Magnetic resonance imaging and computed tomography in the diagnosis of cerebral venous infarction

A clinical observation of the diagnosis of cerebral venous stroke, rare in clinical practice, based on the data of magnetic resonance imaging and computed tomography of the brain, is presented, the semiotics of the revealed changes is described.

Safety analysis and complications of condylar screws in a single-surgeon series of 250 occipitocervical fusions

Objective Condylar screw fixation is a rescue technique and an alternative to the conventional configuration of occipitocervical fusion. Condylar screws are utilized when previous surgical bone removal along the supraocciput has occurred which makes anchoring of a traditional barplate technically difficult or impossible. However, the challenging dissection of C0-1 necessary for condylar screw fixation and the concerns about possible complications have, thus far, prevented the acquisition of large surgical series utilizing occipital condylar screws. In the largest case series to date, this paper aims to evaluate the safety profile and complications of condylar screw fixation for occipitocervical fusion. Methods A retrospective safety and complication-based analysis of occipitocervical fusion via condylar screws fixation was performed. Results A total of 250 patients underwent occipitocervical fusions using 500 condylar screws between September 2012 and September 2018. No condylar screw pullouts, or vertebral artery impingements were observed in this series. The sacrifice of condylar veins during the dissection at C0-1 did not cause any venous stroke. Hypotrophic condyles were found in 36.4% (91 of the 250) cases and did not prevent the insertion of condylar screws. Two transient hypoglossal deficits occurred at the beginning of this surgical series and were followed by recovery a few months later. Corrective strategies were effective in preventing further hypoglossal injuries. Conclusions This surgical series suggests that the use of condylar screws fixation is a relatively safe and reliable option for OC fusion in both adult and pediatric patients. Methodical dissection of anatomical landmarks, intraoperative imaging, and neurophysiologic monitoring allowed the safe execution of the largest series of condylar screws reported to date. Separate contributions will follow in the future to provide details about the long-term clinical outcome of this series.

Radiological aspects of cerebral hyperperfusion syndrome diagnosis. Lecture

Several aspects of diagnostic radiology are considered, particularly concerning the occurrence of stroke and cerebral hyperperfusion after carotid and coronary artery revascularization.Hypoperfusion is the main subject of concern for neurologists and neuroradiologists in the clinical practice, even though hyperperfusion also has an important clinical and prognostic value. Acute pathological hyperperfusion after carotid endarterectomy and venous stroke following cerebral venous sinus thrombosis with a two- or three-fold increase in regional cerebral blood flow have a high risk of hemorrhage. A more favorable condition is benign hyperperfusion with moderate (up to 30%) plethora. It develops during venous stroke as element of the pathogenesis of brain tissue injury after secondary ischemia. Often patients who have undergone the simultaneous carotid and coronary surgery or CABG in the early postoperative period showed signs of neurological deterioration in the form of moderate postischemic hyperperfusion. Timely diagnosis can prevent severe cerebral complications during cerebral venous sinus thrombosis or postoperative adverse events in patients with coronary and carotid artery injuries. CT perfusion is the fastest and most adapted tool for emergency diagnostics, whereas SPECT provides a non-invasive assessment of perfusion and brain tissue metabolism with less radiation and fewer negative effects, such as allergic reactions.

MODERN OUTLOOKS ON RISK FACTORS OF CEREBRAL VENOUS THROMBOSIS

The review presents the main risk factors for cerebral venous thrombosis (CVT). It outlines current understanding of their role in the pathogenesis of venous strokes. The purpose of the review is to systematize the CVT risk factors according to their effect on a particular component of the Virchow’s triad. Pubmed and eLIBRARY, as well as publications and papers on the issue were considered to be the main sources. As a rule, CVT is a multifactorial disease, which is more typical for young people, more often women. However, it can also occur in children and elderly patients. Since CVT does not always have a specific onset, knowledge of risk factors can help in the early disease diagnostics. In comparison with arterial thrombosis, CVT prognosis is generally more favorable. However, the consequences of the disease remain in 15–30 % of patients. The article presents the factors influencing CVT prognosis and outcome. It is considered, that such patients require timely detection and early diagnostics, as it will increase treatment efficacy, reduce after-effects and mortality. Keywords: cerebral venous thrombosis, risk factors, deep vein thrombosis, superficial vein thrombosis, venous stroke. В обзоре представлены основные факторы риска развития церебральных венозных тромбозов (ЦВТ). Обсуждаются современные представления о роли этих факторов в патогенезе венозных инсультов. Целью данного обзора является систематизация факторов риска ЦВТ в зависимости от влияния на тот или иной компонент триады Вирхова. В качестве источников информации использовались данные электронных библиотек Pubmed, eLIBRARY , а также публикации и статьи по данной проблеме. ЦВТ представляет собой, как правило, мультифакторное заболевание, более характерное для лиц молодого возраста, чаще женского пола, но также встречающееся у детей и пожилых пациентов. Поскольку ЦВТ не всегда имеет специфическое начало, знание факторов риска может помочь в ранней диагностике этого заболевания. Прогноз при ЦВТ, по сравнению с артериальным тромбозом, в целом более благоприятный. Однако у 15–30 % пациентов остаются последствия данного заболевания. В статье представлены факторы, влияющие на прогноз и исход ЦВТ. Постулируется, что указанная категория пациентов требует своевременного распознавания и ранней диагностики заболевания, что будет способствовать повышению эффективности лечения, уменьшению последствий патологии и снижению летальности. Ключевые слова: церебральный венозный тромбоз, факторы риска, тромбоз глубоких вен, тромбоз поверхностных вен, венозный инсульт.

DIAGNOSIS OF VENOUS ISCHEMIC STROKE. PART II (ALGORITHMS AND SEMIOLOGY OF DIAGNOSTIC RADIOLOGY. LIMITATIONS IN CLINICAL PRACTICE). A REVIEW

Venous stroke in cerebral venous sinus thrombosis is a rare pathological condition with uncertain diagnostic algorithm to ensure prompt treatment by neurologists and radiologists. All the methods are not obligatory in the workup of acute stroke, except computed tomography (CT) and transcranial Doppler. Researchers and clinicians are commonly guided by their own experiences. Therefore, the diagnosis of venous stroke is an unstable process resulting in its underestimation in the general stroke population. The optimal use of neuroimaging methods within the existing standards of care for patients with stroke, determination of the necessary and sufficient set of diagnostic procedures is an organizational and methodical problem. In addition, there is no complete description of venous ischemic stroke patterns in the medical literature. The article reviews existing evidence-based data on the diagnostic algorithms for venous stroke and discusses the probability of detecting radiologic symptoms based on the diagnostic accuracy and effectiveness of such methods as conventional CT and magnetic resonance imaging (MRI), CT and MR angiography, CT and MR perfusion, transcranial Doppler (TCD) and ultrasound of the brachiocephalic arteries stated in the national and international guidelines, as well as our own experience. Limitations of their use and options to overcome major drawbacks including the introduction of teleradiology are considered.

Parametric Features of Regional Cerebral Blood Flow in Venous Ischemic Stroke

The lecture is devoted to the peculiarities of changes in tissue and cell perfusion of the brain with a rare pathology – venous ischemic stroke. Venous stroke, being a “relatively unknown cerebrovascular disease”, occurs up to 5 % of all cases of stroke. The terms “venous ischemia” and “venous stroke” have long been used in the literature and the definition of the venous nature of stroke should lead to a change in therapeutic tactics. Neuroimaging should ensure the verification of stroke and cerebral venous sinus thrombosis, which are the main cause of such a stroke. A certain “alertness” to the venous nature of the stroke with the expansion of the volume of radiologic methods of investigation and the performance of angiographic and perfusion CT and MR techniques, diffusion MRI allowed to increase the number of diagnosed and verified venous strokes from 0.4 % of the total number of stroke patients to 2.4 %. A distinctive feature of venous ischemic stroke from the arterial is moderate hyperemia in the central part in cases where necrosis does not develop and perifocal hyperperfusion in the development of necrosis. Moderate plethora, defined by perfusion parameters (up to 30 % CBF, CBV, MTT) of CT, MRI and SPECT techniques, and not oligemia is the primary damaging factor of the pathogenesis of venous stroke in contrast to the arterial and hyperemia patterns should be the reference points in emergency diagnosis venous stroke along with tomoangiographic symptoms of cerebral venous sinustrombosis.

DIAGNOSIS OF VENOUS ISCHEMIC STROKE. PART I (CLINICAL POLYMORPHISM). A REVIEW ARTICLE

Venous stroke being “relatively unknown cerebrovascular disease” occurs in 0.55% of all strokes. Specific diagnostic concerns to venous stroke and the expansion of the volume of radiologic examinations from routinely used non-contrast CT to angiographic and perfusion CT- and MRI, diffusion MRI allowed us to increase the number of diagnosed and verified venous ischemic stroke from 0.4% of all strokes treated in our center to 2.4%, resulting in a 6-fold increase within the 5-year period. Symptoms of cerebral venous sinus thrombosis depend on the size and the growth rate of thrombus. In addition, focal neurological symptoms are diverse and largely dependent on thrombus localization and safety of collateral blood flow, as well as patients’ age and severity of cerebral edema. Cerebral symptoms are nonspecific and may occur in varying degrees of severity related to the localization of the pathological process. The routinely used assessment scales such as the National Institutes of Health Stroke Scale (NIHSS), Bartel Index, Rankin Scale do not reliably identify this type of acute ischemic stroke. The leading symptom is headache with the mean visual analogue scale of 7.3±1.6. The tendency towards a less pronounced neurologic deficit at admission and mild disability status at discharge have been found among patients with venous stroke. The clinical course of venous stroke mostly demonstrated a tendency towards rapid regression of focal symptomatology and neurological deficit in comparison with arterial ischemic stroke.