Spontaneous Intracranial Hypotension Due to Skull-Base Cerebrospinal Fluid Leak

Skull Base CSF Leaks: Potential Underlying Pathophysiology and Evaluation of Brain MR Imaging Findings Associated with Spontaneous Intracranial Hypotension

BACKGROUND AND PURPOSE

CSF leaks of the skull base and spine share a common process of CSF volume loss, and yet only the latter has been associated with spontaneous intracranial hypotension (SIH). Despite published claims that only spinal leaks cause SIH, no prior studies have evaluated brain MR imaging in patients with skull base leaks for findings associated with SIH, such as dural enhancement. The purpose of our study was to use a validated brain MR imaging scoring system to evaluate patients with skull base CSF leaks for findings associated with SIH.

MATERIALS AND METHODS

We included patients with confirmed skull base CSF leaks and contrast-enhanced preoperative brain MRI. The preoperative MR images were reviewed for findings associated with SIH by using the Bern score. Patient age, presenting symptoms and their duration, and leak site were also recorded.

RESULTS

Thirty-one patients with skull base CSF leaks were included. Mean Bern score was 0.9 (range 0-4, standard deviation 1.1), and only 1 patient (3%) had dural enhancement. Mean age was 53 years (range 18-76). Mean symptom duration was 1.3 years, with 22 patients presenting within 1 year of symptom onset. Twenty-three patients (74.2%) had intraoperative confirmation of leak from the middle cranial fossa, involving the temporal bone, while 7 (22.6%) had leaks from the anterior skull base. One patient, who had dural enhancement, had an infratentorial CSF leak along the petrous segment of the internal carotid artery.

CONCLUSIONS

Our study provides further evidence that skull base and spinal CSF leaks represent distinct pathophysiologies and present with different brain MRI findings.

Hypermobile Ehlers-Danlos syndrome and spontaneous CSF leaks: the connective tissue conundrum

Collagen, the most abundant protein in the body, is a key component of the extracellular matrix (ECM), which plays a crucial role in the structure and support of connective tissues. Abnormalities in collagen associated with connective tissue disorders (CTD) can lead to neuroinflammation and weaken the integrity of the blood-brain barrier (BBB), a semi-permeable membrane that separates the brain's extracellular fluid from the bloodstream. This compromise in the BBB can result from disruptions in ECM components, leading to neuroinflammatory responses, neuronal damage, and increased risks of neurological disorders. These changes impact central nervous system homeostasis and may exacerbate neurological conditions linked to CTD, manifesting as cognitive impairment, sensory disturbances, headaches, sleep issues, and psychiatric symptoms. The Ehlers-Danlos syndromes (EDS) are a group of heritable CTDs that result from varying defects in collagen and the ECM. The most prevalent subtype, hypermobile EDS (hEDS), involves clinical manifestations that include joint hypermobility, skin hyperextensibility, autonomic dysfunction, mast cell activation, chronic pain, as well as neurological manifestations like chronic headaches and cerebrospinal fluid (CSF) leaks. Understanding the connections between collagen, CSF, inflammation, and the BBB could provide insights into neurological diseases associated with connective tissue abnormalities and guide future research.

Spinal Cerebrospinal Fluid Leak Localization with Digital Subtraction Myelography: Tips, Tricks, and Pitfalls

Cerebrospinal fluid (CSF) leak can cause spontaneous intracranial hypotension (SIH) which can lead to neurologic symptoms, such as orthostatic headache. Over time, imaging techniques for detecting and localizing CSF leaks have improved. These techniques include computed tomography (CT) myelography, dynamic CT myelography, cone-beam CT, MRI, MR myelography, and digital subtraction myelography (DSM). DSM provides the highest sensitivity for identifying leak sites and has comparable radiation exposure to CT myelography. The introduction of the lateral decubitus DSM has proven invaluable in localizing leaks when other imaging tests have been inconclusive.

CSF-Venous Fistula of the Clival Skull Base: A Unique Case Study and Literature Review

An adolescent male presented with orthostatic headaches following head trauma. MRI showed cerebellar tonsil displacement and a bony defect in the clival skull base. Digital subtraction myelography (DSM) confirmed a cerebrospinal fluid-venous fistula (CVF). This was repaired endoscopically. CVFs cause uncontrolled flow of CSF into the venous system resulting in symptoms of intracranial hypotension. They're often difficult to identify on initial imaging. This is the first reported CVF originating in the central skull base, and the first treated via endoscopic trans-nasal approach. CVFs may elude initial imaging, making DSM crucial for unexplained spontaneous intracranial hypotension. Laryngoscope, 134:645-647, 2024.

Surgical Ligation of Spinal CSF-Venous Fistulas after Transvenous Embolization in Patients with Spontaneous Intracranial Hypotension

A spinal CSF-venous fistula is an increasingly recognized type of CSF leak that causes spontaneous intracranial hypotension. The detection of these fistulas requires specialized imaging such as digital subtraction myelography or dynamic CT myelography, and several treatment options are available. A novel treatment for these CSF-venous fistulas consisting of transvenous embolization with the liquid embolic agent Onyx has been described recently, but some patients require further treatment if embolization fails. The purpose of this study was to evaluate the safety and effectiveness of surgery following transvenous embolization. In a series of 6 consecutive patients who underwent surgical ligation of the fistula after endovascular embolization, there were no surgical complications. Postoperatively, complete resolution of symptoms was reported by 5 of the 6 patients, and brain MR imaging findings of spontaneous intracranial hypotension resolved in all patients. This study suggests that surgical ligation of spontaneous spinal CSF-venous fistulas after endovascular embolization is effective and safe.

It is wrong to treat pain in CSF hypotension headache to allow the patient to walk!

It is wrong to treat pain in CSF hypotension headache to allow the patient to walk!