Spinal Dural Arteriovenous Fistula in a Young Male Associated with Craniospinal Leptomeningeal Spread of a Treated High-Grade Glioma.

Spinal dural arteriovenous fistulae (SDAVF) are most commonly idiopathic in origin but may occasionally be seen secondary to surgery, trauma, or inflammation. We report a case of 27-year-old male who came with features of a myelopathy. He was found to have an SDAVF associated with leptomeningeal spread (LMS) of a previously treated high-grade cerebral glioma. Hemorrhagic presentation of gliomas, as in this case, is due to upregulation of vascular endothelial growth factor, which has also been postulated to play a role in the development of SDAVFs. This may suggest a possible mechanism of induction of secondary SDAVFs associated with such tumors. While the coexistence of intracranial neoplasms with vascular malformations has been reported previously, this is the first case report of LMS of a high-grade glioma associated with an SDAVF.

Magnetic resonance imaging of the orbit, Part 1: Basic principles and radiological approach.

Magnetic resonance imaging (MRI) is an eloquent, noninvasive, cross-sectional imaging modality that offers superior tissue characterization of orbital pathologies. The ophthalmologist needs to be aware of the advantages of MRI and its step-wise interpretation in liaison with a radiologist to optimize patient outcomes. In this review, we discuss the basic principles of MRI, some of the commonly used sequences and protocols, the anatomy of the orbit on MRI, and an approach to radiological interpretation.

Magnetic resonance imaging of the orbit, Part 2: Characterization of orbital pathologies.

In this article we focus on a systematic approach to assess common orbital lesions on magnetic resonance imaging (MRI). The identification of the probable compartment or structure of origin helps narrow the differential diagnosis of a lesion. Analyzing the morphology, appearance, and signal intensity on various sequences, the pattern, and degree of contrast enhancement are key to characterize lesions on MRI. Imaging features suggesting cellularity and vascularity can also be determined to help plan for biopsy or surgery of these lesions. MRI can also distinguish active from chronic disease in certain pathologies and aids in selecting appropriate medical management. MRI may thus serve as a diagnostic tool and help in guiding therapeutic strategies and posttreatment follow-up.

Orbital infarction syndrome secondary to rhino-orbital mucormycosis in a case of COVID-19: Clinico-radiological features.

Orbital infarction syndrome is an uncommon pathology with devastating consequences. It is frequently secondary to atherothrombotic phenomena in the internal carotid artery. We report a case of a 66-year-old male with uncontrolled diabetes and use of systemic steroids for COVID-19, who presented with a sudden loss of vision in the left eye, with total ophthalmoplegia and diffuse opacification of the retina. On imaging, he was found to have features of rhino-orbital cellulitis with ischemia of the orbital tissue secondary to isolated ophthalmic artery obstruction (OAO) with a patent internal carotid artery. KOH mount of deep nasal swab was confirmatory of mucor. This is the first reported case of orbital infarction syndrome in the setting of COVID-19.

The importance of repeat digital subtraction myelography in the diagnosis of cryptogenic CSF-venous fistula causing spontaneous intracranial hypotension.

Spontaneous intracranial hypotension (SIH) is a rare disorder that occurs secondary to acquired cerebrospinal fluid (CSF) leaks in the spine. Treatment involves either an epidural blood patch or surgical ligation. Essential to the selecting the optimal management strategy is classifying the type of leak and accurate localization of its level. Hitherto, this has been achieved using conventional imaging methods such as static CT or MR myelography which are adequate for the demonstration of only high flow leaks. Digital subtraction myelography (DSM) is a novel technique which provides superior temporal and spatial resolution in the localization of more challenging slow flow leaks. However, DSM may also be initially non-diagnostic. We report a case of SIH in which repeat DSM revealed a type 3 CSF-venous fistula and demonstrate a possible mechanism of transient CSF leak block resulting in the initial false negative findings based on morphological changes in the culprit nerve sheath diverticulum-pseudomeningocoele complex. The patient underwent successful surgical ligation with clinicoradiological resolution of SIH.

Republished: Primary intraventricular haemorrhage due to rupture of giant varix of the basal vein of Rosenthal in a patient with long-standing direct CCF: angiographic features and treatment considerations.

Direct carotid cavernous fistulae (CCF) are often detected early and treated promptly resulting in a paucity of literature regarding its long-term evolution. We present a case of high flow post-traumatic direct CCF that was neglected for over 6 years and presented with a rare manifestation of primary intraventricular haemorrhage. Occlusions of the primary venous outlets likely resulted in engorgement of the deep venous system. The segmental anatomy of the shunting basal vein is critical to the clinical presentation and may range from basal ganglia or brainstem oedema/infarctions to uniquely, as in our case, isolated intraventricular haemorrhage secondary to variceal rupture. Treatment in such chronic cases requires a consideration of cerebral hyperperfusion syndrome necessitating deconstructive techniques with subsequent anticoagulation to avoid accelerated thrombosis of the venous varices.

Arterial spin labeling hyperperfusion in Rasmussen's encephalitis: Is it due to focal brain inflammation or a postictal phenomenon?

BACKGROUND AND PURPOSE: The study evaluated the utility of arterial spin labeling (ASL) perfusion imaging in Rasmussen's encephalitis (RE). MATERIAL AND METHODS: The hospital electronic database was searched using the search words "encephalitis," "autoimmune encephalitis" and "Rasmussen's encephalitis" for the period of 1 Jan 2015 to 31 Jan 2017. Clinically diagnosed cases of RE for which epilepsy protocol magnetic resonance imaging (MRI) with perfusion imaging (ASL) performed on a 3T scanner were retrieved. The diagnosis of RE was based on Bien's criteria (Bien et al., 2005). We obtained patient's demographic details, clinical features, electrophysiological studies, and follow-up data from electronic hospital records. RESULTS: We included nine patients with RE of whom seven patients showed increased perfusion, and two patients decreased perfusion. Among these patients, MRI changes of gyral hyperintensity without volume loss corresponded to regional ASL hyperperfusion in six patients and ASL hypoperfusion in one patient. Two patients who showed ASL hypoperfusion had corresponding atrophy on MRI. Eight patients of RE had epilepsia partialis continua (EPC) or daily seizures, and one patient was seizure-free post-surgery. Five patients showed a concordance of ASL hyperperfusion with clinical ictal onset zone. Among the seven patients with ASL hyperperfusion, the finding was concordant (complete or partial) with the electroencephalogram (EEG) ictal onset zone in six patients and with interictal epileptiform discharges (IED) in seven patients. CONCLUSION: Increased perfusion in ASL of the involved brain parenchyma in RE is a common MRI finding and may be due to either active inflammation of the brain involved or a seizure-related finding.

Unilateral isolated superior ophthalmic vein thrombosis.

Superior ophthalmic vein (SOV) thrombosis is an uncommon orbital pathology that can present with sudden onset proptosis, conjunctival injection, and visual disturbance. SOV thrombosis is frequently secondary to a cavernous sinus pathology. A 32-year-old female with a known history of autoimmune hemolytic anemia presented with sudden painful proptosis left eye, and on imaging, she was found to have SOV thrombosis without cavernous sinus involvement. She was diagnosed with unilateral isolated SOV thrombosis and was managed conservatively. A careful history and clinical evaluation can help diagnose such rare disorders and initiate appropriate therapy.

Primary intraventricular haemorrhage due to rupture of giant varix of the basal vein of Rosenthal in a patient with long-standing direct CCF: angiographic features and treatment considerations.

Direct carotid cavernous fistulae (CCF) are often detected early and treated promptly resulting in a paucity of literature regarding its long-term evolution. We present a case of high flow post-traumatic direct CCF that was neglected for over 6 years and presented with a rare manifestation of primary intraventricular haemorrhage. Occlusions of the primary venous outlets likely resulted in engorgement of the deep venous system. The segmental anatomy of the shunting basal vein is critical to the clinical presentation and may range from basal ganglia or brainstem oedema/infarctions to uniquely, as in our case, isolated intraventricular haemorrhage secondary to variceal rupture. Treatment in such chronic cases requires a consideration of cerebral hyperperfusion syndrome necessitating deconstructive techniques with subsequent anticoagulation to avoid accelerated thrombosis of the venous varices.