[Surgical Simulation Using a Three-Dimensional Printer].

3D printers have been applied in bone-based surgeries, including craniofacial, plastic, oral, and orthopedic surgeries. The improved capabilities of diagnostic imaging equipment and 3D printers have enabled the development of more precise models, and research on surgical simulations and training in the field of neurosurgery is increasing. This review outlines the use of 3D printers in neurosurgery at our institution in terms of modeling methods and surgical simulations. Modeling with the powder-sticking lamination method using plaster as the material allows drilling, which is a surgical procedure. Therefore, it is useful for simulating skull base tumors, such as petrosectomy in a combined transpetrosal approach or anterior clinoidectomy in an orbitozygomatic approach. The color coding of each part of the model facilitates anatomical understanding, and meshed tumor modeling allows deep translucency. As shown above, the 3D printer's modeling ingenuity allows for useful surgical simulations for each case.

Metastasis infiltrating tumor to meningioma: a case report.

BACKGROUND: There have been many reports of tumor-to-tumor metastasis, in which cancer metastasizes directly into meningiomas. However, metastasis infiltrating tumors in which cancer metastasizes around meningiomas are rare. Therefore, we report a case of metastasis originating from lung cancer that infiltrated meningioma. CASE PRESENTATION: A 79-year-old Japanese woman underwent head magnetic resonance imaging for brain metastasis screening before lung cancer surgery. At that time, asymptomatic meningioma of the left frontal region was accidentally found. Magnetic resonance imaging 6 months later revealed a lesion suspected to be a metastatic brain tumor close to the meningioma. Brain tumor resection was performed, and histopathological diagnosis was meningioma and metastatic brain tumor. Metastatic cancer had invaded the meningioma at the boundary between the brain tumor and metastasis. CONCLUSIONS: A sudden change in imaging findings on routine examination of meningiomas in patients with lung carcinoma may indicate a metastatic brain tumor. The form of cancer metastasis to meningioma is not limited to tumor-to-tumor metastasis, but also includes metastasis infiltrating tumors near the meningioma.

Local and systemic factors associated with quantitative stiffness of carotid plaque.

PURPOSE: Plaque stiffness in carotid artery stenosis is a clinically important factor involved in the development of stroke and surgical complications. The purpose of this study was to clarify which local and systemic factors are associated with the quantitatively measured stiffness of plaque. METHODS: The subjects were 104 consecutive patients who underwent carotid endarterectomy at our institution. To measure quantitative stiffness of plaque, we used an industrial hard meter in the operating room within 1 h after removal of plaque. Local factors related to carotid plaque hardness were evaluated, including maximum intima-media thickness (max IMT), degree of stenosis using the European Carotid Surgery Trial (ECST), presence of ulceration or calcification, and echo brightness on preoperative carotid ultrasound. The degree of stenosis was also evaluated using the North American Symptomatic Carotid Endarterectomy Trial method in digital subtraction angiography. Age, sex, and presence or absence of hypertension, diabetes, and dyslipidemia (low-density lipoprotein cholesterol and triglyceride [TG] levels) served as systemic factors and were compared with the quantitative stiffness of carotid plaque. RESULTS: In multivariate analysis, ECST stenosis degree, calcification, and IMT max as local factors affected plaque stiffness. As a systemic factor, plaque stiffness was statistically significantly negatively correlated with TG values in multivariate analysis (p < 0.05). CONCLUSION: The quantitative stiffness of the plaque was negatively correlated with TG levels as a systemic factor in addition to local factors. This might suggest that reducing high TG levels is associated with plaque stabilization.

Differentiation between Anterior and Posterior Roots Using Compound Muscle Action Potential in Intradural Extramedullary Spinal Tumor Surgery.

This study aims to determine the cutoff values for the compound muscle action potential (CMAP) stimulus in anatomically identified anterior (motor nerve) and posterior roots (sensory nerve) during cervical intradural extramedullary tumor surgery. The connection between CMAP data from nerve roots and postoperative neurological symptoms in thoracolumbar tumors was compared with data from cervical lesions. The participants of the study included 22 patients with intradural extramedullary spinal tumors (116 nerve roots). The lowest stimulation intensity to the nerve root at which muscle contraction occurs was defined as the minimal activation intensity (MAI) in the CMAP. In cervical tumors, the MAI was measured after differentiating between the anterior and posterior roots based on the anatomical placement of the dentate ligament and nerve roots. The MAIs for 20 anterior roots in eight cervical tumors were between 0.1 and 0.3 mA, whereas those for 19 posterior roots were between 0.4 and 2.0 mA. The cutoff was <0.4 mA for both the anterior and posterior roots, and sensitivity and specificity were both 100%. In thoracolumbar tumors, the nerve root was severed in 12 of 14 cases. All MAIs were determined to be at the dorsal roots as their scores were higher than the cutoff and did not indicate motor deficits. The MAIs of the anatomically identified anterior and posterior root CMAPs were found to have a cutoff value of <0.4 mA in the cervical lesions. Similar MAI cutoffs were also applicable to thoracolumbar lesions. Thus, CMAP may be useful in detecting anterior and posterior roots in spinal tumor surgery.

Relationship Between Quantitative Tumor Consistency and Pathological Factors in Intracranial Meningioma.

BACKGROUND: The consistency of intracranial meningiomas is an important clinical factor because it affects the success of surgical resection. This study aimed at identifying and quantitatively measuring pathological factors that contribute to the consistency of meningiomas. Furthermore, we investigated the relationship between these factors and preoperative neuroradiological imaging. METHODS: We analyzed 42 intracranial meningioma specimens, which had been removed at our institution between October 2012 and March 2018. Consistency was measured quantitatively after resection using an industrial stiffness meter. For pathological evaluation, we quantitatively measured the collagen-fiber content through binarization of images of Azan-Mallory-stained section. We assessed calcification and necrosis semi-quantitatively using images acquired of Hematoxylin and Eosin stained samples. The relationship between collagen-fiber content rate and imaging findings was examined. RESULTS: The content of collagen fibers significantly positively correlated with meningioma consistency (p < 0.0001). Collagen-fiber content was significantly higher in low- and iso-intensity regions compared with high-intensity regions on the magnetic resonance T2-weighted images (p = 0.0148 and p = 0.0394, respectively). Calcification and necrosis showed no correlation with tumor consistency. CONCLUSIONS: The quantitative hardness of intracranial meningiomas positively correlated with collagen-fiber content; thus, the amount of collagen fibers may be a factor that determines the hardness of intracranial meningiomas. Our results demonstrate that T2-weighted images reflect the collagen-fiber content and are useful for estimating tumor consistency preoperatively and non-invasively.

A Case of Lateral Ventricular Subependymoma with Intratumoral Hemorrhage via Neuroendoscopic Surgery.

Subependymoma (SE) is a rare, usually asymptomatic, brain tumor predominantly affecting older adults and occurring in the fourth and lateral ventricles. We report a rare case of SE with intratumoral hemorrhage that could be removed by neuroendoscopy. The 81-year-old patient had been followed as an outpatient for 10 years due to an intraventricular tumor. It did not grow over the patient's lengthy follow-up. The patient was transferred to our hospital after he fainted near his home; at the time of admission, he had mild consciousness disturbance, and his Glasgow Coma Scale score was 10 points (E3V3M4). Computed tomography showed intratumoral hemorrhage and slight ventricular enlargement. Magnetic resonance (MR) imaging showed a 4 cm-sized tumor in the anterior horn of the right lateral ventricle. The lesion appeared as a mixed-intensity solid tumor and showed irregular enhancement with gadolinium. The patient underwent neuroendoscopic tumor resection on the 30th day of the patient's hospital stay. A histopathological examination revealed small tumor cells with round nuclei scattered in the glial fibrillary background. Immunostaining was positive for glial fibrillary acidic protein; these findings are consistent with an SE diagnosis. The patient in this study had hypertension and used anticoagulants, risk factors for intratumoral hemorrhage. For intraventricular tumors with bleeding-particularly in older or more physically frail patients-minimally invasive neuroendoscopic surgery should be considered an option for tumor resection.

Quantitative comparison between carotid plaque hardness and histopathological findings: an observational study.

BACKGROUND: Plaque hardness in carotid artery stenosis correlates with cerebral infarction. This study aimed to quantitatively compare plaque hardness with histopathological findings and identify the pathological factors involved in plaque hardness. METHODS: This study included 84 patients (89 lesions) undergoing carotid endarterectomy (CEA) at our institution. Plaque hardness was quantitatively measured immediately after excision using a hardness meter. Collagen and calcification were evaluated as the pathological factors. Collagen was stained with Elastica van Gieson stain, converted to a gray-scale image, and displayed in a 256-step histogram. The median gray-scale median (GSM) was used as the collagen content. The degree of calcification was defined by the hematoxylin-eosin stain as follows: "0:" no calcification, "1:" scattered microcalcification, or "2:" calcification greater than 1 mm or more than 2% of the total calcification. Carotid echocardiographic findings, specifically echoluminance or the brightness of the narrowest lesion of the plaque, classified as hypo-, iso-, or hyper-echoic by comparison with the intima-media complex surrounding the plaque, and clinical data were reviewed. RESULTS: Plaque hardness was significantly negatively correlated with GSM [Spearman's correlation coefficient: -0.7137 (p < 0.0001)]: the harder the plaque, the higher the collagen content. There were significant differences between plaque hardness and degree of calcification between "0" and "2" (p = 0.0206). For plaque hardness and echoluminance (hypo-iso-hyper), significant differences were found between hypo-iso (p = 0.0220), hypo-hyper (p = 0.0006), and iso-hyper (p = 0.0015): the harder the plaque, the higher the luminance. In single regression analysis, GSM, sex, and diabetes mellitus were significant variables, and in multiple regression analysis, only GSM was extracted as a significant variable. CONCLUSIONS: Plaque hardness was associated with a higher amount of collagen, which is the main component of the fibrous cap. Greater plaque hardness was associated with increased plaque stability. The degree of calcification may also be associated with plaque hardness.

A Case of a Ruptured Aneurysm at the Supracallosal Portion (A4-A5) of the Bihemispheric Anterior Cerebral Artery Treated with Endovascular Surgery.

Objective: To report our experience on a rare case of a ruptured aneurysm at the supracallosal portion (A4-A5) of the bihemispheric anterior cerebral artery (ACA), an ACA anomaly, and present that endovascular surgery was a good treatment even for peripheral cerebral aneurysm. Case Presentation: A 53-year-old woman experienced a sudden onset of severe headache and vomiting. Plain CT scan revealed subarachnoid hemorrhage and hematoma in the supracallosal area. Cerebral angiography showed that the left pericallosal artery supplied blood to the bilateral parietal lobes through the bihemispheric artery. A saccular aneurysm was found at the supracallosal portion of the left bihemispheric ACA. Coil embolization of the cerebral aneurysm was performed completely. Conclusion: Several reports have demonstrated an aneurysm with bihemispheric ACA, all treated by neck clipping. In this case, endovascular treatment for intracranial peripheral cerebral aneurysms becomes possible, and treatment indications are said to expand.

The diagnostic value of 123I-IMP SPECT in ocular adnexal lymphoma.

BACKGROUND: N-isopropyl- (123I) p-iodoamphetamine (123I-IMP) is specifically accumulated in primary central nervous system lymphoma (PCNSL) during single-photon emission tomography (SPECT) and contributes to its diagnostic imaging. However, whether 123I-IMP is accumulated in ocular adnexal lymphoma (OAL), one of the malignant intraorbital tumors, remains unclear. This study aimed to evaluate the diagnostic value of 123I-IMP SPECT in OAL. METHODS: Between August 2005 and June 2020, 26 patients with intraorbital tumors underwent neurosurgery at the tertiary care center. Of these, 15 patients who underwent 123I-IMPSPECT before surgery were retrospectively examined. The region of interest was set in the cerebellum ipsilateral to the intraorbital tumor on 123I-IMP SPECT, and the tumor-to-cerebellum ratio (T/C ratio) was calculated using the following formula: T/C ratio = [accumulation of tumor (count/pixel)]/[accumulation of ipsilateral normal cerebellar hemisphere (count/pixel)]. RESULTS: Six patients were included in the OAL group, who were pathologically diagnosed with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), diffuse large B-cell lymphoma (DLBCL), and plasmacytoma. The T/C ratio in the OAL group was statistically higher than that in the non-OAL group (p < 0.01). The optimal cutoff values for both groups were between 0.76 and < 0.93. The sensitivity and specificity were 1.00, respectively. CONCLUSIONS: 123I-IMP SPECT is useful as one of the examinations in the differential diagnoses of OAL, because it showed a significantly higher accumulation in OAL group than in non-OAL group.

Repeated intracranial empyema following cranioplasty in a patient with atopic dermatitis: a case report.

BACKGROUND: Atopic dermatitis is a chronic inflammatory skin disease associated with pruritus. Skin affected by atopic dermatitis not only shows a high percentage of Staphylococcus aureus colonization, but corneal barrier dysfunction is also known to occur. It is considered a risk factor for bacterial infections in various areas of the body. However, the relationship between atopic dermatitis and bacterial infection following neurological surgery has not yet been reported. Here, we present a case of atopic dermatitis in which the surgical site became infected twice and finally resolved only after the atopic dermatitis was treated. CASE PRESENTATION: A 50-year-old Japanese woman with atopic dermatitis underwent cerebral aneurysm clipping to prevent impending rupture. Postoperatively, she developed repeated epidural empyema following titanium cranioplasty. As a result of atopic dermatitis treatment with oral antiallergy medicines and external heparinoids, postoperative infection was suppressed by using an absorbable plastic plate for cranioplasty. The patient's postoperative course was uneventful for 16 months. CONCLUSIONS: Atopic dermatitis is likely to cause surgical-site infection in neurosurgical procedures, and the use of a metal implant could promote the development of surgical-site infection in patients with dermatitis.

Relationship between Preoperative Neuroradiological Findings and Intraoperative Bulbocavernosus Reflex Amplitude in Patients with Intradural Extramedullary Tumors.

The current study aimed to evaluate the relationship between preoperative neuroradiological findings and intraoperative bulbocavernosus reflex (BCR) amplitude in patients with intradural extramedullary tumors. A total of 24 patients with lesions below the 12th thoracic vertebra were included in the analysis. Objective and subjective urinary symptoms were investigated using data obtained from medical records and the core lower urethral symptom score (CLSS) questionnaire. The lesion compression rate was evaluated with MRI. In the epiconus-to-conus medullaris (Epi-CM) group, BCR amplitude changes were found to be correlated with the compression rate (p <0.05). The preoperative CLSS of the group with a BCR amplitude of <50% was worse than that of the group with ≥50% (p <0.01). The group did not experience symptom improvement 6 months postoperatively based on the CLSS. The preoperative CLSS of the group with compression rate of ≥80% on imaging was worse than that of the group with <80% (p <0.05). In the group with preoperative compression rate of ≥80%, CLSS at 1 month and 6 months postoperatively was improved as compared to preoperative CLSS (p <0.01, p <0.05). Hence, BCR amplitude changes are associated with the degree of lesion compression on preoperative images and pre- and postoperative urinary symptoms. Patients with intradural extramedullary Epi-CM lesions with strong compression are likely to present with low BCR amplitude and worsened postoperative symptoms. It is considered that the risk of postoperative urinary symptoms increases even with careful surgical manipulation under these conditions.

[A Case of Mature Teratoma in the Third Ventricle with Holmes Tremor].

Intracranial teratoma is a rare disease that frequently occurs in children and young adults. It comprises of approximately 0.1% of the brain tumors. We report a case of a large mature teratoma in the third ventricle with Holmes tremor. A 5-year-old boy presented with tremors 2 years ago. CT showed a 56×48 mm tumor in the third ventricle and hydrocephalus. The tumor was well demarcated from the surrounding brain tissue and contained calcification. MRI indicated a partially high-intensity signal on T1-weighted and T2-weighted images. The preoperative diagnosis was teratoma. Initially, the tumor was biopsied using neuroendoscopy and the Ommaya reservoir was set. The pathological results showed fat-like tissues and fibroblasts. Subsequently, the tumor was completely removed using the interhemispheric transcallosal transchoroidal approach. The tumor included fat and hair tissues. It also included calcification similar to that observed in a tooth. It was strongly adhered near the pineal gland. Pathologically, the diagnosis was a mature teratoma. Postoperatively, the tremor disappeared and the patient was discharged from the hospital without neurological deficits. We believe that compression of the Guillain-Mollaret triangle was relieved by removal of the tumor. Hence, the tremor disappeared after the operation.

Utility of Schwann/2E and Sox10 in distinguishing CD57-negative olfactory groove schwannoma from olfactory ensheathing cell tumor: A case report and review of the literature.

We herein report a patient who was diagnosed as having olfactory groove schwannoma (OGS) which was negative for CD57 (Leu7) but positive for Schwann/2E and Sox10. A 13-year-old female with a chief complaint of headache was referred to our department due to a tumor lesion in the anterior skull base identified by magnetic resonance imaging (MRI). At the first visit, she did not exhibit altered consciousness, motor palsy, anosmia, seizures, or café au lait spots. On contrast-enhanced computed tomography (CT), a heterogeneously enhanced tumor, 50 × 45 × 50 mm in size, was observed at the anterior skull base. The left cribriform plate was thinner on bone window CT. The tumor exhibited strong, heterogeneous gadolinium enhancement on MRI as well. Slight tumor staining was observed by angiography of the left internal carotid artery but not the left external carotid artery. The patient was preoperatively diagnosed as having meningioma and underwent gross tumor resection via the basal interhemispheric approach. The tumor was strongly positive for S-100 protein and negative for epithelial membrane antigen and CD57 by immunostaining. The tumor was positive for both Schwann/2E and Sox10, which aided in the differential diagnosis between OGSs and olfactory ensheathing cell (OEC) tumors, and the definitive diagnosis was OGS. The assessment of immunoreactivities for Schwann/2E and Sox10 might be necessary to differentiate CD57-negative Schwannomas from OEC tumors.

Comparison of quantitative measurements of central nervous system tumour consistency and the associated preoperative imaging findings.

Purpose: Central nervous system (CNS) tumour consistency is one of the factors determining the difficulty of surgery for such lesions. We measured the consistency of surgically excised CNS tumour specimens using a hardness meter. The purpose of this study was to identify imaging parameters that reflect tumour consistency by comparing preoperative imaging findings with CNS tumour consistency measurements. Material and methods: Of 175 consecutive patients with CNS tumours who underwent surgery at our hospital between October 2012 and October 2018, 127 were included in this study (those whose specimens were difficult to measure were excluded). CNS tumour consistency was measured immediately after surgical excision using a hardness meter and compared with preoperative T1-weighted, T2-weighted (T2WI), fluid attenuated inversion recovery (FLAIR), diffusion-weighted imaging, gadolinium-enhanced magnetic resonance imaging, plain computed tomography (CT), and contrast-enhanced CT findings. Tumour consistency was also subjectively classified by the surgeon into soft, hard, or very hard. Results: The intracranial meningiomas were harder than the metastatic tumours and gliomas (p = 0.03 and p = 0.03, respectively). Among the intracranial meningiomas, the tumours that exhibited high intensity on T2WI were softer than those that displayed isointensity or low intensity (p < 0.001 and p < 0.001, respectively), and the isointense tumours were softer than the low intensity tumours (p = 0.02). Among the metastatic tumours, the tumours that exhibited high intensity on T2WI were softer than those that displayed isointensity or low intensity (p < 0.001 and p < 0.001, respectively). Among the intracranial meningiomas and metastatic tumours, significant correlations were detected between the T2WI findings and subjective tumour consistency according to the surgeon or quantitative tumour consistency (p = 0.01 and p = 0.03, respectively). Conclusions: The preoperative T2WI findings of intracranial meningiomas and metastatic tumours were significantly correlated with quantitatively measured tumour consistency and subjectively evaluated tumour consistency. Therefore, we concluded that T2WI findings are useful for preoperatively predicting the consistency of such tumours.

Three-Dimensional Printed Model for Surgical Simulation of Combined Transpetrosal Approach.

BACKGROUND: The combined transpetrosal approach is a complicated skull base surgery with a high degree of difficulty. Herein, we made a 3-dimensional (3D) printed petrous bone with color-coded anatomic sites and evaluated its usefulness as a model to practice drilling associated with combined transpetrosal surgery. METHODS: To design a 3D model of the petrous bone, we chose a representative epidermoid petroclival tumor case who underwent combined transpetrosal surgery at our hospital. A 3D image of the petrous bone embedded with color-coded anatomic sites, including cranial nerves, brainstem, and internal carotid and vertebrobasilar arteries, was created based on preoperative computed tomography scan, magnetic resonance, and digital subtraction angiography images and was then 3D printed. Thirteen neurosurgeons from our department evaluated the anatomic reproducibility and estimated distance between each anatomic site of the 3D image and model and the usefulness of the model for drilling practice. RESULTS: The anatomic reproducibility of both the 3D image and model was high, and the 3D model was considered good for drilling practice (P < 0.05). The error in the estimated distance between anatomic sites in the 3D model was significantly smaller than that of the 3D image (P < 0.0001). CONCLUSIONS: These results indicate that our 3D printed model is very useful for practice with craniotomy and petrosectomy drilling, necessary in the combined transpetrosal approach.

[Diffuse Astrocytoma with Pilomyxoid Features Presenting as Intratumoral Hemorrhage:A Case Report].

Hemorrhagic low-grade glioma(LGG)without malignant transformation is rare, accounting for less than 1% of cases. To the best of our knowledge, hemorrhagic LGG with an arteriovenous(AV)shunt has not been reported. We report the case of 17-year-old man with LGG with an AV shunt. He presented to our hospital with seizure. Computed tomography(CT)demonstrated a hypodense lesion with mass effect in the right frontal lobe. T1-weighted images(WI)and T2WI on magnetic resonance imaging(MRI)revealed acute-onset hemorrhage in the right frontal lobe. Furthermore, a ring-enhancing lesion was noted on gadolinium(Gd)-DTPA T1WI, and an AV shunt was found in the same region on angiography. Gross total tumor resection was performed. The pathological diagnosis was diffuse astrocytoma with pilomyxoid features(WHO grade II). Without adjuvant therapy, no residual tumor was found on MRI at the 6-year follow-up examination. We treated a case of hemorrhagic LGG with an AV shunt. Intratumoral hemorrhage in LGG may occur and should be considered for the differential diagnosis.

[Acute Changes in the Computed Tomography Findings of Mucocele Combined with Pituitary Adenoma:A Case Report].

INTRODUCTION: We report a rare case in which a pituitary tumor co-occurred with a giant mucocele. The mucocele's computed tomography(CT)values fell markedly when it collapsed, and we report the associated considerations. CASE: This case involved a 42-year-old male patient. For 20 years, his visual acuity had progressively declined, and it suddenly rapidly worsened over a month. Cranial CT revealed a massive tumor in the sphenoid sinus and a pituitary tumor. A region of high absorption extended from the paranasal sinus to the skull base. Two days after the patient's initial presentation, he experienced a sudden loss of vision. Therefore, we performed an urgent re-examination. The CT value of the paranasal lesion was found to have sharply declined. The sinus lesion was diagnosed as a mucocele. Emergent endoscopic surgery was performed. Actinomyces meyeri was detected in the samples cultures. DISCUSSION: The causes of mucocele exhibiting abnormally high signal intensity on CT include the accumulation of hemosiderin due to repeated bleeding in the cyst. Furthermore, we inferred that the Actinomyces meyeri had been taking up metallic elements in vivo for a long time. The marked reduction in the lesion's CT value was considered to have been due to the destruction of the mucocele. The contents of the mucocele flowed out and were replaced with newly produced mucus, which exhibits low absorption values. CONCLUSION: We treated a patient with a giant mucocele involving distraction of the frontal base and a pituitary adenoma. In such cases, surgery should be performed when visual acuity deteriorates suddenly.

[A Case of Male Breast Cancer with Brain Metastasis 24 Years after a Mastectomy].

Male breast cancer accounts for less than 1.0% of all breast cancer cases, and its brain metastasis is very rare. We encountered a male patient in whom brain metastasis occurred more than 20 years after the development of breast cancer. The patient was a 78-year-old male who underwent surgery for right breast cancer 24 years ago. Nausea and anorexia had appeared 2 months earlier, and the patient was referred to our department because a brain tumor was suspected on MRI. A 4×4-cm tumorous lesion was observed in the right temporal lobe, and it was heterogeneously enhanced with gadolinium. Suspecting a metastatic brain tumor, tumor resection with craniotomy was performed. Through pathological examination, the patient was diagnosed with brain metastasis of the breast cancer. Whole-brain irradiation was additionally performed. The patient recovered smoothly without neurological deficit and was discharged. No intracranial recurrence was noted on follow-up imaging, but the general condition aggravated, and the patient died after 13 months. Breast cancer in males may metastasize to the brain after a prolonged period in rare cases, for which follow-up examinations by imaging may be necessary.

Acute contrecoup epidural hematoma that developed without skull fracture in two adults: two case reports.

BACKGROUND: The incidence of acute epidural hematoma not accompanied by fracture is low, and it mostly occurs right below the impact point in children. Acute epidural hematoma on the contralateral side of the impact point without fracture is very rare. CASE PRESENTATION: Case 1: a 52-year-old Japanese woman fell and was bruised in the left occipital region, and acute epidural hematoma developed in the right frontal region. No fracture line was observed in the right frontal region on head computed tomography or during surgery, and the source of bleeding was the middle meningeal artery. Case 2: a 56-year-old Japanese man fell down the stairs and was bruised in the right occipital region, and acute epidural hematoma developed in the right occipital supra- and infratentorial regions and left frontal region. Separation of the lambdoid suture was noted in the right occipital region, but no fracture line was present in the left frontal region on either head computed tomography or during surgery, and the source of bleeding was the middle meningeal artery. CONCLUSIONS: Two rare cases of frontal contrecoup acute epidural hematoma without facture near the hematoma were reported. It is possible that the dura mater detaches from the inner surface of the skull due to cavitation theory-related negative pressure and blood vessels in the dura mater are damaged, causing contrecoup acute epidural hematoma even though no fracture occurs, for which careful course observation is necessary.

Clinical Characteristics of Subarachnoid Hemorrhage with an Intracerebral Hematoma and Prognostic Factors.

BACKGROUND: Subarachnoid hemorrhage (SAH) with an intracerebral hematoma (ICH) shows an unfavorable prognosis. In the present study, we examined the characteristics of SAH with ICH and its prognosis. METHODS: Subjects comprised 218 patients with SAH who underwent surgery between January 2007 and December 2015. We compared age, sex, the location of the aneurysm, treatment procedures, medical history (hypertension, diabetes, and heart disease), the Glasgow Coma Scale (GCS) score on admission, rerupture rate, hydrocephalus, the diameter of the aneurysm, cerebral vasospasm, perioperative cardiopulmonary complications, and the Glasgow Outcome Scale (GOS) score after 2 months between patients with SAH with and without ICH. The interval from the onset of SAH until surgery, the location of ICH, and hematoma volume were investigated as prognostic factors for SAH with ICH. RESULTS: Among all subjects, 82 had SAH with ICH. GCS scores on admission were poorer in patients with SAH with ICH than in those without ICH (P < .001), and middle cerebral artery aneurysms were more likely to form hematomas (P < .001). GOS scores after 2 months were also poorer in patients with SAH with ICH (P < .01). The size of aneurysms was larger in the 82 patients with SAH with ICH than in those without ICH (P < .001), and the rerupture rate was higher (P < .001). The unfavorable prognosis of patients with SAH with ICH was associated with age and GCS score on admission. CONCLUSIONS: A young age and a favorable GCS score on admission may be associated with a favorable prognosis for patients with SAH with ICH, and SAH with ICH may easily rerupture.