{"title":"Leptomeningeal Dissemination in TERT Promoter-mutant Anaplastic Pleomorphic Xanthoastrocytoma Responding to BRAF-MEK Inhibition: A Case Report.","authors":"Ryota Kitano, Hiroaki Nagashima, Hiroki Goto, Shunsuke Yamanishi, Masamitsu Nishihara, Kazuhiro Tanaka, Yoshihiro Muragaki, Takashi Sasayama","doi":"10.2176/jns-nmc.2026-0094","DOIUrl":"10.2176/jns-nmc.2026-0094","url":null,"abstract":"<p><p>Pleomorphic xanthoastrocytoma is a rare brain tumor that frequently harbors the oncogenic <i>BRAF V600E</i> mutation. Approximately 28.6%-47% of high-grade pleomorphic xanthoastrocytomas are associated with <i>TERT</i> promoter mutation and leptomeningeal dissemination, for which no established treatment exists and the prognosis remains poor. Combination therapy with BRAF and MEK inhibitors has demonstrated efficacy in <i>BRAF V600E</i>-mutant brain tumors. We report a case of a 22-year-old man with a right temporal lobe tumor initially diagnosed as World Health Organization grade 2 pleomorphic xanthoastrocytoma after gross total resection. Two years later, the tumor recurred and underwent malignant transformation to World Health Organization grade 3 pleomorphic xanthoastrocytoma. At the third resection, pathological and genomic analyses confirmed <i>BRAF V600E</i> mutation together with <i>TERT</i> promoter mutation. Following chemoradiotherapy, spinal leptomeningeal dissemination developed. After spinal irradiation, dabrafenib plus trametinib was initiated, resulting in partial radiological response and symptomatic improvement. Although regrowth occurred 10 months after initiation of targeted therapy, the patient remains alive at the time of writing. Here, we report a case of recurrent anaplastic <i>BRAF V600E</i>-mutant pleomorphic xanthoastrocytoma with leptomeningeal dissemination that showed a transient but clinically meaningful response to combined BRAF-MEK inhibition and spinal radiation therapy. In addition, this case raises the possibility of an association between <i>TERT</i> promoter mutation and leptomeningeal dissemination, although further studies are required to clarify this relationship.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"393-399"},"PeriodicalIF":0.0,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13549706/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148908512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NMC case report journalPub Date : 2026-08-14eCollection Date: 2026-01-01DOI: 10.2176/jns-nmc.2026-0112
Jiro Akimoto, Yuta Nakamura, Hirokazu Fukuhara
{"title":"Severe Central Nervous System Fungal Infection Following Tirabrutinib Administration in a Patient with Refractory Primary Central Nervous System Lymphoma: A Case Report.","authors":"Jiro Akimoto, Yuta Nakamura, Hirokazu Fukuhara","doi":"10.2176/jns-nmc.2026-0112","DOIUrl":"10.2176/jns-nmc.2026-0112","url":null,"abstract":"<p><p>Tirabrutinib, an inhibitor of Bruton's tyrosine kinase-a hub gene for primary central nervous system lymphoma proliferation-is a novel therapeutic agent for relapsed and refractory primary central nervous system lymphoma. We report a case of severe <i>Aspergillus</i> encephalitis following tirabrutinib administration. A man in his 50s suddenly presented with left sided hemiparesis, and neuroimaging suggested a primary central nervous system lymphoma in the right parietal lobe. The results of the tissue biopsy revealed a diagnosis of CD20-positive diffuse large B-cell lymphoma. Despite treatment with high-dose methotrexate combined with rituximab, neurological symptoms rapidly deteriorated. We suspected that the growth of the tumor led to an impending brain herniation, so we planned radiation therapy. However, the patient contracted coronavirus disease 2019. Therefore, we decided to administer tirabrutinib, which can be administered orally. The tumor shrank dramatically, and improvement in neurological symptoms was observed. However, due to onset of liver dysfunction, tirabrutinib was discontinued. Immediately thereafter, the primary central nervous system lymphoma began to progress again, necessitating the re-administration of tirabrutinib. Concurrently, a cerebral abscess developed in the basal ganglia. Subsequently, a fatal subcortical hemorrhage occurred. Brain tissue obtained during hematoma evacuation led to a histological diagnosis of <i>Aspergillus</i> cerebral vasculitis. We started treatment with voriconazole first, and then added amphotericin B, but multiple cerebral abscesses developed and progressed to encephalitis, resulting in death. Burton's tyrosine kinase is a gene crucial for the general antifungal immunity, and when using Burton's tyrosine kinase inhibitors, physician should always be mindful of preventing, detecting early, and addressing fungal infections to avoid fatal adverse events like in this case.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"377-383"},"PeriodicalIF":0.0,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13549676/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148908501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NMC case report journalPub Date : 2026-07-29eCollection Date: 2026-01-01DOI: 10.2176/jns-nmc.2026-0106
Toshiaki Inomo, Masahiro Aoyama
{"title":"Anterior Approach Using Transvertebral Discectomy for C2-C3 Disc Herniation: Case Report.","authors":"Toshiaki Inomo, Masahiro Aoyama","doi":"10.2176/jns-nmc.2026-0106","DOIUrl":"https://doi.org/10.2176/jns-nmc.2026-0106","url":null,"abstract":"<p><p>C2-C3 disc herniation is an extremely rare condition, accounting for <1% of all cervical disc herniations. Discectomy using the posterior transdural or anterior transretropharyngeal approach has been used for its treatment. However, there are still concerns regarding the invasiveness and potential complications of these techniques. Herein, we report a case of C2-C3 disc herniation treated with transvertebral discectomy, assisted by an intraoperative navigation system. An 80-year-old woman presented with worsening numbness and pain in the left upper extremity, as well as gait instability. Magnetic resonance imaging revealed a left-dominant C2-C3 disc herniation compressing the spinal cord. As symptoms showed minimal improvement with conservative treatment, surgical intervention was performed. Through a 4-cm transverse incision on the left side of the neck and a 6-mm bone window, a transvertebral discectomy was performed to remove the C2-C3 disc herniation. An intraoperative navigation system was used to enhance surgical accuracy. The herniated disc fragment was successfully removed via the transvertebral approach without intraoperative complications. Intraoperative navigation helped ensure a safe and accurate surgical procedure. The patient's symptoms improved immediately, and she was discharged to home 1 week later. Transvertebral discectomy enables minimally invasive removal of C2-C3 disc herniation. Combined preoperative magnetic resonance imaging and intraoperative computed tomography using navigation system supports a safer and more comprehensive removal.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"355-360"},"PeriodicalIF":0.0,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489728/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NMC case report journalPub Date : 2026-07-29eCollection Date: 2026-01-01DOI: 10.2176/jns-nmc.2026-0109
Kei Miyata, Katsuyuki Asaoka, Keisuke Ohmae
{"title":"Transorbital Penetrating Brain Injury Extending into the Prepontine Region: A Case Successfully Managed via Anterior Petrosectomy.","authors":"Kei Miyata, Katsuyuki Asaoka, Keisuke Ohmae","doi":"10.2176/jns-nmc.2026-0109","DOIUrl":"https://doi.org/10.2176/jns-nmc.2026-0109","url":null,"abstract":"<p><p>Transorbital penetrating brain injuries are rare and may cause fatal damage depending on their trajectory. We report a case of a man in his 60s with a transorbital injury caused by wooden chopsticks extending to the prepontine region. Imaging demonstrated that the foreign bodies passed through the superior orbital fissure and cavernous sinus, reaching the prepontine region; however, no major vascular injury was identified. Emergency surgery using a frontotemporal craniotomy combined with anterior petrosectomy (Kawase approach) enabled wide exposure of the trajectory at the upper clivus and prepontine space, allowing for the safe removal of fragmented foreign bodies and adhering paper under direct visualization. Postoperatively, no carotid-cavernous fistula was detected; however, brainstem contusion resulted in severe neurological deficits, and the patient died from aspiration-related complications. This approach provides effective exposure for managing transorbital penetrating injuries extending to the upper clivus or prepontine space.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"333-339"},"PeriodicalIF":0.0,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489695/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Intraoperative Near-infrared Spectroscopy Findings Reflecting Cerebrovascular Autoregulation during Staged Angioplasty for Severe Carotid Artery Stenosis: A Case Report.","authors":"Norihiro Iwamoto, Shin-Ichiro Osawa, Norio Narita, Hiroyuki Sakata, Hidenori Endo","doi":"10.2176/jns-nmc.2025-0403","DOIUrl":"https://doi.org/10.2176/jns-nmc.2025-0403","url":null,"abstract":"<p><p>Cerebral hyperperfusion syndrome is a potentially life-threatening complication following carotid artery stenting, particularly in patients with impaired cerebrovascular autoregulation. Staged angioplasty has been proposed to reduce this risk by gradually restoring blood flow and promoting recovery of autoregulatory function. However, it remains unclear how autoregulation responds intraoperatively during each stage of staged angioplasty. We report a case of a 79-year-old man with progressive ischemic stroke caused by severe stenosis of the right internal carotid artery. Preoperative cerebral blood flow was reduced in the right hemisphere. Three months after stroke onset, first-stage percutaneous transluminal angioplasty was performed under near-infrared spectroscopy monitoring. Following balloon dilatation, the minimal lumen diameter increased from 0.4 mm to 1.0 mm, and a marked increase in regional cerebral oxygen saturation on the affected side prompted termination of further dilation. Postoperative imaging showed improved perfusion without signs of cerebral hyperperfusion syndrome. Nineteen days later, definitive carotid artery stenting was performed. Although the lumen diameter increased by 2.7 mm during the stenting procedure, there was no sustained increase in regional cerebral oxygen saturation, and no hyperperfusion or neurological symptoms developed. These contrasting intraoperative responses suggested that cerebral autoregulation was impaired before the first-stage percutaneous transluminal angioplasty procedure but had recovered by the time of the second. This case highlights the potential value of real-time near-infrared spectroscopy monitoring in assessing cerebral autoregulation and guiding intraoperative decision-making during staged angioplasty. Timely identification of hyperperfusion risk using this approach may improve the safety of carotid interventions, particularly in high-risk patients with compromised hemodynamic reserve.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"347-353"},"PeriodicalIF":0.0,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Peri-ictal Hyperperfusion Revealed by Arterial Spin Labeling Perfusion Images in 2 Patients with Post-aneurysmal Subarachnoid Hemorrhage Epilepsy and Associated Old Infarction in the Middle Cerebral Artery Territory.","authors":"Takato Morioka, Satoshi Inoha, Akifumi Yokomizo, Takafumi Shimogawa, Nobutaka Mukae, Kazuhisa Kuwabara, Ayumi Yonamoto, Masayuki Yanagida, Fumihito Mugita, Ayumi Sakata, Hiroshi Shigeto, Koji Yoshimoto","doi":"10.2176/jns-nmc.2026-0116","DOIUrl":"https://doi.org/10.2176/jns-nmc.2026-0116","url":null,"abstract":"<p><p>To make a pathophysiological diagnosis of post-aneurysmal subarachnoid hemorrhage epilepsy, which has complex pathologies, in a neuro-emergency setting, peri-ictal magnetic resonance imaging including arterial spin labeling perfusion images was conducted in 2 patients with associated old infarction due to vasospasm in the middle cerebral artery territory. In patient 1, who had a localized infarction and no apparent circulatory disturbance in the middle cerebral artery territory on interictal magnetic resonance imaging, focal to bilateral tonic-clonic seizures developed twice within 1 year after the subarachnoid hemorrhage onset. In both events, peri-ictal hyperperfusion was observed in a tight anatomical relationship with the infarction. In patient 2, who had extensive infarction and circulatory disorders in the middle cerebral artery area, the fourth focal to bilateral tonic-clonic seizures developed 27 years after the subarachnoid hemorrhage. In this event, peri-ictal hyperperfusion was observed predominantly in the ipsilateral frontal interhemispheric cortex in the anterior cerebral artery territory, slightly away from the infarction. Further case observations with peri-ictal magnetic resonance imaging, in addition to electroencephalography, would help to clarify the complex pathologies of post-subarachnoid hemorrhage epilepsy.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"369-375"},"PeriodicalIF":0.0,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489729/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fatal Delayed Stent-edge Rupture Confirmed by Autopsy after Stent-assisted Coil Embolization for a Blood Blister-like Aneurysm.","authors":"Akina Hirohashi, Masahiro Nishihori, Takashi Izumi, Shunsaku Goto, Satoshi Ito, Nobuhiko Mizutani, Hiroki Shimizu, Ryuichi Fukuyama, Shinsuke Muraoka, Issei Takeuchi, Ryuta Saito","doi":"10.2176/jns-nmc.2026-0042","DOIUrl":"https://doi.org/10.2176/jns-nmc.2026-0042","url":null,"abstract":"<p><p>Blood blister-like aneurysms of the internal carotid artery are uncommon lesions that often present with subarachnoid hemorrhage and are considered part of the spectrum of intracranial arterial dissections. Although endovascular treatment options have expanded in recent years, serious complications remain a clinical concern. We report the case of a 42-year-old woman with a ruptured blood blister-like aneurysm arising from the anterior wall of the internal carotid artery who was treated with stent-assisted coil embolization. The initial postoperative course was uneventful and follow-up imaging showed no evidence of aneurysmal recurrence. However, the patient died 3 months after treatment. Autopsy revealed rupture of the parent artery at the opposite wall of the distal stent edge, with extravascular exposure of the stent. Histopathological examination demonstrated disruption of the internal elastic lamina extending both distal and proximal to the aneurysm, indicating that arterial dissection was more extensive than detectable by angiography. This case suggests that multiple factors, including stent-induced vessel straightening, incomplete wall apposition, antithrombotic therapy, and pre-existing wall fragility, may contribute to delayed stent-edge rupture following stent-assisted coil embolization for blood blister-like aneurysms. Careful selection of stent type and length to adequately cover the dissected segment may be important to reduce the risk of delayed parent artery failure.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"361-367"},"PeriodicalIF":0.0,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489727/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cranioplasty for a Cranial Bone Defect Associated with Giant Congenital Melanocytic Nevus.","authors":"Tomoki Nawashiro, Michihiro Kurimoto, Risa Ito, Shione Nakamoto, Ayumi Ono, Tsuyoshi Morishita, Mihoko Kato","doi":"10.2176/jns-nmc.2026-0097","DOIUrl":"https://doi.org/10.2176/jns-nmc.2026-0097","url":null,"abstract":"<p><p>Giant congenital melanocytic nevi of the scalp are rare congenital melanocytic lesions associated with cranial bone defects. Cranioplasty can be technically challenging, particularly in the absence of normal subcutaneous tissues and dissection planes. However, few surgical reports have focused on these technical difficulties. A girl (age: 6 years and 5 months) with a congenital pigmented scalp lesion, slightly to the right of the midline, underwent postnatal cranial computed tomography scanning that revealed a large cranial bone defect extending from the frontal to parietal bones. Histopathological examination of a biopsy specimen revealed a blue nevus. Considering the patient's normal neurodevelopment and the non-progression of the bone defect during follow-up, elective cranioplasty was planned before school admission. Cranioplasty using a custom-made artificial bone was performed in collaboration with plastic surgeons. Intraoperative findings revealed the absence of normal subcutaneous tissue and the subgaleal dissection plane. The dermis directly adhered to the cranial bone and dura mater, and partially to arachnoid-like tissue. Sharp dissection under careful tension was undertaken with minimal dural injury to preserve scalp viability. Postoperatively, subcutaneous fluid collection and minor scalp necrosis occurred and were successfully managed with local wound care and continuous swimming-cap compression. Congenital melanocytic scalp lesions may be associated with cranial bone defects and loss of normal tissue planes, with severe adhesions between the scalp and intracranial structures. Surgeons should consider these anatomical abnormalities when planning cranioplasty and customize surgical strategies to preserve scalp viability while minimizing intracranial complications.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"341-345"},"PeriodicalIF":0.0,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489725/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tractography Guided Endoport-assisted Superior Parietal Lobe Trans-sulcus Approach for Trigone Meningioma: A Technical Note.","authors":"Atsushi Okano, Hideki Matsumoto, Takayuki Hara, Masanori Yoshino","doi":"10.2176/jns-nmc.2025-0411","DOIUrl":"10.2176/jns-nmc.2025-0411","url":null,"abstract":"<p><p>The trigone of the lateral ventricle is surrounded by important white matter fibers, making it difficult to approach. White matter fibers, such as the superior longitudinal fasciculus, optic radiation, arcuate fasciculus, and inferior fronto-occipital fasciculus, can be clearly depicted by tractography. We propose the safest approach to a trigonal tumor of the lateral ventricle via the superior parietal lobe using tractography. Case: A 49-year-old female presented to our hospital with a chronic headache. Magnetic resonance imaging revealed a meningioma with partial hydrocephalus in the trigone of the left lateral ventricle. After total gross resection, the patient exhibited no cranial nerve, visual, sensorimotor, or language deficits. However, there was a mild acalculia right after surgery, from which the patient made an excellent recovery with no neurological deficits at 3 months after surgery. The endoport-assisted superior parietal lobe trans-sulcus approach using tractography is the safest approach to the trigonal lesion, as it protects the most important white matter fibers around the lateral ventricular trigone.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"317-321"},"PeriodicalIF":0.0,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13423722/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148655567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distal Anterior Inferior Cerebellar Artery Aneurysm Associated with Arteriovenous Malformation: A Case Report.","authors":"Kojiro Ishikawa, Hirohito Tatematsu, Taku Yamamoto, Masato Ohito, Yuki Yoshizawa, Tomomi Kawaguchi, Shigekazu Nakamura, Kenichi Wakabayashi","doi":"10.2176/jns-nmc.2026-0020","DOIUrl":"10.2176/jns-nmc.2026-0020","url":null,"abstract":"<p><p>Aneurysms associated with arteriovenous malformations occur in up to 20% of cases, but distal anterior inferior cerebellar artery aneurysms associated with arteriovenous malformations are extremely rare. We report a case of a ruptured distal anterior inferior cerebellar artery aneurysm associated with a cerebellar arteriovenous malformation in a 71-year-old man presenting with subarachnoid hemorrhage. Digital subtraction angiography revealed a cerebellar arteriovenous malformation supplied mainly by the right anterior inferior cerebellar artery and a fusiform aneurysm located at the meatal loop within the internal auditory canal. The aneurysm was considered the most likely rupture point based on the hemorrhage distribution and angiographic findings. Endovascular treatment was attempted to prevent re-rupture. Due to challenging distal catheterization and unattainable complete coil embolization of the aneurysm, the aneurysm and a short proximal segment of the parent artery were occluded. Postoperatively, the patient developed a mild hearing loss without brainstem infarction. Subsequent arteriovenous malformation resection via lateral suboccipital craniotomy led to complete obliteration. Parent artery occlusion reduced arteriovenous malformation flow and served as preoperative embolization to facilitate safe surgical removal. This case highlights the importance of individualized treatment strategies for rare distal anterior inferior cerebellar artery aneurysms associated with arteriovenous malformations and suggests that parent artery occlusion with subsequent staged arteriovenous malformation resection can be an effective approach.</p>","PeriodicalId":101331,"journal":{"name":"NMC case report journal","volume":"13 ","pages":"311-316"},"PeriodicalIF":0.0,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13423725/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148655552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}