Microsurgical Approach for True Posterior Communicating Artery Aneurysms: Literature Review and Illustrative Case.

True posterior communicating artery (PCoA) aneurysms are rare. Although true PCoA aneurysms have been reported to be located close to the internal carotid artery, at the middle part of PCoA, or close to the posterior cerebral artery; the best surgical approach to treat true PCoA aneurysms in each location remains unclear. We conducted a literature review using data from PubMed. Data on demographics, location, and projecting direction of the aneurysm, surgical approach, and surgical complications were collected. A total of 47 true PCoA aneurysms were included. Twenty-nine aneurysms originated from the proximal portion, 10 from the middle portion, and 6 from the distal portion; there were two giant aneurysms. The ipsilateral pterional approach was used for 37 true PCoA aneurysms (27 in proximal portion, 8 in middle portion, and 2 in distal portion of PCoA). The anterior temporal approach was used for two distal-portion aneurysms and one giant aneurysm. The anterior subtemporal approach was used for one distal-portion aneurysm. The subtemporal approach was used for two middle-portion aneurysms and one giant aneurysm. The contralateral pterional approach was used for two proximal-portion and one distal-portion aneurysms. Although most true PCoA aneurysms can be treated by the pterional approach, other means such as anterior temporal and subtemporal approaches can be applicable for aneurysms in the middle and distal portions of the PCoA or giant aneurysms. Surgeons should select an appropriate approach for each aneurysm while considering the advantages and disadvantages of each technique.

Influence of Microcatheter Position on First-pass Success of Thrombectomy for Acute Ischemic Stroke.

OBJECTIVE: In acute ischemic stroke, patient outcomes can be improved by first-pass successful recanalization of the occluded vessel. This study investigated whether microcatheter position could influence the success of first-pass recanalization. METHODS: We retrospectively analyzed 59 consecutive acute ischemic stroke patients who underwent intra-arterial thrombectomy with stent retrievers for middle cerebral artery (M1) occlusion. Angiography findings obtained via the first pass of the microcatheter were analyzed. The microcatheter was considered to be inserted into M2 segments that gave rise to parietal arteries (M2P) if the anterior or posterior parietal artery was observed. Recanalization results were compared between patients with and without microcatheter insertion into M2P. The angle and diameter of vessels were measured using post-procedural magnetic resonance angiography. RESULTS: The rate of first-pass successful recanalization (modified thrombolysis in cerebral infarction score of ≥2b) was significantly higher in patients with microcatheter insertion into M2P than in those without (56% vs. 22%, P = 0.016). The number of passes was lower in patients with first-pass microcatheter insertion into M2P than in those without (1.8 ± 1.0 vs. 2.5 ± 1.5, P = 0.05). The mean diameter of M2P was significantly larger than that of the other M2 (1.9 ± 0.6 mm vs. 1.7 ± 0.5 mm, P = 0.035). The M1/M2P angle was significantly smaller than that between M1 and the other M2. (49° ± 32° vs. 67° ± 31°, P = 0.006). CONCLUSIONS: First-pass microcatheter insertion into M2P may contribute to fast successful recanalization in patients with M1 occlusion who undergo intra-arterial thrombectomy using stent retrievers.

Hemorrhagic stroke associated with essential thrombocythemia: Case report and literature review.

Hemorrhagic stroke associated with essential thrombocythemia (ET) is very infrequent. Herein, we report a case of a 33-year-old woman with a 2-year history of ET who developed intracerebral and subarachnoid hemorrhage. Angiography demonstrated severe vessel irregularity in the bilateral cerebral arteries. Molecular genetic testing revealed a calreticulin mutation. To our knowledge, hemorrhagic stroke has been reported in only six other patients with ET, and this is the first report of hemorrhagic stroke in an ET patient with a calreticulin mutation. We review the current literature and discuss the possible underlying mechanisms.

BMP4 induces asymmetric cell division in human glioma stem-like cells.

Glioblastoma (GBM) is a malignant tumor with a high recurrence rate and has very poor prognosis in humans. The median survival is still <2 years. Therefore, a new treatment strategy should be established. Recently, this cancer has been thought to be heterogeneous, consisting of cancer stem cells (CSCs) that are self-renewable, multipotent, and treatment resistant. So various strategies targeting glioma stem-like cells (GSCs) have been investigated. This study focused on strategies targeting GSCs through the induction of differentiation using bone morphogenetic protein 4 (BMP4). The expression of CD133, a cancer stem cell marker, under BMP4 treatment in GSCs was examined using flow cytometry, western blotting, and quantitative PCR. Immunofluorescent staining of GSCs was also performed to examine the type of cell division: asymmetric cell division (ACD) or symmetric cell division (SCD). We obtained the following results. The BMP4 treatment caused downregulation of CD133 expression. Moreover, it induced ACD in GSCs. While the ACD ratio was 23% without BMP4 treatment, it was 38% with BMP4 treatment (P=0.004). Furthermore, the tumor sphere assay demonstrated that BMP4 suppresses self-renewal ability. In conclusion, these findings may provide a new perspective on how BMP4 treatment reduces the tumorigenicity of GSCs.

Aspiration Catheter Reach to Thrombus (ART) Sign in Combined Technique for Mechanical Thrombectomy: Impact for First-Pass Complete Reperfusion.

OBJECTIVE: The important factor for successful first-pass complete reperfusion (FPR) after combined techniques for mechanical thrombectomy (MT) is unclear. We consider that for successful FPR, the aspiration catheter (AC) should reach to and hold the thrombus before the device is pulled out. Therefore, we defined an ART (AC reached thrombus) sign characterized by the cessation of reverse blood flow in aspiration pump and deformation of stent retriever (SR) at the tip of AC. The purpose of this study was to identify the impact of the ART sign on the outcomes of the combined techniques. METHODS: A retrospective analysis was conducted between January 2015 and September 2018 on the data of consecutive patients who underwent MT for anterior circulation stroke using both SR and AC at the first-pass procedure. We divided the patients into 2 groups based on whether the first-pass procedure achieved the ART sign (ARTs group) or not (Non-ARTs group). The primary endpoint was FPR defined as modified thrombolysis in cerebral infarction (mTICI) score of 3. RESULTS: Sixty-six patients were included in our study (n = 38, ARTs group; n = 28, Non-ARTs group). There were no differences at mTICI 2b/3 (97.3% versus 89.2%, P = .30), but the FPR and mTICI3 were more common in the ARTs group (81.5% versus 14.2%, P < .001; and 89.4% versus 32.1%, P < .001, respectively). CONCLUSIONS: ART sign in combined technique was found to be an important factor for successful FPR.

Stabilization of vulnerable carotid plaques with proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, a novel class of monoclonal antibodies, reduce low-density lipoprotein cholesterol levels and improve outcomes of myocardial infarction and stroke. However, the effects of PCSK9 inhibitors on carotid plaques remain unclear. We describe three patients treated with PCSK9 inhibitor alirocumab for progressive carotid stenosis despite lipid-lowering statin therapy. All three patients had vulnerable plaques on magnetic resonance (MR) plaque imaging. After alirocumab treatment initiation, no patients suffered stroke or adverse events, and the stabilization of the carotid plaques was observed on MR plaque imaging.

Status epilepticus induced by treatment with dopamine agonist therapy for giant prolactinoma: a case report.

BACKGROUND: Dopamine agonists are the standard first-line medical therapy for prolactinoma. We report a rare case of giant prolactinoma with a first epileptic seizure due to rapid reduction of the tumor as a complication of dopamine agonist therapy. CASE PRESENTATION: A 27-year-old Japanese man presented to our institution with a history of visual disturbance for 1 year and general fatigue for 3 months. Magnetic resonance imaging showed a tumor that arose from the pituitary and extended to the bilateral anterior skull base, the clivus, and the cavernous sinus, with compression of the optic chiasm and the bilateral frontal and temporal lobes. On the basis of the patient's serum concentration of prolactin, we diagnosed a prolactinoma and started dopamine agonist therapy with cabergoline. The patient had a general seizure immediately after starting dopamine agonist therapy and required general anesthetic treatment following the rapid reduction of the tumor. We speculated that the rapid reduction of the tumor resulted in the retraction of the surrounding brain structure, and the epileptic seizure was then induced by dopamine agonist therapy. CONCLUSIONS: We report a rare case of giant prolactinoma with a first epileptic seizure immediately after the initiation of dopamine agonist therapy. Clinicians need to be aware that the rapid reduction of a giant prolactinoma by dopamine agonist therapy may cause an epileptic seizure.

Curved Planar Reformation for the Evaluation of Hydromyelia in Patients With Scoliosis Associated With Spinal Dysraphism.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: Scoliosis and hydromyelia have frequently been observed in patients with spinal dysraphism. We investigated the applicability of curved planar reformation (CPR) for evaluating hydromyelia in patients with scoliosis associated with spinal dysraphism. SUMMARY OF BACKGROUND DATA: It is quite difficult to evaluate scoliosis and hydromyelia in patients with spinal dysraphism. METHODS: We identified 11 patients with scoliosis and a Cobb angle of >20° among 107 spinal dysraphism patients. In addition to routine T1- and T2-weighted axial and sagittal MRI, we obtained three-dimensional constructive interference in steady-state magnetic resonance imaging (MRI) as sagittal cross-section volume images. The spinal cord and hydromyelia were rendered into a single-plane, two-dimensional image using the straightened CPR technique. In cases of scoliosis with hydromyelia, the sagittal length and maximal diameters of hydromyelia and the spinal cord were measured by three examiners. Measurement errors among examiners were evaluated using standard deviation (SD) and coefficient of variation (CV). RESULTS: Each series of image sets provided a straightened CPR image that clearly delineated the entire length of the linearized spinal cord in a single plane. The straightened CPR image also demonstrated the accurate lengths and estimated volume of hydromyelia. Given that three of the 11 patients underwent serial MRI during this period, we were able to accurately compare volume changes. In the sagittal length of the hydromyelia, SD and CV were smaller with the straightened CPR technique than with the conventional T2 WI sagittal section in all cases, showing a statistically significant difference between both techniques (SD: P = 0.014, CV: P = 0.013). Even in the measurements, the difference in CV between both techniques was close to statistical significance. CONCLUSION: The straightened CPR technique is useful for accurately identifying volume changes in hydromyelia, even in patients with severe scoliosis. LEVEL OF EVIDENCE: 1.

Brain metastasis from primary peritoneal carcinoma: Case report and literature review.

Here, we describe a patient with primary peritoneal carcinoma (PPC) who developed a late, solitary brain metastasis. It is a case of a 68-year-old female presented with a 1-month history of progressive gait disturbance who had undergone a surgical resection of PPC five years prior, followed by adjuvant chemotherapy. An MRI revealed a 4.6cm mass lesion in her right cerebellum. The patient underwent total removal of the tumour. The histopathology was consistent with a brain metastasis due to PPC. This condition is a rare malignancy of peritoneum, and only six cases of brain metastasis have been reported in PPC patients to date. Due to the prolongation of survival resulting from advanced chemotherapy for PPC, more patients will live long enough to develop brain metastases.

[A Case of Aplastic or Twig-Like Middle Cerebral Artery Presenting with an Intracranial Hemorrhage Two Years after a Transient Ischemic Attack].

Aplastic or twig-like middle cerebral artery (Ap/T-MCA) is a rare anatomical anomaly, which can be associated with intracranial hemorrhage and cerebral ischemia. A 52-year-old woman who presented with sudden headache was admitted to our hospital. Computed tomography (CT) and magnetic resonance imaging showed no abnormality; however, magnetic resonance angiogram revealed an occlusion or severe stenosis in the left middle cerebral artery. Three-dimensional CT angiography demonstrated severe stenosis in the left middle cerebral artery. The patient was discharged without any neurological deficit; however, she subsequently complained of temporary weakness in the right hand. It was possibly due to a transient ischemic attack; therefore, cilostazol 200 mg/day was administered for prevention of cerebral ischemia. Single photon emission computed tomography(with or without administration of acetazolamide)showed neither significant decrease in the cerebral blood flow nor cerebrovascular reactivity; hence, surgical revascularization was not performed. However, two years after the initial admission, she was urgently admitted to our hospital with sudden headache and nausea followed by aphasia and weakness of the right extremities. CT images showed diffuse subarachnoid hemorrhage and intracerebral hemorrhage in the left temporo-parietal lobe. Cerebral angiography revealed that the left middle cerebral artery was Ap/T-MCA without cerebral aneurysms. The patient was treated conservatively, and she eventually recovered without any neurological deficit except mild aphasia. Since Ap/T-MCA is associated with both hemorrhagic and ischemic stroke, antiplatelet therapy should be administered carefully. Moreover, it is necessary to consider extracranial-intracranial bypass to reduce hemodynamic stress on the abnormal vessels.

[A case of cerebellar variant of posterior reversible encephalopathy syndrome in puerperium].

A 29-year-old woman complained of headache and nausea several hours after delivery, followed by mild disturbance of consciousness. Physical examination revealed hypertension, systemic edema, nystagmus, dysarthria, and cerebellar ataxia. Computed tomography showed low attenuation areas in the cerebellum, and MR imaging revealed vasogenic edema in the cerebellum. MR angiography and MR venography demonstrated no significant abnormalities. We diagnosed a cerebellar variant of posterior reversible encephalopathy syndrome(PRES), and treated the patient immediately with antihypertensive drug and diuretic. The symptoms dramatically improved and MR imaging ten days after admission revealed disappearance of the vasogenic edema in the cerebellum. She was discharged without any sequelae. Though a cerebellar variant of PRES is very rare, rapid diagnosis and treatment is important for good prognosis when the disease is encountered.

[Blood blister-like aneurysm on the posterior wall of the internal carotid artery causing subarachnoid hemorrhage: a case report].

We report a case of blood blister-like aneurysm(BBA)on the posterior wall of the internal carotid artery(ICA)causing subarachnoid hemorrhage(SAH). A 45-year-old man suffering from SAH(WFNS grade 5)was referred to our hospital. 3D-CT angiography showed a BBA on the posterior wall of the ICA. The aneurysm had been enlarged for a few days. Therefore we performed coil embolization. Four weeks after the operation, the aneurysm was found to have regrown. In the second operation the aneurysm was successfully treated by the ICA proximal occlusion with extracranial-intracranial bypass. Postoperative follow-up cerebral angiography detected no aneurysm. To our knowledge, BBA on the posterior wall of the ICA is rare. Radical surgery with bypass should be performed as soon as possible when the BBA is found to regrow. We discuss the clinical characteristics with a review of the literature.

[Successful microvascular decompression of the medulla oblongata for a case with respiratory failure: case report].

We report a case of the medulla oblongata syndrome successfully treated by microvascular decompression surgery. The patient was a 75-year-old woman and had been suffering from gradual progressive dyspnea since July, 2009. Two month later, intubation and medial ventilator treatments were began because of severe respiratory problems. The central respiratory problems were considered in extensive testing by the physician. The head MR imaging showed that the left vertebral artery had markedly compressed the medulla oblongata. We thought that her respiratory problems were associated with this vertebral artery compression of the medulla oblongata. We performed the microvascular decompression surgery by left trans-condylar fossa approach. Her hypoventilation graduately improved after the surgery and she needed neither ventilator nor oxygen in several months. She is able to perform daily activities by herself. We report the case, and discuss the cause of respiratory problems especially by compression of the medulla oblongata.