Cerebral infarction following administration of andexanet alfa for anticoagulant reversal in a patient with traumatic acute subdural hematoma.

Background: Anticoagulants prevent thrombosis in patients with atrial fibrillation (AF) and venous thromboembolism but increase the risk of hemorrhagic complications. If severe bleeding occurs with anticoagulant use, discontinuation and rapid reversal are essential. However, the optimal timing for resuming anticoagulants after using reversal agents remains unclear. Here, we report early cerebral infarction following the use of andexanet alfa (AA), a specific reversal agent for factor Xa inhibitors, in a patient with traumatic acute subdural hematoma (ASDH). The possible causes of thromboembolic complication and the optimal timing for anticoagulant resumption are discussed. Case Description: An 84-year-old woman receiving rivaroxaban for AF presented with impaired consciousness after a head injury. Computed tomography (CT) revealed right ASDH. The patient was administered AA and underwent craniotomy. Although the hematoma was entirely removed, she developed multiple cerebral infarctions 10 h after the surgery. These infarctions were considered cardiogenic cerebral embolisms and rivaroxaban was therefore resumed on the same day. This case indicates the possibility of early cerebral infarction after using a specific reversal agent for factor Xa inhibitors. Conclusion: Most studies suggest that the safest time for resuming anticoagulants after using reversal agents is between 7 and 12 days. The present case showed that embolic complications may develop much earlier than expected. Early readministration of anticoagulant may allow for adequate prevention of the acute thrombotic syndromes.

Ultra-High-Molecular-Weight Polyethylene Merlon Shape: Novel Fixation of Artificial Bone for Cranioplasty.

BACKGROUND: Cranioplasty is a surgical procedure widely performed for repairing cranial defects caused by external decompression surgery for cerebrovascular disease or traumatic brain injury. We devised a new cranioplasty method using artificial bone made up of ultra-high molecular-weight polyethylene, with serrated wings on the edge. We named this newly designed artificial bone as Merlon shape. OBJECTIVE: To describe our initial experience with the Merlon shape and evaluate its usefulness and safety in cranioplasty. METHODS: The serrated wings of the Merlon shape were preoperatively designed for solid fixation and improving cosmetic results by reducing the thickness of the artificial bone. We evaluated 25 patients who underwent cranioplasty with the Merlon shape between December 2018 and December 2021. The causes of bone defects in these patients (male: 9, female: 16; median age: 62 years) were subarachnoid hemorrhage (n = 14), cerebral infarction (n = 8), and traumatic brain injury (n = 3). RESULTS: There were no postoperative adverse events such as infection, bone resorption, implant exposure, or graft sinking in 24 patients during an average follow-up period of 19 months. One patient experienced acute epidural hemorrhage and required reoperation. CONCLUSION: This is the first report on the use of the ultra-high molecular-weight polyethylene Merlon shape. Our initial 4-year case series showed good outcomes with this method.

Incidence of Chronic Subdural Hematoma after Mild Head Trauma in Elderly Patients with or without Pre-traumatic Conditioning of Anti-thrombotic Drugs.

Anti-thrombotic drugs may increase the risk for chronic subdural hematoma (CSDH). However, whether to continue or discontinue/counteract these drugs has not been investigated in patients with mild head trauma. CSDH incidence after mild head trauma, as well as the risk for CSDH in patients with anti-thrombotic drugs, were investigated in this study. The study included 765 consecutive elderly (>65 y.o.) patients with mild head trauma and an initial Glasgow Coma Scale (GCS) score of 14 or 15. All patients received initial CT within 24 hours after trauma and were re-examined 30 days after trauma to detect CSDH formation, repeating for every 30 days to examine symptomatic CSDH progression. Patients were divided into two groups, with anti-thrombotic drugs (n = 195) or without them (n = 263), to investigate the influence of pre-traumatic conditioning with anti-thrombotic drugs on CSDH. The whole sample was 458 out of 765 cases. The incidence of CSDH formation was 91 out of 458 cases (19.9%) after mild head trauma, with no significant difference between with and without anti-thrombotic drugs. CSDH progressed as symptomatic in 21 out of 458 cases (4.6%), with no significant difference between with and without anti-thrombotic drugs. Pre-traumatic conditioning with anti-thrombotic drugs and its continuation after trauma did not affect the incidence of formation or symptomatic progression of CSDH. This finding suggests that discontinuing and/or counteracting anti-thrombotic drugs may be unnecessary in patients with mild head trauma.

Delayed Recurrence of Choroid Plexus Carcinoma in the Sacral Spinal Cord 17 Years after Its Initial Presentation.

Choroid plexus carcinomas (CPCs) are rare malignant tumors of neuro-ectodermal origin, accounting for less than 1% of all intracranial tumors. The recurrence rates of CPCs are very high and typically occur in the short-term following surgery, even after gross total removal. Here we present a rare case of CPC with spinal metastasis, which occurred long after its initial presentation. A 25-year-old woman with a history of increased intracranial pressure underwent resection for a tumor of the fourth ventricle, with a histopathological diagnosis of CPC. After tumor resection, she received 30 Gy of radiation therapy to the craniospinal axis and 20 Gy to the primary site, followed by nimustine hydrochloride chemotherapy. The residual lesion completely responded to these treatments. She suffered sensory loss in the sacral region 13 years later, followed by refractory skin ulcer in the sacral region 17 years after the initial treatments. Magnetic resonance imaging at 17 years after the initial treatments showed tumor in the sacral region, which was enlarged upon follow-up after 18 months, causing incontinence and loss of urinary intention. She underwent tumor resection, with a histological diagnosis of recurrent CPC. She received salvage re-irradiation. This case shows that CPC can spread via the cerebrospinal fluid pathways and cause spinal metastasis, with relatively slow clinical course. The present case suggests that patients with CPCs may need long-term follow-up imaging of the total neural axis to identify late recurrence at both the primary site and spinal metastasis.

Marked Reduction of Cerebral Vasospasm with Intrathecal Urokinase Infusion Therapy after Endovascular Coil Embolization of the Aneurysmal Subarachnoid Hemorrhage: A Case Series.

Delayed cerebral vasospasms after subarachnoid hemorrhage (SAH) are a risk factor for poor prognosis after successful treatment of ruptured intracranial aneurysms. Different strategies to remove clots from the subarachnoid space and prevent vasospasms have different outcomes. Intrathecal urokinase infusion therapy combined with endovascular treatment (EVT) can reduce the incidence of symptomatic vasospasms. To analyze the relationship between symptomatic vasospasms and residual SAHs after urokinase infusion therapy, we retrospectively reviewed the records of 348 consecutive patients managed with EVT and intrathecal urokinase infusion therapy for aneurysmal SAH at our institution between 2010 and 2021. Among them, 163 patients met the study criteria and were classified into two groups according to the presence of residual SAH in the cisterns, Sylvian fissures, and frontal interhemispheric fissure. The incidence of symptomatic vasospasms and the clinical outcomes were assessed. In total, eight (5.0%) patients developed symptomatic vasospasms. Patients with symptomatic vasospasms had a significantly higher incidence of residual SAH in the Sylvian or frontal interhemispheric fissures than those without (P <.0001). No patient with SAHs resolved by urokinase infusion therapy developed symptomatic vasospasms. However, the two groups did not differ significantly in terms of modified Rankin scale scores at discharge. Treatment with intrathecal urokinase infusion after EVT for aneurysmal SAH can substantially reduce the risk of clinically evident vasospasms.

Arteriovenous malformation of the trigeminal nerve root presented with venous congestive edema of the medulla oblongata and upper cervical cord: illustrative case.

BACKGROUND: Arteriovenous malformation (AVM) of the trigeminal nerve root (TNR) is a rare subtype of the lateral pontine AVM. Most of them are diagnosed when they bleed or exert trigeminal neuralgia. Venous congestive edema is a rare phenomenon caused by TNR AVMs. OBSERVATIONS: An 82-year-old man was admitted with progressive limb weakness and dysphasia. Magnetic resonance imaging (MRI) revealed extensive edema of the medulla oblongata and the upper cervical cord with signal flow void at the C3 anterior spinal cord. Vertebral angiography revealed a small nidus fed mainly by the pontine perforating arteries (PPAs). The anterior pontomesencephalic vein (AMPV) was dilated, functioning as the main drainage route. This suggests that venous hypertension triggered the brainstem and upper cervical cord edema. MRI with gadolinium enhancement showed that the nidus was located around the right TNR. Because the nidus sat extrinsically on the pial surface of the right TNR's base, microsurgical obliteration with minimum parenchymal injury was achieved. Postoperative MRI showed disappearance of the brainstem and cervical cord edema with improved clinical symptoms. LESSONS: TNR AVM is rarely associated with brainstem and upper cervical cord edema caused by venous hypertension of the congestive drainage system.

Reducing Surgeon's Physical Stress in Minimally Invasive Neurosurgery.

BACKGROUND AND STUDY AIMS: Various minimally invasive approaches are used in neurosurgery. Surgeons must perform nondynamic fine movements in a narrow corridor, so specially designed surgical devices are essential. Unsophisticated instruments may pose potential hazards. The purpose of this study was to assess the factors associated with muscle fatigue during minimally invasive neurosurgery and to investigate whether physical stress can be reduced by refining the devices used. MATERIAL AND METHODS: Four physical aspects of a handpiece were investigated: torque of conduits (0.20, 0.28, and 0.37 kgf*cm), shape of hand grip (five types), angle of the nozzle (0, 20, and 40 degrees), and weight balance (neutral, proximal, and distal). To evaluate muscle fatigue, surface electromyography was recorded from the extensor carpi radialis muscle and flexor carpi radialis muscle during a geometric tracing task. The maximum voluntary contraction (MVC) of each muscle and %MVC (muscle contraction during a task/MVC × 100) were used as the indexes of muscle fatigue. RESULTS: The shape of the hand grip significantly reduced %MVC, which is associated with muscle fatigue. The torque of conduits and angle of the nozzle tended to reduce muscle fatigue but not significantly. Weight balance did not affect muscle fatigue. Based on these results, we made two refined models: model α (torque of conduits 0.2 kgf*cm, angle of nozzle 20 degrees, neutral balance, hand grip with a 2.9 × 2.0-cm oval section with angled finger rest), and model ß (torque of conduits 0.2 kgf*cm, angle of nozzle 20 degrees, neutral balance, hand grip with a 2.9-cm round section with a curved finger rest). The %MVC was significantly decreased with both types (p < 0.05 and p < 0.01, respectively), indicating reduction of muscle fatigue. CONCLUSIONS: The geometrically refined surgical device can improve muscle load during surgery and reduce the surgeon's physical stress, thus minimizing the risk of complications.

Neurolymphomatosis in a cat.

A 9-year-old male mixed breed cat showed chronic progressive neurological symptoms, which are represented by ataxia and seizures. At necropsy, spinal roots and spinal ganglions at the level of sixth cervical nerve to second thoracic nerve were bilaterally swollen and replaced by white mass lesions. Right brachial plexus and cranial nerves (III, V and VII) were also swollen. A mass lesion was found in the right frontal lobe of the cerebrum. Histologically, neoplastic lymphocytes extensively involved the peripheral nerves, and they infiltrated into the cerebral and spinal parenchyma according to the peripheral nerve tract. Immunohistochemically, most neoplastic lymphocytes were positive for CD20. The clinical and histological features in this case resemble those of neurolymphomatosis in humans.