Spontaneous intracranial hypotension mimicking iatrogenic spinal cerebrospinal fluid leaks.

OBJECTIVE: To raise awareness that patients with persistent post-dural puncture headache should be considered for evaluation of spontaneous cerebrospinal fluid (CSF) leak. BACKGROUND: Spontaneous intracranial hypotension (SIH) due to a spinal CSF leak may occur following more-or-less trivial traumatic events. We report our experience with spontaneous spinal CSF leaks that occur following percutaneous or open spine procedures, a potential source of diagnostic confusion. METHODS: In a retrospective cohort study, using a prospectively maintained database of patients with SIH, we identified all new patients evaluated between January 1, 2022, and June 30, 2023, who were referred for evaluation of an iatrogenic spinal CSF leak but were found to have a spontaneous spinal CSF leak. RESULTS: Nine (4%) of the 248 patients with SIH were originally referred for evaluation of an iatrogenic spinal CSF leak. The spinal procedures included epidural steroid injections, laminectomies, epidural anesthesia, and lumbar puncture. Brain magnetic resonance imaging (MRI) showed changes in intracranial hypotension in seven of the nine patients (78%). The spontaneous CSF leak was found to be at least five levels removed from the spinal procedure in all patients. CONCLUSIONS: A spontaneous spinal CSF leak should be suspected in patients with recalcitrant orthostatic headaches following a spinal procedure, even if symptoms of the leak occur within hours of the spinal procedure and especially if brain MRI is abnormal.

Lateral Spinal CSF Leaks in Patients with Spontaneous Intracranial Hypotension: Radiologic-Anatomic Study of Different Variants.

BACKGROUND AND PURPOSE: Spinal CSF leaks cause spontaneous intracranial hypotension. Several types of leaks have been identified, and one of these types is the lateral dural tear. Performing myelography with the patient in the decubitus position allows precise characterization of these leaks. The purpose of the current study was to describe the different variants of spontaneous lateral CSF leaks. MATERIALS AND METHODS: This retrospective cohort study included a consecutive group of patients with spontaneous intracranial hypotension and lateral CSF leaks who underwent digital subtraction myelography in the decubitus position and underwent surgery to repair the CSF leak between July 2018 and June 2023. RESULTS: The mean age of the 53 patients (37 women and 16 men) was 35.5 years. Three different variants of lateral CSF leak could be identified. Forty-nine patients (92.5%) had a lateral dural tear associated with the nerve root sleeve. The dural tear was at the axilla of the nerve root sleeve in 36 patients (67.9%) and at the shoulder in 13 patients (24.5%). Four patients (7.5%) had a lateral dural tear at the level of the pedicle that was not associated with the nerve root sleeve. Findings on digital subtraction myelography were concordant with intraoperative findings in all patients. An extradural CSF collection was seen in all patients with a lateral dural tear associated with the nerve root sleeve but in only 2 of the 4 patients with the pedicular variant of a lateral dural tear. CONCLUSIONS: We identified 3 variants of spontaneous lateral dural tears. Most lateral dural tears are associated with extradural CSF collections and arise from either the axilla (67.9%) or the shoulder (24.5%) of the nerve root sleeve. Lateral dural tears at the level of the pedicle (7.5%) not associated with the nerve root sleeve are uncommon and may require specialized imaging for their detection.

Optic Nerve Sheath MR Imaging Measurements in Patients with Orthostatic Headaches and Normal Findings on Conventional Imaging Predict the Presence of an Underlying CSF-Venous Fistula.

BACKGROUND AND PURPOSE: Spontaneous spinal CSF leaks typically cause orthostatic headache, but their detection may require specialized and invasive spinal imaging. We undertook a study to determine the value of simple optic nerve sheath MR imaging measurements in predicting the likelihood of finding a CSF-venous fistula, a type of leak that cannot be detected with routine spine MR imaging or CT myelography, among patients with orthostatic headache and normal conventional brain and spine imaging findings. MATERIALS AND METHODS: This cohort study included a consecutive group of patients with orthostatic headache and normal conventional brain and spine imaging findings who underwent digital subtraction myelography under general anesthesia to look for spinal CSF-venous fistulas. RESULTS: The study group consisted of 93 patients (71 women and 22 men; mean age, 47.5 years; range, 17-84 years). Digital subtraction myelography demonstrated a CSF-venous fistula in 15 patients. The mean age of these 8 women and 7 men was 56 years (range, 23-83 years). The mean optic nerve sheath diameter was 4.0 mm, and the mean perioptic subarachnoid space was 0.5 mm in patients with a CSF-venous fistula compared with 4.9 and 1.2 mm, respectively, in patients without a fistula (P < .001). Optimal cutoff values were found at 4.4 mm for optic nerve sheath diameter and 1.0 mm for the perioptic subarachnoid space. Fistulas were detected in about 50% of patients with optic nerve sheath diameter or perioptic subarachnoid space measurements below these cutoff values compared with <2% of patients with optic nerve sheath diameter or perioptic subarachnoid space measurements above these cutoff values. Following surgical ligation of the fistula, optic nerve sheath diameter increased from 4.0 to 5.3 mm and the perioptic subarachnoid space increased from 0.5 to 1.2 mm (P < .001). CONCLUSIONS: Concerns about a spinal CSF leak should not be dismissed in patients with orthostatic headache when conventional imaging findings are normal, and simple optic nerve sheath MR imaging measurements can help decide if more imaging needs to be performed in this patient population.

The Role of Cellular Immunity and Adaptive Immunity in Pathophysiology of Brain and Spinal Cord Tumors.

Major advances have been made in our understanding of CNS tumors, especially glioma, however, the survival of patients with malignant glioma remains poor. While radiation and chemotherapy have increased overall survival, glioblastoma multiforme (GBM) still has one of the worst 5-year survival rates of all human cancers. Here, in this chapter, the authors review the abrogation of the immune system in the tumor setting, revealing many plausible targets for therapy and the current immunotherapy treatment strategies employed. Notably, glioma has also been characterized as a subset of primary spinal cord tumor and current treatment recommendations are outlined here.

Placement of Stereotactic Electroencephalography Depth Electrodes Using the Stealth Autoguide Robotic System: Technical Methods and Initial Results.

BACKGROUND: Robotic systems are gaining acceptance as a preferred tool for the placement of electrodes for stereotactic electroencephalography (SEEG) studies. OBJECTIVE: To describe the technical methods for insertion of SEEG using the Medtronic Stealth Autoguide robotic system and detailed outcomes in the initial 9 patients implanted. METHODS: Nine patients underwent placement of electrodes for SEEG studies with the use of the Autoguide system. Patients had at least 10 electrodes placed. Targets were planned on a Stealth S8 planning station, and electrodes were placed under general anesthesia. A technique for placement is described in detail. Patient outcomes and accuracy of electrode placement were evaluated. Methods to improve accuracy were investigated. Comparison of postoperative MRIs with preoperative planning MRIs was performed to determine the accuracy of electrode placement. RESULTS: One hundred two electrodes were placed in 9 patients. Methods for placement and technical nuances are detailed. The distance from the planned target to the actual position of the electrode tip was measured in 8 of the 9 patients. The mean Euclidean distance was 4.67 ± 0.27 mm. There was 1 placement-related hemorrhage deficit in the first patient, and no deaths or infections. Adequate positioning of electrodes for seizure monitoring was obtained in all patients. CONCLUSION: Autoguide can be used for placement of electrodes for SEEG studies with acceptable degrees of patient safety, accuracy, and efficiency. Considering the cost of Autoguide compared with other robotic devices, it may be attractive option.