Spontaneous Intracranial Hypotension: Clinical Presentation, Diagnosis, and Treatment Strategies

Spontaneous intracranial hypotension (SIH) typically presents as an acute orthostatic headache during an upright position, secondary to spinal cerebrospinal fluid leaks. New evidence indicates that a lumbar puncture may not be essential for diagnosing every patient with SIH. Spinal neuroimaging protocols used for diagnosing and localizing spinal cerebrospinal fluid leaks include brain/spinal MRI, computed tomography myelography, digital subtraction myelography, and radionuclide cisternography. Complications of SIH include subdural hematoma, cerebral venous thrombosis, and superficial siderosis. Treatment options encompass conservative management, epidural blood patches, and surgical interventions. The early application of epidural blood patches in all patients with SIH is suggested.

Outcome of epidural blood patch for imaging-negative spontaneous intracranial hypotension

BACKGROUND

Spontaneous intracranial hypotension is diagnosed by an abnormal finding in brain MRI, spinal imaging, or lumbar puncture. However, the sensitivity of each test is low. We investigated whether patients with suspected spontaneous intracranial hypotension and negative imaging findings would respond to epidural blood patch.

METHODS

We prospectively recruited patients with new-onset orthostatic headache admitted at the Samsung Medical Center from January 2017 to July 2021. In patients without abnormal imaging findings and no history of prior epidural blood patch, treatment outcome-defined as both 50% response in maximal headache intensity and improvement of orthostatic component-was collected at discharge and three months after epidural blood patch.

RESULTS

We included 21 treatment-naïve patients with orthostatic headache and negative brain and spinal imaging results who received epidural blood patch. After epidural blood patch (mean 1.3 times, range 1-3), 14 (66.7%) and 19 (90.5%) patients achieved both 50% response and improvement of orthostatic component at discharge and three months post-treatment, respectively. Additionally, complete remission was reported in 11 (52.4%) patients at three-month follow-up, while most of the remaining patients had only mild headaches. Among nine (42.9%) patients who underwent lumbar puncture, none had an abnormally low opening pressure (median 13.8 cm H₂O, range 9.2-21.5).

CONCLUSION

Given the high responder rates of epidural blood patch in our study, empirical epidural blood patch should be considered to treat new-onset orthostatic headache, even when brain and spinal imaging are negative. The necessity of lumbar puncture is questionable considering the high response rate of epidural blood patch and low rate of "low pressure."

Low-pressure headaches following foramen magnum decompression secondary to absorption of cerebrospinal fluid into the venous system of the diploic space

INTRODUCTION

We describe a case of a patient who suffered low-pressure headaches secondary to absorption of cerebrospinal fluid into the venous system of the diploic space following a foramen magnum decompression. This case is important as it describes a physiologically plausible but previously undescribed complication of a common surgical intervention.

CASE

A nine-year-old boy underwent a foramen magnum decompression for a Chiari malformation (Type I). Five years after his initial decompression, his original symptoms returned and he underwent further decompression with short-term relief of symptoms. He then began to describe low-pressure headaches. Comprehensive investigations revealed a small posterior pseudomeningocoele that had extended into the diploic space at the site of the previous surgery to the occipital bone. It was postulated that the diploic space may be acting as an additional site for reabsorption of his CSF, and as a result of this, he was experiencing consistently low-pressure symptoms. His symptoms have completely resolved following surgical intervention to seal the site of communication with the diploic space.

DISCUSSION

We review recent literature that supports this theory through an understanding of the anatomy of the diploic venous system and also its physiological behaviour as demonstrated in recent cadaveric and porcine studies.

Resolution of idiopathic intracranial hypertension after sustained lowering of cerebrospinal fluid pressure

Idiopathic intracranial hypertension (IIH) is a syndrome of headache due to raised intracranial pressure (ICP) where the cerebrospinal fluid (CSF) is normal and there is no alternative pathology on imaging. The aetiology is unknown. This review questions many of the prevailing views regarding aetiology and treatment of IIH. It explores the concept that there is a vicious cycle of fluctuating raised ICP leading to secondary compression of the transverse sinuses and further elevation of ICP. It also raises the question as to whether this vicious cycle could be relieved by prolonged drainage of CSF as seen in Lumbar puncture induced low-pressure headache or alternatively a lumbar drain.