Recurrent syncope due to refractory cerebral venous sinus thrombosis and transient elevations of intracranial pressure

Recurrent reflex syncope in idiopathic intracranial hypertension patient resolved after lumbar puncture: pathogenetic implications

BACKGROUND

Idiopathic intracranial hypertension is a disease characterized by increased intracranial cerebrospinal fluid volume and pressure without evidence of other intracranial pathology. Dural sinuses are rigid structures representing a privileged low-pressure intracranial compartment. Rigidity of dural sinus ensures that the large physiologic fluctuations of cerebrospinal fluid pressure associated with postural changes or to Valsalva effect cannot be transmitted to the sinus. An abnormal dural sinus collapsibility, especially when associated with various anatomical sinus narrowing, has been proposed as a key factor in the pathogenesis of idiopathic intracranial hypertension. This pathogenetic model is based on an excessive collapsibility of the dural sinuses that leads to the triggering of a self-limiting venous collapse positive feedback-loop between the cerebrospinal fluid pressure, that compresses the sinus, and the increased dural sinus pressure upstream, that reduces the cerebrospinal fluid reabsorption rate, increasing cerebrospinal fluid volume and pressure at the expense of intracranial compliance and promoting further sinus compression. Intracranial compliance is the ability of the craniospinal space to accept small volumetric increases of one of its compartments without appreciable intracranial pressure rise. In idiopathic intracranial hypertension, a condition associated with a reduced rate of CSF reabsorption leading to its volumetric expansion, a pathologically reduced IC precedes and accompanies the rise of ICP. Syncope is defined as a transient loss of consciousness due to a transient cerebral hypoperfusion characterized by rapid onset, short duration, and spontaneous complete recovery. A transient global cerebral hypoperfusion represents the final mechanism of syncope determined by cardiac output and/or total peripheral resistance decrease. There are many causes determining low cardiac output including reflex bradycardia, arrhythmias, cardiac structural disease, inadequate venous return, and chronotropic and inotropic incompetence. Typically, syncopal transient loss of consciousness is mainly referred to an extracranial mechanism triggering a decrease in cardiac output and/or total peripheral resistance. Conversely, the association of syncope with a deranged control of intracranial compliance related to cerebral venous outflow disorders has been only anecdotally reported.

CASE PRESENTATION

We report on a 57-year-old woman with daily recurrent orthostatic hypotension syncope and idiopathic intracranial hypertension-related headaches, which resolved after lumbar puncture with cerebrospinal fluid subtraction.

CONCLUSIONS

A novel mechanism underlying the triggering of orthostatic syncope in the presence of intracranial hypertension-dependent reduced intracranial compliance is discussed.

Solitary intraventricular tumors in dogs and cats treated with radiotherapy alone or combined with ventriculoperitoneal shunts: A retrospective descriptive case series

BACKGROUND

Intraventricular tumors are rare, optimal treatment is not defined. Symptomatic patients often exhibit life-threatening hydrocephalus. With several months time-to-effect after radiotherapy (RT), increased intracranial pressure is concerning. This increase in pressure can be overcome by ventriculoperitoneal shunting (VPS).

OBJECTIVES

Retrospective evaluation of outcome and complications in dogs and cats with intracranial tumors treated with either RT or VPS/RT.

ANIMALS

Twelve client-owned cats and dogs.

METHODS

Dogs and cats with symptomatic intraventricular tumors treated with definitive-intent RT or VPS/RT were included in a retrospective, descriptive case series. Complications, tumor volume evolution, time-to-progression, and survival time were determined.

RESULTS

Twelve animals were included: 1 cat and 5 dogs treated with single-modality RT and 4 cats and 2 dogs treated with VPS/RT. Neurological worsening seen in 4/6 animals during single-modality RT and 2/6 died during RT (suspected brain herniation). All dogs with VPS normalized clinically by the end of RT or earlier. Complications occurred in 4/6 animals, all but 1 were successfully managed surgically. Imaging follow-up in 8 animals surviving RT showed a marked decrease in tumor volume. Median survival time was 162 days (95% confidence interval [CI]: 16; infinity) for animals treated with RT and 1103 days (95%CI: 752; infinity) for animals treated with VPS/RT. Median time-to-progression was 71 days (95%CI: 7; infinity) and 895 days (95%CI: 704; infinity) for each group, respectively. Two dogs died because of intraventricular metastasis 427 and 461 days after single-modality RT.

CONCLUSIONS AND CLINICAL IMPORTANCE

Ventriculoperitoneal shunting led to rapid normalization of neurological signs and RT had a measurable effect on tumor volume. Combination of VPS/RT seems to be beneficial.

Clinical Mimics: An Emergency Medicine-Focused Review of Syncope Mimics

BACKGROUND

Syncope is an event that causes a transient loss of consciousness (LOC) secondary to global cerebral hypoperfusion. The transient nature of the event can make diagnosis in the emergency department (ED) difficult, as symptoms have often resolved by time of initial presentation. The symptoms and presentation of syncope are similar to many other conditions, which can lead to difficulty in establishing a diagnosis in the ED.

OBJECTIVE

This review evaluates patients presenting with a history concerning for possible syncope, mimics of syncope, and approach to managing syncope mimics.

DISCUSSION

Syncope is caused by transient LOC secondary to global cerebral hypoperfusion. Many conditions can present similarly to syncope, making diagnosis in the ED difficult. Some of the most emergent conditions include seizures, stroke, metabolic disorders, and head trauma. Other nonemergent conditions include cataplexy, pseudosyncope, or deconditioning. Many laboratory studies and imaging can be nondiagnostic during ED evaluation. For patients presenting with apparent syncope, immediate treatment should focus on identifying and treating life-threatening conditions. History and physical examination can help guide further diagnostic evaluation and management.

CONCLUSIONS

Patients with apparent syncope should be evaluated for potential immediate life-threatening conditions. A thorough history and physical examination can aid in distinguishing syncope from common mimics and help identify and subsequently treat life-threatening conditions.

Current approaches to the clinical assessment of syncope in pediatric population

INTRODUCTION

Syncope is one of the most common clinical problem in children. This disorder is characterized by transient, spontaneously self-terminating loss of consciousness with brief duration and complete recovery. This situation is usually alarming for the families of patients. The mechanism of syncope is transient global brain hypoperfusion to levels below those tolerated by cerebrovascular autoregulation. Syncope can occur with many different etiologies in the pediatric population.

CLASSIFICATION

Syncopes are divided into three major categories as neurally mediated syncope, cardiovascular-mediated syncope, and non-cardiovascular syncope.

CLINICAL FEATURES

The major challenge in the assessment of children with syncope is that most children are asymptomatic at the time of their presentation, therefore making a careful and detailed history and a comprehensive physical examination essential in all patients. A trigger stimulus is detected in some cases, and this is an important clinical clue for the diagnosis. Cardiac causes of syncope in children are rare but can be life threatening and have the highest risk of morbidity and mortality. Misdiagnosis of epilepsy is common in patients presenting with syncope; therefore, the differential diagnosis between epileptic seizures and syncope is very important. It should be remembered that the evaluation of syncope in children is costly and diagnostic workup has a limited diagnostic yield.

CONCLUSION

The aim of this article is to present different types of syncope and to provide new practical clinical approaches to the diagnosis, investigation, and management in the pediatric population.

Subdural Hematoma Presenting as Recurrent Syncope

BACKGROUND

Syncope is a common emergency department (ED) complaint. Recurrent syncope is less common, but may be concerning for serious underlying pathology. It often requires a broad diagnostic evaluation that may include neurologic imaging.

CASE PRESENTATION

We present the case of a 75-year-old man with non-small-cell carcinoma who presented to the ED for recurrent syncope after coughing spells over the 2 weeks preceding his arrival at the ED. He had a normal cardiac evaluation, however, he had some subacute neurologic changes that prompted obtaining a computed tomography (CT) scan of the head. This led to the diagnosis of atraumatic subdural hematoma that was causing transient transtentorial herniation leading to the recurrent syncope. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be aware that recurrent syncope is a possible presentation of increased intracranial pressure that may be due to a mass lesion, particularly if the patient has any acute or subacute neurologic changes. Although this association with a subdual hematoma is rare, other cases of mass lesions leading to syncope after coughing spells have been reported in the literature.