The mobile stroke unit (MSU) was developed for rapid initiation of stroke treatment, and it operates mainly in the United States and European countries. An MSU is a specialized ambulance equipped with a small X-ray computed tomography (CT) scanner and telemedicine system, enabling the diagnosis and treatment of patients at emergency sites or rendezvous points with a standard ambulance and subsequent triaging to optimal hospitals. In treatments with recombinant tissue plasminogen activator for ischemic stroke patients, prospective multicenter trials in the United States and Germany reported that compared with standard ambulances, MSUs produced significantly better outcomes. Similarly, increased cost-effectiveness of treatment on MSUs was reported in recent studies. However, in Japan, the MSU has not yet been introduced because available CT scanners remain unapproved. Following approval, the problem of the expensive introductory and operating costs of MSU must be addressed, especially in underserved rural and remote regions. For this solution, small, light, cheap, and low-output diagnostic head scanners have been developed using recent technology of X-ray tomosynthesis or microwave electromagnetic imaging. These devices can be easily equipped on both standard ambulances and MSUs or on airplanes or helicopters as air-MSUs. In this review, we focus on providing an overview of the current progress and challenges of MSUs, and discussing the potential utility of on-board diagnostic imaging devices that have been recently developed or tested.

Objective: To review the treatment of cervical internal carotid artery dissection resulting in intracranial large vessel occlusion. Methods: Two hundred and ninety patients who underwent mechanical thrombectomy at our hospital from April 2015 to March 2022 were included. The diagnosis was comprehensive, including clinical symptoms and imaging findings. Initial symptoms, neurological findings, images, treatments, and outcomes were collected retrospectively. Results: The study included five patients (2%) with cervical internal carotid artery dissection. The mean age of the patients was 47 years, accounting for 26% (4/19) among those under 55 years. Only two of the five patients presented with head or neck pain. For cervical internal carotid artery dissection, three patients underwent percutaneous transluminal angioplasty. Of these three patients, one patient underwent parent artery occlusion and another underwent carotid artery stenting one month later. The other two patients were treated conservatively for internal carotid artery dissection. All patients showed improved symptoms after treatment. Conclusion: Internal carotid artery dissection is a common cause of severe stroke in young patients, even in the absence of pain. Mechanical thrombectomy is effective in the treatment of intracranial large vessel occlusion due to cervical internal carotid artery dissection. Good outcomes were achieved in this study with individualized case-specific treatment.

Brain infarction associated with subclavian artery stenosis is rare. We report the clinical condition and endovascular treatment of a case of subclavian artery stenosis with repeated posterior circulation infarction. A 65-year-old man was admitted for bilateral cerebellar infarction. The patient was initially treated with antithrombotic drugs for embolic stroke of an undetermined source, but he developed recurrent posterior circulation embolism four times over the previous 2 months. Repeated examination revealed right subclavian artery stenosis, which was considered to be the source of the embolism because of an absence of other possible causes. We performed stenting for the stenosis. For this case, we deployed protection devices in the right common carotid artery and the right vertebral artery in order to mitigate the risk of distal embolism via the vessels adjacent to the lesion during the percutaneous transluminal angioplasty and stenting procedure. At the 2-year follow-up, no restenosis or reccurent infarction was observed. Although it is a rare condition, subclavian artery stenosis should be considered as a source of embolism when surveying cryptogenic stroke etiology. Distal protection is effective to avoid complications in endovascular treatment for right subclavian artery stenosis.

A 43-year-old woman suffered from cardiopulmonary arrest due to ventricular fibrillation during a business meeting at our hospital, but spontaneous circulation was restored with the use of a direct current defibrillator. Her left ventricular ejection fraction decreased to 30%, but no significant coronary artery stenosis was observed. Due to significant decline in left ventricular function and acute heart failure, an intra-aortic balloon pump (IABP) was inserted into the descending thoracic aorta via the right femoral artery to initiate assisted circulation. A CT scan of the head led to the diagnosis of severe subarachnoid hemorrhage caused by a ruptured cerebral aneurysm, and cardiac dysfunction associated with Takotsubo cardiomyopathy was determined. With the use of IABP, her hemodynamics stabilized, and a ventricular drain was inserted to control intracranial pressure. The left internal carotid artery aneurysm was embolized from the right brachial artery via the aortic arch in a manner that did not interfere with the IABP. Improvements in cardiac function were observed over time, resulting in removal of IABP on day 3 of onset and good outcome. Even when IABP is used to stabilize hemodynamics of patients with severe subarachnoid hemorrhage, early intracranial pressure control and aneurysm treatment to prevent rerupture may lead to good outcome, unless the initial CT scan shows critical brain damage.

Heparin is an essential drug that is widely used during endovascular treatment. A serious adverse reaction to this drug is heparin-induced thrombocytopenia (HIT), which is characterized by thrombocytopenia and a high risk of thrombosis. However, reports of HIT during neurointerventional surgery have been limited. Herein, we report a case of acute multiple cerebral thromboses due to HIT during coil embolization for a cerebral aneurysm. The patient was a 52-year-old woman with a left basilar artery–superior cerebellar artery (SCA) aneurysm. Coil embolization was performed with a balloon-assisted technique. After coil insertion, the final angiography showed occlusion of the right anterior inferior cerebellar artery and thrombi in the right SCA and left posterior cerebral artery. Once we suspected HIT, we immediately discontinued heparin and administered argatroban. However, multiple cerebral infarctions were detected by postoperative magnetic resonance imaging. Since delayed recognition and treatment of HIT could cause critical damage, we should be aware of the risk of HIT and begin treatment for HIT when performing an endovascular procedure.

A healthy 27-year-old man was admitted to our hospital because of fever and a generalized convulsion. He was diagnosed with moderate I COVID-19 by rapid antigen testing, followed by mild pneumonia in the peripheral area of both lungs on chest computed tomography. Although his symptoms worsened to moderate II severity after admission, they were alleviated by dexamethasone. He was subsequently discharged from the hospital. However, two days following discharge, i.e., 20 days after the disease onset, he was rushed to the emergency room for mild left hemiparesis. He was rehospitalized with a diagnosis of infarction in the right middle cerebral artery territory and thrombosis of the left sigmoid sinus. Other than a slightly elevated D-dimer level of 1.32 µg/ml (<1.0 µg/ml), no other coagulation system abnormalities or risk factors for thrombosis were evident. Based on the longitudinal changes on brain magnetic resonance imaging after admission, the infarction was attributed to arterial dissection. The patient was treated conservatively with anticoagulation and antihypertensive management because the infarction was completed before the readmission. Following the treatment, he was discharged without neurological deficits. To the best of our knowledge, this is the first report of a case of COVID-19 that presented simultaneously with concomitant cerebrovascular disorders having different mechanisms, arterial dissection, and sinus thrombosis.

A 43-year-old woman was presented to our hospital with headache and difficulties in writing, speech and listening comprehension that had started one day earlier. A CT scan showed a high-density area in the subcortical region and adjacent cortical vessels in the parietal lobe. T2* images showed linear structures of low-intensity signal in the same area. MRV scan showed poor delineation of the left parietal cortical vein, and the diagnosis of subcortical hemorrhage due to cerebral venous thrombosis was made. Blood tests and body CT revealed iron-deficiency anemia and myoma uteri of 8 cm in diameter, respectively. Neither deficiency in protein S/C or antithrombin 3, nor antiphospholipid antibodies was found. Antihypertensive therapy and anti-edema therapy for cerebral hemorrhage, iron supplementation therapy for anemia on the second day, and anticoagulation therapy on the third day were initiated. Thereafter, the symptoms gradually improved but the right lower quarter blindness, mild sensory aphasia, and agraphia remained. She was transferred to the hospital for rehabilitation on the 20th day. In cases of cerebral hemorrhage with iron-deficiency anemia, venous thrombosis should be considered.

Intravascular large B-cell lymphoma (IVLBCL) is a disease in which lymphoma proliferates within vessels and is characterized by anemia, hypoalbuminemia, and high levels of serum lactate dehydrogenase. We experienced a case of IVLBCL that was difficult to diagnose because cerebral infarctions preceded these symptoms. A 65-year-old man was admitted to our hospital due to dizziness. Head magnetic resonance imaging showed new infarctions in multiple areas. Transesophageal echocardiography revealed a thrombus in the auricle of the left atrium, and we started anticoagulation therapy. However, he had relapses of cerebral infarctions. During the course of the disease, a slight fever appeared, and anemia, hypoalbuminemia, and high levels of serum lactate dehydrogenase and soluble interleukin-2 receptors were observed. We performed a random skin biopsy and diagnosed IVLBCL. He was treated with chemotherapy, but he died three years later. In this case, a thrombus in the auricle of his left atrium made distinguishing IVLBCL from cardiogenic cerebral embolism difficult until he showed systemic symptoms. IVLBCL should be considered when relapses of cerebral infarction occur within a short period of time while on anticoagulation therapy.

We describe a case of infective endocarditis (IE) caused by Lactobacillus rhamnosus. A 34-year-old man without any basic disease complained of headache, and left intracranial hemorrhage was pointed out with a CT scan. After admission, his blood cultures proved Lactobacillus rhamnosus, and vegetations on the aortic valve were detected in the transthoracic echocardiography. He was diagnosed with infective endocarditis, and intracranial hemorrhage was extrapolated from the rupture of intracranial mycotic aneurysms. He had eaten over ten times larger amount of yogurt than that of recommended, and this consumption was thought to be the cause of Lactobacillus bacteremia. Antibiotic therapy was administered, but new right intracranial hemorrhage was detected during hospitalization. Contrast-enhanced CT revealed an aneurysm in the hemorrhage. The mycotic aneurysm had gradually grown, so a trapping of the aneurysm was performed at 21 days after admission. Aortic valve replacement was performed at 33 days after admission. Persisted fine motor deficit and higher brain dysfunctions remained; he changed the hospital for continuing rehabilitation. Lactobacillus rhamnosus are broadly available as probiotic products, and there are a few case reports about IE by Lactobacillus rhamnosus caused by excessive consumption of yogurt. We should keep in mind that such excess intake of yogurt-related products may cause IE and detailed questions about medical history may help us to diagnose.