Restricted Diffusion in the Optic Nerve Head After Shock-Induced Anterior Ischemic Optic Neuropathy.

ABSTRACT: Shock-induced anterior ischemic optic neuropathy (SIAION) is a known type of optic neuropathy in patients who experienced shock related to different etiologies such as anemia and severe intradialytic hypotension like in our patient. Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common acute unilateral known type of optic neuropathy in older patients with vasculopathic risk factors such as hypertension, diabetes mellitus, and obstructive sleep apnea. Although SIAION and NAION are similar optic neuropathies due to ischemia and, in particular, hypotension, they may have different pathogenic mechanisms (e.g., acute shock or intradialytic hypotension vs nocturnal hypotension), laterality (e.g., unilateral vs bilateral), and severity (e.g., light perception or worse vision). We presented a case with restricted diffusion on the apparent diffusion coefficient and the diffusion weighted imaging confined to the optic disc head in a patient with pallid edema after intradialytic hypotension. Although DWI of the optic nerve is neither 100% specific nor 100% sensitive for ischemia, we believe that restricted diffusion of the optic nerve head in our case is a clinico-radiologic correlate to pallid edema in SIAION.

Localizing Thalamomesencephalic Afferent and Efferent Pupillary Defects.

ABSTRACT: A 42-year-old Algerian man presented for binocular oblique diplopia, hypersomnolence with drop attacks, bilateral hearing loss, and thoracic pain. He had a right thalamomesencephalic hemorrhage due to an underlying cavernous malformation treated with subtotal surgical resection. On neuro-ophthalmic examination, the patient had a left relative afferent pupillary defect and a right oculosympathetic efferent pupillary defect (i.e., Horner syndrome) in addition to other thalamomesencephalic eye and neurologic signs (right fourth nerve palsy, hearing loss, hemiparesis, and thalamic pain). Clinicians should recognize the localizing value of this unique constellation of mesencephalic afferent and efferent pupillary defects.

Neuro-Ophthalmic Manifestations of Intracranial Malignancies.

BACKGROUND: To describe the various neuro-ophthalmic presentations, key exam features, and clinical findings associated with 5 common primary and secondary intracranial malignancies. EVIDENCE ACQUISITION: Retrospective PubMed search and review of published case reports, case series, observational studies, book chapters, and review articles examining the neuro-ophthalmic features of intracranial malignancies including primary glial neoplasms (e.g., glioblastoma multiforme), primary and secondary lymphoma, intracranial metastases, carcinomatous/lymphomatous meningitis, and intracranial germ cell tumors. The search strategy used to perform the retrospective review included the aforementioned tumor type (e.g., glioblastoma multiforme) and the following terms and Boolean operators: AND ("visual loss" OR "papilledema" OR "diplopia" OR "ophthalmoplegia" or "neuro-ophthalmology" OR "proptosis"). RESULTS: The rate of growth and the location of an intracranial tumor are essential factors in determining the neuro-ophthalmic presentation of certain intracranial malignancies. Primary malignant brain glial neoplasms commonly present with visual afferent complaints (e.g., unilateral or bilateral visual acuity or visual field defects, bitemporal or homonymous hemianopsia), pupil abnormalities (relative afferent pupillary defect), and optic atrophy or papilledema. Primary intraocular lymphoma (with or without central nervous system lymphoma) typically presents as a painless bilateral vitritis. Secondary intracranial malignancies have variable afferent and efferent visual pathway presentations. Carcinomatous/lymphomatous meningitis is associated with diplopia (e.g., multiple ocular motor cranial neuropathies with or without vision loss from papilledema or compressive/infiltrative optic neuropathy). Intracranial germ cell tumors can present with a chiasmal syndrome or dorsal midbrain syndrome. CONCLUSION: Intracranial malignancies can present with neuro-ophthalmic symptoms or signs depending on topographical localization. Specific neuro-ophthalmic presentations are associated with different malignant intracranial tumors. Clinicians should be aware of the common malignant intracranial tumors and their associated clinical presentations in neuro-ophthalmology.

Checkerboard Visual Field Defect in Occipital Stroke.

A 74-year-old man with vasculopathic risk factors presented to the emergency room with a chief complaint of peripheral vision loss resulting from an intracranial hemorrhage in his right parietal and occipital lobes. Urgent craniotomy and ventriculostomy led to a stable clinical condition with subsequent development of a crossed quadrant homonymous hemianopsia (checkerboard visual field) due to a new right parieto-occipital infarct superimposed on a prior left occipital infarct. This uncommon visual field defect represents juxtaposed homonymous quadrantanopias that produce a striking checkerboard appearance that is almost pathognomonic for bilateral occipital lesions.

Remote Pontine Hemorrhage After Left Frontal Lobe Meningioma Resection Presenting as Bilateral Internuclear Ophthalmoplegia.

Postoperative hemorrhages are relatively common complications of surgical procedures including craniotomies, and these typically occur at or near the operative site. Bleeding in remote areas (e.g., posterior fossa) after supratentorial craniotomy can occur and may be associated with a high morbidity and mortality. Although remote cerebellar hemorrhage after craniotomy is well described, remote pontine hemorrhage is less common. We describe a bilateral internuclear ophthalmoplegia due to an RPH after otherwise uncomplicated resection of a frontal meningioma. Clinicians should be aware that neuro-ophthalmic findings can occur from hemorrhages remote from the operative site.