Disorders Nerve Cranial• 7 SECTIONMotor Ocular Multiple

Bilateral Ophthalmoplegia

Key Facts

•Binocular ductional deficits that cannot be attributed to dysfunction of a single ocular motor cranial nerve

•May have ptosis, anisocoria and/or reduced pupil constriction to light, and reduced sensation or pain in distribution of trigeminal nerve

•May have proptosis, resistance to retropulsion of eyes, and congested eyelids or conjunctiva

•Lesions may lie in extraocular muscles, orbits, cavernous sinuses, basal meninges, brainstem, or cerebrum

•Common causes:

•bilateral orbital lesions • myasthenia gravis • Fisher syndrome • cavernous sinus lesions

Clinical Findings

•Binocular ductional deficits

•May also have ptosis, pupil or trigeminal abnormalities, and orbital congestive features

•Doll’s head maneuver enhances ductions in progressive supranuclear palsy and bilateral frontoparietal infarcts

•Progressive supranuclear palsy:

•parkinsonian features • neck rigidity • stance and gait instability

•Fisher syndrome:

•absent deep tendon reflexes • ataxia

•Myasthenia gravis:

•no pain • pupils normal • positive edrophonium • AChRAb and EMG tests (see above)

•Botulism:

•mydriasis • loss of accommodation • diarrhea or constipation

•Pituitary apoplexy:

•headache • bitemporal hemianopia • addisonian features • fever

•meningismus • photophobia

•Wernicke encephalopathy:

•altered cognition • ataxia

•Thalamic infarction or hemorrhage:

•depressed consciousness • limb paralysis • ataxia

•Bilateral frontoparietal infarcts:

•doll’s head maneuver enhances ductions • patient unable to interpret visual arrays (simultanagnosia) or point accurately to objects (optic ataxia)

•quadriparesis

Ancillary Testing

•Thalamic and frontoparietal infarcts: MRI shows lesions

•Myasthenia gravis: edrophonium, AChRAb, and EMG tests may be confirmatory

•Wernicke encephalopathy: MRI may show signal alterations in medial thalamus

•Paranasal sinus disease: MRI shows lesions; endoscopic biopsy, smear, and culture help in diagnosis

•Fisher syndrome: lumbar puncture shows high protein, nerve conduction studies may show slowed conduction, and antiganglioside antibody GQ1b often positive

•Bilateral orbital lesions: imaging and biopsy help in diagnosis

•Bilateral cavernous sinus lesions: lumbar puncture may show cells

•Botulism: stool sample reveals the toxin

•Whipple disease: Polymerase Chain Reaction (PCR) of spinal fluid shows organism and small intestine biopsy shows typical pathology

Disorders Nerve Cranial• 7 SECTIONMotor Ocular Multiple

Bilateral Ophthalmoplegia (Continued)

Differential Diagnosis

•Graves disease

•Genetic extraocular myopathy

•Orbital myositis

•Orbital tumor

•Traumatic orbitopathy

•Bilateral cavernous sinus disease

•Bilateral paranasal sinus disease

•Myasthenia gravis

•Botulism

•Fisher syndrome

•Wernicke disease

•Thalamic infarct, hemorrhage, tumor

•Progressive supranuclear palsy

•Whipple disease

•Bilateral frontoparietal infarcts

Treatment

•Thalamic and bilateral frontoparietal infarcts: supportive care

•Wernicke disease: intravenous thiamine 100 mg

•Fisher syndrome: plasmapheresis or intravenous immunoglobulin if severe or worsening, otherwise observe or use corticosteroids

•Botulism: supportive care and antitoxin if necessary

•Bilateral paranasal sinus disease: debridement and anti-infective drugs

•Bilateral cavernous sinus disease: depends on cause

•Pituitary apoplexy: corticosteroids, surgery

Prognosis

•Thalamic disease: eye movements may recover but ataxia and extremity weakness usually permanent

•Wernicke disease: eye movements recover but may have residual memory loss

•Botulism: recovery usually complete if supportive care is prompt and adequate

•Paranasal and cavernous sinus disease: depends on cause

•Progressive supranuclear palsy: gradual decline in arousal level, ability to stand and walk, swallow, talk

Disorders Nerve Cranial• 7 SECTIONMotor Ocular Multiple

Direct Carotid–cavernous Fistula

Key Facts

•Abnormal connection between intracavernous carotid artery and cavernous sinus venous plexus

•Hole in cavernous carotid artery caused by trauma, atherosclerosis, or elastic tissue degeneration

•Florid proptosis, eyelid swelling, corkscrew conjunctival injection and chemosis, ductional deficits, increased IOP, and/or retinal venous congestion (red-eyed shunt)

•If fistula drains posteriorly, may have cranial neuropathies but no orbital congestion (white-eyed shunt)

•Treat promptly by endovascular methods

Clinical Findings

•Periocular pain, eyelid swelling, proptosis

•Arterialized corkscrew conjunctival injection, chemosis

•Diplopia, reduced ocular ductions

•Optic nerve dysfunction

•Elevated IOP

•Retinal vein engorgement, perivenous hemorrhages

•Pulse-synchronous bruit (whooshing sound)

Ancillary Testing

•MRI or CT usually shows dilated superior ophthalmic vein and enlargement of extraocular muscles, but fistula may not be evident except on magnetic resonance angiography source images

•On catheter angiography, internal carotid artery injection shows very premature appearance of dye in cavernous sinus and sometimes intracavernous carotid hole, aneurysm, or dysplasia

Differential Diagnosis

•Graves disease

•Orbital myositis

•Orbital tumor

•Traumatic orbitopathy

•Other causes of cavernous sinus syndrome

Treatment

• Should be closed by endovascular methods (coiling, stenting, trapping) if possible

Prognosis

•With experienced interventionalists, can usually be successfully closed with tolerable risk

Fig. 7.5 Direct carotid–cavernous fistula. Hemorrhagic conjunctival chemosis reflects severe orbital venous hypertension.

Fig. 7.6 Right direct carotid–cavernous fistula. The hyperemic optic disc and dilated retinal veins in the right eye reflect venous hypertension. This sign, which is not often present, increases the urgency of treatment.

Fistula cavernous–Carotid Direct