Diagnosis and treatment evaluation in patients with spontaneous intracranial hypotension

Abstract

Spontaneous intracranial hypotension is characterized by an orthostatic headache and audiovestibular symptoms alongside a myriad of other non-specific symptoms. It is caused by an unregulated loss of cerebrospinal fluid at the spinal level. Indirect features of CSF leaks are seen on brain imaging as signs of intracranial hypotension and/or CSF hypovolaemia as well as a low opening pressure on lumbar puncture. Direct evidence of CSF leaks can frequently, but not invariably, be observed on spinal imaging. The condition is frequently misdiagnosed due to its vague symptoms and a lack of awareness of the condition amongst the non-neurological specialities. There is also a distinct lack of consensus on which of the many investigative and treatment options available to use when managing suspected CSF leaks. The aim of this article is to review the current literature on spontaneous intracranial hypotension and its clinical presentation, preferred investigation modalities, and most efficacious treatment options. By doing so, we hope to provide a framework on how to approach a patient with suspected spontaneous intracranial hypotension and help minimize diagnostic and treatment delays in order to improve clinical outcomes.

Keywords: CSF hypovolaemia; CSF hypovolemia; CSF leak; CSF venous fistula; orthostatic headache; spontaneous intracranial hypotension.

Figure 1

Radiological features of spontaneous intracranial hypotension. (A) T1W coronal post-contrast MRI sequence showing diffuse smooth pachymeningeal thickening and enhancement. (B) Enlargement of pituitary gland seen on T1W sagittal MRI sequence. (C) T2W axial MRI sequence showing distension of the transverse venous sinuses. (D) Ventral extradural CSF collection seen on T2W axial MRI sequence. (E) White arrowheads highlighting a ventral longitudinal extradural CSF collection (SLEC) in the cervical spine on T2W sagittal MRI sequence. (F) T1W sagittal MRI sequence demonstrating brainstem sagging. (G) A right-sided thoracic CSF venous fistula shown with contrast extravasation into a paraspinal vein on right decubitus CT myelography. (H) Extravasation of CSF through a ventral dural tear on CT myelography.