To provide for the progressively aging society in Japan, a governmental act promoting reorganization to establish sustainable social security systems has been enforced since April 2017. Long before this act was promulgated, the number of individuals transported by ambulance had been gradually increasing, and in recent years the elderly (aged ≥ 75 years) have accounted for approx. 40% of all individuals taken to a hospital by ambulance in Japan. It is likely that most of those individuals are receiving long‒term nursing care in their own homes or institutions and may request that an ambulance be dispatched due to aspiration pneumonia, exacerbation of chronic heart failure and so on, resulting in repeated uses of ambulance services. In light of this, the role of the country’s emergency medical service system could be regarded as an integral factor in the process of long‒term nursing care.

  In disasters such as floods and earthquakes, the proportion of victims aged ≥ 65 years among the dead or missing has been rising year by year. This rate of increase is far higher than the increase in the aging of Japan’s rapidly graying society. Strategies for dealing with natural disasters in our country thus ought to focus on senior evacuees who are already receiving or need daily nursing care and social support. The relatively large‒scale regional core hospitals in Japan should take the initiative in devising and carrying out plans for healthcare disaster resilience in their respective medical care zones. The accreditation of the hospitals for this purpose by the Joint Commission will provide a powerful incentive to contribute to regional healthcare coalitions and to regional healthcare disaster resilience. The emergency medical function — especially in large hospitals — will be a great help to establishing the framework of healthcare disaster resilience throughout Japan.

  In parallel with Japan’s ultra‒aging society, traffic accidents involving aged drivers with impaired cognitive function have been becoming more common. Our institute has attempted to determine whether individuals with neurological impairment have sufficient ability to drive a vehicle safely. The Trial Making Test‒A and B (TMT‒A/B) and the Stroke Drivers Screening Assessment (SDSA) have been described as reliable evaluation methods for stroke patients. Here, we assessed the driving ability of 141 patients by the SDSA, TMT‒A and B, and the Hasegawa Dementia Scale‒Revised (HDS‒R) in conjunction with their age, sex, laterality of lesion, disease subtype (including stroke divided into its ischemic vs. hemorrhagic), head trauma, and other diseases. The patients were 100 males and 41 females, mean age 67.1 years. Ninety‒six patients (68.1%) cleared. Of the 119 stroke patients (84.4%), 83 had ischemic and 36 had hemorrhagic subtypes. A univariate analysis including age, HDS‒R, and TMT‒A and B scores revealed that these factors significantly affected SDSA success, and the subsequent multivariate analysis identified TMT‒B as the only significant factor. There was no significant relationship between SDSA success and sex, lesion laterality, or disease subtype. Physicians who treat patients with neurological impairment should aggressively assess their patients’ driving ability. However, in rural areas in which individuals are car‒dependent, a stereotypic driving ability assessment might be difficult. Efforts to ensure the safe driving ability of patients should be based on medical care but also on social and legal interventions on a region‒wide or nationwide basis.

  Although the prognosis of brain abscesses has improved recently, it remains a high‒mortality disease that can lead to severe sequelae. Standard treatment has not been established, and challenges include the selection of antibiotics, indications for surgery, and standardization of surgical procedures. We enrolled patients treated at two general hospitals for a brain abscess between April 2014 and March 2021 and divided them by outcome: the good (modified Rankin Scale [mRS]: 0‒2) and poor (mRS: 3‒6) outcome groups. We retrospectively reviewed clinical features and outcomes and investigated risk factors associated with poor outcomes. Twenty patients’ cases were evaluated: mean age 66.7 ± 15.8 (range, 40‒87) years; 15 males, five females. Fourteen patients (70%) underwent surgery, and the other six were treated with antibiotics without surgery. The causative organisms were identified in 15 patients (75%). Dental and oral infections accounted for most of the presumed causative diseases. Our analyses revealed the following as risk factors associated with poor outcome: a past medical history of cerebrovascular disease, moderate or higher disturbance of consciousness on admission, and complications of ventriculitis. The following were not associated with poor outcome: age, pre‒onset mRS, fever as an initial symptom, white blood cell count and C‒reactive protein levels before treatment, the abscess diameter and location, complications of cerebral herniation and subdural abscess, identification rate of the causative organism, duration of antibiotics, and epilepsy complications. The causative organisms were confirmed in all cases in the early‒surgery patients (who underwent surgery ≤ 72 h after the administration of antibiotics), although this difference between them and the other patients was nonsignificant. Aggressive aspiration can be considered for patients with severe consciousness disturbance and/or high risk of ventriculitis, and it is important to manage the underlying disease and begin rehabilitation from the early hospitalization stage. Since cerebral abscesses caused by dental/oral infections have tended to increase in number in Japan, it is essential to select antibiotics that are sensitive to anaerobic bacteria in empirical antibiotic therapy. The appropriate empirical antibiotic therapy may reduce the sensitivity of causative organisms in surgical specimens, but it should not be expected to have an effect when early surgery is performed.

  The first author (G. Fujiwara) had the precious opportunity to study at the Trauma Center of Khon Kaen Hospital in Thailand for a short period of time. In Japan, the number of trauma cases including neurotrauma has been decreasing in recent years due to the development of automotive engineering, motorcycle helmet use, and stricter penalties for drunk driving. Dr. Fujiwara was the first Japanese trainee at the Center to receive training in neurotrauma, and he observed more than 100 cases of neurotrauma and participated in 12 emergency surgeries during a one‒month training. We believe that this training is useful for young neurosurgeons in Japan, where the number of neurotrauma cases is decreasing.

  We report the case of a 73‒year‒old woman with a history of hepatitis C who experienced a sudden occipital headache. The patient arrived at our hospital by ambulance. Head computed tomography revealed a subarachnoid hemorrhage and a left internal carotid‒posterior communicating artery bifurcation aneurysm. Hence, craniotomy aneurysm clipping was performed.

  Hematemesis due to the rupture of esophageal varices occurred during antithrombotic therapy for cerebral vasospasm on Day 8. Additionally, on Day 10, the patient suffered impaired consciousness and left hemiplegia due to right internal carotid artery stenosis.

  On day 11, the patient underwent carotid endarterectomy, followed by endoscopic injection sclerotherapy on Day 32. Six months later, the patient was discharged with a modified Rankin Scale score of 2. No recurrence of esophageal varices had been noted four years later.

  Cirrhosis has been associated with aneurysmal subarachnoid hemorrhages. Gastrointestinal bleeding, including bleeding due to ruptured esophagogastric varices, may occur during antithrombotic therapy. While treating stroke patients with a history of cirrhosis, neurosurgeons should collaborate with hepatologists and specialists in hemorrhage management.

  We report three consecutive cases of severe cerebral venous sinus thrombosis treated with an endovascular mechanical thrombectomy using a stent retriever and an aspiration catheter. (1) A 76‒year‒old man presented with headache and left hemiparesis and subsequently developed status epilepticus. (2) A 57‒year‒old woman presented with impaired consciousness. (3) A 30‒year‒old man presented with headache and progressive deterioration of consciousness. In all three cases, diagnostic imaging revealed thrombosis of multiple cerebral venous sinuses, including the superior sagittal sinus and bilateral transverse sinuses. After an endovascular mechanical thrombectomy with a stent retriever, all three patients recovered without severe neurological deficits. Endovascular mechanical thrombectomy is an effective method for achieving early recanalization and thus improving the clinical and radiological outcomes of patients with severe cerebral venous sinus thrombosis. Although the accumulation of more cases is needed, a stent retriever and an aspiration catheter appear to be safe and effective devices for endovascular thrombectomy.

  There are limited reports of pituitary apoplexy showing a fulminant clinical course. A 38‒year‒old Japanese woman was admitted to the emergency room 4 hr after suddenly developing a headache. She had recently noticed changes in her facial appearance and that her ring and shoe sizes had increased. She presented no neurological symptoms and was diagnosed with pituitary apoplexy based on computed tomography (CT) and magnetic resonance imaging (MRI) findings. Based on her basal levels of pituitary hormones and the results of the pituitary stimulation test, we suspected a growth hormone (GH)‒producing pituitary adenoma. She exhibited left abducens nerve palsy 20 hr after disease onset, followed by mild disturbance of consciousness and a high fever of 39.9° at 27 hr and 30 hr post‒disease onset, respectively. After neurological worsening was confirmed, transsphenoidal surgery was performed at 37 hr after onset. Poor arousal and dilated pupils were noted immediately after surgery. CT showed no intracranial hemorrhage, but the entire brain was markedly swollen. Contrast‒enhanced CT scans were performed to examine cerebral circulation: poor intracranial filling was observed. We considered cytokine storms induced by the release of cytokines from tumor necrotic tissues as a possible cause and thus measured serum interleukin (IL)‒4, ‒6, ‒8, ‒10, and tumor necrosis factor‒α levels. The serum IL‒6 level was abnormally high (257 pg/mL), but the IL‒6 level in the resected tissue was nearly 30 times higher (7660 pg/g tissue). We speculated that the abnormally high IL‒6 level was caused by tumor necrosis. We further postulate that a large number of cytokines released from tumor necrotic tissues into the basal cistern may have induced a severe vasospasm and subsequent acute brain swelling.

  Pseudoaneurysms of the middle meningeal artery (PMMAs) are rare and usually present an epidural hematoma. We report an extremely rare case of PMMA that developed a delayed intracerebral hematoma (ICH). The 94‒year‒old Japanese male patient, who had been in a traffic accident, recovered well after the conservative therapy, but on the 12th day after his admission, he suddenly deteriorated with loss of consciousness and anisocoria. Head CT demonstrated an ICH in the right temporal lobe with intraventricular hemorrhage. CT angiography revealed an aneurysm of the MMA underneath the temporal bone fracture. He underwent an emergency craniotomy for the removal of the ICH. The intraoperative and pathological findings were consistent with PMMA. We have identified only five prior cases of delayed ICH caused by a PMMA. Most of the prior PMMAs are associated with an ipsilateral temporal rim fracture. Clinicians should be aware PMMA is one of the causes of delayed ICH after head trauma.

  Parasellar lesions such as pituitary adenoma and craniopharyngioma may present with obstructive hydrocephalus due to tumors inside the third ventricle, and urgent treatment for acute hydrocephalus is required when the neurological symptoms worsen rapidly. In the treatment of acute hydrocephalus and tumor removal, it is essential that the chosen strategy be based on the patient’s condition and the nature of the tumor or, in the case of emergency surgery, based on factors such as the specialized neurosurgeons and instruments that the hospital can provide. We report 6 cases of parasellar tumors that required treatment for acute hydrocephalus. In two cases of pediatric craniopharyngioma, the third ventricular tumor at the obstruction site was partially removed in emergency surgery to palliatively resolve hydrocephalus, and radical tumor removal was then performed several months later. In 3 patients with adult craniopharyngioma, infantile immature teratoma, and pituitary adenoma with a third ventricular lesion, emergency surgery for hydrocephalus was performed solely with the placement of ventricular drainage or an Ommaya reservoir, and radical tumor removal was performed a few days later. Instead of emergency hydrocephalus surgery, one patient with pituitary adenoma presenting with progressive obstructive hydrocephalus underwent early endonasal surgery to treat the hydrocephalus and the tumor in a single stage. In the case of pediatric craniopharyngioma, the relief of acute hydrocephalus may improve nutritional status, helping the patient to gain weight, and contribute to the growth of the craniofacial structure. It may therefore be possible to wait for several months for extended endonasal surgery, which is a radical operation. Pituitary adenomas that extend to the third ventricle, unlike normal cases, directly invade the subarachnoid space beyond the diaphragm and are often prone to bleeding, making surgery difficult. Care must be taken as the superior hypophyseal artery distributing the optic chiasm runs within the tumor. Although acute hydrocephalus with parasellar tumors is rare, it is known to occur. It is important to select the appropriate surgical procedure in consideration of the nature of the tumor and the overall treatment plan.

  Favorable outcomes have recently been reported regarding coil embolization for acute cerebral aneurysms, even in cases of severe subarachnoid hemorrhage in older adults. Several reports have demonstrated that neuroendoscopic hematoma evacuation is better than ventricular drainage alone in patients with massive intraventricular hemorrhaging. In the present older adult patient with a casting intraventricular hematoma, we performed a combined treatment of cerebral aneurysm coil embolization and neuroendoscopic hematoma evacuation for acute severe subarachnoid hemorrhage, which has a particularly poor prognosis. Aggressive treatment is often avoided in older adult patients due to the risks posed by surgical invasiveness and disease severity. There are only a few reports of surgery for managing similar cases, and those reports identified the safety of the surgical procedures as an area of concern.

  Spontaneous intracranial hypotension (SIH) is often associated with chronic subdural hematoma (CSDH). We report two cases of CSDH with a small amount of hematoma, which was not an indication for burr hole drainage; however, each case was assessed as requiring urgent imaging and received an epidural blood patch (EBP). Case 1 was a 66‒year‒old Japanese man who visited our hospital with a complaint of orthostatic headache. Head computed tomography (CT) showed disappearance of the basilar cistern, and an EBP was successfully applied to improve this condition. Case 2 was a 40‒year‒old Japanese man who also complained of an orthostatic headache. Head CT showed downward deviation of the cerebellar tonsil, and an EBP was successfully applied to improve this condition. These cases indicate that an EBP for patients with CSDH combined with SIH is a useful treatment that can improve symptoms while avoiding complications of burr hole drainage when the amount of hematoma is small.

  We report a case of ruptured vertebral artery dissecting aneurysm (VADA) involving the origin of the posterior inferior cerebellar artery (PICA) that was treated by short segment internal trapping. A 66‒year‒old woman presented with headache and disturbed consciousness. Her Computed Tomography (CT) scan of the brain revealed a subarachnoid hemorrhage and angiogram revealed left VADA involving the PICA. Endovascular internal trapping of the enlarged distal VADA was performed and the ruptured VADA was treated by short segment occlusion using coil embolization, while the PICA was preserved. After 4 weeks, follow‒up angiography revealed dilatation of the left vertebral artery, located at the proximal end of the dissection. The patient was managed conservatively. Follow‒up angiography at 9 weeks showed complete resolution of the left vertebral artery dilatation. She had an uneventful clinical course. In conclusion, short segment internal trapping can be used to treat ruptured VADA involving the PICA.