A 72-year-old woman presents with the acute onset of double vision. The second image disappears if she covers either eye. The ocular motor nerve most likely to be impaired in this patient is the
     a. Oculomotor
     b. Trochlear
     c. Abducens
     d. Ciliary
     e. Müller’s

Answer 15

C

(Victor, p 286.) Injury to the sixth nerve produces a lateral rectus palsy. This type of ocular motor paresis is twice as common as a third-nerve palsy and 6 times as common as fourth-nerve problems. With lateral rectus weakness, the affected eye will remain inverted on attempts to look straight ahead.

Question 16

376. A 7-year-old girl acutely develops double vision that worsens over the course of a few days. Examination reveals a sixth-nerve (abducens) palsy. She is most likely to have which of the following?
     a. Pontine glioma
     b. Medullary glioma
     c. Mesencephalic infarction
     d. Pontine infarction
     e. Medullary infarction

Answer 16

A

(Victor, pp 286–287.) An abducens dysfunction with lateral rectus palsy may develop in children with increased intracranial pressure or with direct damage to the brainstem. With a brainstem glioma, both brainstem damage and increased intracranial pressure may develop secondary to the tumor. The adult who develops an acute abducens palsy is also at high risk for tumor. Metastatic lesions from the nasopharynx are especially likely in the adult, but vascular disease is also a significant cause of ocular motor dysfunction in adults, especially in the elderly.

Question 17

377. A 6-year-old girl has left facial pain and blurry vision. Careful examination reveals a deficit of the abducens nerve. Which of the following is the most likely etiology?
     a. Ischemia
     b. Infection
     c. Neoplasm
     d. Trauma
     e. Hemorrhage

Answer 17

B

(Victor, p 286.) Gradenigo syndrome arises with an osteomyelitis of the petrous pyramid. The abducens and trigeminal nerves are affected as they pass close to the tip of the petrous bone. Chronic ear infections may extend to the petrous pyramid and produce this syndrome if they are not properly managed.

Question 18

378. A 19-year-old man is hit in the face with a lead pipe. The ocular motor muscle most likely to be injured in this case is that innervated by the
     a. Superior division of the third cranial nerve
     b. Inferior division of the third cranial nerve
     c. Fourth (trochlear) cranial nerve
     d. Sixth (abducens) cranial nerve
     e. Long ciliary nerve

Answer 18

C

(Victor, p 287.) The fourth cranial nerve innervates the superior oblique muscle. Because this muscle extends far anterior in the orbit, it is at high risk of injury with trauma to the orbit or the full face. The third nerve is especially vulnerable to pressure from aneurysms, but it is usually not disturbed with head trauma unless there are local fractures impinging on it. Injury to the fourth nerve with facial trauma will usually induce a slight head tilt to compensate for impaired intorsion of the affected eye.

Question 19

379. A 17-year-old girl develops a painful vesicular rash around her left eye. This is followed by blurry vision that occurs only when both eyes are open. She is diagnosed with varicella zoster ophthalmicus. Which ocular motor nerve is most likely to be affected?
     a. Superior division of the third
     b. Inferior division of the third
     c. Fourth (trochlear)
     d. Sixth (abducens)
     e. Long ciliary

Answer 19

C

(Victor, p 287.) Varicella zoster, previously known as herpes zoster, spreads to the face along the trigeminal nerve. The fourth nerve is presumably involved because it shares its nerve sheath with the ophthalmic division of the trigeminal nerve. The third and sixth nerves may also be involved with varicella zoster, but this occurs much less frequently than involvement of the fourth nerve.

Question 20

380. A 32-year-old woman has an MRI done because of a first seizure. No etiology for the seizure is found, but there is the incidental finding of an aneurysm. The aneurysm is 5 mm and affects the posterior communicating artery. It is very close to the third cranial nerve. The initial sign of pressure on the third nerve is usually impaired
     a. Adduction
     b. Abduction
     c. Depression
     d. Elevation
     e. Pupillary constriction

Answer 20

E

(Victor, pp 282–299.) The pupilloconstrictor fibers of the third nerve lie superficially on the nerve. Lesions compressing the nerve impinge on these fibers before they disturb the ocular motor fibers. The third nerve is not involved in abduction of the globe; this is accomplished by the abducens nerve, which controls the lateral rectus muscle.

Question 21

381. A 58-year-old man with type 2 diabetes presents with the acute onset of double vision. Examination reveals a deficit of the third cranial nerve. A third-nerve palsy associated with diabetes mellitus is usually characterized by
     a. Poor pupillodilation
     b. Poor pupilloconstriction
     c. Sparing of pupillary function
     d. Inversion of the affected eye
     e. Upward deviation of the affected eye

Answer 21

C

(Victor, p 287.) The vessel usually obstructed with diabetic third-nerve injury is deep in the third nerve. The superficial fibers to the iris are supplied by a separate set of vessels, and these are usually spared with diabetes mellitus. The affected person may complain of pain in and about the eye with the damaged third nerve.

Question 22

382. A 65-year-old man is having a neurological exam because of tingling in his feet. During the course of the examination, it is noticed that pupillary constriction occurs with attempted adduction of the globe. This suggests which of the following?
     a. Mesencephalic infarction
     b. Pontine glioma
     c. Acute glaucoma
     d. Iridocyclitis
     e. Aberrant third-nerve regeneration

Answer 22

E

(Victor, p 287.) Oculomotor fibers that have been damaged reversibly may regenerate and connect to the wrong target. This aberrant regeneration is seen most often with lesions that chronically compress the third nerve. Aneurysms, cholesteatomas, and neoplasms should be suspected in the person exhibiting this type of disturbance.

Question 23

383. Evidence of internuclear ophthalmoplegia (INO) indicates
     a. A mesencephalic or pontine injury
     b. Thalamic hemorrhage
     c. Cerebellar dysfunction
     d. Cortical injury in the frontal eye fields
     e. Medullary infarction

Answer 23

A

(Victor, pp 274, 289–290.) In the MLF syndrome, the patient has incomplete adduction ipsilateral to the lesion in the MLF on conjugate lateral gaze. On attempted conjugate lateral gaze away from the side of the lesion, the patient has nystagmus in the abducting eye. The fast component of the nystagmus is directed temporally.

Question 24

384. The most likely diagnosis in a 30-year-old woman with evidence of bilateral injury to the medial longitudinal fasciculus (MLF) is
     a. Progressive supranuclear palsy
     b. MS
     c. Subacute sclerosing panencephalitis (SSPE)
     d. Progressive multifocal leukoencephalopathy (PML)
     e. Botulism

Answer 24

B

(Victor, p 289.) Vascular disease may produce bilateral injury to the MLF in the elderly, but it is an unlikely explanation in the young adult. Injury to the MLF in MS is demyelinating. Bilateral MLF syndromes associated with optic atrophy are virtually diagnostic of MS in persons under 40 years of age.

Question 25

385. A 42-year-old man has horizontal nystagmus in primary gaze and while looking to both the left and the right. The only other examination finding is a slight gait ataxia. The most likely cause of this patient’s induced nystagmus is which of the following? a. Hysteria b. Drug intoxication c. Eyestrain d. Myopia e. Hypermetropia

Answer 25

B (Victor, p 291.) Alcohol and barbiturates are the drugs that most often cause nystagmus. A variety of hypnotic and antiepileptic drugs are also often implicated because they are widely used by the general population. Although the severity of nystagmus in the two eyes may be unequal, it is invariably worse in the horizontal plane of gaze when the nystagmus is an adverse effect of drug use.

Question 26

386. The child with rapid downward deviation of both eyes followed by slow upward conjugate eye movements probably has a. SSPE b. MS c. Pontine glioma d. Cervicomedullary junction ischemia e. Cerebral palsy (CP)

Answer 26

C (Victor, p 292.) The phenomenon described is commonly referred to as ocular bobbing. It is an involuntary movement that usually develops with pontine damage. Damage to the cerebellum occasionally produces a similar disturbance of eye movements.

Question 27

387. A 25-year-old male is being evaluated. Rhythmic jerk nystagmus is elicited by having the patient look at a rotating drum with stripes on it. This finding suggests which of the following? a. Drug toxicity b. Brainstem ischemia c. Parinaud syndrome d. Unilateral parietal lobe damage e. No pathologic lesion in the brain

Answer 27

E (Victor, pp 291–292.) This type of nystagmus is called optokinetic nystagmus. It is a pattern of eye movements that should be elicitable with the normal patient. If the nystagmus is less obvious on rotating the drum in a given direction, the patient may have a parietal lesion responsible for the asymmetric response.

Question 28

388. A 36-year-old man abruptly loses vision in one eye. His retina appears cloudy and grayish yellow with narrowed arterioles. The fovea appears cherry red, and the vessels that are obvious appear to have segmented columns of blood. This man probably has a. Chorioretinitis b. Occlusion of the central retinal vein c. Occlusion of the central retinal artery d. Optic neuritis e. Tay-Sachs disease

Answer 28

C (Victor, pp 255–256.) Occlusion of the central retinal artery may be due to atheromatous particles, fibrin-platelet emboli, or local retinal artery compression. The visual loss is usually painless and irreversible. Occlusion of the internal carotid artery—the artery from which the ophthalmic and ultimately the retinal arteries originate—need not produce ischemic damage to the retina if collateral supply to the retinal artery is sufficient.

Question 29

389. A 62-year-old man with hypertension has an episode in which he suddenly loses vision in his left eye. He is outside walking up the street, as he does every day, when suddenly the vision in his left eye goes black. When he closes his right eye, he can barely see at all. Within 2 h, his vision is back to normal. Amaurosis fugax usually arises because of disease in which of the following arteries? a. Middle cerebral b. Posterior cerebral c. Anterior cerebral d. Internal carotid e. Anterior choroidal

Answer 29

D (Victor, pp 834, 860.) Emboli that arise in or travel through the internal carotid artery may exit to the ophthalmic artery and cause obstruction. The transient ischemia that occurs before the embolus breaks up usually produces transient visual loss in the ipsilateral eye. Amaurosis fugax is by definition a fleeting loss of vision.

Question 30

390. A 5-year-old girl sustains a cut on her face from broken glass. Initially, the injury appears superficial except for a small area of deeper penetration just above the right eyebrow. Within 4 days, the child complains of periorbital pain and double vision. The tissues about the eye are erythematous, and the eye appears to bulge slightly. The optic disc is sharp, and no afferent pupillary defect is apparent. Visual acuity in the affected eye is preserved. This child probably has a. Orbital cellulitis b. Cavernous sinus thrombosis c. Transverse sinus thrombosis d. Optic neuritis e. Diphtheritic polyneuropathy

Answer 30

A (Braunwald, p 174.) The fact that vision is preserved excludes optic neuritis and cavernous sinus thrombosis. Optic neuritis will produce pain in the affected eye and may be associated with a normal optic disc, but visual acuity should be deficient and an afferent pupillary defect should be apparent. Cavernous sinus thrombosis usually produces proptosis and pain, but impaired venous drainage from the eye should interfere with acuity, and the retina should appear profoundly disturbed. With a diphtheritic polyneuropathy, an ophthalmoplegia may develop, but this would not be limited to one eye and is not usually associated with facial trauma. Transverse sinus thrombosis may produce cerebrocortical dysfunction or stroke, but ophthalmoplegia would not be a manifestation of this problem.

Question 31

391. An otherwise healthy young woman has poorly responsive pupils that are dilated. Visual acuity is normal. A careful neurologic examination reveals bilaterally absent Achilles tendon jerks. This woman probably has a. A cervical spinal cord tumor b. A brainstem glioma c. MS d. A posterior communicating artery aneurysm e. Benign tonic pupillary dilatation

Answer 31

E (Victor, pp 297–298.) This pupillary abnormality is called Adie’s tonic pupil. It is usually seen in otherwise healthy young women and may occur in isolation or in association with absent tendon reflexes. Local trauma to the eye should be considered if only one pupil is affected. If both pupils are affected, drug use should be considered. It is probably due to degeneration of the ciliary ganglia. Although the cause is obscure, it may reflect a mild polyneuropathy. In most cases this is a benign phenomenon.

Question 32

392. With neurosyphilis, the pupil a. Is completely normal b. Reacts poorly to light but accommodates well c. Accommodates poorly but reacts well to light d. Is pinpoint and regular in shape e. Is fixed and dilated

Answer 32

B (Victor, p 297.) The patient with neurosyphilis may develop an Argyll Robertson pupil. The pupil is usually poorly reactive to light, small, and irregular in shape. Both eyes or only one eye may be affected. Although reactivity to light is deficient, pupillary accommodation with changes in distance from the eye is usually good. The pupillary reaction may, however, be complicated by optic atrophy, which also may develop as a consequence of neurosyphilis. Pinpoint pupils are seen in pontine disease due to interruption of the pupillodilator pathways in the brainstem. The fixed and dilated pupil is generally a sign of third-nerve injury due to compression of the nerve by a vascular or other mass. In the patient with diminished consciousness and contralateral hemiparesis, the concern is for herniation. Other, more benign causes of the fixed and dilated pupil include uveitis, Adie’s tonic pupil, and drug-induced iridoplegia (i.e., paralysis of the iris by intentional or accidental application of sympathomimetic or anticholinergic medications).

Question 33

A 60-year-old right-handed man underwent heart transplantation 2 weeks ago for severe ischemic cardiomyopathy. He had an uneventful post-operative course and went home after 1 week. He is now readmitted from an outside hospital where he was admitted with headaches, increasing confusion, and a generalized seizure. He relates that he has had difficulty seeing for several days. On exam, he has a blood pressure of 180/100. His pupils are equal and reactive, but he has difficulty reading and finding objects presented to him. Motor and sensory function are normal. An MRI shows several areas of T2 signal abnormality in the occipital and parietal lobe white matter bilaterally. A diffusion-weighted MRI sequence, sensitive to the changes of acute infarction, is negative. 393. This patient’s history, exam, and laboratory findings are most consistent with which of the following diagnoses? a. Cyclosporine toxicity b. Steroid psychosis c. Occipital lobe infarction d. Ischemic optic neuropathies e. Retinal detachment

Answer 33

A (Victor, pp 1285–1286.) Cyclosporine and tacrolimus (FK 506) may both induce a syndrome resembling hypertensive encephalopathy, which has been called by some reversible posterior leukoencephalopathy, although it involves more than white matter and may also occur in the anterior frontal regions. In the setting of cyclosporine use, patients may develop headache, visual dysfunction related to occipital lobe dysfunction, confusion, and seizures. Usually there is associated hypertension. The visual loss may include cortical blindness or scotomas. Imaging may show bilateral, more or less symmetrical signal changes in the white matter and occasionally the cortex of the occipital and parietal lobes.

Question 34

A 60-year-old right-handed man underwent heart transplantation 2 weeks ago for severe ischemic cardiomyopathy. He had an uneventful post-operative course and went home after 1 week. He is now readmitted from an outside hospital where he was admitted with headaches, increasing confusion, and a generalized seizure. He relates that he has had difficulty seeing for several days. On exam, he has a blood pressure of 180/100. His pupils are equal and reactive, but he has difficulty reading and finding objects presented to him. Motor and sensory function are normal. An MRI shows several areas of T2 signal abnormality in the occipital and parietal lobe white matter bilaterally. A diffusion-weighted MRI sequence, sensitive to the changes of acute infarction, is negative. 394. The patient recovers from this event, and a follow-up MRI 1 month later is completely normal. Six months later, he again presents with visual loss. About 2 weeks before, he began to notice difficulty seeing the television. Within 1 week, he noticed that the inferior field of vision in the right eye was much worse than the top of his vision. Within a few more days, he noticed the bottom of the vision in his left eye worsen as well. This has been painless. He has otherwise felt well, without headaches or cognitive changes. An ophthalmologist saw bilateral papillitis with white exudates of the nasal part of the discs. There is no history of alcohol use, and the patient has stopped smoking since his heart transplant. On examination, he appears well. Blood pressure is 160/80; pulse is 100 and regular. There are no carotid bruits. Pupils are equal and reactive. Visual acuity is 20/400 OU, with central-inferior scotomas (left larger than right). Neurologic exam is otherwise normal. An MRI scan with and without gadolinium contrast agent, including orbital cuts, is negative, as is CSF examination. This patient’s history, exam, and laboratory findings are now most consistent with which of the following diagnoses? a. Cyclosporine toxicity b. Occipital lobe lymphoma c. Tobacco-alcohol amblyopia d. Ischemic optic neuropathies e. Retinal detachment

Answer 34

D (Victor, pp 262–263.) Ischemic optic neuropathy, often called anterior ischemic optic neuropathy (AION), is the most common cause of acute monocular blindness. This condition presents as sudden, painless loss of vision in one eye. Symptoms may progress over several days, and the visual loss is permanent. The visual field defect is typically an inferior altitudinal defect, with involvement of central vision and a consequent loss of acuity. In up to one-third of patients, the opposite eye may become involved soon afterward. Hypertension and diabetes mellitus appear to be risk factors, as for most small-vessel disease. The responsible arterial occlusion is of the posterior ciliary artery, a branch of the ophthalmic artery, which supplies the optic nerve. Typically, this condition is not associated with carotid artery disease. Giant cell arteritis (temporal arteritis) needs to be excluded, because it can be treated with steroids.

Question 35

A 60-year-old right-handed man underwent heart transplantation 2 weeks ago for severe ischemic cardiomyopathy. He had an uneventful post-operative course and went home after 1 week. He is now readmitted from an outside hospital where he was admitted with headaches, increasing confusion, and a generalized seizure. He relates that he has had difficulty seeing for several days. On exam, he has a blood pressure of 180/100. His pupils are equal and reactive, but he has difficulty reading and finding objects presented to him. Motor and sensory function are normal. An MRI shows several areas of T2 signal abnormality in the occipital and parietal lobe white matter bilaterally. A diffusion-weighted MRI sequence, sensitive to the changes of acute infarction, is negative. 395. Three months later, the patient’s vision is essentially unchanged. He is able to see in his superior fields, but cannot drive. Funduscopic exam at this time is likely to show which of the following? a. Papilledema b. Optic disc pallor c. Retinal exudates d. Retinal vein enlargement e. Drusen f. Absence of venous pulsations g. Corkscrew vessels h. Tilted discs

Answer 35

B (Victor, pp 262–263.) At the time of the initial injury to the optic nerve, the nerve may appear swollen on funduscopy. As the swelling resolves, however, the disc typically appears pale. This optic nerve pallor serves as a sign of previous injury, and it may be seen after injury due to either infarction (as in ischemic optic neuropathy) or inflammation of the optic nerve (as in MS and optic neuritis).

Question 36

396. A 30-year-old woman with diabetes mellitus and menstrual irregularities complains of chronic headaches with blurring of vision. On examination, she has a lantern jaw, prominent nose, spade-shaped hands, and prominent supraorbital ridges. She is slightly taller than other members of her family. (SELECT 1 FIELD)

Answer 36

C (Victor, pp 265–267.) This woman has acromegaly, presumably as a result of a pituitary tumor. The growth hormone–secreting tumor responsible will compress the optic chiasm as it extends superiorly out of the sella turcica. Transsphenoidal resection of the tumor may be feasible if the tumor has not extended too far to the side of the sella turcica. Pressure on the optic chiasm will produce a bitemporal hemianopsia.

Question 37

397. A 17-year-old woman with recurrent enuresis notes pain and visual problems in her left eye. Six months before the development of the visual difficulty, she had transient weakness in both legs for 2 days. Her parents noted slurring and slowing of her speech that appeared to persist long after the transient gait ataxia and leg weakness resolved. (SELECT 1 FIELD)

Answer 37

A (Victor, pp 265–267.) Multiple sclerosis probably caused the ataxia, paraparesis, and dysarthria evident in this young woman. Her loss of vision is presumably due to optic neuritis. This would typically affect only one eye at a time, but the other eye would eventually be involved. The loss of vision would be for the entire visual field of one eye acutely. As the monocular blindness cleared, the patient would be left with an enlarged blind spot.

Question 38

398. A 40-year-old man suffers a gunshot wound to the back of the head. An MRI reveals extensive damage to the left occipital lobe with sparing of the right occipital lobe. (SELECT 1 FIELD)

Answer 38

D (Victor, pp 265–267.) Damage to the left calcarine cortex of the occipital lobe will produce a right homonymous hemianopsia. This will usually split the field of vision exactly at its point of fixation. In rare instances, macular vision from both eyes is preserved, a phenomenon usually referred to as macular sparing.

Question 39

399. A 51-year-old woman complains of progressive loss of visual acuity in her left eye. Over the course of 5 years, her acuity has deteriorated from 20/20 to 20/400. An MRI of her brain reveals a large meningioma impinging on the left side of the optic chiasm. There is no associated hydrocephalus. (SELECT 1 FIELD)

Answer 39

B (Victor, pp 265–267.) With a lesion impinging on the chiasm from one side, there should be a field cut in the contralateral field of the contralateral eye. The ipsilateral eye may exhibit little more than an enlarged blind spot that impinges on central vision, a pattern called a centrocecal scotoma. With more substantial damage to the fibers from the eye ipsilateral to the chiasmatic lesion, the patient may have a left nasal hemianopsia, but this rarely appears.

Question 40

400. A 65-year-old man develops language problems with no loss of consciousness. He is found to have a receptive aphasia, and an MRI scan confirms an area of infarction in the left temporal lobe confined to structures above and lateral to the temporal horn of the lateral ventricle. (SELECT 1 FIELD)

Answer 40

E (Victor, pp 265–267.) Temporal lobe damage produces a superior homonymous quandrantanopsia if there is damage to the optic radiation from the lateral geniculate. Only the lower fibers in this radiation swing superficially in the temporal lobe, extending in front of the temporal horn of the lateral ventricle before swinging back as Meyer’s loop to connections in the occipital lobe. Fibers for the superior visual field are in the lower part of the optic radiation.