Neuro-Ophthalmic Emergencies for the Neurologist

Abstract

A variety of acute neurologic disorders present with visual signs and symptoms. In this review the authors focus on those disorders in which the clinical outcome is dependent on timely and accurate diagnosis. The first section deals with acute visual loss, specifically optic neuritis, ischemic optic neuropathy (ION), retinal artery occlusion, and homonymous hemianopia. The authors include a discussion of those clinical features that are helpful in distinguishing between inflammatory and ischemic optic nerve disease and between arteritic and nonarteritic ION. The second section concerns disc edema with an emphasis on the prevention of visual loss in patients with increased intracranial pressure. The third section deals with abnormal ocular motility, and includes orbital inflammatory disease, carotid-cavernous fistulas, painful ophthalmoplegia, conjugate gaze palsies, and neuromuscular junction disorders. The final section concerns pupillary abnormalities, with a particular emphasis on the dilated pupil and on carotid artery dissection. Throughout there are specific guidelines for the management of these disorders, and areas are highlighted in which there is ongoing controversy.

Neuro-ophthalmological emergency disorders: A general view

“…Symptoms associated with neuro-ophthalmic disorders usually include afferent visual system disorders such as optic neuritis (especially Multiple Sclerosis (MS)), vision-related migraines, optic neuropathy, papilledema, pseudotumor cerebri, brain tumors or strokes, and the efferent visual system disorders such as anisocoria and other pupil abnormalities, diplopia and other visual disturbances (phospenes, etc. ), un-explained vision loss, sudden temporary or permanent visual loss, ophthalmoplegia, ptosis, eyelid and facial spasms, eye movement disorders in paralitic or restrictive types (thyroid eye disease, Myasthenia gravis, nystagmus, blepharospasm, and acute visual perception disorders or high cortical visual dysfunctions [1][2][3][4][5][6][7][8][9]. However, the neuro-ophthalmological emergencies constitute vision or life-threatening conditions if diagnosis and treatments are not made promptly.…”

“…The common neuro-ophthalmological emergency disorders are arteritic anterior ischemic optic neuropathy (AAION), pituitary apoplexy, cavernous sinus thrombosis, rino-orbital-cerebral mucormycosis (ROCM), isolated third nerve palsy, multiple unilateral or bilateral oculomotor palsies, acute methanol toxication, Tolosa-Hunt syndrome, Miller Fisher Syndrome and Horner syndrome [1][2][3][4][5][13][14][15]. The main signs of the life or sight-threatening neuro-ophthalmological emergency conditions include diplopia, ptosis (acute painful or chronic painless), transient visual loss, anisocoria, acute painful or painless homonymous hemianopsia, acute bitemporal hemianopsia, severe pain in head/neck, painful ophthalmoplegia and ocular motility disorder [1][2][3][4][5][6][7][8][9].…”

“…Because the compressive lesions of CN3 usually affect both the central somatomotor ibers and the peripheral superomedial pupillary ibers and they cause the pupil-involving CN3 palsy. However, ischemic lesions of the nerve involve only the central somatomotor ibers, so, ischemic CN3 palsy has no a pupillary involvement [1][2][3][4][5][6][7][8][9]. The main mechanisms of the aneurysmal CN3 palsy, including direct compression by an enlarged aneurysmal sac, subarachnoid blood irritation, or aneurysm pulsation.…”

“…Because the pupil-involving CN3 palsy especially with an acute headache may be an indicator of an aneurysm, potentially fatal event, in case of its rupture or leak and subarachnoid hemorrhage. However, it should be remembered that a posterior communicating artery (PCOM) aneurysm may present initially with normal pupils [2,[6][7][8][9]. Posterior communicating artery (PCA) aneurysms present with III nerve palsy 30% to 60% of the times, and approximately 40% of aneurysms are located at the level of PCA, the ophthalmic artery, and the cavernous sinus.…”

“…Besides an aneurysm and vascular pathology, giant cell arteritis (GCA), pituitary apoplexy, demyelinating disease (MS), midbrain infarction, CN3 schwannoma/meningioma or cerebral metastasis, trauma and ophthalmoplegic migraine may also cause the CN3 palsy with pupil involvement. Although Myasthenia gravis (MG) may mimic a CN3 palsy, the pupil is never be involved in MG [1][2][3][4][5][6][7][8][9][10][11][12]. Myasthenia gravis is a neuromuscular disease leading to increasing muscle weakness and fatigue at the end of the day.…”