Severe Intraoperative Orbital Venous Congestion during Resection of a Frontal Meningioma Presenting with Post-operative Vision Loss and Ophthalmoplegia: A Case Report.

We describe a unique case of a middle-aged man who noticed complete vision loss in the right eye after awaking from resection of a large right-sided frontal meningioma. Visual acuity was hand motions, and there were multiple signs of right orbital venous congestion. Magnetic resonance imaging and venography (MRI/V) of the brain and orbits demonstrated expected post-operative findings with no evidence of cavernous sinus thrombosis or fistula. Empiric treatment with intravenous antibiotics and intravenous methylprednisolone were ineffective. Immediate post-operative computerised tomography (CT) images were re-reviewed and revealed right restricted diffusion of the entire intraorbital right optic nerve. Discussion with the neurosurgical team revealed that during craniotomy, a prominent diploic venous plexus in the frontal bone adjacent to the meningioma was identified and coagulated with bone wax. Review of pre-operative imaging revealed large diploid flow voids in the right frontal bone, corresponding to the intraoperative findings. This prominent venous plexus appeared to drain from the meningioma posteriorly into the vein of Labbe. A second pathway drained anteriorly through the right angular vein into the orbit. We hypothesise that the posterior outflow pathway was coagulated intraoperatively, causing redirection of all venous outflow from the meningioma into the right orbit through the anterior pathway. This resulted in significant orbital hypertension with manifest signs and symptoms. Furthermore, sudden rise in intraorbital pressure led to infarction of the optic nerve, leaving the patient with hand motions vision. We suggest that pre-operative vascular imaging should be performed in patients with large meningiomas, as pre-operative embolisation of venous outflow channels may prevent severe post-operative complications.

Two Cases of Segmental Disc Oedema and Normal Visual Acuity in Giant Cell Arteritis.

Giant cell arteritis (GCA) frequently involves the ocular circulation. Arteritic anterior ischemic optic neuropathy (AAION) is the most common presentation, producing severe vision loss with a characteristic waxy pallor of the optic disc. Optic disc ischemia in AAION is related to underlying systemic vasculitis, which must be treated aggressively with systemic steroids in order to minimize the risk of fellow eye involvement. In contrast, non-arteritic AION (NAION) is thought to result from localized hypoperfusion of the posterior ciliary arteries and mainly presents with segmental optic disc oedema. This condition is usually seen in individuals with crowded optic discs as well as predisposing vascular risk factors and does not require specific treatment. Distinguishing these two entities is important and often challenging. We describe two cases of biopsy-confirmed AAION presenting as segmental disc oedema with the absence of pallor, suggesting specific and isolated involvement of the posterior ciliary arteries in GCA affecting the ophthalmic circulation. This emphasizes the importance of maintaining a high index of suspicion for GCA, particularly when atypical features are present or systemic findings accompany acute vision loss.

Yield of screening blood work and MRI of the brain and orbits in the work-up of unilateral chronic optic neuropathy.

BACKGROUND/OBJECTIVES: No guidelines exist for the investigation of treatable causes of chronic optic neuropathy, including sarcoidosis, lupus, and syphilis. The purpose of this study was to determine the diagnostic yield of screening blood work (ACE (Angiotensin Converting Enzyme) for sarcoidosis, Antinuclear Antibodies (ANA) for lupus, CMIA (chemiluminescence microparticle enzyme immunoassay) for syphilis) and contrast-enhanced MRI brain and orbits in atypical unilateral chronic optic neuropathy. SUBJECTS/METHODS: Retrospective review from February 2012 to June 2018 at a neuro-ophthalmology practice. Six hundred and eighty-three consecutive charts with optic neuropathy were reviewed. Inclusion criteria were unilateral chronic optic neuropathy and a work-up including contrast-enhanced MRI brain and orbits, CBC, ESR, CRP, ANA, CMIA, and ACE. Exclusion criteria were optic nerve swelling in either eye on initial assessment or an established cause of optic neuropathy. The main outcome measure was diagnostic yield. RESULTS: Fifty-seven patients were included. One patient had elevated ACE, seven had positive ANA titers, and three had positive CMIA. Zero patients were diagnosed with sarcoidosis, one patient was diagnosed with lupus-related optic neuropathy, and one patient was diagnosed with syphilitic optic neuropathy. The diagnostic yield of ACE was 0%, ANA was 1.75%, and CMIA was 1.75%. MRI revealed planum sphenoidale meningioma causing compressive optic neuropathy in one patient, giving it a diagnostic yield of 1.82%. CONCLUSION: Routine screening blood work (ACE, ANA, CMIA) and MRI brain and orbits for chronic idiopathic unilateral optic neuropathy has low diagnostic yield, especially if clinical suspicion for syphilis, lupus, and sarcoidosis is low. MRI should still be performed in all cases in order to rule out compressive lesions.

Acute bithalamic infarct manifesting as sleep-like coma: A diagnostic challenge.

Bilateral thalamic infarction (BTI) typically presents as a sleep-like coma (SLC) without localizing signs, posing a diagnostic challenge that may lead the treating physician to search for toxic or metabolic causes and delay treatment. We review our experience with BTI of different etiologies, and emphasize the critical role of timely imaging, diagnosis, and management in a series of 12 patients with a presentation of SLC and acute BTI who were managed in our Medical Centers from 2006-2015. In 11/12, urgent head CT scans showed normal brain tissue, while diffusion-weighted (DWI) MRI revealed symmetric bilateral thalamic hyperintense lesions with variable degrees of brainstem involvement. In 1/12, CT scans revealed a contralateral subacute stroke from a thalamic infarct 1month earlier with a unilateral hyperintense lesion on DWI-MRI. From clinical and imaging findings (DWI-MRI, CT angiography and venography), etiology was attributed to embolic causes (cardio-embolism, artery-to-artery mechanism), small vessel disease, or deep sinus vein thrombosis secondary to dural arteriovenous (AV) fistula. Three patients had good outcomes after prompt diagnosis and optimal treatment in <3hours (intravenous tissue plasminogen activator in two patients cardio-embolic etiology and neuro-endovascular repair in one patient with venous infarction due to a dural AV fistula). The diagnosis was made beyond the therapeutic window in seven patients, who were left with significant neurological sequelae. Higher awareness of BTI presenting as SLC is warranted. Optimal patient management includes urgent DWI-MRI. In cases of BTI, further imaging workup is indicated to provide a comprehensive assessment for etiology. Early diagnosis and prompt, targeted intervention are crucial.