Two-Stage Anatomic Myocutaneous Flap Dissection in Cranioplasty: Technical Nuances and Single-Surgeon Experience.

BACKGROUND AND OBJECTIVES: Temporalis muscle management remains one of the most challenging aspects of cranioplasty, which accounts for considerable rates of dissection-related complications. Since 2019, the senior author has developed and consistently used a methodical, two-stage anatomic dissection technique to separate the scalp and temporalis muscle from the underlying brain. This technique is believed to facilitate dissection and minimize the risk of brain injury, while optimizing cosmetic outcomes. METHODS: All patients who underwent cranioplasty between January 2019 and February 2023 were identified from a prospectively maintained database. Charts were retrospectively reviewed. Demographic, clinical, and procedural data were extracted and analyzed. RESULTS: Twenty-nine patients, 20 men and 9 women with a median age of 37 years (range 17-72), were identified. Indications for craniectomy were traumatic brain injury in 18 (62.1%), hemorrhagic stroke in five (17.2%), ischemic stroke in four (13.8%), and aneurysmal subarachnoid hemorrhage in two (6.9%). Median precranioplasty modified Rankin Scale and Glasgow Coma Scale scores were 5 (range in series: 0-5) and 14 (range in series: 3-15), respectively. The median time to cranioplasty was 131 days (32-1717). Cranioplasty was technically successful in all patients, with a median operative time of 106 minutes (62-182). There were no intraoperative complications. Postoperative complications occurred in three patients (10.3%): hemorrhagic brain contusion (n = 1), meningitis (n = 1), and seizure (n = 1). Of those, one patient (3.4%) died 2 weeks after surgery from suspected pulmonary embolism. After a median follow-up of 4 months (1-44), all 28 survivors have either remained clinically stable or exhibited neurological improvement. Cosmetic results were good or excellent in 27 (96.4%) and fair in one (3.6%). CONCLUSION: Two-stage anatomic dissection of the scalp and temporalis muscle during cranioplasty can maximize surgical efficiency and result in excellent outcomes. Cranioplasty should be considered a low-risk, low-complexity neurosurgical procedure. Safe and efficient management of the temporalis muscle is key.

Emergency decompressive surgery in patients with transtentorial brain herniation and pupillary abnormalities: the importance of improved pupillary response after osmotherapy and surgery.

OBJECTIVE: The predictors of survival and functional recovery following emergency decompressive surgery in patients with transtentorial brain herniation, particularly those with pupillary abnormalities, have not been established. In this study, the authors aimed to assess the outcome of patients with intracranial mass lesions, transtentorial brain herniation, and nonreactive mydriasis, following emergency surgical decompression. METHODS: A retrospective chart review was performed of all patients with transtentorial herniation and pupillary abnormalities who underwent craniotomy or craniectomy at two trauma and stroke centers between 2016 and 2022. The functional outcome was determined using the modified Rankin Scale (mRS). RESULTS: Forty-three patients, 34 men and 9 women with a mean age of 47 years (range 16-92 years), were included. The underlying etiology was traumatic brain injury in 33 patients, hemorrhagic stroke in 8 patients, and tumor in 2 patients. The median preoperative Glasgow Coma Scale score was 3 (range 3-8), and the median midline shift was 9 mm (range 1-29 mm). Thirty-two patients (74.4%) had bilaterally fixed and dilated pupils. The median time to surgery (from pupillary changes) was 133 minutes (mean 169 minutes, range 30-900 minutes). Eighteen patients (41.9%) died postoperatively. After a median follow-up of 12 months (range 3-12 months), 11 patients (26.8%) had a favorable functional outcome, while 10 remained severely disabled (mRS score 5). On univariate analysis, younger age (p < 0.001), less midline shift (p = 0.049), and improved pupillary response after osmotic therapy (p < 0.01) or decompressive surgery (p < 0.001) were associated with favorable outcomes at 3 months. CONCLUSIONS: With aggressive medical and surgical management, patients with transtentorial brain herniation, including those with bilaterally fixed and dilated pupils, may have considerable rates of survival and functional recovery. Young age, less midline shift, and improved pupillary response following osmotic therapy or decompressive surgery are favorable prognosticators.

Gunshot Wound to the Posterior Fossa With a Transcerebellar Retromesencepahlic Bullet Path, Transient Mutism, and Unexpected Functional Recovery: The Pivotal, Energy-Absorbing Function of the Petrous Bone and Tentorial Leaflet.

Given the abundance of vital neurovascular structures, gunshot wounds (GSWs) to the posterior fossa are generally fatal. We present a unique such case where a bullet entered the petrous bone, traversed the cerebellar hemisphere and overlying tentorial leaflet, and reached the dorsal aspect of the midbrain, resulting in transient cerebellar mutism with an unexpectedly favorable functional recovery. A 17-year-old boy sustained a GSW to the left mastoid region with no exit wound and presented with agitation and confusion, ultimately leading to a coma. Head CT revealed a bullet trajectory through the left petrous bone, left cerebellar hemisphere, and left tentorial leaflet, with a retained bullet fragment in the quadrigeminal cistern, overlying the dorsal aspect of the midbrain. Computed tomography venography (CTV) demonstrated thrombosis of the left transverse and sigmoid sinuses and the internal jugular vein. The patient's hospital course was marked by the development of obstructive hydrocephalus, secondary to delayed cerebellar edema with fourth ventricular effacement and aqueductal compression, possibly worsened by concomitant left sigmoid sinus thrombosis. Following the emergency placement of an external ventricular drain and two weeks of mechanical ventilation, the patient's level of consciousness improved significantly, with excellent brainstem and cranial nerve function, ultimately leading to successful extubation. Although the patient exhibited cerebellar mutism secondary to his injury, his cognitive abilities and speech improved significantly during rehabilitation. At his three-month outpatient follow-up, he was ambulatory, independent in his daily living activities, and able to verbally communicate using full sentences. Though exceptional, survival and functional recovery may occur after a GSW to the posterior fossa. A basic understanding of ballistics and the importance of biomechanically resilient anatomic barriers, such as the petrous bone and tentorial leaflet, can help predict a good outcome. Lesional cerebellar mutism tends to have a favorable prognosis, especially in young patients with central nervous system plasticity.

Dialysis Disequilibrium Syndrome and Intracranial Pressure Fluctuations in Neurosurgical Patients Undergoing Renal Replacement Therapy: Systematic Review and Pooled Analysis.

BACKGROUND: Dialysis disequilibrium syndrome is a rare, well-known, potentially life-threatening complication of renal replacement therapy (RRT), often involving cerebral edema and increased intracranial pressure (ICP). However, the impact of RRT on ICP and rate of dialysis disequilibrium syndrome in neurosurgical patients have not been systematically assessed. METHODS: In February 2022, a systematic review following PRISMA guidelines was conducted using various combinations of 9 keywords in the MEDLINE database. Eleven papers were selected. Individual patient data were extracted, pooled, and analyzed. RESULTS: Fifty-eight patients, 44 men and 14 women with a mean age of 48 years (6-78 years), were analyzed. Neurosurgical conditions included the following: spontaneous intracranial hemorrhage (n = 27), traumatic brain injury (n = 16), ischemic stroke/anoxic brain injury (n = 6), intracranial tumor (n = 6), and others (n = 3). Neurosurgical interventions included the following: craniotomy/craniectomy (n = 23), external ventricular drain or ICP monitor placement (n = 16), and burr hole or twist drill craniostomy (n = 4). Intermittent dialysis was used in 33 patients, continuous RRT in 20, and a combination thereof in 4. During RRT, ICP increased in 35 patients (60.3%), remained unchanged in 20, and decreased in 3. Thirty-four patients (65.4%) died. Intermittent dialysis was associated with increased ICP (73% vs. 37.5%, P = 0.01) and mortality (75% vs. 39.1%, P = 0.01). CONCLUSIONS: In neurosurgical patients, ICP increases during RRT are common, affecting up to 60%, and potentially life-threatening, with mortality rates as high as 65%. The use of a continuous rather than intermittent RRT technique may reduce the risk of this complication. Prospective studies are warranted.

Through-and-through stab wound of the cervical spinal canal with retained weapon but no neurological repercussions: an exceptionally rare injury and the case for direct withdrawal. Illustrative case.

BACKGROUND: Nonmissile penetrating spinal injuries are rare and potentially debilitating. Such injuries can sometimes be complicated by the retention of a foreign body, which is usually part of the assailant's weapon, making their management even more problematic. OBSERVATIONS: We present a unique case of stab wound to the neck with a retained ice pick, traversing the spinal canal from one intervertebral foramen to the other, yet with no ensuing neurological damage to the patient. After carefully analyzing the weapon's trajectory on computed tomography and ruling out vertebral artery injury via catheter angiography, the ice pick was successfully withdrawn under general anesthesia and intraoperative neurophysiological monitoring, averting the need for a more invasive surgical procedure. LESSONS: Stab wounds of the spinal canal with a retained foreign body can occasionally be managed by direct withdrawal. Whether this simple technique is a safe alternative to open surgical exploration should be determined on a case-by-case basis after careful review of spinal and vascular imaging. The absence of significant neurological or vascular injury is an absolute prerequisite for attempting direct withdrawal. Moreover, preparations should be made for possible conversion to open surgical exploration in the rare event of active hemorrhage, expanding hematoma, or acute neurological deterioration.

Skull Reconstruction Using a Custom-Made, Three-Dimensional-Printed, Hydroxyapatite-Titanium Cranioplasty Implant: Largest Single-Center U.S. Experience.

OBJECTIVE: Although several material options, both natural and synthetic, are available for cranioplasty, the rate of implant-related complications has remained high. A relatively novel, synthetic hydroxyapatite-titanium implant, which combines biocompatibility with biomechanical resilience, has been reported to reduce tissue inflammation, infection, and explantation rates, while delivering superior cosmetic results. However, despite such promising preliminary reports, clinical data supporting its use have remained scarce. METHODS: All the patients who had undergone cranioplasty between 2019 and 2022 using this implant were identified from a prospectively maintained database. Medical records were retrospectively reviewed and the following variables recorded: demographic data, clinical data, radiologic findings, operative details, complications (implant-related and unrelated), and outcomes. RESULTS: A total of 18 patients (12 men and 6 women), with a mean age of 39 years (range, 20-70 years), were identified. The indications for craniectomy were traumatic brain injury (n = 13; 72.2%), hemorrhagic stroke (n = 3; 16.7%), and ischemic stroke (n = 2; 11.1%). The median time to cranioplasty was 140 days (range, 51-1717 days). The median modified Rankin scale score before cranioplasty was 4 (range, 0-5). Cranioplasty was technically successful in all 18 patients. Minor postoperative complications, none related to the implant, were managed conservatively in 3 patients (16.6%), including a small intraparenchymal hematoma in 1, an extra-axial hematoma in 1, and a seizure in 1. Of these 3 patients, 1 (5.6%) died 1 week later of a suspected pulmonary embolism. No implant-related complications occurred after a median follow-up of 6 months (range, 1-38 months). All 17 survivors exhibited some degree of neurologic improvement. The cosmetic result was good or excellent for all patients. CONCLUSIONS: Our experience, the largest in the United States, confirms the previously reported benefits associated with the use of 3-dimensional-printed hydroxyapatite-titanium cranioplasty implants.

Bilaterally Fixed and Dilated Pupils Are Not the Kiss of Death in Patients with Transtentorial Herniation: A Single Surgeon's Experience.

BACKGROUND: Bilaterally fixed and dilated pupils in the setting of transtentorial herniation have traditionally been considered a sign of futility. Such patients are often denied life-saving surgery based on the premise that meaningful functional recovery would be extremely unlikely. We sought to determine the survival and functional outcome in a cohort of patients who underwent aggressive medical and surgical management. METHODS: Charts of all patients managed by a single surgeon over a 42-month period were retrospectively reviewed. Functional outcome was determined using modified Rankin Scale (mRS). Outcome was classified as good (mRS score 0-3), acceptable (mRS score 4), or poor (mRS score 5-6). RESULTS: Patients were 7 men and 2 women with a mean age of 36 years (range, 16-66 years). Etiologies included stroke (4 patients), traumatic brain injury (4 patients), and malignant cerebral edema (1 patient). Preoperative Glasgow Coma Scale scores ranged from 3 to 7, and midline shift was 7-16 mm. All patients received emergency osmotic therapy before decompressive surgery. Time to surgery (from pupillary changes) was <150 minutes for all patients (median 94 minutes; range, 50-148 minutes). At 3 months, 5 patients (55.6%) had recovered, achieving a good (n = 3) or acceptable (n = 2) outcome. The other 4 patients failed to recover and ultimately died of their injury. CONCLUSIONS: In well-selected patients with transtentorial herniation and bilaterally fixed and dilated pupils, aggressive and timely medical and surgical management may lead to substantial rates of survival and favorable functional outcome. Preconceived notions of a universally grim prognosis in such patients can lead to self-fulfilling prophecies.

Dural-Based Posterior Fossa Medulloblastoma Mimicking a Petrous Meningioma in Late Adulthood.

Background: Medulloblastoma of the posterior fossa is commonly encountered in pediatric populations but rarely reported in adults. Adult cases of medulloblastoma typically occur in younger patients, tend to arise intra-axially within the cerebellar hemisphere, and usually exhibit classic histopathologic features. Case Report: A 54-year-old male presented with headaches, dizziness, gait instability, and frequent falls that had worsened during the prior 3 months. Imaging and histopathologic analysis revealed extra-axial, dural-based posterior fossa medulloblastoma with desmoplastic/nodular histopathology, mimicking a petrous meningioma. The mass occupied the left cerebellopontine angle. The patient underwent microsurgical gross total resection of the tumor followed by proton beam radiation therapy and was disease-free at 1-year follow-up. Conclusion: Few dural-based posterior fossa medulloblastomas resembling petrous meningiomas have been reported, and to our knowledge, this is the first description of a case to be treated successfully with proton beam therapy in an older adult. Although rare, medulloblastoma can occur extra-axially in the cerebellopontine angle of older adults, potentially mimicking a petrous meningioma. This rare possibility should always be kept in mind, especially if expectant, nonsurgical management is being considered. To optimize outcome, posterior fossa medulloblastoma should be treated with aggressive microsurgical resection followed by radiation therapy. When available, proton beam therapy should be considered.

Are Bilaterally Fixed and Dilated Pupils the Kiss of Death in Patients with Transtentorial Herniation? Systematic Review and Pooled Analysis.

OBJECTIVE: Bilaterally fixed and dilated pupils (BFDP) in the setting of transtentorial herniation due to a space-occupying lesion have traditionally been considered a sign of futility. As a result, such patients may be denied life-saving decompressive surgery, resulting in very high mortality rates. We sought to determine the survival rate and functional outcomes in patients with transtentorial herniation and BFDP following emergency decompressive surgery. METHODS: This was a systematic review of MEDLINE, Embase, Cochrane, and Google Scholar databases, using a combination of 15 prespecified keywords, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology. Individual patient data were extracted, pooled, and analyzed. RESULTS: Twenty-two studies totaling 503 patients were included. Study designs were as follows: prospective cohort (n = 1), retrospective cohort (n = 15), and case report (n = 6). Nearly two thirds of patients (67.7%) were male. The mean age was 41 years (range = 3-82). The median preoperative Glasgow coma scale was 3 (range = 3-6). Nearly two thirds (66.9%) underwent surgical decompression within 2 hours of pupillary changes. The mean follow-up was 7 months (range = 1-40). Two thirds (67%) died. Among survivors, 50.5% had severe disability (Glasgow outcome scale = 2-3), while 49.5% had a good outcome (Glasgow outcome scale 4-5), representing 17% of the whole population. Given the methodological limitations, the prognostic value of age, Glasgow coma scale, and time to surgery could not be determined. CONCLUSIONS: The literature suggests a rate of favorable recovery approaching 17% following decompressive surgery in patients with transtentorial herniation and BFDP, secondary to space-occupying lesions. In the setting of stroke or trauma, the clinical finding of BFDP should not be solely relied on as an indicator of futility. Prospective studies are warranted.

Microsurgical Management of Complex Hypothalamic Hamartomas in the Era of Minimally Invasive Therapy: A Case Series and Narrative Review.

BACKGROUND: There has been a paradigm shift in the management of hypothalamic hamartoma (HH) from traditional microsurgical techniques to less invasive alternatives. However, large and extensive HH may fail to respond to these therapies, necessitating craniotomies. METHODS: All patients who underwent microsurgical resection of a complex HH by the 2 senior authors from 2011 to 2021 were included. Charts were retrospectively reviewed and demographic, clinical, imaging, and outcome data were recorded. RESULTS: Eight patients (mean age, 7 years) were included. Two had failed previous treatments. All 7 presented with gelastic seizures and cognitive dysfunction, 6 showed central precocious puberty, and 3 had behavioral problems. The mean lesion size was 21.6 mm and all had interpeduncular extension, 5 had intraventricular extension (Delalande type I, 3; type III, 4; type IV, 1). A frontotemporal orbitozygomatic approach with optic nerve decompression was used in all patients, supplemented by another approach in 3 (endoscopic transventricular, 3; transcallosal, 1). Gross total resection was achieved in 6 patients and subtotal resection in 2. Transient complications occurred in 3 patients (37.5%): self-limited sodium imbalance (n = 3), subdural hygroma (n = 2). Permanent complications occurred in 2 patients (25%): perforator infarct (n = 1) and short-term memory loss (n = 1). All patients experienced seizure resolution with preserved hypothalamic-pituitary axis function. After a mean follow-up of 41 months (range, 2-66 months), 7 patients remained seizure free, and 1 had rare seizures. Cognitive and behavioral symptoms improved in all patients. CONCLUSIONS: For large HH with interpeduncular extension, microsurgery via the frontotemporal orbitozygomatic approach is a safe and highly effective treatment modality.

Equivalency of Protection From Natural Immunity in COVID-19 Recovered Versus Fully Vaccinated Persons: A Systematic Review and Pooled Analysis.

We present a systematic review and pooled analysis of clinical studies to date that (1) specifically compare the protection of natural immunity in the COVID-recovered versus the efficacy of complete vaccination in the COVID-naive, and (2) the added benefit of vaccination in the COVID-recovered, for prevention of subsequent SARS-CoV-2 infection. Using the PRISMA 2020 guidance, we first conducted a systematic review of available literature on PubMed, MedRxIV and FDA briefings to identify clinical studies either comparing COVID vaccination to natural immunity or delineating the benefit of vaccination in recovered individuals. After assessing eligibility, studies were qualitatively appraised and formally graded using the NOS system for observational, case-control and RCTs. Incidence rates were tabulated for the following groups: never infected (NI) and unvaccinated (UV), NI and vaccinated (V), previously infected (PI) and UV, PI and V. Pooling were performed by grouping the RCTs and observational studies separately, and then all studies in total. Risk ratios and differences are reported for individual studies and pooled groups, in 1) NPI/V vs PI/UV and 2) PI/UV vs PI/V analysis. In addition, the number needed to treat (NNT) analysis was performed for vaccination in naïve and previously infected cohorts. Nine clinical studies were identified, including three randomized controlled studies, four retrospective observational cohorts, one prospective observational cohort, and a case-control study. The NOS quality appraisals of these articles ranged from four to nine (out of nine stars). All of the included studies found at least statistical equivalence between the protection of full vaccination and natural immunity; and, three studies found superiority of natural immunity. Four observational studies found a statistically significant incremental benefit to vaccination in the COVID-recovered individuals. In a total pooled analysis, the incidence in NPI/V trended higher than PI/UV groups (RR=1.86 [95%CI 0.77-4.51], P=0.17). Vaccination in COVID-recovered individuals provided modest protection from reinfection (RR=1.82 [95%CI 1.21-2.73], P=0.004), but the absolute risk difference was extremely small (AR= 0.004 person-years [95% CI 0.001-0.007], P=0.02). The NNT to prevent one annual case of infection in COVID-recovered patients was 218, compared to 6.5 in COVID-naïve patients, representing a 33.5-fold difference in benefit between the two populations. COVID-recovered individuals represent a distinctly different benefit-risk calculus. While vaccinations are highly effective at protecting against infection and severe COVID-19 disease, our review demonstrates that natural immunity in COVID-recovered individuals is, at least, equivalent to the protection afforded by complete vaccination of COVID-naïve populations. There is a modest and incremental relative benefit to vaccination in COVID-recovered individuals; however, the net benefit is marginal on an absolute basis. Therefore, vaccination of COVID-recovered individuals should be subject to clinical equipoise and individual preference.

Sinking bullet syndrome: A unique case of transhemispheric migration.

BACKGROUND: Spontaneous migration of retained intracranial bullet fragments is an increasingly recognized phenomenon. However, such migration is usually limited in extent, since it occurs along the bullet tract or cerebrospinal fluid (CSF) spaces. Transhemispheric migration through an intact cerebral hemisphere has not been previously reported. OBSERVATIONS: A 20-year old man sustained a gunshot wound (GSW) to the head with a left parieto-occipital entry point, resulting in retained bullet fragments within the anterior right frontal lobe. The patient developed medically refractory intracranial hypertension, necessitating a left decompressive hemicraniectomy. He exhibited a favorable postoperative course, with gradual neurologic recovery, and was ultimately discharged to a rehabilitation facility. Notwithstanding, serial head CT scans during the first 2 weeks revealed gradual transhemispheric migration of bullet fragments from the right frontal pole to the right occipital pole, traveling through largely intact, uninjured brain tissue. LESSONS: Transhemispheric migration of bullet fragments via intact brain tissue may rarely occur. While the exact mechanisms underlying this phenomenon remain unclear, potential factors may include: bullet weight, CSF pulsations, dissection through white matter tracts, and biomechanical effects of large skull defects. Bullet migration does not necessarily delay or prevent neurologic recovery.

Beware the Wandering Needle: Inadvertent Intramedullary Injection During an Attempted Cervical Medial Branch Block.

A 27-year-old man developed sudden neck pain, severe quadriparesis, and right shoulder allodynia during an outpatient cervical medial branch block procedure. Cervical spine imaging revealed evidence of an interlaminar needle trajectory with abnormal signal in the right hemicord at the level of C4, consistent with intramedullary injection and contusion. Following a 48-hour stay in the intensive care unit, during which hemodynamic vasopressor support was administered to optimize spinal cord perfusion, the patient exhibited almost complete neurologic recovery with resolution of the neuropathic pain. He was eventually discharged home and underwent outpatient physical therapy for a mild residual right hemiparesis.

Minimally Invasive Microsurgical Technique for Evacuation of Deep Intracerebral Hematomas.

Despite the lack of conclusive outcome data, surgical evacuation of large, symptomatic intracerebral hematomas (ICH) may be offered to patients on a case-by-case basis, aiming to prevent brain herniation, control intracranial pressure, relieve symptoms, and possibly facilitate or accelerate recovery.1-3 For deep ICH, minimally invasive techniques, which limit operative damage to healthy brain tissue, are generally preferred. Although new tube and endoscope-based techniques are currently being studied,4-7 those elaborate techniques are not widely available and often require special equipment and/or expensive disposable material. In this operative video (Video 1), we demonstrate a minimally invasive microsurgical approach for the evacuation of deep ICH, which relies on the use of careful preoperative planning, frameless stereotactic neuronavigation, and meticulous microsurgical technique. This technique involves small craniotomies, infracentimetric corticotomies, and physiologic subcortical white matter dissection, leading to very limited disruption of healthy brain tissue, akin to tube and endoscope-based procedures. We acknowledge that this technique or a modification thereof may currently be in use by other neurosurgeons in their practice.8 However, to the best of our knowledge, a step-by-step microsurgical video illustration of this technique has not been previously published. Although this technique can be broadly used by neurosurgeons, irrespective of the hospital setting, it would be particularly valuable in settings where expensive cutting-edge technology is not readily available.

Retained bullet in the cervical spinal canal and the associated surgical management conundrum: case report and review of the literature.

INTRODUCTION: Gunshot wounds (GSW) to the cervical spine remain uncommon. Surgery often does not yield significant neurological improvement and the decision to utilize surgery depends on a number of factors. We describe the case of a 28 year-old male suffering a complete spinal cord injury (SCI) secondary to a bullet lodged in the cervical spinal canal. We present the unique radiological findings and review the indications for and utility of spine surgery for cervical GSW. CASE PRESENTATION: The patient was a 28 year-old male involved in a motor vehicle accident immediately after sustaining a gunshot wound to the cervical spine. Neurologic exam revealed a complete SCI at the C4 level. CT scan revealed a retained bullet in the spinal canal at the C4/5 level without vascular injury or unstable vertebral fracture. He was managed nonoperatively, however, he remained ventilator dependent and ultimately expired secondary to cardiac arrest from a suspected pulmonary embolism. DISCUSSION: We present a case of complete SCI secondary to a retained bullet in the cervical spine. These cases can be managed both operatively and nonoperatively. Given the high risk of morbidity and overall poor neurological recovery after surgical intervention for SCI secondary to GSW, physicians must understand the appropriate indications for surgical intervention. These indications include, but are not limited to, progressive neurological deficit, cerebrospinal fluid leak, spinal instability, and acute lead toxicity.

Monitoring Treatment Effectiveness in Intracranial Arteriovenous Shunt Lesions: Emerging Role of Quantitative Magnetic Resonance Venography for Intracranial Arteriovenous Shunts.

BACKGROUND: Quantitative magnetic resonance angiography (qMRA) using noninvasive optimal vessel analysis (NOVA) is a novel noninvasive imaging technique that is being increasingly used to measure blood flow in extracranial and intracranial arteries. By providing important quantitative flow data, NOVA qMRA can facilitate the management of cerebrovascular disease. While the same technology can also be applied to measure flow in intracranial and extracranial veins, NOVA quantitative MRV (qMRV) is only rarely used in neurovascular practice. CASE DESCRIPTION: We report interesting qMRV data in 2 patients with symptomatic intracranial arteriovenous shunts: a 61-year-old man with a left transverse-sigmoid dural arteriovenous fistula and a 40-year-old woman with a left parietal arteriovenous malformation. In each patient, NOVA qMRV demonstrated significant reduction of intracranial venous outflow after therapeutic obliteration of the shunt lesion, heralding marked clinical improvement. CONCLUSIONS: To the best of our knowledge, this is the first report of successful clinical application of NOVA qMRV in adult patients with intracranial arteriovenous malformations or dural arteriovenous fistulas. We propose that NOVA qMRV is a promising technique for noninvasive measurement of intracranial and extracranial venous blood flow and for monitoring treatment effectiveness in patients with intracranial arteriovenous shunt lesions.

How reliable is CT angiography in the etiologic workup of intracranial hemorrhage? A single surgeon's experience.

OBJECTIVES: CT angiography (CTA) is gradually replacing digital subtraction angiography (DSA) in the etiologic workup of intracranial hemorrhage, though debate persists regarding its diagnostic accuracy. To better define the role of CTA in a pragmatic, real-world setting, we reviewed the experience of a single dual vascular-endovascular neurosurgeon. PATIENTS AND METHODS: Nontraumatic intracranial hemorrhage cases managed by the senior author over a 15-month period were retrieved from a prospectively maintained database. Cases where a hypertensive etiology was presumed were excluded. Demographics, intracranial hemorrhage pattern, CTA and DSA findings were recorded. RESULTS: The study cohort consists of 59 cases where both CTA and DSA were obtained, including 32 women and 27 men with mean age 50 years (18-83). Intracranial hemorrhage pattern was: aneurysmal subarachnoid hemorrhage (SAH) in 37, perimesencephalic SAH (PMSAH) in 8, intraparenchymal in 11, intraventricular in 2, subdural in 1. The overall yield of vascular imaging was 62.7 % (37/59): 29 saccular aneurysms, 4 dissecting aneurysms, 4 microarteriovenous malformations (microAVMs). The specificity and positive predictive value of CTA were 100 %. Its sensitivity and negative predictive value were only 89.2 % and 84.6 %, respectively. CTA missed 4 lesions: 2 dissecting aneurysms, 1 microAVM, 1 small saccular aneurysm. Of 8 patients with PMSAH, 3 (37.5 %) had a vascular lesion: 1 vertebrobasilar dissection, 1 cerebellar microAVM, 1 basilar tip aneurysm. Of those, 2 were missed by CTA. CONCLUSIONS: DSA may identify a lesion in up to 15 % of intracranial hemorrhage cases with negative CTA. Excessive reliance on CTA can be potentially hazardous, especially in the setting of PMSAH.