Long-term sequelae of herpes simplex virus encephalitis-related white matter injury: correlation of neuropsychological outcome and diffusion tensor imaging.

The pathophysiology of the memory impairment following Herpes Simplex virus encephalitis is not yet established and understood. This study attempts to elucidate the role of white matter injury and its impact on neuropsychological outcome in patients with history of Herpes Simplex virus encephalitis. This is a single-institution prospective study assessing 9 patients and 15 matched controls utilizing a combination of MRI with diffusion tensor imaging and neuropsychological testing. Tract-based spatial statistics analysis was performed and correlated with neuropsychological outcomes. Significantly decreased fractional anisotropy (FA) values were noted in corpus callosum, corona radiata, left posterior thalamic radiation, cingulum, superior longitudinal fasciculus, fornix, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and uncinated fasciculus. Impaired facial recognition significantly correlated with reduction in FA of right uncinate fasciculus, right inferior longitudinal fasciculus, and splenium genu of corpus callosum. FA value of left cingulum significantly correlated with logical memory, auditory verbal learning. FA value of fornix correlated with visual recognition; FA value of left uncinate fasciculus with auditory verbal learning and delayed recall. In conclusion, this study demonstrates microstructural abnormalities involving several white matter tracts corresponding to neuropsychological deficits.

Imaging features of rosette-forming glioneuronal tumours (RGNTs): A Series of seven cases.

OBJECTIVE: Rosette-forming glioneuronal tumours (RGNTs) are a recently described, rare, distinct nosological entity of the glioneuronal family. We describe imaging findings (CT and MRI) in seven patients with RGNTs. MATERIALS AND METHODS: This retrospective study includes seven RGNT patients (4 male, 3 female; age range: 7-42 years; mean age: 25 years) diagnosed and treated at our institute. MR studies were performed on 3 T and 1.5-T clinical MR systems. All patients were reviewed by two experienced neuroradiologists and imaging findings were tabulated. RESULTS: Five tumours were located in the posterior fossa, and two were in the pineal region. One of the tumours demonstrated multiple satellite lesions, which involved the midbrain, pons, medulla as well as the cervical cord. Tumours located in the pineal region compressed the 3rd ventricle/aqueduct and extended below the tentorium cerebelli. All the tumours demonstrated enhancement, and susceptibility was evident in six of the seven patients. CSF dissemination was present in two patients. CONCLUSION: RGNTs are usually solid-cystic tumours and frequently demonstrate peripheral/heterogeneous enhancement upon post-contrast study. Haemorrhage is a common feature which may not be evident on CT. Cerebrospinal fluid (CSF) dissemination is a feature and appropriate imaging should be performed whenever an RGNT is suspected. KEY POINTS: CT and MRI findings of seven RGNT cases were retrospectively reviewed. RGNTs are predominantly posterior fossa tumours. RGNTs are typically T1 hypointense and T2 hyperintense. Haemorrhage and peripheral/heterogeneous enhancement are common features of RGNTs. CSF dissemination is a feature of RGNTs and requires appropriate imaging.

Unruptured Intradural Posterior Circulation Dissecting/Fusiform Aneurysms Natural History and Treatment Outcome.

BACKGROUND: The natural history and outcome of unruptured posterior circulation dissecting fusiform aneurysms is not fully understood. These have a high risk of morbidity and mortality, not only due to natural history but also due to the challenging and controversial treatment approaches currently available compared to other types of intracranial aneurysms. METHODS: We performed a retrospective study of a prospectively collected aneurysm database at a quaternary neurovascular hospital. We included consecutive patients with unruptured intradural vertebrobasilar dissecting aneurysms between January 2000 and July 2016 who were followed to 2020. Description of baseline, procedural, and outcomes data was performed. Comparisons of patient who had aneurysm rupture on follow-up, increase in 2 or more points of mRS in follow-up and progression of the aneurysm was performed. RESULTS: Seventy patients with 78 fusiform posterior circulation aneurysms were identified. Thirty-nine (55.7%) patients were male with a mean age of 51.7 years (SD ± 17.6). When multiple, aneurysms were more likely to be fusiform (60%) than saccular (40.0%). Baseline diameter (measured on CTA/MRA/DSA), length as well as symptomatic presentation were significantly higher in aneurysms which grew over time. Coronary disease, diabetes and growth were associated an >2 increase in mRS. Diabetes as well as initial symptomatic presentation were associated with rupture. CONCLUSIONS: Unruptured dissecting/fusiform aneurysm are associated with a considerable rate of rupture during follow-up. Growth is associated with morbidity even in the absence of rupture. Initial large size, coronary disease, diabetes, and to a lesser extent female gender may merit closer follow-up and/or prophylactic treatment.

Pial arteriovenous fistula: A clinical and neuro-interventional experience of outcomes in a rare entity.

PURPOSE: Pial arteriovenous fistulae (PAVF) are rare intracranial vascular malformations, predominantly seen in children and distinct from arteriovenous malformations and dural arteriovenous fistulae. PAVF often leads to high morbidity and mortality. The aim of our study was to describe the clinical features and endovascular management of PAVF at various intracranial locations; to analyze the use of liquid embolic agents and coils alone or in combination in the treatment of PAVF and to analyze the outcome of embolization. MATERIALS AND METHODS: Retrospective review of diagnostic angiography and neurointerventional database of our institution identified a cohort of 15 patients with non-galenic PAVF from 2008 to 2014 out of 6750 patients. Fourteen patients were treated endovascularly with coils and liquid embolic materials in combination or alone. Patients were followed up for evaluation of prognosis. RESULTS: Age of the patients ranged from 3 to 37 years. Most patients were male and most common presentation was headache followed by seizure. Most common location of fistula was frontal lobe. The most common type was single artery single hole fistula with venous varix. Satisfactory obliteration was seen in all cases. One patient developed intraparenchymal hematoma on the first post procedural day and outcome was poor. CONCLUSIONS: PAVF are rare intracranial vascular malformations which can effectively be managed endovascularly with liquid embolic, coils alone, or in combination. Complete occlusion of the fistula can be achieved in most cases in a single sitting with a reasonable morbidity related to the procedure, compared with the natural history of this disease.

Mechanical Thrombectomy for Cerebral Venous Sinus Thrombosis: A Case Series and Technical Note.

BACKGROUND: Cerebral venous sinus thrombosis is a rare cause of acute stroke. It may lead to hemorrhagic venous infarctions, brain swelling, or raised intracranial pressure and can be associated with significant mortality and morbidity. Low-molecular-weight heparin is the mainstay of treatment. Endovascular treatment is reserved for patients who deteriorate despite medical management. METHODS: Retrospective evaluation of our institutional databases from 2018-2019 revealed 7 patients who underwent aspiration thrombectomy using large-bore aspiration catheters for recanalization of the dural sinuses with or without intrasinus thrombolysis during the procedure. Their clinical, imaging findings, endovascular technique, and outcome are discussed. RESULTS: We treated 7 patients who did not respond to best medical management. Aspiration thrombectomy was the primary mode of endovascular treatment. Adjuvant low-dose (10 mg recombinant tissue plasminogen activator), short-duration (20-minute) intrasinus thrombolysis was used in 4 patients only during the procedure. Headache was the most common symptom, followed by seizures, focal neurologic deficits, and vomiting. There was improvement in clinical condition within 24 hours of procedure in all patients. The 30-day modified Rankin Scale score was 0 in 6 patients. One patient had residual hemiparesis and aphasia. There were no procedure-related complications. CONCLUSIONS: The described technique appears to be simple, safe, and effective and results in a relatively short procedure time in achieving complete or partial recanalization of the dural sinuses in patients who deteriorate despite clinical management. Endovascular thrombectomy along with conventional medical management restores the final drainage pathway of the brain with good clinical outcome.

Overview of endovascular thrombectomy accessibility gap for acute ischemic stroke in Asia: A multi-national survey.

Endovascular thrombectomy revolutionized the treatment of acute ischemic stroke. Nevertheless, access to endovascular thrombectomy is limited in many parts of the world. Asia holds 60% of the world's population and its countries carry some of the highest stroke disease burden. To understand the availability of endovascular thrombectomy and intravenous thrombolysis in this region, we interviewed stroke neurologists and neuro-interventionists of 19 Asian countries, and found a large disparity in access to endovascular thrombectomy and intravenous thrombolysis between high- and low-income countries. Lack of neuro-interventionists, comprehensive stroke units, stroke triage systems and high treatment cost are the major obstacles to wider accessibility of endovascular thrombectomy, especially among developing countries. The potential solutions to provide equitable access to stroke revascularization therapy are discussed.

Neuroimaging features of fatal high-altitude cerebral edema.

Acute high-altitude cerebral edema can occur in an unacclimatised individual on exposure to high altitudes and sometimes it can be fatal. Here we have described the neuroimaging features of a patient who suffered from fatal high altitude cerebral edema. Available literature is reviewed. Probable pathogenesis is discussed. The risk of acute mountain sickness is reported up to 25% in individuals who ascend to an altitude of 3500 meter and in more than 50% subjects at an altitude of 6000 meter. The lack of availability of advanced imaging facilities at such a higher altitude makes imaging of such condition a less described entity.

[Dyke Davidoff Masson Syndrome Presenting with Intellectual Disability with Behavioral Problems and Substance Use Disorder: A Case Report]. / Davranis Sorunlariyla Birlikte Zekâ Geriligi ile Giden Dyke Davidoff Masson Sendromu ve Madde Kullanim Bozuklugu: Olgu Sunumu.

Dyke Davidoff Masson Syndrome (DDMS) is a rare condition withvaried presentation. Characteristic features are cerebral hemiatrophy,enlargement of ipsilateral ventricle, enlargement of ipsilateral air sinusesand clinical finding of contralateral hemiparesis or hemiplegia andseizures. DDMS may have comorbid intellectual disability or speechdisorder but presentation with psychiatric disorders is rare. We presenta case of DDMS who first came to attention with behavioral problemsassociated with aggression, social disinhibition and with alcohol andcannabis use disorder.

Subconjunctival Fat Prolapse: What Radiologists Need to Know?

Subconjunctival fat prolapse is a rare benign entity or disease presenting as fat containing epibulbar mass in lateral canthus region. Weakness of Tenon's capsule secondary to age, trauma or any surgery leads to herniation of intraconal fat. Radiologists should be aware of the condition and its imaging features. We report a case of 70-year-old obese man presenting with bilateral soft yellowish lateral canthal mass. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) showed typical imaging features of epibulbar fatty lesion in continuation with the intraconal fat.

Trigeminal neuralgia caused by a new variant of persistent trigeminal artery associated with agenesis of internal carotid artery.

We report a hitherto undescribed persistent carotid vertebral anastomosis associated with ipsilateral internal carotid artery agenesis and bilateral duplication of the intradural vertebral arteries. This rare anomaly was detected on MRI, supplemented by CT angiography while evaluating for cause trigeminal neuralgia in a 37-year-old woman. The aberrant vessel was seen to cause thinning and lateral displacement of the left trigeminal nerve on CISS 3D images. Also noted was a bilateral vertebral artery duplication of the PSA variant with the posterior inferior cerebellar artery arising from the medial limb of the duplication on the left.

T1 Hyperintense Prepontine Mass with Restricted Diffusion--A White Epidermoid or a Neuroenteric Cyst?

Neuroenteric cysts (NC) are benign, congenital malformation which are of endodermal origin commonly located in the central nervous system. We report a case of intracranial NC with squamous metaplasia and xanthogranulomatous response masquerading as a white epidermoid on conventional MRI sequences. Lesion showed two components on T2W-images. We observed differential diffusion characteristics including fractional anisotropy, radial diffusivity and axial diffusivity within the two components of the lesion.