Anatomic and MRI bases for medullary infarctions with patients' presentation.

OBJECTIVE: There is a low incidence of the medullary infarctions and sparse data about the vascular territories, as well as a correlation among the anatomic, magnetic resonance imaging (MRI) and neurologic signs. MATERIALS AND METHODS: Arteries of the 10 right and left sides of the brain stem were injected with India ink, fixed in formalin and microdissected. The enrolled 34 patients with medullary infarctions underwent a neurologic, MRI and Doppler examination. RESULTS: Four types of the infarctions were distinguished according to the involved vascular territories. The isolated medial medullary infarctions (MMIs) were present in 14.7%. The complete MMIs comprised one bilateral infarction (2.9%), whilst the incomplete and partial MMIs were observed in 5.9% and 8.9%, respectively. The anterolateral infarctions (ALMIs) were very rare (2.9%). The complete and incomplete lateral infarctions (LMIs), noted in 35.3%, comprised 11.8% and 23.6%, respectively, that is, the anterior (5.9%), posterior (8.9%), deep (2.9%), and peripheral (5.9%). Dorsal ischemic lesions (DMIs) occurred in 11.8%, either as a complete (2.9%), or isolated lateral (5.9%) or medial infarctions (2.9%). The remaining ischemic regions belonged to various combined infarctions of the MMI, ALMI, LMI and DMI (35.3%). The infarctions most often affected the upper medulla (47.1%), middle (11.8%), or both (29.5%). Several motor and sensory signs were manifested following infarctions, including vestibular, cerebellar, ocular, sympathetic, respiratory and auditory symptoms. CONCLUSIONS: There was a good correlation among the vascular territories, MRI ischemia features, and neurologic findings regarding the medullary infarctions.

Anatomic and MRI Bases for Pontine Infarctions with Patients Presentation.

OBJECTIVES: There are scarce data regarding pontine arteries anatomy, which is the basis for ischemic lesions following their occlusion. The aim of this study was to examine pontine vasculature and its relationships with the radiologic and neurologic features of pontine infarctions. MATERIALS AND METHODS: Branches of eight basilar arteries and their twigs, including the larger intrapontine branches, were microdissected following an injection of a 10% mixture of India ink and gelatin. Two additional brain stems were prepared for microscopic examination after being stained with luxol fast blue and cresyl violet. Finally, 30 patients with pontine infarctions underwent magnetic resonance imaging (MRI) in order to determine the position and size of the infarctions. RESULTS: The perforating arteries, which averaged 5.8 in number and 0.39 mm in diameter, gave rise to paramedian and anteromedial branches, and also to anterolateral twigs (62.5%). The longer leptomeningeal and cerebellar arteries occasionally gave off perforating and anterolateral twigs, and either the lateral or posterior branches. Occlusion of some of these vessels resulted in the paramedian (30%), anterolateral (26.7%), lateral (20%), and combined infarctions (23.3%), which were most often isolated and unilateral, and rarely bilateral (10%). They were located in the lower pons (23.3%), middle (10%) or rostral (26.7%), or in two or three portions (40%). Each type of infarction usually produced characteristic neurologic signs. The clinical significance of the anatomic findings was discussed. CONCLUSIONS: There was a good correlation between the intrapontine vascular territories, the position, size and shape of the infarctions, and the type of neurologic manifestations.

Disseminated cerebral cryptococcosis after silent West Nile virus infection in a patient with polycythemia vera: A case report and review of the literature.

Although disseminated cryptococcosis can occur occasionally, it is most commonly seen in immunodeficient patients. In 2005, a 43-year-old man was diagnosed with polycythemia vera. Following in 2018, he experienced an unknown-cause fever and headache. To establish the source of the symptoms, a magnetic resonance imaging scan of the brain was performed, which indicated meningeal and gyral-leptomeningeal thickening and several localized T2 hyperintense lesions measuring up to 10 × 14 mm in diameter. Cryptococcus neoformans was then cultivated from cerebrospinal fluid. Serum IgM antibodies against West Nile Virus were positive. After 8 weeks of treatment with amphotericin B and fluconazole, the overall condition improved, and the cerebrospinal fluid control culture became negative. The symptoms returned shortly after discontinuing antifungal therapy, necessitating the reintroduction of fluconazole. Currently, the patient is stable and responding positively to ruxolitinib. Here, it is demonstrated how a patient with polycythemia vera due to immunological weakness might develop disseminated cryptococcosis of the brain after West Nile virus infection.

Overcoming the IOTLB wall for multi-100-Gbps Linux-based networking.

This article explores opportunities to mitigate the performance impact of IOMMU on high-speed network traffic, as used in the Linux kernel. We first characterize IOTLB behavior and its effects on recent Intel Xeon Scalable & AMD EPYC processors at 200 Gbps, by analyzing the impact of different factors contributing to IOTLB misses and causing throughput drop (up to 20% compared to the no-IOMMU case in our experiments). Secondly, we discuss and analyze possible mitigations, including proposals and evaluation of a practical hugepage-aware memory allocator for the network device drivers to employ hugepage IOTLB entries in the Linux kernel. Our evaluation shows that using hugepage-backed buffers can completely recover the throughput drop introduced by IOMMU. Moreover, we formulate a set of guidelines that enable network developers to tune their systems to avoid the "IOTLB wall", i.e., the point where excessive IOTLB misses cause throughput drop. Our takeaways signify the importance of having a call to arms to rethink Linux-based I/O management at higher data rates.

Evolution of acute "black hole" lesions in patients with relapsing-remitting multiple sclerosis.

OBJECTIVE: Gadolinium-enhanced T1-weighted lesions are a well-established marker of areas with acute inflammatory activity. A majority of these gadolinium-enhanced T1 lesions are isointense relative to the surrounding white matter, but 20-40% of such active lesions will evolve during one year into areas of low signal ("black hole"). This study sought to characterize evolution of "black hole" lesions in patients with relapsing-remitting multiple sclerosis (MS) using the magnetic resonance imaging (MRI), which measures active lesions via the count of new or enlarged T2 and gadolinium-enhanced T1-weighted lesions. MATERIALS AND METHODS: This was a prospective, observational case-series study which utilized pre- and post-gadolinium contrast T1-weighted and Proton density MRI scans. Twenty-nine patients (8 males and 21 females) with average age of 38.86 ± 6.58 years and disease duration of 5.75 ± 7.00 years were used to analyze 196 acute demyelinating plaques detected on MRI images during the 24-month follow-up of post-gadolinium signal intensity enhancement of MS plaques. RESULTS: Significant difference in black hole development was found between the shapes of acute and chronic "black holes". Ring-shaped and patchy plaques were 4.09 (1.87-8.91) times more likely and 1.49 (0.71-3.12) times less likely to develop an acute "black holes" than homogeneous plaques, respectively. Acute plaques with higher lesion-to-CSF SI ratio and larger surface area showed a greater tendency to develop into acute and chronic "black holes". CONCLUSIONS: The value of lesion-to-CSF SI ratio and surface area were found as the predictors of the "black hole" formation.

Quantitative and Qualitative Characteristics of Atherosclerotic Plaques on Carotid Arteries in Patients with Antiphospholipid Syndrome: The Role of MDCT Angiography.

INTRODUCTION: Antiphospholipid syndrome (APS) is an autoimmune disease characterised by arterious and venous thrombosis, miscarriage, and the presence of antiphospholipid antibodies (aPL) in the blood. As we know, APS is also characterised by accelerated atherosclerotic degeneration with an increased risk of thrombosis in all blood vessels, including the carotid arteries. Carotid artery stenosis can manifest in many different ways. The aim of this study is to present the results of our multidetector computerised tomography angiography (MDCTA) analysis of the carotid arteries in patients with primary and secondary APS compared with a control group. MATERIALS AND METHODS: This study examined 50 patients with primary antiphospholipid syndrome (PAPS) and 50 patients with secondary antiphospholipid syndrome (SAPS). The results were compared with a control group also comprising 50 patients. The groups were analysed with respect to age, sex and the presence of well-established risk factors for vascular disease. The study was conducted using MDCTA, where we analysed the quantitative and qualitative (morphologic) characteristics of carotid artery lesions. RESULTS: Patients from the control group had significantly elevated levels of cholesterol and triglycerides in comparison with patients with PAPS and SAPS (p < 0.001 and p < 0.05). The results show that carotid artery lesions were significantly more common in patients with APS (PAPS, n = 40, CI95: 0.50-0.75, p = 0.0322 and SAFS, n = 54, CI95: 0.59-0.80, p = 0.0004) than within the control group (n = 23). There was a statistically significant difference between patients with APS and the control group with respect to lesions in the distal segments (n = 27, CI95: 0.67-0.95, p = 0.0001), bulbi and proximal segments (n = 21, CI95: 0.84-1.00, p = 0.000005). The number of patients with one lesion (L) (n = 27) was significantly greater than the number of those with three (n = 10, CI95: 0.56-0.86, p = 0.0051) or four (n = 3, CI95: 0.73-0.98, p = 0.00001) lesions. There were also more patients with two lesions (n = 24) than those with four (n = 3) (CI95: 0.71-0.97, p = 0.00005). Carotid artery stenosis was shown as a percentage of the carotid artery lumen diameter (%DS). Stenosis of up to 30%, was more common in patients in the PAPS group (n = 12) than in the control group (n = 3) (CI95: 0.52-0.96, p = 0.0201), while the SAPS group (n = 17) had an even larger disparity (CI95: 0.62-0.97, p = 0.0017). We observed a highly significant difference in the frequency of stenoses between 30% and 50% DS between the PAPS group (n = 24) and the control group (n = 7) (CI95: 0.59-0.90, p = 0.0023), as well as the SAPS group (n = 30) (CI95: 0.65-0.92, p = 0.0002). A qualitative analysis of plaque morphology revealed that patients with PAPS had significantly more soft tissue lesions (n = 23) compared with calcified lesions (n = 2) (CI95: 0.74-0.99, p = 0.00003), as well as more mixed plaques (n = 9) and calcified plaques (n = 2) (CI95: 0.48-0.98, p = 0.0348). Patients within the SAPS group had significantly more soft tissue (n = 35) than calcified lesions (n = 3) (CI95: 0.79-0.98, p = 0.00000021), as well as more mixed lesions (n = 21) compared with calcified (n = 3) (CI95: 0.68-0.97, p = 0.0002). CONCLUSIONS: Our study shows that subclinical manifestations of carotid artery lesions were more common in patients with APS. We came to the conclusion that MDCTA is an accurate diagnostic method because it is a safe method that provides us with a great quantity of accurate information about the characteristics of atheromatous plaques, which aids us in the further planning of treatment for patients with APS.

Multiple lateral sinus pericranii--A case report.

INTRODUCTION: Sinus pericranii is a rare vascular anomaly. It is characterized by abnormal communication between the extracranial and intracranial venous system, usually involving the superior sagittal sinus and occasionally the transverse sinus. Off the midline lesions are extremely rare. Multiplicity, associated venous lakes, venous angioma and lateral location are unusual and unique presentation of sinus pericranii. CASE REPORT: A case of multiple congenital off-midline sinus pericranii in the left frontotemporal and parietal region is presented. Magnetic resonance imaging showed an extracranial vascular anomaly connected with the intracranial venous system through abnormal diploic or emissary veins. The lesions were removed completely by surgery. CONCLUSION: Sinus pericranii is a rare vascular malformation with unique clinical and radiological features. Sinus pericranii may cause fatal complications, and it must be treated by surgical or endovascular procedures.

Posterior reversible encephalopathy syndrome--A case report.

INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is characterized by the following symptoms: seizures, impaired consciousness and/or vision, vomiting, nausea, and focal neurological signs. Diagnostic imaging includes examination by magnetic resonance (MR) and computed tomography (CT), where brain edema is visualized bilaterally and symmetrically, predominantly posteriorly, parietally, and occipitally. CASE REPORT: We presented a 73-year-old patient with the years-long medical history of hypertension and renal insufficiency, who developed PRES with the symptomatology of the rear cranium. CT and MR verified changes in the white matter involving all lobes on both sides of the brain. After a two-week treatment (antihypertensive, hypolipemic and rehydration therapy) clinical improvement with no complications occurred, with complete resolution of changes in the white matter observed on CT and MR. CONCLUSION: PRES is a reversible syndrome in which the symptoms withdraw after several days to several weeks if early diagnosis is made and appropriate treatment started without delay.

Bilateral hippocampal infarction and amnesia: A case report.

INTRODUCTION: The hippocampus along with other structures of the medial temporal lobe plays an important role in the process of learning and memory consolidation. Bilateral hippocampal lesions lead to persistent anterograde amnesia while unilateral damage results in milder, content-specific forms of amnesia. Hippocampus may be affected by an acute or chronic pathologic process from a wide spectrum of neurological disorders. CASE REPORT: A 61-year-old female patient with a long history of hypertension, glucose intolerance, hypercholesterolemia and depression was hospitalized for acute anterograde amnesia, which led to repeated excessive drug taking. By further examinations that included laboratory tests, electroencephalography, Doppler sonography of intra- and extracranial vessels and neurovisualization methods [multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) of the brain] bilateral hippocampal ischemia that occurred at different times was detected. Cognitive and neuropsychological evaluation revealed an isolated severe damage of episodic memory with the inability of retention of new information which persisted at the control examination three months later. The assumed mechanism of occurrence of ischemia in this case could be arterioarterial embolism. CONCLUSION: Although ischemic stroke is one of the most common neurological diseases, ischemic stroke of the hippocampus is rare, the isolated bilateral presentation with clinical signs of severe amnestic syndrome in particular. Timely recognition and modern therapeutic approach could have a favorable impact on the recovery from severe neurological, cognitive deficit. It could be suggested that in patients with the clinical image of acute anterograde amnesia and vascular risk factors the MSCT examination of the brain with computed tomography perfusion and angiography is performed immediately upon hospitalization.