The Mc4r gene is responsible for the development of experimentally induced testicular teratomas.

Teratomas in mice, composed of different tissue types, are derived from primordial germ cells in the fetal gonads. Previously, we identified a locus responsible for experimental testicular teratoma (ETT) formation on chromosome 18, referred to as ett1. The strongest candidate sequence in the ett1 locus was found to be a missense mutation in the melanocortin 4 receptor (Mc4r), Mc4rG25S. We established a strain with a point mutation in the Mc4r gene in the ETT-nonsusceptible LT strain, called LT- Mc4rG25S, by genome editing. Surprisingly, highly developed ovarian teratomas (OTs), rather than testicular teratomas, appeared in the LT-Mc4rG25S strain. The results demonstrated that Mc4r is also one of the genes responsible for OT formation and suggested that missense mutations in Mc4r promote teratoma formation in both sexes. In this study, we performed ETT experiments in different host-graft combinations of the LT-Mc4rG25S and LT strains. Furthermore, the expression of MC4R in germ cells in the testis was demonstrated. Expression of Mc4r in testis was also confirmed by RT-PCR. The results demonstrated that MC4R is expressed in germ cells in the testis and that a point mutation in the Mc4r gene is responsible for ETT formation.

Duplicated middle cerebral artery associated with aneurysm at M1/M2 bifurcation: a case report.

BACKGROUND: A duplicated middle cerebral artery arises from the internal carotid artery and supplies blood to the middle cerebral artery territory. A duplicated middle cerebral artery is sometimes associated with an intracranial aneurysm. Most aneurysms associated with duplicated middle cerebral artery are located at the origin of the duplicated middle cerebral artery. An aneurysm located at the distal middle cerebral artery is not common. CASE PRESENTATION: We encountered a 62-year-old Asian man with duplicated middle cerebral artery associated with aneurysms at the M1/M2 junction of the duplicated middle cerebral artery and top of the internal carotid artery. CONCLUSIONS: In cases of duplicated middle cerebral artery, association with a distal aneurysm on the duplicated middle cerebral artery is rare. However, the aneurysm may be formed on the thicker middle cerebral artery due to hemodynamic stress.

Thromboembolic complications during endovascular treatment of ruptured cerebral aneurysms.

Background In cases of subarachnoid hemorrhage due to aneurysm rupture, the administration of an anticoagulant or antiplatelet agent involves the risk of rebleeding from the aneurysm. There is a possibility of inducing thromboembolic events during the endovascular embolization of ruptured cerebral aneurysms. Patients and methods From April 2006 to March 2017, we treated a total of 70 patients with ruptured cerebral aneurysms with an endovascular technique. Among them, five patients (7.1%) showed intra-arterial thrombus formation. The aneurysms were located at the anterior communicating artery and basilar artery in two patients each, and on the internal carotid artery at the bifurcation of the anterior choroidal artery (AChoA) in one. In these patients, the clinical course, radiological findings, and management were retrospectively reviewed. Results Thrombus formation was observed in the posterior cerebral artery, anterior cerebral artery (A2), AChoA, and middle cerebral artery. The timing of thrombus formation was during coil delivery in four cases, and guiding catheter advancement in one. As for thrombus management, for all patients, administrations of heparin and antiplatelet agents were performed. For four patients, urokinase injection into the affected arteries was added after the completion of embolization. Cerebral infarction was postoperatively identified in two patients, but no hemorrhage was noted. Conclusion Administrations of heparin and antiplatelet drugs should be performed appropriately during procedures, and close observation of the arterial condition on angiography is necessary. Once thromboembolism occurs during the endovascular embolization of ruptured cerebral aneurysms, adequate heparinization, and antiplatelet therapy should first be performed.

Agenesis of the Left Internal Carotid Artery Associated with Dolichoectatic Intracranial Arteries.

A 28-year-old man without a significant medical history visited our hospital complaining of a headache. Computed tomography (CT) demonstrated thick, calcified vertebral artery (VA) and basilar artery (BA), despite the patient being young. Magnetic resonance angiography demonstrated the absence of the left internal carotid artery (ICA). The right ICA, the bilateral VA, and the BA were well developed and dolichoectatic. CT revealed the absence of the carotid canal on the left side. The condition was diagnosed as congenital agenesis of the left ICA with dolichoectatic changes in 3 other arteries. In a young patient with thick, calcified intracranial arteries, close examination is necessary, because vascular anomalies such as ICA agenesis may exist.

Superficial Temporal Artery-Middle Cerebral Artery Bypass Using a Thick STA after Endarterectomy: A Rescue Technique.

Background and Objective Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is a procedure to reconstruct cerebral blood flow in the MCA territory. In some cases, the STA wall is thickened and the size discrepancy between STA and MCA is apparent. In such a situation, STA-MCA bypass is challenging. We present two patients who underwent STA-MCA bypass using STA in which a thickened intima was removed. We discuss the usefulness of this rescue technique. Patients and Results A patient with an atherosclerotic MCA occlusion and another with an occluded internal carotid artery are included. Endarterectomy of STA was performed before or during anastomosis, and the intima-resected STA was anastomosed to MCA. In both cases, the STA was thick and hard, and it was difficult to anastomose the STA as it was to the MCA. Patency of the bypass was confirmed by postoperative angiography. Conclusion Endarterectomy of a thickened STA might be an effective rescue technique in cases with severely atherosclerotic STA in STA-MCA bypass.

Pseudoaneurysm formation due to rupture of intracranial aneurysms: Case series and literature review.

Background Intracranial pseudoaneurysm formation due to a ruptured non-traumatic aneurysm is extremely rare. We describe the radiological findings and management of pseudoaneurysms due to ruptured cerebral aneurysms in our case series and previously reported cases. Patients and methods Four additional and 20 reported patients presenting with subarachnoid hemorrhage (SAH) are included. Radiological findings and clinical features of these patients were reviewed. Results In our series, three-dimensional computed tomographic angiography (3D-CTA) and/or angiography showed an irregular- or snowman-shaped cavity extending from the parent artery. The radiological examination additionally revealed delayed filling and retention of contrast medium. These findings were the same as previously reported cases. One patient underwent direct clipping of the true aneurysm. For the other three patients with aneurysms at the basilar and anterior communicating arteries, the true portion of the aneurysm was embolized with platinum coils. During the procedures, care was taken not to insert the coils into the distal pseudoaneurysm portion to prevent rupture. The review of 24 cases revealed that the location of the aneurysms was most frequent in the anterior communicating artery (41.7%), and 86.7% of patients were in a severe stage of SAH (>Grade 3 in WFNS or Hunt & Kosnik grading) implying abundant SAH. Conclusions Pseudoaneurysm formation in SAH after non-traumatic aneurysm rupture is rare. However, in cases with an irregular-shaped aneurysm cavity, pseudoaneurysm formation should be taken into consideration.

Post-ischaemic hyperperfusion in traumatic middle cerebral artery dissection detected by arterial spin labelling of magnetic resonance imaging.

We report a patient with a traumatic middle cerebral artery dissection, which showed hyperperfusion in the territory supplied by the left middle cerebral artery. A 45-year-old man experienced speech disturbance and motor weakness in his right hemibody on the day following mild head trauma. His symptoms worsened on the fourth day. Magnetic resonance imaging showed narrowing in the left M1 portion of the middle cerebral artery. Angiography showed narrowing and dilatation in the left middle cerebral artery trunk. The lesion was diagnosed as a dissection of the middle cerebral artery. Arterial spin labelling of magnetic resonance imaging and single photon emission computed tomography showed increased cerebral blood flow in the left temporal region compared with the right. The patient was treated conservatively and the symptoms gradually improved. The hyperperfusion observed on arterial spin labelling and single photon emission computed tomography gradually improved and disappeared on the 25th day. This is the first reported case of traumatic middle cerebral artery dissection, which showed post-ischaemic hyperperfusion in the territory of the affected artery. To detect hyperperfusion in the brain, arterial spin labelling is a useful technique.

Cavernous Sinus Dural Arteriovenous Fistula Patients Presenting With Headache as an Initial Symptom.

Cavernous sinus (CS) dural arteriovenous fistula (dAVF) patients presenting with only headache as an initial symptom are not common. Patients with CS-dAVF commonly present with symptoms related to their eyes. In all three patients, headache was the initial symptom. Other symptoms related to the eyes developed 1 - 7 months after headache. In one patient, headache was controlled by sumatriptan succinate, but not diclofenac sodium or loxoprofen sodium. In another patient, headache was controlled by loxoprofen sodium. In the third patient, headache was improved by stellate ganglion block. In all patients, magnetic resonance angiography (MRA) in the early stage of the clinical course showed abnormal blood flow in the CS. However, reflux to the superior ophthalmic vein (SOV) was not detected. As treatment, transarterial and transvenous embolizations were necessary for one patient, and transvenous embolization was performed for another patient with significant blood flow to the SOV and cortical veins. On the other hand, manual compression of the bilateral carotid arteries at the neck resulted in disappearance of the fistula in the third patient. In all patients, the symptoms improved after the disappearance of blood reflux to the CS. The refluxed blood to the CS might cause elevation of the CS pressure and stimulate the trigeminal nerve in the dural membrane, resulting in headache before developing reflux in an anterior direction. CS-dAVF could induce both migraine and common headache. In cases with blood reflux to the CS on magnetic resonance imaging and/or MRA even without eye symptoms, a differential diagnosis of CS-dAVF should be taken into consideration.

Intraparenchymal hemorrhage from dural metastasis of breast cancer mimicking meningioma.

Intraparenchymal hemorrhage from dural metastasis of breast cancer is rare. A 54-year-old woman without a significant medical history showed altered consciousness and left hemiparesis. Radiological examination revealed an extra-axial mass in the right middle fossa with intraparenchymal hemorrhage and another mass invading the skull in the right parietal region. The pre-operative diagnosis was a sphenoid ridge meningioma presenting with intraparenchymal hemorrhage and another meningioma in the convexity. The tumors and hematoma were removed. Pathological findings of the tumors were compatible with adenocarcinoma. Systemic examination revealed breast cancer with metastasis to the spine. Although the radiological findings were similar to those of meningioma, a differential diagnosis of metastatic brain tumor with intraparenchymal hemorrhage should be taken into consideration.

Subarachnoid and intracerebral hemorrhage from intracranial hemangiopericytoma: An uncommon cause of intracranial hemorrhage.

BACKGROUND: Hemorrhage from an intracranial tumor is well known but uncommon. In cases of subarachnoid hemorrhage, aneurysm rupture is a main cause. CASE DESCRIPTION: A 64-year-old woman presented with sudden-onset motor aphasia. Computed tomography revealed subarachnoid hemorrhage, and intracerebral hemorrhage in the left temporal lobe. From the findings of pre-enhancement computed tomography, hemorrhage from a left middle cerebral artery aneurysm was initially suspected. Further radiological examinations demonstrated an enhanced mass with dural attachment in the left temporal region, but no vascular abnormality. Emergency craniotomy was performed, and the tumor and intracerebral hematoma were removed. The hemorrhage from fragile tumor vessels may destroy the tumor tissue and spread into the temporal lobe and subarachnoid space. Pathological examination of the tumor yielded findings consistent with hemangiopericytoma. Post-operatively, the patient was treated to prevent vasospasm. CONCLUSION: Although an intracranial tumor including hemangiopericytoma uncommonly causes subarachnoid hemorrhage, it should be taken into consideration as a source of intracranial hemorrhage.

Pseudoaneurysm Formation in Intracerebral Hematoma due to Ruptured Middle Cerebral Artery Aneurysm.

We report the case of a ruptured middle cerebral artery aneurysm that showed pseudoaneurysm formation in an intracerebral hematoma. A 61-year-old man who was taking warfarin complained of dysarthria. Three days later, he was found unconscious, and computed tomography on admission showed subarachnoid hemorrhage and an intracerebral hematoma in the left temporal lobe. Three-dimensional computed tomographic angiography showed an irregular-shaped aneurysm-like cavity extending from the left middle cerebral artery into the hematoma. Intraoperative observation revealed that the aneurysm itself was small and the lesion observed on computed tomography was a pseudoaneurysm that had formed in the hematoma. Pathologic examination of the aneurysm demonstrated that there was a thrombus at its tip. In this report, radiologic characteristics of three-dimensional computed tomographic angiography and etiology of a pseudoaneurysm in an intracerebral hematoma due to aneurysm rupture are discussed.

Isolated index finger palsy due to cortical infarction.

The case of an 86-year-old man presenting with isolated left index finger palsy caused by infarction on the lateral side of the right precentral knob is presented. Embolization from aortic atheroma was considered the cause of infarction. Cases with selective palsy of a particular group of fingers without sensory deficits due to cortical infarction of the precentral knob have been reported by several authors, and predominant weakness of radial-side fingers is known to be usually caused by laterally located infarction of the precentral knob. Among the previous reports, only 1 case involved isolated index finger palsy by an atypical, medially located infarction of the precentral knob in association with a concurrent nonrelated lesion. This is the first reported isolated index finger palsy caused by a single lateral precentral knob infarction.