Tag: Spontaneous intracranial hypotension

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Unraveling the cause of microspurs in spontaneous intracranial hypotension type 1: discogenic origin or calcified Hofmann’s ligament?

J Neurosurg Spine 44:315–319, 2026

This clinical study investigates the origin of ventral spinal microspurs causing spontaneous intracranial hypotension (SIH) type 1, comparing discogenic lesions with fibrotic tissue consistent with Hofmann’s ligament. Retrospective histopathological reanalysis of 27 surgically resected microspurs showed both discogenic and fibrotic origins, with 13 discogenic, 9 fibrotic, and 5 unclassifiable cases, and no significant differences in spur length, location, or CT density.

The authors conclude that ventral CSF leaks can arise from calcified intervertebral discs as well as calcified or fibrotic Hofmann’s ligaments, expanding the pathophysiological understanding of SIH and highlighting limitations from retrospective design, small sample size, and histological classification challenges.

Etiology of Microspurs: Microspurs causing ventral CSF leaks in spontaneous intracranial hypotension (SIH) type 1 can originate from both calcified intervertebral discs (discogenic) and calcified fibrous tissue associated with Hofmann’s ligament, not exclusively from disc material.

Histopathological Classification: Microspurs were histopathologically classified as either discogenic (cartilage/fibrocartilaginous tissue, often with secondary calcification) or fibrotic (hypercellular fibrous tissue with or without calcification, suggestive of Hofmann’s ligament).

Distribution: Most microspurs were located in the thoracic spine, with about one-third found at the cervicothoracic or thoracolumbar junctions, and the rest in the midthoracic region.

Imaging Findings: There was no statistically significant difference in microspur length or CT density (Hounsfield units) between discogenic and fibrotic (Hofmann’s ligament) origins, limiting the ability of imaging to distinguish between them preoperatively.

Clinical Implications: Both discogenic and fibrotic origins should be considered in the diagnosis and surgical planning for SIH with ventral CSF leaks, as relying solely on the discogenic theory may overlook alternative etiologies.

Pathophysiological Mechanism: Calcified microspurs, whether from discs or Hofmann’s ligament, may cause dural tears due to mechanical stress at spinal junctions or in regions with a narrow spinal canal.

Limitations: The study’s retrospective design, small sample size, and challenges in histopathological classification (lack of specific markers, possible sampling errors) limit the generalizability and precision of findings

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Microsurgical Repair of Ventral Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension: Efficacy and Safety of Patch-Sealing Versus Suturing

 

Operative Neurosurgery 28:379–385, 2025

This study compares microsurgical suturing and patch-sealing techniques for repairing ventral cerebrospinal fluid leaks in spontaneous intracranial hypotension. Both methods are equally effective, but sealing is faster and involves less spinal cord manipulation, potentially reducing surgical complications.

Study Overview and Methods

• Compared microsurgical suture vs. patch-sealing for ventral dural leaks in SIH patients.

• Retrospective analysis conducted between 2013 and 2023 at a single center.

• 85 patients with Type 1 SIH leaks were included in the study.

Results

• No significant difference in headache resolution between techniques (89% vs 94%).

• Sealing technique was significantly faster than suturing (139 vs 169 minutes).

• Complication rates: 23% in suture group, 9% in sealing group (not statistically significant).

Clinical Outcomes

• No significant difference in postoperative Bern-Score between techniques.

• SLEC-positive postoperative rate: 13% in suture group, 22% in sealing group.

• 90% of patients reported headache improvement post-surgery.

Discussion

• Both techniques are effective, but sealing minimizes spinal cord manipulation.

• Sealing preferred due to faster surgery time and fewer complications.

• Limitations include retrospective design and potential selection bias.

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Distinct Pattern of Membrane Formation With Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension

Operative Neurosurgery 26:71–77, 2024

To systematically describe pertinent, intraoperative anatomic findings encountered when approaching spinal cerebrospinal fluid (CSF) leaks and CSF-venous fistulas in spontaneous intracranial hypotension (SIH).

METHODS: In a retrospective study, we included surgically treated patients suffering from SIH at our institution from April 2018 to March 2022. Anatomic, intraoperative data were extracted from operative notes and supplemented with data from surgical videos and images. Prominent anatomic features were compared among different types of CSF leaks.

RESULTS: The study cohort consists of 120 patients with a mean age of 45.2 years. We found four distinct patterns of spinal membranes specifically associated with different types of CSF leaks: (i) thick, dorsal membranes, which were hypervascular and may mimic the dura (pseudodura); (ii) thin, lateral membranes encapsulating a ventral epidural CSF compartment (confining the spinal longitudinal extradural CSF collection); (iii) ventral membranes constituting a transdural funnel–like CSF channel; and (iv) lateral membranes forming spinal cysts/meningeal diverticulae associated with lateral CSF leaks. The latter three types resemble a layer of arachnoid herniated through the dural defect.

CONCLUSION: We describe four distinct spinal (neo-)membranes in association with spinal CSF leaks. Formation of these membranes, or emergence by herniation of arachnoid through a dural defect, constitutes a specific pathoanatomic feature of patients with SIH and CSF leaks. Recognition of these membranes is of paramount importance for diagnosis and treatment of patients with spinal CSF leaks.

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Dural sac shrinkage signs on magnetic resonance imaging at the thoracic level in spontaneous intracranial hypotension

Acta Neurochirurgica (2021) 163:2685–2694

Spontaneous intracranial hypotension (SIH) is secondary to a cerebrospinal fluid leak at the spinal level without obvious causative events. Several signs on brain and cervical spine magnetic resonance (MR) imaging (MRI) have been associated with SIH but can be equivocal or negative. This retrospective study sought to identify characteristic SIH signs on thoracic spinal MRI.

Methods Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed.

Results The most prevalent findings on T2-weighted MRI at the thoracic level were anterior shift of the spinal cord (96.3%) and dorsal dura mater (81.5%), probably caused by dural sac shrinkage. These dural sac shrinkage signs (DSSS) were frequently accompanied by cerebrospinal fluid collection in the posterior epidural space (77.8%) and a prominent epidural venous plexus (77.8%). These findings disappeared in all six patients who underwent post-EBP spinal MRI. Dural enhancement and brain sagging were minimum or absent on the cranial MR images of seven patients, although DSSS were obvious in these seven patients. For 23 patients with SIH and 28 healthy volunteers, a diagnostic test using thoracic MRI was performed by 13 experts to validate the usefulness of DSSS. The median sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of the DSSS were high (range, 0.913–0.931).

Conclusions Detection of DSSS on thoracic MRI facilitates an SIH diagnosis without the use of invasive imaging modalities. The DSSS were positive even in patients in whom classic cranial MRI signs for SIH were equivocal or minimal.

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

Neurosurgery 88:931–941, 2021

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. Themajority of fistulaswere in the thoracic spine and slightlymore 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.

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