Spontaneous intracranial hypotension: diagnostic and therapeutic implications in neurosurgical practice

Efficacy of Epidural Blood Patching or Surgery in Spontaneous Intracranial Hypotension: A Systematic Review and Evidence Map

BACKGROUND

Spontaneous intracranial hypotension is an important cause of treatable secondary headaches. Evidence on the efficacy of epidural blood patching and surgery for spontaneous intracranial hypotension has not been synthesized.

PURPOSE

Our aim was to identify evidence clusters and knowledge gaps in the efficacy of treatments for spontaneous intracranial hypotension to prioritize future research.

DATA SOURCES

We searched published English language articles on MEDLINE (Ovid), the Web of Science (Clarivate), and EMBASE (Elsevier) from inception until October 29, 2021.

STUDY SELECTION

We reviewed experimental, observational, and systematic review studies assessing the efficacy of epidural blood patching or surgery in spontaneous intracranial hypotension.

DATA ANALYSIS

One author performed data extraction, and a second verified it. Disagreements were resolved by consensus or adjudicated by a third author.

DATA SYNTHESIS

One hundred thirty-nine studies were included (median, 14 participants; range, 3-298 participants). Most articles were published in the past decade. Most assessed epidural blood patching outcomes. No studies met level 1 evidence. Most were retrospective cohort or case series (92.1%, n = 128). A few compared the efficacy of different treatments (10.8%, n = 15). Most used objective methods for the diagnosis of spontaneous intracranial hypotension (62.3%, n = 86); however, 37.7% (n = 52) did not clearly meet the International Classification of Headache Disorders-3 criteria. CSF leak type was unclear in 77.7% (n = 108). Nearly all reported patient symptoms using unvalidated measures (84.9%, n = 118). Outcomes were rarely collected at uniform prespecified time points.

LIMITATIONS

The investigation did not include transvenous embolization of CSF-to-venous fistulas.

CONCLUSIONS

Evidence gaps demonstrate a need for prospective study designs, clinical trials, and comparative studies. We recommend using the International Classification of Headache Disorders-3 diagnostic criteria, explicit reporting of CSF leak subtype, inclusion of key procedural details, and using objective validated outcome measures collected at uniform time points.

Cerebrospinal Fluid-Venous Fistulas: A Systematic Review and Examination of Individual Patient Data

BACKGROUND

Spontaneous intracranial hypotension (SIH) is usually caused by a spinal cerebrospinal fluid (CSF) leak. CSF-venous fistula is an underdiagnosed cause of spinal CSF leak, as it is challenging to identify on myelography.

OBJECTIVE

To review existing literature to summarize common presentations, diagnostic imaging modalities, and current treatment strategies for CSF-venous fistulas.

METHODS

We conducted a systematic review using PubMed, Embase, Scopus, and Web of Science databases to identify studies discussing CSF-venous fistulas. Titles and abstracts were screened. Studies meeting prespecified inclusion criteria were reviewed in full.

RESULTS

Of 180 articles identified, 16 articles met inclusion criteria. Individual patient data was acquired from 7 studies reporting on 18 patients. CSF-venous fistula most frequently presented as positional headache. Digital subtraction myelography provided greatest detection of CSF-venous fistula in the lateral decubitus position and detected CSF-venous fistula in all individual patient cases. Dynamic computed tomography (CT) myelogram enabled detection and differentiation of CSF-venous fistulas from low-flow epidural leaks. The majority of fistulas were in the thoracic spine and slightly more common on the right. Epidural blood patch (EBP) provided temporary or no relief in all individual patients. Resolution or improvement of clinical symptoms and radiologic normalization were observed in all surgically treated patients.

CONCLUSION

Although rare, CSF-venous fistula is an important cause of spinal CSF leak contributing to SIH. Dynamic CT myelogram and digital subtraction myelography, particularly in the lateral decubitus position, are the most accurate and effective diagnostic imaging modalities. EBPs often provide only transient relief, while surgical management is preferred.

A rare case of orthostatic headache due to spontaneous intracranial hypotension

Headache is one of the most common clinical entities, and has a long list of differential diagnoses; however, one of the more uncommon causes of postural headache is spontaneous intracranial hypotension. It is important that clinicians be aware of this condition, as it is often overlooked, leading to invasive and unnecessary diagnostic testing. A good history and physical exam, paired with an MRI of the brain is sufficient to make the diagnosis of SIH, relieve the symptomology of the patient in a quick and efficient manner, and avoid costly invasive procedures.

C1-C2 cryptic cerebrospinal fluid leak directly identified by pressurized radionuclide cisternography: Case report and review of the literature

Background:

Patients with chronic postural headaches may suffer from spontaneous intracranial hypotension (SIH). Trauma, degenerative disc spurring and connective tissue disorders are documented risk factors; in most cases there is no inciting event. Despite sophisticated means of evaluating the neuraxis, many cerebrospinal fluid (CSF) leaks are radiographically occult and treatment is focused on thoracic and cervical-thoracic regions. Although lumbar epidural blood patch (EBP) is the initial treatment of choice after failed conservative management, several studies document the need for treatment aimed at the specific leak area.

Case Description:

This report describes the case of a 42-year-old female with scleroderma and sudden onset postural headaches. Magnetic resonance imaging revealed diffuse pachymeningeal enhancement suggestive of intracranial hypotension. Computed tomographic myelography demonstrated a collection of fluid ventral to the cervical thecal sac; an exact location for CSF egress was not identified. Conservative measures followed by lumbar EBP failed to alleviate her symptoms. The patient underwent placement of a lumbar drain and dynamic radionuclide cisternography (RIC). Panoramic images of the spine were taken at the time of the pressurized saline injection. The CSF leak was clearly visualized at C1–2. Treatment was focused at this region using percutaneous injection of autologous blood and fibrin glue.

Conclusion:

SIH is disabling if left untreated. Spinal CSF leaks are often discrete and difficult to identify using static imaging. The use of pressurized, RIC by lumbar drain injection allows for the real-time evaluation of CSF dynamics and can more precisely identify slow flow leaks often missed with static imaging.