Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension: Exploring the viability of non-contrast FLAIR as a substitute for contrast-enhanced T1WI in assessing pachymeningeal thickening

PURPOSE

To avoid contrast administration in spontaneous intracranial hypotension (SIH), some studies suggest accepting diffuse pachymeningeal hyperintensity (DPMH) on non-contrast fluid-attenuated inversion recovery (FLAIR) as an equivalent sign to diffuse pachymeningeal enhancement (DPME) on contrast-enhanced T1WI (T1ce), despite lacking thorough performance metrics. This study aimed to comprehensively explore its feasibility.

METHODS

In this single-center retrospective study, between April 2021 and November 2023, brain MRI examinations of 43 patients clinically diagnosed with SIH were assessed using 1.5 and 3.0 Tesla MRI scanners. Two radiologists independently assessed the presence or absence of DPMH on FLAIR and DPME on T1ce, with T1ce serving as a gold-standard for pachymeningeal thickening. The contribution of the subdural fluid collections to DPMH was investigated with quantitative measurements. Using Cohen's kappa statistics, interobserver agreement was assessed.

RESULTS

In 39 out of 43 patients (90.7%), pachymeningeal thickening was observed on T1ce. FLAIR sequence produced an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 72.1%, 71.8%, 75.0%, 96.6%, and 21.4% respectively, for determining pachymeningeal thickening. FLAIR identified pachymeningeal thickening in 28 cases; however, among these, 21 cases (75%) revealed that the pachymeningeal hyperintense signal was influenced by subdural fluid collections. False-negative rate for FLAIR was 28.2% (11/39).

CONCLUSION

The lack of complete correlation between FLAIR and T1ce in identifying pachymeningeal thickening highlights the need for caution in removing contrast agent administration from the MRI protocol of SIH patients, as it reveals a major criterion (i.e., pachymeningeal enhancement) of Bern score.

Superficial Cerebellar Siderosis and Spontaneous Intracranial Hypotension Secondary to Dural Tear

Spinal dural tears are being increasingly recongnized to cause superficial siderosis and intracranial hypotension. We report a patient with chronic headache who was detected to have cerebellar superficial siderosis and subtle signs of intracranial hypotension on imaging. Spinal imaging showed an upper thoracic dural tear secondary to a paradiscal osteophyte. She improved significantly with surgical repair of the tear. We highlight the importance of recognizing superficial sideorsis in patients with chronic headache as it serves as a marker for dural tear and intracranial hypotension.

[Guidelines for the Diagnosis and Treatment of Spontaneous Intracranial Hypotension]

Spontaneous intracranial hypotension (SIH) is a syndrome characterized by disabling orthostatic headache, due to reduced cerebrospinal fluid (CSF) volume probably caused by a CSF fistula. It affects mostly women of working-age, although it is probably underdiagnosed. The aim of this article is to present a practical approach to the diagnosis and treatment of SIH. After a description of its symptoms and signs, we present a step-by-step approach to the confirmation of the diagnosis and treatment, considering different clinical scenarios. This is intended to guide clinical decision making, through a systematized and individualized management, aimed at the best interest of the patient.

Update on primary headache associated with sexual activity and primary thunderclap headache

BACKGROUND

This narrative review aims to provide an update on primary headache associated with sexual activity and primary thunderclap headache.

METHODS

We conducted a literature search on PubMed with the keywords "headache associated with sexual activity", "sexual headache", "orgasmic cephalalgia", and "coital cephalalgia" in addition to "thunderclap headache" to assess the appropriateness of all published articles in this review.

RESULTS

Primary headache associated with sexual activity is a "primary" headache precipitated by sexual activity, which occurs as sexual excitement increases (progressive at onset), or manifests as an abrupt and intense headache upon orgasm (thunderclap at onset) or combines these above two features. Primary headache associated with sexual activity is diagnosed after a thorough investigation, including appropriate neuroimaging studies, to exclude life-threatening secondary causes such as subarachnoid hemorrhage. According to the criteria of the third edition of the International Classification of Headache Disorders, primary thunderclap headache is also a diagnosis by exclusion. The pathophysiology of primary headache associated with sexual activity and primary thunderclap headache remains incompletely understood. Treatment may not be necessary for all patients since some patients with primary headache associated with sexual activity and primary thunderclap headache have a self-limiting course.

CONCLUSION

A comprehensive neuroimaging study is needed for distinguishing primary headache associated with sexual activity or primary thunderclap headache from secondary causes. Primary headache associated with sexual activity and primary thunderclap headache are self-limited diseases and the prognoses are good, but some patients with primary headache associated with sexual activity may have a prolonged course.

Treating Spontaneous Intracranial Hypotension with an Anesthetic Modality: The Role of the Epidural Blood Patch

Background: Spontaneous intracranial hypotension (SIH) is a rare syndrome characterized by heterogeneity of presentation and prognosis, which can occasionally result in serious complications, such as the formation of subdural hematomas (SDHs). This case series aims to emphasize that SIH remains a diagnostic and therapeutic challenge; it can present with a broad clinical spectrum of symptoms, can lead to SDH and, if conservative treatment fails, an epidural blood patch (EBP) is a viable treatment option. Although the exact etiology of SIH is not known, it is believed to be due to cerebrospinal fluid (CSF) leak or a low CSF pressure. Case Series: Three patients (two males and one female) with ages ranging between 38 and 53 years old who presented with complaints of not only an orthostatic headache, but also a variety of symptoms of SIH, including the formation of two SDHs in one of them, were included in this series. These patients did not respond to conservative management and, subsequently, given the clinical and radiological evidence of SIH, were referred to the Anesthesiology Department for an EBP. Diagnostic workup was facilitated by imaging modalities, including magnetic resonance imaging (MRI) of the brain and spinal cord, prior to the EBP. All three patients were subjected to an EBP with an 18-gauge epidural needle. A total of between 30 and 43 mL of autologous blood was collected from the patients and was injected into the epidural space under strict aseptic conditions. Two lumbar (L₁-L₂, L₂-L₃) EBPs and one thoracic (T₁₁-T₁₂) EBP were performed on the three patients, respectively. All patients reported complete resolution of symptoms following the EBPs, while MRI improved substantially. Conclusions: This report describes three cases of SIH with CSF leak originating from the cervical, the thoracic and the lumbar level. The EBP restored CSF pressure and relieved the patients' persistent symptoms. MRI helps in revealing indirect signs of a low volume of CSF, though it may not be possible to locate the actual site of the leak. In conclusion, EBP is a well-accepted and beneficial treatment modality for SIH when conventional measures fail.

Efficacy and safety of cervicothoracic epidural blood patch for patients with spontaneous intracranial hypotension

BACKGROUND

Epidural blood patch (EBP) is a generally effective treatment for spontaneous intracranial hypotension (SIH) caused by cerebrospinal fluid (CSF) leakage through the spinal dura mater. It is still unclear, however, whether application near the leakage site (targeted EBP) is more effective than distal application (untargeted EBP). Further, EBP targeted to high thoracic or cervical spine levels is infrequent due to greater technical requirements and potential complications. Here we examined the safety and efficacy of EBP applied to high thoracic or cervical spine levels.

METHODS

We retrospectively reviewed the clinical and outcome data of 13 patients receiving cervical or high thoracic EBP for SIH. All patients were referred by neurologists following poor response to conservative treatment and presented with persistent headache aggravated by orthostatic changes.

RESULTS

Neuroimaging confirmed CSF leakage, and targeted EBP resulted in immediate pain improvement. Repeated injections provided additional improvement for patients with recurrent headache. No serious adverse events were documented during follow-up.

CONCLUSION

Based on recent studies and our clinical experience, we conclude that EBP targeted to the high thoracic and cervical spine is safe and effective for early-stage SIH.