Idiopathic Intracranial Hypertension Progressing to Venous Sinus Thrombosis, Subarachnoid Hemorrhage, and Stroke

A New Insight in Nonaneurysmal Subarachnoid Hemorrhage: the Potential Role of the Internal Jugular Veins

BACKGROUND

 Causes of the nonaneurysmal subarachnoid hemorrhage (na-SAH) are still debated. Many studies confirmed the possible involvement of the intracranial venous system, in particular variants of the basal vein of Rosenthal.

STUDY OBJECT

 The aim of this study is to investigate the role of extracranial venous system, in particular the jugular drainage, in the na-SAH pathophysiology.

MATERIALS AND METHODS

 This is a multicenter retrospective study including patients suffering from na-SAH who were radiologically screened to exclude vascular malformations. The course of the internal jugular veins was evaluated to reveal any stenosis (caliber reduction >80%). Particular attention was paid at the passage between the styloid process and the arch of C1 to detect possible compression. As a control group, we enrolled patients who underwent CT angiograms and/or cerebral DSAs in the past 2 years.

RESULTS

 We included 194 patients. The na-SAH group consisted of 94 patients, whereas the control group consisted of 100 patients. Fifty patients of the control group underwent a CT angiography for an ischemic cerebrovascular disease or trauma and 50 patients for an SAH due to a ruptured aneurysm. A significant jugular stenosis was found in 49 (52.1%) patients in the na-SAH group and in 18 (18%) patients in the control group. At univariate and multivariate analysis, the difference was statistically significant (p < 0.0001).

CONCLUSIONS

 This is the first study investigating the correlation between jugular stenosis and the occurrence of na-SAH. The impaired venous outflow due to reduced venous caliber could result in an engorgement of the upstream intracranial veins with transient hypertensive phases facilitating ruptures. Further larger prospective studies are necessary to confirm these data.

Dural venous sinus thrombosis after lumbar puncture in a patient with idiopathic intracranial hypertension

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is one of the most common causes of papilloedema seen by ophthalmologists and neurologists. Patients with IIH routinely undergo lumbar puncture (LP) for diagnosis. Dural venous sinus thrombosis (DVST) is a rare complication of cerebrospinal fluid pressure (CSF)-lowering procedures such as lumbar puncture and epidural and may be an intracranial complication of IIH.

CASE DESCRIPTION

A 29-year-old obese woman was diagnosed with severe idiopathic intracranial hypertension (IIH) after she presented with new-onset headache, pulsatile tinnitus and blurred vision. Magnetic resonance imaging (MRI) and venography (MRV) were normal apart from signs of intracranial hypertension. Lumbar puncture (LP) revealed an opening pressure of 40 cm of water. Due to the severity of the papilloedema and vision loss, she was referred for a ventriculoperitoneal shunt and found to have venous sinus thrombosis involving the superior sagittal sinus on the pre-operative computed tomography (CT) head 5 days after the LP. CT venography (CTV) one day later and MRV 3 days later showed significant worsening as the thrombosis extended into the deep venous system. She was started on therapeutic heparin and her symptoms and vision improved and she did not develop any neurological complications.

CONCLUSIONS

DVST should be considered in IIH patients who have worsening papilloedema or symptoms of intracranial hypertension. Repeat venous imaging can prevent devastating consequences such as venous infarcts of haemorrhage in these patients.

Headaches Due to Low and High Intracranial Pressure

PURPOSE OF REVIEW

Headache disorders attributed to low and high intracranial pressure are commonly encountered in specialty headache practices and may occur more frequently than realized. While the headaches resulting from intracranial pressure disorders have what are conventionally thought of as defining characteristics, a substantial minority of patients do not manifest the "typical" features. Moreover, patients with intracranial pressure disorders may also have a preexisting primary headache disorder. Heightening the complexity of the presentation, the headaches of intracranial pressure disorders can resemble the phenotype of a primary disorder. Lastly, patients with so-called intracranial "hypotension" often have normal CSF pressure and neuroimaging studies. Thus, a high index of suspicion is needed. The published literature has inherent bias as many types of specialists evaluate and treat these conditions. This article reviews the key points to emphasize the history, examination, and laboratory evaluation of patients with intracranial pressure disorders from a neurologist's perspective.

RECENT FINDINGS

Lumbar puncture opening pressure in patients with spontaneous intracranial hypotension was low enough to meet diagnostic criteria (≤60 mm CSF) in only 34% of patients in one study. Most patients had an opening pressure in the low normal to normal range, and 5% had an opening pressure of 200 mm CSF or more. Diskogenic microspurs are a common cause of this syndrome. The Idiopathic Intracranial Hypertension Treatment Trial found that most participants had a headache phenotype resembling migraine or tension-type headache. No "typical" or characteristic headache phenotype was found, and headache-related disability was severe at baseline. Headache disability did not correlate with the lumbar puncture opening pressure at baseline or at the 6-month primary outcome period. Although participants who were randomly assigned to acetazolamide had a lower mean CSF opening pressure at 6 months, headache disability in that group was similar to the group who received placebo.

SUMMARY

Significant overlap is seen in the symptoms of high and low CSF pressure disorders and in those of primary headache disorders. Neurologists are frequently challenged by patients with headaches who lack the typical clinical signs or imaging features of the pseudotumor cerebri syndrome or spontaneous intracranial hypotension. Even when characteristic symptoms and signs are initially present, the typical features of both syndromes tend to lessen or resolve over time; consider these diagnoses in patients with long-standing "chronic migraine" who do not improve with conventional headache treatment. While the diagnostic criteria for pseudotumor cerebri syndrome accurately identify most patients with the disorder, at least 25% of patients with spontaneous intracranial hypotension have normal imaging and over half have a normal lumbar puncture opening pressure. Detailed history taking will often give clues that suggest a CSF pressure disorder. That said, misdiagnosis can lead to significant patient morbidity and inappropriate therapy.