Delayed Migration of Onyx Embolic Agent after Preoperative Embolization of an Arteriovenous Malformation in a Pediatric Patient: A Case Report and Review of the Literature.

INTRODUCTION: Brain arteriovenous malformations (AVMs) are increasingly being treated with Onyx liquid embolic agent (Onyx, Medtronic, Inc.). The phenomenon of delayed Onyx migration is not well documented in the literature. Moreover, the clinical presentation associated with Onyx migration is not well understood. CASE PRESENTATION: A pediatric patient with a history of neonatal seizures was referred to our institution upon experiencing daily headaches with photophobia, phonophobia, and sleep disturbance. Cerebral angiography revealed an AVM of the medial left cerebellar hemisphere. Preoperative embolization with Onyx liquid embolic achieved 25% closure of the AVM nidus. Upon developing worsening headaches the following day, new perinidal parenchymal edema was revealed on MRI, and urgent angiography demonstrated delayed migration of Onyx into the venous drainage. The patient underwent emergency resection of the AVM due to the risk of hemorrhage resulting from venous outflow obstruction. CONCLUSION: Our report and literature review demonstrate that while the delayed, unexpected migration of Onyx embolic material has been alluded to in a handful of papers, this phenomenon is not well documented. Future research is needed to understand the frequency of delayed Onyx migration from brain AVMs and the possible clinical presentations to look for. The sudden development of headaches and other signs of perilesional edema, in particular, should prompt repeat angiographic examination due to the possibility of delayed liquid embolic migration.

Contralateral approach for the treatment of a distal supraclinoid aneurysm: a technical case report.

BACKGROUND: When treating intracranial aneurysms with open microsurgery, rare cases arise in which an ipsilateral approach leads to poor visualization, lack of proximal control, or potential damage to nearby vital structures due to the anatomy of the aneurysm. CASE DESCRIPTION: We describe a patient with a small, unruptured aneurysm arising from the medial aspect of the distal supraclinoid internal carotid artery (ICA), just below the ICA bifurcation. A contralateral surgical approach was chosen because our view of the aneurysm from an ipsilateral approach would have been obstructed by the ICA. The contralateral approach provided excellent exposure of the aneurysm and allowed for precise clip placement without complications. CONCLUSIONS: Contralateral approaches may be a good option for some small medially pointing aneurysm of large proximal cerebral arteries.

Repair of the superior sagittal sinus following penetrating intracranial injury caused by nail gun accident: case report and technical note.

We report a 45-year-old man who suffered a penetrating nail gun injury resulting in damage to the lateral edge of the superior sagittal sinus. The injury was successfully treated via a parasagittal craniotomy that enabled removal of the nail under direct vision, allowing for rapid suturing of the sagittal sinus. Two neurosurgeons worked together; one carefully withdrew the tip of the nail back into the sinus itself while the second rapidly sutured the hole in the inner superior sagittal sinus leaflet. Postoperatively, the patient made a rapid recovery without neurological deficit.

Preventing cerebral spinal fluid leakage following endoscopy through a burr hole using a novel watertight closure: technical note.

BACKGROUND: Cerebrospinal fluid (CSF) leakage is a common complication after neuroendoscopic surgery through a burr hole and can lead to further complications including infection. METHODS: We describe the use of a dural substitute larger than the burr hole itself, placed over the burr hole and then secured underneath a burr hole cover by microscrews running through the graft itself into the underlying skull. RESULTS: This simple technical modification contributes to achieving a watertight seal to aid in preventing CSF leakage in this setting. CONCLUSIONS: Our technical modification of endoscopy through a burr hole may help to prevent postoperative CSF leak and secondary CSF infections.

Technical note: the use of frameless stereotactic guidance in the treatment of peripheral intracranial aneurysms.

Frameless stereotactic guidance (FSG) has previously been reported to have advantages over intraoperative computed tomography (CT) and frame-based imaging guidance methods in the targeting of intracranial lesions. We report our experience using FSG to minimize brain dissection during microsurgical repair of peripheral aneurysms. We used FSG as a surgical adjunct in the management of 91 peripheral aneurysms. It was used to localise and avoid larger bridging veins, enabling us to minimise unnecessary brain dissection by coming directly down on the aneurysm dome in unruptured lesions or targeting the parent artery just proximal to the aneurysm in ruptured cases. We treated 72 aneurysms located on the distal ACA (79%), 7 on the PCA (7.7%), 6 on the MCA distal to the MCA bifurcation (6.6%), and 6 on the SCA (6.6%). There were no complications related to FSG use. However, we noted a tendency to create an overly limited corridor to the aneurysm, which did not allow sufficient proximal or distal control of the parent artery. In these cases, we had to widen our exposure by further opening the interhemispheric fissure to obtain more proximal control once the aneurysm was reached. Subsequently, we learned to avoid this problem by creating a slightly wider corridor during the initial exposure. Using FSG as a surgical adjunct for peripheral intracranial aneurysms allowed us to safely limit craniotomy size and brain dissection while more confidently exposing these unusually situated lesions, facilitating aneurysm clipping in our series.

Non-islet cell tumor-induced hypoglycemia in the setting of metastatic intracranial hemangiopericytoma: case report and review of the literature.

Intracranial hemangiopericytoma, particularly in the setting of extracranial metastatic disease, can cause severe hypoglycemia; but there is limited description of this phenomenon in the neurosurgical literature. We report the case of a male patient with recurrent meningeal hemangiopericytoma that had metastasized to multiple extracranial locations, who presented with severe, symptomatic hypoglycemia and abnormal levels of insulin, pro-insulin, insulin-like growth factors I and II, and C-peptide. This case highlights the association between hemangiopericytoma and abnormal levels of peptide hormones involved in glucose homeostasis, which may serve as a warning sign for hemangiopericytoma and/or metastatic disease.

Intraventricular haemorrhage due to re-ruptured arteriovenous malformation cleared with tissue plasminogen activator administered through a pre-existing ventriculoperitoneal shunt.

In the context in intraventricular haemorrhage (IVH), intrathecal thrombolytic agents administered in conjunction with extraventricular drainage have been demonstrated to clear larger volumes of blood and reduce mortality rates. However, patients with arteriovenous malformations (AVM) have been mostly excluded from clinical trials. We describe a patient with hydrocephalus secondary to a ruptured AVM who was treated via external ventriculostomy, which was subsequently converted to a ventriculoperitoneal shunt (VPS). Eight months later, the AVM re-ruptured, causing IVH and rendering the patient comatose. Taking into consideration the patient's poor outlook, a single dose of intraventricular tissue plasminogen activator (t-PA) was administered through the shunt reservoir. The shunt maintained its function and the patient's condition ultimately improved. This impressive case demonstrates the utility of t-PA administered through an existing VPS in the setting of IVH due to ruptured AVM, highlighting its lifesaving potential in the appropriate patient and overall decrease in the cost of care by mitigating the need for shunt revision.

Case report and literature review of BRAF-V600 inhibitors for treatment of papillary craniopharyngiomas: A potential treatment paradigm shift.

WHAT IS KNOWN AND OBJECTIVE: The BRAF-V600E genetic mutation offers a potential targeted therapy for the treatment of papillary craniopharyngiomas. CASE SUMMARY: A 35-year-old man underwent a craniotomy and subtotal resection of a large BRAF-V600E-positive papillary craniopharyngioma before referral to our institution. Our treatment included the BRAF-V600 inhibitor dabrafenib mesylate (75 mg, twice/day) and trametinib dimethyl sulfoxide (2 mg/day). The residual tumour decreased in size by 95% over 21 months without negative side effects. WHAT IS NEW AND CONCLUSION: We reviewed the literature on BRAF-V600E inhibition as a non-invasive method of treating papillary craniopharyngiomas harbouring the BRAF-V600E mutation.

Procedural complications in patients undergoing microsurgical treatment of unruptured intracranial aneurysms: a single-center experience with 1923 aneurysms.

BACKGROUND: With the growing use of endovascular therapy (EVT) to manage unruptured intracranial aneurysms (IAs), detailed information regarding periprocedural complication rates of microsurgical clipping and EVT becomes increasingly important in determining the optimal treatment for individual cases. We report the complication rates associated with open microsurgery in a large series of unruptured IAs and highlight the importance of maintaining surgical skill in the EVT era. METHODS: We reviewed all cases of unruptured IAs treated with open microsurgery by a single neurosurgeon between July 1997 and June 2019. We analyzed surgical complications, deaths, and patient-reported outcomes. RESULTS: A total of 1923 unruptured IAs in 1750 patients (mean age 44 [range: 6-84], 62.0% [1085/1750] female) were treated surgically during the study period. Of the aneurysms treated, 84.9% (1632/1923) were small, 11.1% (213/1923) were large, and 4.1% (78/1923) were giant. Aneurysm locations included the middle cerebral artery (44.2% [850/1923]), internal carotid artery (29.1% [560/1923]), anterior cerebral artery (21.0% [404/1923]), and vertebrobasilar system (5.7% [109/1923]). The overall mortality rate was 0.3% (5/1750). Surgical complications occurred in 7.4% (129/1750) of patients, but only 0.4% (7/1750) experienced permanent disability. The majority of patients were able to return to their preoperative lifestyles with no modifications (95.9% [1678/1750]). CONCLUSIONS: At a high-volume, multidisciplinary center, open microsurgery in carefully selected patients with unruptured IAs yields favorable clinical outcomes with low complication rates. The improvement of EVT techniques and the ability to refer cases for EVT when a high complication rate with open microsurgery was expected have contributed to an overall decrease in surgical complication rates. These results may serve as a useful point of reference for physicians involved in treatment decision-making for patients with unruptured IAs.

Delayed sudden hearing recovery after treatment of a large vertebral artery aneurysm causing hearing loss and imbalance: a case report.

PURPOSE: Cerebral aneurysms that compress cranial nerve VIII can cause hearing loss and imbalance. Hearing function that does not recover after aneurysm occlusion can signal neurological damage with the potential for permanent deafness. CASE DESCRIPTION: A 72-year-old woman presented with gradually worsening left-sided hearing loss and imbalance over a period of 10 years. She was found to have a lesion of the cerebellopontine angle, which proved to be a large fusiform vertebral artery aneurysm with mass effect on cranial nerve VIII. The patient underwent surgical clip occlusion of the vertebral artery distal to the posterior inferior cerebellar artery and proximal to the aneurysm, which no longer filled on catheter angiography. Postoperatively, the patient experienced delayed complete loss of ipsilateral hearing on the third post-operative day. Otherwise, she made a good recovery with improvement in her balance issues. At that time, we suspected that delayed occlusion of a perforating vessel had probably caused irreversible hearing loss. Ten months later, the patient awoke with significant subjective recovery of her hearing. Audiometry confirmed substantial improvement in her hearing likely due to the aneurysm shrinking away from and decompressing the cranial nerve. CONCLUSION: This case highlights the continued usefulness of vascular occlusion in the management of selected cases of intracranial aneurysms and also that neurological function may recover suddenly, even in very delayed fashion, following treatment.

Bilateral Vestibular Schwannomas in a Patient with Ring Chromosome 22: Case Report and Review of the Literature.

INTRODUCTION: Ring chromosome 22 (r[22]) can lead to the development of intracranial tumors such as meningiomas, neurofibromas, and schwannomas similar to neurofibromatosis 2 (NF2). CASE PRESENTATION: An 18-year-old female with r(22) and a history of global development delay and cognitive impairment presented with sudden hearing loss. MRI revealed bilateral vestibular schwannomas. Given documented audiologic decline in the patient's hearing, the larger tumor was treated with CyberKnife fractionated stereotactic radiosurgery, and the smaller tumor is being monitored. CONCLUSION: This case provides further evidence that patients with r(22) can develop clinical features of NF2, including the development of bilateral vestibular schwannomas, and should be monitored for hearing disturbances starting in puberty as a warning sign for these tumors.

Cognitive deficits among patients surviving aneurysmal subarachnoid hemorrhage. A contemporary systematic review.

BACKGROUND: Subarachnoid hemorrhage (SAH) is associated with high rates of morbidity, including neurological and cognitive deficits that may be difficult to identify and quantify. This review provides an update on the cognitive deficits that may result from spontaneous aneurysmal SAH (aSAH) and identifies factors that may help predict and manage these deficits at discharge and thereafter. MATERIALS AND METHODS: We conducted a systematic review of PubMed and Google Scholar to identify studies published between 2010 and 2019 that assessed cognitive deficits at discharge and during follow-up in patients with aSAH. Full-text articles were assessed for information regarding cognitive testing and factors that may be associated with functional outcomes in this population. RESULTS: We reviewed 65 studies published since 2010 that described the cognitive deficits associated with non-traumatic aSAH. Such deficits may impact functional outcomes, quality of life, and return to work and may result in cognitive impairments, such as memory difficulties, speech problems, and psychiatric disorders. CONCLUSIONS: Patients with aSAH, even those that appear normal at the time of hospital discharge, may harbor cognitive deficits that are difficult to detect, yet can interfere with daily functioning. Further research is needed to provide additional information and to identify stronger correlations to be used in the identification, treatment, and amelioration of long-term cognitive deficits in aSAH patients, including those who are discharged with good clinical outcomes scores.

Adenosine-induced transient asystole to control intraoperative rupture of intracranial aneurysms: institutional experience and systematic review of the literature.

BACKGROUND: Intraoperative rupture of an intracranial aneurysm is a life-threatening situation that carries a high risk of morbidity and mortality. Since 2000, adenosine has been used successfully to induce transient hypotension and/or asystole to control bleeding and facilitate surgical clipping of aneurysms that rupture intraoperatively. Given the paucity of reports describing this method in a limited number of patients, we performed a systematic review of the literature detailing the use and outcomes of this technique. METHODS: The authors performed a systematic review and identified all studies in which adenosine was used in the setting of an intracranial aneurysm that ruptured intraoperatively. We then determined overall morbidity and mortality rates, adding an additional six of our own patients. RESULTS: Data was analyzed for a total of 29 patients, including 23 previously reported patients from the literature and 6 additional cases from our own experience (mean age 54.8 years, 58.6% female). Most patients (82.8%, 24/29) presented with subarachnoid hemorrhage (SAH). Overall mean dose of adenosine was 51.8 mg. Successful clipping was achieved in 100% of patients. Transient or permanent morbidity was reported in 5/29 (17.2%) and the overall mortality rate was 31% (9/29), which occurred primarily due to an initial severe SAH and its resultant complications. CONCLUSIONS: Adenosine-induced circulatory arrest appears to safely control intraoperative bleeding and facilitate the clipping of ruptured intracranial aneurysms based on the limited published literature available. Further studies comparing patient outcomes using this technique to traditional approaches are required to validate the safety and efficacy of adenosine in this high-risk setting.

Primary intracranial angiomatoid fibrous histiocytoma: a case report and literature review.

Angiomatoid fibrous histiocytoma (AFH) is a tumour primarily occurring in the extremities which can very rarely occur as an isolated intracranial lesion. We report a case of a 22-year-old woman presenting with generalized seizure and visual field deficit due to an occipital mass, which immunohistochemistry showed to be an AFH.

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass via retrograde arterial anastomosis in a patient with common carotid artery occlusion: a case report.

The standard superficial temporal artery to middle cerebral artery (STA-MCA) bypass depends on adequate antegrade flow in the STA. In the setting of occlusion of the common or external carotid arteries, revascularization requires modification of the standard bypass procedure. A patient with prior history of irradiation for head and neck carcinoma presented with an ischemic injury and fluctuating neurologic deficit not responsive to medical therapy. His left common carotid artery was occluded, but angiographic evaluation demonstrated retrograde filling of his left STA. Reverse STA-MCA bypass was performed, taking advantage of spontaneous collateralization which allowed for retrograde filling of the STA.

Microvascular decompression with partial occipital condylectomy in a case of pediatric spasmodic torticollis.

Spasmodic torticollis is a rare, neurologic disorder that is caused by abnormal nerve compression of the 11th cranial nerve by blood vessels or bony protrusions. It is typically treated pharmacologically and, if necessary, with surgical intervention. We report a unique case of spasmodic torticollis in a 15-year-old female that involved abnormal compression of the left 11th cranial nerve (CN) by the left vertebral artery, displaced by a hypertrophic left occipital condyle. After treatment with Botox was unsuccessful, the patient was treated with microvascular decompression and occipital condylectomy that adequately relieved the abnormal compression of CN XI. Mild symptoms persisted, and the patient underwent a partial section of the sternocleidomastoid muscle 1 year later, after which torticollis symptoms resolved.

De novo cavernous malformation arising in the wall of vestibular schwannoma following stereotactic radiosurgery: case report and review of the literature.

We report a novel case of a radiation-induced cavernous malformation developing in a vestibular schwannoma previously treated with stereotactic radiosurgery. Eleven years after treatment, the patient presented with a large predominantly cystic lesion in the cerebellopontine angle. We performed surgery, and a solid vascular lesion was identified within the schwannoma, which was determined to be a cavernous malformation after histopathological analysis. We review the literature of radiation-induced cavernous lesions, illustrating that while rare, these lesions do pose concern as a long-term complication of brain radiation therapy. We also discuss the possibility that radiation-induced cavernous malformation-like lesions are pathologically distinct from cavernous malformations.

Unexpected immediate postoperative resolution of long-standing neurological deficits following extracranial-intracranial bypass: a report of three cases.

While intracranial ischemic insults often result in neuronal death and permanent neurological deficits, some patients may develop potentially reversible neurological dysfunction from persistent hypoperfusion, as surviving neurons remain in an "idling" state. We report a unique series of three patients with long-standing neurological deficits who underwent EC-IC bypass for repeated TIAs and demonstrated unexpected, rapid resolution of long-standing pre-existing neurological deficits. We suggest that these individuals harbored regions of underperfused, idling neurons that responded rapidly to restored cerebral reperfusion.

Surgical treatment of a gauzoma with associated obliterative arteriopathy and review of the literature.

We report a case of a 50-year-old woman whose 0.5 mm middle cerebral artery (MCA) aneurysm was treated with gauze wrapping at an outside facility. She returned 9 months later with seizures and an inflammatory process in the region of the prior aneurysm. Surgical re-exploration at that time was aborted. Two years later, she presented with a gauzoma associated with local inflammatory response and severe narrowing of the MCA. A common carotid artery to MCA bypass was performed, followed by surgical removal of the gauze and inflammatory material. Over a 3-month period, she recovered with significant improvement in her preoperative neurological deficits.

Vascular malformations of the brain.

Vascular malformations of the brain are a heterogeneous group of disorders involving the blood vessels of the brain. These entities are relatively rare; therefore, most primary care physicians are somewhat unfamiliar with their clinical implications and management. Vascular malformations of the brain range from the completely benign capillary telangiectasia to the potentially fatal arterio-venous malformation. This article reviews the distinct natural histories, etiologies and treatments of four major types of malformations: capillary telangiectasia, developmental venous anomaly, cavernous malformation and arteriovenous malformation.