Impact of Stereotactic Ventriculocisternostomy on Delayed Cerebral Infarction and Outcome After Subarachnoid Hemorrhage.

Background and Purpose- Delayed cerebral infarction (DCI) is an important cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH). Stereotactic catheter ventriculocisternostomy (STX-VCS) and fibrinolytic/spasmolytic lavage is a new method for DCI prevention. Here, we assess the effects of implementing STX-VCS in an unselected aSAH patient population of a tertiary referral center. Methods- Retrospective cohort study of all consecutive aSAH patients admitted to a neurosurgical referral center during a 7-year period (April 2012 to April 2019). Midterm STX-VCS was introduced and offered to patients at high risk for DCI. We compared the incidence and burden of DCI, neurological outcome, and the use of induced hypertension and endovascular rescue therapy in this consecutive aSAH population 3.5 years before versus 3.5 years after STX-VCS became available. Results- Four hundred thirty-six consecutive patients were included: 222 BEFORE and 214 AFTER. Fifty-seven of 214 (27%) patients received STX-VCS. Stereotactic procedures resulted in one (2%) subdural hematoma. Favorable neurological outcome at 6 months occurred in 118 (53%) patients BEFORE and 139 (65%) patients AFTER (relative risk, 0.79 [95% CI, 0.66-0.95]). DCI occurred in 40 (18.0%) patients BEFORE and 17 (7.9%) patients AFTER (relative risk, 0.68 [95% CI, 0.57-0.86]), and total DCI volumes were 8933 (100%) and 3329 mL (36%), respectively. Induced hypertension was used in 97 (44%) and 30 (15%) patients, respectively (relative risk, 0.55 [95% CI, 0.46-0.65]). Thirty (13.5%) patients BEFORE versus 5 (2.3%) patients AFTER underwent endovascular rescue therapies (relative risk, 0.17 [95% CI, 0.07-0.42]). Conclusions- Selecting high-risk patients for STX-VCS reduced the DCI incidence, burden, and related mortality in a consecutive aSAH patient population. This was associated with an improved neurological outcome.

Non-invasive biomarkers for spontaneous intracranial hypotension (SIH) through phase-contrast MRI.

BACKGROUND AND OBJECTIVE: Spontaneous intracranial hypotension (SIH) is an underdiagnosed disease. To depict the accurate diagnosis can be demanding; especially the detection of CSF-venous fistulas poses many challenges. Potential dynamic biomarkers have been identified through non-invasive phase-contrast MRI in a limited subset of SIH patients with evidence of spinal longitudinal extradural collection. This study aimed to explore these biomarkers related to spinal cord motion and CSF velocities in a broader SIH cohort. METHODS: A retrospective, monocentric pooled-data analysis was conducted of patients suspected to suffer from SIH who underwent phase-contrast MRI for spinal cord and CSF velocity measurements at segment C2/C3 referred to a tertiary center between February 2022 and June 2023. Velocity ranges (mm/s), total displacement (mm), and further derivatives were assessed and compared to data from the database of 70 healthy controls. RESULTS: In 117 patients, a leak was located (54% ventral leak, 20% lateral leak, 20% CSF-venous fistulas, 6% sacral leaks). SIH patients showed larger spinal cord and CSF velocities than healthy controls: e.g., velocity range 7.6 ± 3 mm/s vs. 5.6 ± 1.4 mm/s, 56 ± 21 mm/s vs. 42 ± 10 mm/s, p < 0.001, respectively. Patients with lateral leaks and CSF-venous fistulas exhibited an exceptionally heightened level of spinal cord motion (e.g., velocity range 8.4 ± 3.3 mm/s; 8.2 ± 3.1 mm/s vs. 5.6 ± 1.4 mm/s, p < 0.001, respectively). CONCLUSION: Phase-contrast MRI might become a valuable tool for SIH diagnosis, especially in patients with CSF-venous fistulas without evidence of spinal extradural fluid collection.

Pilot study on high-resolution radiological methods for the analysis of cerebrospinal fluid (CSF) shunt valves.

OBJECTIVES: Despite their life-saving capabilities, cerebrospinal fluid (CSF) shunts exhibit high failure rates, with a large fraction of failures attributed to the regulating valve. Due to a lack of methods for the detailed analysis of valve malfunctions, failure mechanisms are not well understood, and valves often have to be surgically explanted on the mere suspicion of malfunction. The presented pilot study aims to demonstrate radiological methods for comprehensive analysis of CSF shunt valves, considering both the potential for failure analysis in design optimization, and for future clinical in-vivo application to reduce the number of required shunt revision surgeries. The proposed method could also be utilized to develop and support in situ repair methods (e.g. by lysis or ultrasound) of malfunctioning CSF shunt valves. MATERIALS AND METHODS: The primary methods described are contrast-enhanced radiographic time series of CSF shunt valves, taken in a favorable projection geometry at low radiation dose, and the machine-learning-based diagnosis of CSF shunt valve obstructions. Complimentarily, we investigate CT-based methods capable of providing accurate ground truth for the training of such diagnostic tools. Using simulated test and training data, the performance of the machine-learning diagnostics in identifying and localizing obstructions within a shunt valve is evaluated regarding per-pixel sensitivity and specificity, the Dice similarity coefficient, and the false positive rate in the case of obstruction free test samples. RESULTS: Contrast enhanced subtraction radiography allows high-resolution, time-resolved, low-dose analysis of fluid transport in CSF shunt valves. Complementarily, photon-counting micro-CT allows to investigate valve obstruction mechanisms in detail, and to generate valid ground truth for machine learning-based diagnostics. Machine-learning-based detection of valve obstructions in simulated radiographies shows promising results, with a per-pixel sensitivity >70%, per-pixel specificity >90%, a median Dice coefficient >0.8 and <10% false positives at a detection threshold of 0.5. CONCLUSIONS: This ex-vivo study demonstrates obstruction detection in cerebro-spinal fluid shunt valves, combining radiological methods with machine learning under conditions compatible to future in-vivo application. Results indicate that high-resolution contrast-enhanced subtraction radiography, possibly including time-series data, combined with machine-learning image analysis, has the potential to strongly improve the diagnostics of CSF shunt valve failures. The presented method is in principle suitable for in-vivo application, considering both measurement geometry and radiological dose. Further research is needed to validate these results on real-world data and to refine the employed methods. In combination, the presented methods enable comprehensive analysis of valve failure mechanisms, paving the way for improved product development and clinical diagnostics of CSF shunt valves.

Selective intra-carotid blood cooling in acute ischemic stroke: A safety and feasibility study in an ovine stroke model.

Selective therapeutic hypothermia (TH) showed promising preclinical results as a neuroprotective strategy in acute ischemic stroke. We aimed to assess safety and feasibility of an intracarotid cooling catheter conceived for fast and selective brain cooling during endovascular thrombectomy in an ovine stroke model.Transient middle cerebral artery occlusion (MCAO, 3 h) was performed in 20 sheep. In the hypothermia group (n = 10), selective TH was initiated 20 minutes before recanalization, and was maintained for another 3 h. In the normothermia control group (n = 10), a standard 8 French catheter was used instead. Primary endpoints were intranasal cooling performance (feasibility) plus vessel patency assessed by digital subtraction angiography and carotid artery wall integrity (histopathology, both safety). Secondary endpoints were neurological outcome and infarct volumes.Computed tomography perfusion demonstrated MCA territory hypoperfusion during MCAO in both groups. Intranasal temperature decreased by 1.1 °C/3.1 °C after 10/60 minutes in the TH group and 0.3 °C/0.4 °C in the normothermia group (p < 0.001). Carotid artery and branching vessel patency as well as carotid wall integrity was indifferent between groups. Infarct volumes (p = 0.74) and neurological outcome (p = 0.82) were similar in both groups.Selective TH was feasible and safe. However, a larger number of subjects might be required to demonstrate efficacy.

Surgical removal of a symptomatic paracondylar process.

The paracondylar process is a rare congenital abnormality of the craniocervical junction that has been identified as a causative agent for severe headache, neck pain, and restricted head movement. Although conservative treatment is usually sufficient, the authors report the case of a symptomatic paracondylar process in a young patient who required surgical intervention.

Doppler-sonographically guided resection of central nervous system hemangioblastomas.

BACKGROUND: Central nervous system (CNS) hemangioblastomas are a benign condition, which can be permanently cured by complete surgical removal. However, the vascular nature of these lesions and difficulties in localizing the tumors account for operative morbidity and recurrence. Power Doppler flow sonography has been proven useful during surgical removal of other vascular lesions. OBJECTIVE: To evaluate the usefulness of Power Doppler flow sonography for hemangioblastoma. METHODS: We used the SonoWand Invite (Sonowand AS, Trondheim, Norway) intraoperative navigation system in a consecutive series of hemangioblastomas operated on at our institution. Patients with von Hippel-Lindau (VHL) disease as well as sporadic hemangioblastomas were included. RESULTS: The system was used on n = 64 consecutive hemangioblastomas operated on at our institution from 2007 to 2009. The tumors were localized in the cerebellum (n = 26), spinal cord (n = 27), brainstem (n = 10), and supratentorial (n = 1). In VHL disease was diagnosed 53 patients, and germline mutations of the VHL tumor suppressor gene were identified in 98%. Average tumor size was 1782 mm and 45% of the tumors were cystic. Forty-two of 64 tumors could be localized by grayscale sonography. All tumors were visible on power Doppler flow sonography. However, in 40 cases, only the pathological vessels and not the solid tumor itself enhanced on power Doppler. Postoperative MRI follow-up revealed remnant/recurrent tumors in 2 cases. CONCLUSION: Power Doppler flow sonography is a sensitive intraoperative tool to guide the surgical approach and resection and provides reliable resection control in surgery of CNS hemangioblastoma.

Rupture of a spinal artery aneurysm attributable to exacerbated Sjögren syndrome: case report.

OBJECTIVE: Presentation of a patient with acute subarachnoid hemorrhage from a ruptured spinal artery aneurysm attributable to exacerbated Sjögren syndrome. CLINICAL PRESENTATION: A 46-year-old woman with symptoms of exacerbated Sjögren syndrome experienced the acute onset of extreme headache accompanied by nuchal rigidity. INTERVENTION: A computed tomographic scan revealed subarachnoid hemorrhage. Angiography showed an isolated aneurysm of a branch of the right vertebral artery that was a feeding artery of the anterior spinal artery. Neither operative clipping nor endovascular coiling of the aneurysm was reasonable, owing to the high risk of occluding the anterior spinal artery during the intervention. Further diagnostic measures confirmed Sjögren syndrome and revealed cryoglobulinemic vasculitis, membranoproliferative glomerulonephritis with acute renal failure, Hashimoto thyroiditis, and acute hydrocephalus. In the course of conservative treatment, the patient recovered completely from the subarachnoid hemorrhage. One year after treatment with glucocorticoids and immunosuppressive agents, both the aneurysm and the vasculitis could no longer be detected on conventional angiography. CONCLUSION: Generally, spinal artery aneurysms are exceptionally rare, and few cases of rupture with subsequent subarachnoid hemorrhage have been published. We report on a ruptured spinal aneurysm attributable to Sjögren syndrome-associated cryoglobulinemic vasculitis. Conservative treatment with glucocorticoids and immunosuppressive agents led to resolution of the vasculitic spinal aneurysm.