Convexity Dural Arteriovenous Fistula without Cortical Venous Reflux Presenting with Pure Acute Subdural Hematoma

Hemorrhagic changes in a dural arteriovenous fistula are typically associated with cortical venous reflux and occur as intracerebral or subarachnoid hemorrhages. A convexity dural arteriovenous fistula (DAVF) usually flows directly into the cortical veins and exhibits cortical venous reflux. Herein, we report a rare case of a convexity DAVF without cortical venous reflux presenting with a pure acute subdural hematoma. A 19-year-old man complaining of headache without any history of head injury was diagnosed with a left acute subdural hematoma on magnetic resonance imaging (MRI) and referred to our hospital. The patient was conscious and exhibited no neurological signs. The MRI did not reveal any possible abnormalities leading to hemorrhage. Cerebral angiography revealed a dural arteriovenous fistula in the left parietal cranium with a feeder from the middle meningeal artery and a drainer into the main transverse sinus via a diploic vein. Part of the shunt blood flowed into the superior sagittal sinus from the meningeal vein; however, there was no reflux into the cortical vein or stasis of the cerebral vein, suggesting venous hypertension. A convexity DAVF was diagnosed as the source of bleeding, and transarterial embolization was performed. The patient recovered without any neurological deficits. In the absence of trauma, an acute subdural hematoma requires an appropriate evaluation of the vascular lesions and a treatment plan.

Intraoperative Integrated Diagnostic System for Malignant Central Nervous System Tumors

PURPOSE

The 2021 World Health Organization (WHO) classification of central nervous system (CNS) tumors uses an integrated approach involving histopathology and molecular profiling. Because majority of adult malignant brain tumors are gliomas and primary CNS lymphomas (PCNSL), rapid differentiation of these diseases is required for therapeutic decisions. In addition, diffuse gliomas require molecular information on single-nucleotide variants (SNV), such as IDH1/2. Here, we report an intraoperative integrated diagnostic (i-ID) system to classify CNS malignant tumors, which updates legacy frozen-section (FS) diagnosis through incorporation of a qPCR-based genotyping assay.

EXPERIMENTAL DESIGN

FS evaluation, including GFAP and CD20 rapid IHC, was performed on adult malignant CNS tumors. PCNSL was diagnosed through positive CD20 and negative GFAP immunostaining. For suspected glioma, genotyping for IDH1/2, TERT SNV, and CDKN2A copy-number alteration was routinely performed, whereas H3F3A and BRAF SNV were assessed for selected cases. i-ID was determined on the basis of the 2021 WHO classification and compared with the permanent integrated diagnosis (p-ID) to assess its reliability.

RESULTS

After retrospectively analyzing 153 cases, 101 cases were prospectively examined using the i-ID system. Assessment of IDH1/2, TERT, H3F3AK27M, BRAFV600E, and CDKN2A alterations with i-ID and permanent genomic analysis was concordant in 100%, 100%, 100%, 100%, and 96.4%, respectively. Combination with FS and intraoperative genotyping assay improved diagnostic accuracy in gliomas. Overall, i-ID matched with p-ID in 80/82 (97.6%) patients with glioma and 18/19 (94.7%) with PCNSL.

CONCLUSIONS

The i-ID system provides reliable integrated diagnosis of adult malignant CNS tumors.

Preoperative Rehearsal Sketch for Cerebral Aneurysm Clipping Improves the Accuracy and the Safety of the Surgical Procedure

OBJECTIVE

With advances in endovascular therapy, the number of cerebral aneurysm clippings has been decreasing. However, some patients are indicated for clipping surgeries. In such circumstances, preoperative simulation is important for the safety and educational aspects of the operation. Herein, we introduce a simulation method using the preoperative rehearsal sketch and report its applicability.

METHODS

We compared the preoperative rehearsal sketch with the surgical view for all patients who underwent cerebral aneurysm clipping by neurosurgeons below the seventh grade between April 2019 and September 2022 in our facility. The aneurysm, running of parent and branched arteries, perforators, veins, and clip working were evaluated by senior doctors and scored as follows: correct, 2; partially correct, 1; incorrect, 0; and total score, 12. We retrospectively evaluated the relationship between these scores and postoperative perforator infarctions and, in addition, compared that between simulated and not simulated cases.

RESULTS

In the simulated cases, the total scores did not correlate with perforator infarctions, but assessments of the aneurysm, perforators, and clip working affected the total score (P = 0.039, 0.014, and 0.049, respectively). Moreover, perforator infarctions were significantly less in the simulated cases (6.3% vs. 38.5%; P = 0.03).

CONCLUSIONS

Precise interpretations of preoperative images and considerations of three-dimensional images are imperative to perform safe and accurate surgeries using preoperative simulation. Although perforators are not always detected preoperatively, it is possible to presume in the surgical view using anatomic knowledge. Therefore, drawing the preoperative rehearsal sketch improves the safety of surgical procedure.

Basilar Artery Occlusion Caused by Extracranial Vertebral Artery Dissection on Its Entry into the Transverse Foramen of the C6 Vertebra: Case Report

Objective

Basilar artery occlusion (BAO) is an infrequent form of acute life-threatening stroke and may occur secondary to vertebral artery dissection (VAD). VAD, which occurs spontaneously and sometimes results from mechanical stress or blunt force trauma to the neck, sometimes occurs in the V1-V2 junction, but there are not many reported cases of those. Herein, we report a pictorially illustrative and clinically informative case of VAD in the V1-V2 junction following BAO.

Case Presentation

The patient was a 27-year-old woman who was transferred to our hospital with abrupt severe unconsciousness. On admission, she presented with generalized convulsions and respiratory arrest, and pan-scan CT and CTA indicated BAO. We performed mechanical thrombectomy and achieved recanalization of the basilar artery, and she was diagnosed with BAO secondary to the right VAD at the entry of the C6 transverse foramen (V1-V2 junction). In hindsight, she had scapula and back pain before the onset. She recovered with a modified Rankin scale score of 3 after 90 days from the onset.

Conclusion

VAD sometimes occurs at its entry into the transverse foramen of the C6 vertebra. In this case, VAD may be affected by minor trauma and potentially histological fragility due to the embryonic development process. Although BAO is sometimes difficult to diagnose because it presents with various symptoms, BAO secondary to VAD should be considered in cases of abrupt severe unconsciousness preceded by neck, scapula, or back pain in young and healthy persons.

Primary central nervous system other iatrogenic immunodeficiency-associated lymphoproliferative disorders presenting as extraosseous plasmacytoma with a progressive clinical course: A case report and literature review

Other iatrogenic immunosuppressive-associated lymphoproliferative disorders (OIIA-LPDs) rarely occur in the central nervous system (CNS). Additionally, they almost always present as lymphoma and withdrawal by cessation of immunosuppressive treatment. We report a case of primary CNS OIIA-LPD that presented as extraosseous plasmacytoma (EP) with a progressive clinical course in spite of immunosuppressive treatment cessation. A 78-year-old man with a history of rheumatoid arthritis (RA) presented with a month-long headache. Magnetic resonance imaging showed mass lesions in the left temporal lobe, left middle fossa, and intradural cervical spine. The left temporal lesion was resected and diagnosed as EP histologically, and OIIA-LPD presented as plasmacytoma integrally due to his history of immunosuppressive treatment using tacrolimus for RA. Despite immunosuppressive treatment cessation, OIIA-LPD lesions did not regress but, on the contrary, showed a progressive clinical course. Considering his advanced age and renal dysfunction, postoperative treatment with radiation and moderate chemotherapy using prednisolone were administrated. Subsequently, the disease state stabilized, and the patient had a Karnofsky performance status score of 90 for 6 months; however, the tumor recurred with meningeal dissemination, and he died 8 months after treatment. Types of OIIA-LPD onset as EP and its progressive clinical course resistant to cessation of immunosuppressive treatment are rare. Moreover, this OIIA-LPD disease state worsened despite its radiosensitivity. We believe the progressive clinical course of this OIIA-LPD case with its high cell proliferation is similar to Epstein-Barr virus negative plasmablastic lymphoma, which could lead to a poor outcome.

Antiplatelet therapy for standalone coiling of ruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

Endovascular embolization using standalone coils is the preferred treatment option for ruptured cerebral aneurysms to avoid the use of dual antiplatelet therapy with stent coiling or endoluminal flow diversion devices. However, it has been reported that patients undergoing the standalone coiling approach are at risk for periprocedural thromboembolism. Therefore, this systematic review and meta-analysis was performed to clarify the risks and benefits of antiplatelet therapy (AT) during coiling procedures performed to treat ruptured aneurysms, including the incidence of early thromboembolic events, hemorrhagic and delayed ischemic events, as well as clinical outcomes.

METHODS

A comprehensive search of three databases was performed for articles from inception to June 2021. After fulfilling the inclusion criteria, five studies were included in this meta-analysis and 462 patients with aneurysmal subarachnoid hemorrhage (aSAH) were identified who underwent endovascular standalone coiling treatment. Aneurysm location, patient characteristics, and aSAH grades were comparable between the AT and non-AT groups.

RESULTS

AT significantly decreased the incidence of thromboembolic events immediately after the coiling procedures compared with non-AT (OR 3.42; 95% CI 1.77 to 6.61, p<0.001). The incidences of hemorrhage, delayed ischemia, and clinical outcomes with or without AT were not significantly different between groups.

CONCLUSIONS

Although this study showed no beneficial effect of AT on clinical outcomes, the results suggest that AT could be combined with standalone coiling to avoid thromboembolism during the perioperative period. A large prospective study and/or an additional meta-analysis would be required to further investigate how AT benefits standalone coil embolization in aSAH.

Spinal Cord Infarction after Mechanical Thrombectomy for Acute Basilar Artery Occlusion: A Case Report and Review of the Literature

Objective

We report a case of spinal cord infarction following mechanical thrombectomy for acute basilar artery occlusion, and describe the pathophysiological mechanism of spinal cord infarction and its possible prevention.

Case Presentation

A 70-year-old man developed dysarthria and left-sided sensory impairment and was then diagnosed with acute basilar artery occlusion. Mechanical thrombectomy was performed using a 6-Fr guiding sheath via the left vertebral artery (VA). Complete recanalization was achieved within 1.5 hours. However, toward the end of the procedure, the guiding sheath was wedged in the distal portion of the VA. Postoperatively, left-sided flaccid paralysis and right-sided sensory deficit were observed. Cervical magnetic resonance imaging (MRI) demonstrated an acute spinal cord infarction on the left side, at the level of C3. The cause of infarction was suspected to be the wedging of the guiding sheath during the procedure.

Conclusion

Spinal cord infarction is a rare but serious complication of mechanical thrombectomy for acute basilar artery occlusion. The selection of appropriate procedure, device, and safe access route are essential for the success of a mechanical thrombectomy for acute basilar artery occlusion.

Safety and Efficacy of Preoperative Embolization in Patients with Meningioma

Preoperative embolization for intracranial meningioma has remained controversial for several decades. In this study, we retrospectively reviewed our experience of embolization using particulate embolic material and coil to clarify the therapeutic efficacy, safety, and risk of complication. Methods  We reviewed 69 patients who underwent embolization with particulate embolic material followed by surgical resection. An additional 6 procedures were included for patients in whom recurrence was treated, for a total of 75 procedures of preoperative embolization. We analyzed the following clinical data: age, sex, tumor size pathology, complications related to embolization, and surgeon's opinion on the intraoperative ease of debulking and blood transfusion. Embolization was performed mainly from the branches of the external carotid artery. Results  No allogenic blood transfusions were needed for any patients. The surgeon had the opinion that whitening and softening of the tumor allowed for easy debulking during decompression of the tumor in most of the patients. Hemorrhagic complications were seen in two patients after embolization. Emergency tumor removal was performed in both of those patients, and they were recovered well after surgery. Transient cranial nerve palsy was seen in one patient. One ischemic complication and one allergic complication occurred. Conclusion  Preoperative embolization could give us an advantage in surgery for meningioma. The procedure reduces intraoperative blood loss and operating time by softening the tumor consistency. However, we must pay attention to the possibility of embolic complications and keep the preparation of emergency craniotomy, particularly in patients with large meningiomas.

Orbital Abducens Nerve Schwannoma: A Case Report and Review of the Literature

Intraorbital schwannoma is a rare tumor which accounts for about 1-2% of all neoplasms of the orbit. Orbital schwannomas most commonly arise from the sensory branches of the trigeminal nerve. On the other hand, intraorbital abducens nerve schwannomas are extremely rare, with a search of the English literature identifying only four cases of intraorbital abducens nerve schwannoma. This is the 5th reported case of an orbital schwannoma arising from the terminal branch of the abducens nerve to the lateral rectus muscle. We report a case of an intraorbital abducens nerve schwannoma in a 51-year-old man with no signs of neurofibromatosis. The tumor was totally excised with functional preservation of the nerve by a zygomatic approach with lateral orbitotomy. With knowledge of these anatomic features, total removal of the tumor with preservation of the abducens nerve function might be possible.

Therapeutic Suggestions for Chronic Subdural Hematoma Associated with Idiopathic Thrombocytopenic Purpura: A Case Report and Literature Review

A 66-year-old woman who was previously diagnosed with idiopathic thrombocytopenic purpura (ITP) presented with mild right-sided hemiparesis and drowsiness. Head computed tomography (CT) imaging demonstrated a massive left chronic subdural hematoma (CSDH) with a midline shift. Because initial laboratory data showed a significantly decreased blood platelet count (0.3 × 10⁴/mm³), medical treatments such as platelet transfusion, intravenous immunoglobulin (IVIG), and high-dose corticosteroid therapy, were initiated. She clinically and radiologically responded well to these treatments without any surgical intervention. In addition to presenting our case, we searched the PubMed and Ichushi Web databases to comprehensively illustrate clinical characteristics and treatment outcomes of similar cases. Including the present case, we found 19 reports and 23 cases of CSDH associated with ITP in the literature, and assessed 17 reports and 21 cases that were written in English and Japanese. None or mild neurological symptom were seen in 13 cases, and severe, such as coma and hemiparesis, were described in the younger 8 cases with significant difference. All except one were first treated with medical therapies. Most cases of the former group responded well to conservative therapy. On the other hand, most in the latter eventually needed surgical treatment in addition except recent two cases including the present case. CSDH associated with ITP is rarely described, and its management remains controversial. However, this report highlights multiple continuous medical treatments under strict observation and general care might be a useful alternative to avoid surgery in cases presenting with severe neurological deficits and extremely low platelet counts.

Critical ventriculo-peritoneal shunt failure due to peritoneal tuberculosis: Case report and diagnostic suggestions for abdominal pseudocyst

Background:

Tuberculous peritonitis (TBP) is a well-known complication of ventriculo-peritoneal (VP) shunt treatment for hydrocephalus resulting from tuberculous meningitis (TBM). However, a case of hydrocephalus unrelated to TBM resulting from VP shunt malfunction due to TBP has not been reported.

Case Description:

A 21-year-old male presented with nausea, abdominal pain, and headache. VP and cysto-peritoneal (CP) shunts had been inserted to treat hydrocephalus due to a suprasellar arachnoid cyst, replaced the VP and removed the CP in his childhood. Computed tomography demonstrated acute hydrocephalus and an abdominal pseudocyst surrounding the distal end of the peritoneal tube. Initial laboratory data showed elevated white blood cell count and C-reactive protein level, but no causative pathogen was identified. External drainage of cerebrospinal fluid (CSF) and of the fluid in the peritoneal cyst was established, and empirical antibiotic therapy was initiated. Bacterial cultures eventually revealed Mycobacterium tuberculosis infection, and TBP was diagnosed. The patient responded well to antituberculosis (anti-TB) agents and insertion of a ventriculo-pleural shunt.

Conclusion:

This case highlights the possibility of CSF shunt failure and concomitant neurological sequelae from TB infection even when the pathogen has not invaded the central nervous system, as in TBM. Moreover, TBP is rare in developed countries and therefore may be misdiagnosed because of nonspecific clinical features and low sensitivity of common TB screening methods.