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Cover Neurosurgical Focus: Video

Treatment of an acutely ruptured complex fusiform middle cerebral artery aneurysm with flow diverting stenting and adjunctive coil embolization

Guilherme Barros and Michael R. Levitt

This technical video demonstrates the treatment of an acutely ruptured, large, complex left fusiform middle cerebral artery (MCA) aneurysm with endovascular flow diversion with adjunctive coiling in a 27-year-old female. Two telescoping flow-diverting stents (Pipeline Flex) were placed, with partial coiling of a saccular portion of the aneurysm. Technical challenges, alternative treatment, intraoperative and postoperative antiplatelet management, vasospasm treatment, and clinical and radiographic follow-up are described.

The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2249

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Cover Journal of Neurosurgery: Pediatrics

Insular epilepsy masquerading as multifocal cortical epilepsy as proven by depth electrode

Case report

Michael R. Levitt, Jeffrey G. Ojemann, and John Kuratani

The insular cortex is an uncommon epileptogenic location from which complex partial seizures may arise. Seizure activity in insular epilepsy may mimic temporal, parietal, or other cortical areas. Semiology, electroencephalography, and even surface electrocorticography recordings may falsely localize other cortical foci, leading to inaccurate diagnosis and treatment. The use of insular depth electrodes allows more precise localization of seizure foci. The authors describe the case of a young girl with seizures falsely localized to the cortex, with foci arising from the insula, as proven by depth electrode recordings. Resection of the insula yielded seizure control.

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Cover Journal of Neurosurgery: Spine

Reversible coma and Duret hemorrhage after intracranial hypotension from remote lumbar spine surgery: case report

Robert H. Bonow, James W. Bales, Ryan P. Morton, Michael R. Levitt, and Fangyi Zhang

Intracranial hypotension is a rare condition caused by spontaneous or iatrogenic CSF leaks that alter normal CSF dynamics. Symptoms range from mild headaches to transtentorial herniation, coma, and death. Duret hemorrhages have been reported to occur in some patients with this condition and are traditionally believed to be associated with a poor neurological outcome. A 73-year-old man with a remote history of spinal fusion presented with syncope and was found to have small subdural hematomas on head CT studies. He was managed nonoperatively and discharged with a Glasgow Coma Scale score of 15, only to return 3 days later with obtundation, fixed downward gaze, anisocoria, and absent cranial nerve reflexes. A CT scan showed Duret hemorrhages and subtle enlargement of the subdural hematomas, though the hematomas remained too small to account for his poor clinical condition. Magnetic resonance imaging of the spine revealed a large lumbar pseudomeningocele in the area of prior fusion. His condition dramatically improved when he was placed in the Trendelenburg position and underwent repair of the pseudomeningocele. He was kept flat for 7 days and was ultimately discharged in good condition. On long-term follow-up, his only identifiable deficit was diplopia due to an internuclear ophthalmoplegia. Intracranial hypotension is a rare condition that can cause profound morbidity, including tonsillar herniation and brainstem hemorrhage. With proper identification and treatment of the CSF leak, patients can make functional recoveries.

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Cover Journal of Neurosurgery: Pediatrics

Resolution of syndromic craniosynostosis-associated Chiari malformation Type I without suboccipital decompression after posterior cranial vault release

Case report

Michael R. Levitt, Toba N. Niazi, Richard A. Hopper, Richard G. Ellenbogen, and Jeffrey G. Ojemann

Chiari malformation Type I (CM-I) is associated with syndromic and nonsyndromic craniosynostosis in pediatric patients, and the surgical management of CM-I in such cases is controversial. Previous guidelines have recommended simultaneous cranial vault expansion and suboccipital decompression. However, spontaneous resolution of CM-I has been observed, and the combined procedure carries additional surgical risks. The authors report the case of a 6-month-old boy with Crouzon syndrome, CM-I, and a cervical syrinx who underwent posterior cranial vault release without suboccipital decompression. Imaging at the 3-month follow-up visit demonstrated complete resolution of the CM-I, improvement in CSF flow, and reduction in the size of the syrinx. This case suggests that up-front suboccipital decompression may not be necessary in patients with craniosynostosis and CM-I. A strategy of initial cranial vault release, followed by watchful waiting and radiographic surveillance, is proposed.

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Cover Neurosurgical Focus

Endovascular treatment of complex dural arteriovenous fistula using the dual-microcatheter technique

Michael R. Levitt, Joshua W. Osbun, John D. Nerva, and Louis J. Kim

A 71-year-old woman presented with headache and dilated vessels on CTA. Angiography demonstrated a complex dural arteriovenous fistula with retrograde cortical venous hypertension, supplied by branches of internal and external carotids bilaterally into a fistulous pouch paralleling the left transverse and sigmoid sinuses, which was occluded at the jugular bulb. The patient refused treatment and was lost to follow-up, returning with sudden confusion and hemianopsia from left temporo-occipital hemorrhage. Transvenous endovascular embolization was performed using the dual-microcatheter technique with a combination of coiling and Onyx copolymer, completely occluding the sinus and fistula while preserving normal venous drainage.

The video can be found here: http://youtu.be/u_4Oc7tSmDM.

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Cover Neurosurgical Focus

Transcranial Doppler ultrasonography in neurological surgery and neurocritical care

Robert H. Bonow, Christopher C. Young, David I. Bass, Anne Moore, and Michael R. Levitt

Transcranial Doppler (TCD) ultrasonography is an inexpensive, noninvasive means of measuring blood flow within the arteries of the brain. In this review, the authors outline the technology underlying TCD ultrasonography and describe its uses in patients with neurosurgical diseases. One of the most common uses of TCD ultrasonography is monitoring for vasospasm following subarachnoid hemorrhage. In this setting, elevated blood flow velocities serve as a proxy for vasospasm and can herald the onset of ischemia. TCD ultrasonography is also useful in the evaluation and management of occlusive cerebrovascular disease. Monitoring for microembolic signals enables stratification of stroke risk due to carotid stenosis and can also be used to clarify stroke etiology. TCD ultrasonography can identify patients with exhausted cerebrovascular reserve, and after extracranial-intracranial bypass procedures it can be used to assess adequacy of flow through the graft. Finally, assessment of cerebral autoregulation can be performed using TCD ultrasonography, providing data important to the management of patients with severe traumatic brain injury. As the clinical applications of TCD ultrasonography have expanded over time, so has their importance in the management of neurosurgical patients. Familiarity with this diagnostic tool is crucial for the modern neurological surgeon.

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Cover Neurosurgical Focus

Magnetic resonance vessel wall imaging in cerebrovascular diseases

Christopher C. Young, Robert H. Bonow, Guilherme Barros, Mahmud Mossa-Basha, Louis J. Kim, and Michael R. Levitt

Cerebrovascular diseases manifest as abnormalities of and disruption to the intracranial vasculature and its capacity to carry blood to the brain. However, the pathogenesis of many cerebrovascular diseases begins in the vessel wall. Traditional luminal and perfusion imaging techniques do not provide adequate information regarding the differentiation, onset, or progression of disease. Intracranial high-resolution MR vessel wall imaging (VWI) has emerged as an invaluable technique for understanding and evaluating cerebrovascular diseases. The location and pattern of contrast enhancement in intracranial VWI provides new insight into the inflammatory etiology of cerebrovascular diseases and has potential to permit earlier diagnosis and treatment. In this report, technical considerations of VWI are discussed and current applications of VWI in vascular malformations, blunt cerebrovascular injury/dissection, and steno-occlusive cerebrovascular vasculopathies are reviewed.

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Cover Journal of Neurosurgery

Association of calcium channel blockers with lower incidence of intracranial aneurysm rupture and growth in hypertensive patients

*Qingyuan Liu, Jiangan Li, Yisen Zhang, Xinyi Leng, Mahmud Mossa-Basha, Michael R. Levitt, Shuo Wang, and Chengcheng Zhu

OBJECTIVE

Calcium channel blockers (CCBs) are antihypertensive agents with potential vascular protection effects. This study investigated whether CCB usage was associated with a lower incidence of unruptured intracranial aneurysm (UIA) instability (growth and rupture) in patients with hypertension.

METHODS

UIA patients were included in two prospective, multicenter cohort studies (IARP-CP and 100-Project cohorts). All patients received conservative treatment and were regularly followed up every 6 months by CT angiography for 2 years. Patients taking CCBs at least 5 days per week were considered CCB users; otherwise, they were considered non-CCB users. The primary endpoint was UIA instability (rupture, growth of > 20% and/or 1 mm in any dimension, or appearance of a new dome irregularity on imaging follow-up).

RESULTS

A total of 392 UIA patients with hypertension (191 male, 201 female; median age 57 years) were included with a mean follow-up duration of 21.7 ± 5.2 months. The primary endpoint was met in 81 patients (20.7%) during follow-up, including 68 patients with aneurysms that grew and 13 with aneurysms that ruptured. CCB users had a lower UIA instability rate than non-CCB users (27/237 [11.4%] vs 54/155 [34.8%], p < 0.001). Multivariable Cox analysis demonstrated that CCB use was associated with a lower risk of UIA instability (HR 0.37, 95% CI 0.22–0.61; p < 0.001). The protective effect of CCB use was consistent in patients taking a single antihypertensive agent (HR 0.22, 95% CI 0.12–0.40; p < 0.001) and patients taking > 1 antihypertensive agent (HR 0.42, 95% CI 0.20–0.87; p = 0.021). For patients with controlled hypertension, CCB use was still associated with a lower risk of UIA instability (HR 0.22, 95% CI 0.09–0.52; p = 0.001).

CONCLUSIONS

In UIA patients with hypertension, CCB use was associated with a lower incidence of aneurysm instability.

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Cover Journal of Neurosurgery

Vessel wall MRI characteristics of endovascularly treated aneurysms: association with angiographic vasospasm

Mahmud Mossa-Basha, Thien J. Huynh, Daniel S. Hippe, Peter Fata, Ryan P. Morton, and Michael R. Levitt

OBJECTIVE

The aim of this paper was to evaluate the association between intracranial vessel wall MRI enhancement characteristics and the development of angiographic vasospasm in endovascularly treated aneurysm patients.

METHODS

Consecutive cases of both ruptured and unruptured intracranial aneurysms that were treated endovascularly, followed by intracranial vessel wall MRI in the immediate postoperative period, were included. Two raters blinded to clinical data and follow-up imaging independently evaluated for the presence, pattern, and intensity of wall enhancement. Development of angiographic vasospasm was independently evaluated. Delayed cerebral ischemia; cerebral infarct; procedural details; and presence and grade of subarachnoid, parenchymal, and intraventricular hemorrhage were evaluated. Statistical associations were determined on a per–vessel segment and per-patient basis.

RESULTS

Twenty-nine patients with 30 treated aneurysms (8 unruptured and 22 ruptured) were included in this study. Interobserver agreement was substantial for the presence of enhancement (κ = 0.67) and nearly perfect for distribution (κ = 0.87) and intensity (κ = 0.84) of wall enhancement. Patients with ruptured aneurysms had a significantly greater number of enhancing segments than those with unruptured aneurysms (29.9% vs 7.2%; OR 5.5, 95% CI 2.2–13.7). For ruptured cases, wall enhancement was significantly associated with subsequent angiographic vasospasm while controlling for grade of hemorrhage (adjusted OR 3.9, 95% CI 1.7–9.4). Vessel segments affected by balloon, stent, or flow-diverter use demonstrated greater enhancement than those not affected (OR 22.7, 95% CI 5.3–97.2 for ruptured; and OR 12.9, 95% CI 3.3–49.8 for unruptured).

CONCLUSIONS

Vessel wall enhancement after endovascular treatment of ruptured aneurysms is associated with subsequent angiographic vasospasm.

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Cover Journal of Neurosurgery: Pediatrics

Low-dose head computed tomography in children: a single institutional experience in pediatric radiation risk reduction

Clinical article

Ryan P. Morton, Renee M. Reynolds, Rohan Ramakrishna, Michael R. Levitt, Richard A. Hopper, Amy Lee, and Samuel R. Browd

Object

In this study, the authors describe their experience with a low-dose head CT protocol for a preselected neurosurgical population at a dedicated pediatric hospital (Seattle Children's Hospital), the largest number of patients with this protocol reported to date.

Methods

All low-dose head CT scans between October 2011 and November 2012 were reviewed. Two different low-dose radiation dosages were used, at one-half or one-quarter the dose of a standard head CT scan, based on patient characteristics agreed upon by the neurosurgery and radiology departments. Patient information was also recorded, including diagnosis and indication for CT scan.

Results

Six hundred twenty-four low-dose head CT procedures were performed within the 12-month study period. Although indications for the CT scans varied, the most common reason was to evaluate the ventricles and catheter placement in hydrocephalic patients with shunts (70%), followed by postoperative craniosynostosis imaging (12%). These scans provided adequate diagnostic imaging, and no patient required a follow-up full-dose CT scan as a result of poor image quality on a low-dose CT scan. Overall physician comfort and satisfaction with interpretation of the images was high. An additional 2150 full-dose head CT scans were performed during the same 12-month time period, making the total number of CT scans 2774. This value compares to 3730 full-dose head CT scans obtained during the year prior to the study when low-dose CT and rapid-sequence MRI was not a reliable option at Seattle Children's Hospital. Thus, over a 1-year period, 22% of the total CT scans were able to be converted to low-dose scans, and full-dose CT scans were able to be reduced by 42%.

Conclusions

The implementation of a low-dose head CT protocol substantially reduced the amount of ionizing radiation exposure in a preselected population of pediatric neurosurgical patients. Image quality and diagnostic utility were not significantly compromised.