Effectiveness of hinge craniotomy as an alternative to decompressive craniectomy for acute subdural hematoma.

BACKGROUND: Acute subdural hematoma (ASDH) is a life-threatening condition, and hematoma removal is necessary as a lifesaving procedure when the intracranial pressure is highly elevated. However, whether decompressive craniectomy (DC) or conventional craniotomy (CC) is adequate remains unclear. Hinge craniotomy (HC) is a technique that provides expansion potential for decompression while retaining the bone flap. At our institution, HC is the first-line operation instead of DC for traumatic ASDH, and we present the surgical outcomes. METHODS: From January 1, 2017, to December 31, 2022, 372 patients with traumatic ASDH were admitted to our institution, among whom 48 underwent hematoma evacuation during the acute phase. HC was performed in cases where brain swelling was observed intraoperatively. If brain swelling was not observed, CC was selected. DC was performed only when the brain was too swollen to allow replacement of the bone flap. We conducted a retrospective analysis of patient demographics, prognosis, and subsequent cranial procedures for each technique. RESULTS: Of the 48 patients, 2 underwent DC, 23 underwent HC, and 23 underwent CC. The overall mortality rate was 20.8% (10/48) at discharge and 30.0% (12/40) at 6 months. The in-hospital mortality rates for DC, HC, and CC were 100% (2/2), 21.7% (5/23), and 13.0% (3/23), respectively. Primary brain injury was the cause of death in five patients whose brainstem function was lost immediately after surgery. No fatalities were attributed to the progression of postoperative brain herniation. In only one case, the cerebral contusion worsened after the initial surgery, leading to brain herniation and necessitating secondary DC. CONCLUSIONS: The strategy of performing HC as the first-line operation for ASDH did not increase the mortality rate compared with past surgical reports and required secondary DC in only one case.

Case of Cerebrospinal Fluid Leakage Nine Years after Pituitary Gamma Knife Surgery for Poststroke Thalamic Pain Syndrome.

Pituitary gamma knife surgery (GKS) is a treatment option for poststroke thalamic pain syndrome. Complications such as hypopituitarism, transient enuresis, and transient hyponatremia have been reported. However, cerebrospinal fluid (CSF) leakage has not yet been reported as a complication of pituitary GKS for poststroke thalamic pain syndrome. Herein, we report a case of delayed CSF rhinorrhea that developed 9 years after GKS for poststroke thalamic pain syndrome. A 64-year-old man presented to our hospital with bacterial meningitis and CSF rhinorrhea. Pituitary GKS for poststroke thalamic pain had been performed 9 years prior to his admission to our hospital. Computed tomography revealed pneumocephalus, fluid in the sphenoid and maxillary sinuses, and a partial bony defect of the sella turcica floor with communication between the paranasal and intracranial spaces. The CSF rhinorrhea resolved with bed rest and a lumbar CSF drain but recurred several days later. The patient underwent direct endoscopic surgical repair of the skull base. The sellar floor was covered with an autologous fascia graft harvested from the rectus sheath, and the sphenoid sinus was packed with abdominal fat grafts. The patient recovered, and the CSF rhinorrhea has not recurred for 2 years. Long-term follow-up is necessary after pituitary GKS, considering the complication of delayed CSF leakage.

Transarterial embolization for convexity dural arteriovenous fistula with or without pial arterial supply: A report of four patients.

Background: Convexity dural arteriovenous fistulae (dAVF) usually reflux into cortical veins without involving the venous sinuses. Although direct drainage ligation is curative, transarterial embolization (TAE) may be an alternative treatment. Case Description: Between September 2018 and January 2021, we encountered four patients with convexity dAVFs. They were three males and one female; their age ranged from 36 to 73 years. The initial symptom was headache (n = 1) or seizure (n = 2); one patient was asymptomatic. In all patients, the feeders were external carotid arteries with drainage into the cortical veins; in two patients, there was pial arterial supply from the middle cerebral artery. All patients were successfully treated by TAE alone using either Onyx or N-butyl cyanoacrylate embolization. Two patients required two sessions. All dAVFs were completely occluded and follow-up MRI or angiograms confirmed no recurrence. Conclusion: Our small series suggests that TAE with a liquid embolic material is an appropriate first-line treatment in patients with convexity dAVFs with or without pial arterial supply.

Case Report: Bow Hunter's Syndrome Caused by Compression of Extracranially Originated Posterior Inferior Cerebellar Artery.

Bow hunter's syndrome (BHS) is most commonly caused by compression of the vertebral artery (VA). It has not been known to occur due to an extracranially originated posterior inferior cerebellar artery (PICA), the first case of which we present herein. A 71-year-old man presented with reproducible dizziness on leftward head rotation, indicative of BHS. On radiographic examination, the bilateral VAs merged into the basilar artery, and the left VA was predominant. The right PICA originated extracranially from the right VA at the atlas-axis level and ran vertically into the spinal canal. During the head rotation that induced dizziness, the right PICA was occluded, and a VA stenosis was revealed. Occlusion of the PICA was considered to be the primary cause of the dizziness. The patient underwent surgery to decompress the right PICA and VA via a posterior cervical approach. Following surgery, the patient's dizziness disappeared, and the stenotic change at the right VA and PICA improved. The PICA could be a causative artery for BHS when it originates extracranially at the atlas-axis level, and posterior decompression is an effective way to treat it.

Variations and management for patients with craniocervical junction arteriovenous fistulas: Comparison of dural, radicular, and epidural arteriovenous fistulas.

BACKGROUND: Craniocervical junction arteriovenous fistulas (CCJAVFs) are known to be rare, but variations and clinical behaviors remain controversial. METHODS: A total of 11 CCJAVF patients (M: F=9:2, age 54-77 years) were investigated. Based on the radiological and intraoperative findings, they were categorized into three types: dural AVF (DAVF), radicular AVF (RAVF), and epidural AVF (EDAVF). RESULTS: There were four symptomatic patients (subarachnoid hemorrhage in two, myelopathy in one, and tinnitus in one) and seven asymptomatic patients in whom coincidental CCJAVFs were discovered on imaging studies for other vascular diseases (arteriovenous malformation in one, intracranial DAVF in two, ruptured cerebral aneurysm in two, and carotid artery stenosis in two). Of these 11 patients, 2 (18.2%) had multiple CCJAVFs. Of 14 lesions, the diagnoses were DAVF in 5, RAVF in 3, and EDAVF in 6 (C1-C2 level ratio =5:0, 2:1, 3:3). Patients with DAVF/RAVF in four lesions with intradural venous reflux underwent surgery, although an RAVF remained in one lesion after embolization/radiation. Since all six EDAVFs, two DAVFs, and one RAVF had neither feeder aneurysms nor significant symptoms, no treatment was provided; of these nine lesions, one DAVF and one RAVF remained unchanged, whereas six EDAVFs showed spontaneous obliteration within a year. Unfortunately, however, one DAVF bled before elective surgery. CONCLUSION: CCJAVFs have many variations of shunting site, angioarchitecture, and multiplicity, and they were frequently associated with coincidental vascular lesions. For symptomatic DAVF/RAVF lesions with intradural drainage, surgery is preferred, whereas asymptomatic EDAVFs without dangerous drainage may obliterate during their natural course.

Ruptured Basilar Artery Perforator Aneurysm: A Case Report and Review of the Literature.

Basilar artery perforator aneurysms (BAPAs) are a rare cause of subarachnoid hemorrhage (SAH), and the natural history is still unknown. Herein, we report a case of ruptured BAPA that appeared during the observation period and then spontaneously disappeared; we have also conducted a review of the literature and performed an analysis based on the type of management. This case of BAPA had a unique course, and our observations may help establish a treatment strategy. A 60-year-old man presented with acute diffuse SAH, World Federation of Neurosurgical Societies (WFNS) Grade II and Fisher Grade 3. Initial three-dimensional digital subtraction angiography (DSA) did not show the source of the hemorrhage. DSA performed on day 39 showed a BAPA with a diameter of 3 mm at the posterior surface of the upper third of the basilar artery. Conservative treatment was chosen. DSA performed on day 64 showed complete resolution of the aneurysm. BAPAs are likely pseudoaneurysms, and not saccular aneurysms, caused due to dissection of basilar perforator arteries. BAPAs are often not recognized on initial imaging, and hence, it is necessary to repeat the DSA examination. Considering the relatively high rate of spontaneous resolution, we chose conservative management. When BAPAs enlarge or do not disappear after conservative treatment, additional therapy such as multiple stents should be considered.

Posttraumatic Cerebrospinal Fluid Leak Associated with an Upper Cervical Meningeal Diverticulum.

BACKGROUND: Spontaneous intracranial hypotension (SIH) has been increasingly recognized as a phenomenon caused by cerebrospinal fluid (CSF) leaks; however, its pathogenesis remains unclear. CASE DESCRIPTION: We report 2 cases of SIH resulting from CSF leak from a meningeal diverticulum at the C2 nerve root sleeve. The first case is that of a 46-year-old man who experienced orthostatic headache after a bicycle accident at age 45. Computed tomography (CT) myelography revealed CSF leaks at the C1-2 level. He underwent epidural blood patch therapy, but it was unsuccessful. Next, we performed direct surgery and found a meningeal diverticulum originating from the left C2 nerve root; therefore, we ligated the diverticulum. His symptoms and image findings strikingly improved after surgery. The second case is that of a 45-year-old man who experienced orthostatic headache 1 month after jumping into a river. Magnetic resonance imaging of the head showed bilateral subdural hematoma. CT myelography revealed CSF leaks at the C1-2 level and multiple cyst formations at the cervical and thoracic nerve root sleeves. epidural blood patch was performed, and his symptoms immediately improved. CONCLUSIONS: Recent studies have reported that meningeal diverticulum is involved in various cases of CSF leaks. The 2 cases indicate that traumatic accidents, such as back-and-forth neck movement or falls, presumably induce an increase in CSF pressure, followed by the rupture of an existing meningeal diverticulum, leading to CSF leak.