Published papers

49 microRNAs those express in SAH patients’ sera lower than 1/4 and other 27 microRNAs those expressed more than twice compared to those in control sera were identified. Degeneration of basal membrane, and peeling of endofeet of astrocyte from basal membrane was identified in hippocampus of mouse SAH model 1 day after procedure (duration of ICP elevation in the model was as long as 5 s). Three days after procedure, GFAP positive cell was decreased at the same site but no quantitative nor morphological change in neuron was observed. From the current result, we speculate degeneration of NVU starts abound microvasculature after SAH, and emerges to surrounding astrocyte that leads to neurological deterioration.

We investigated effects of diazoxide, a selective opener of mitochondrial ATP-sensitive K+ (mitoKATP) channels, against brain damage after middle cerebral artery occlusion (MCAO) in male Wistar rats. Diazoxide (0.4 or 2 mM in 30 μl saline) or saline (sham) was infused into the right lateral ventricle 15 min before MCAO. Neurological score was improved 24 h later in the animals treated with 2 mM diazoxide (13.8 ± 0.7, n = 13) compared with sham treatment (9.5 ± 0.2, n = 6, P < 0.01). The total percent infarct volume (MCAO vs. contralateral side) of sham treatment animals was 43.6 ± 3.6% (n = 12). Treatment with 2 mM diazoxide reduced the infarct volume to 20.9 ± 4.8% (n = 13, P < 0.05). Effects of diazoxide were prominent in the cerebral cortex. The protective effect of diazoxide was completely prevented by the pretreatment with 5-hydroxydecanoate (100 mM in 10 μl saline), a selective blocker of mitoKATP channels (n = 6). These results indicate that selective opening of the mitoKATP channel has neuroprotective effects against ischemia-reperfusion injury in the rat brain.

We investigated effects of diazoxide, a selective opener of mitochondrial ATP-sensitive K+ (mitoKATP) channels, against brain damage after middle cerebral artery occlusion (MCAO) in male Wistar rats. Diazoxide (0.4 or 2 mM in 30 μl saline) or saline (sham) was infused into the right lateral ventricle 15 min before MCAO. Neurological score was improved 24 h later in the animals treated with 2 mM diazoxide (13.8 ± 0.7, n = 13) compared with sham treatment (9.5 ± 0.2, n = 6, P < 0.01). The total percent infarct volume (MCAO vs. contralateral side) of sham treatment animals was 43.6 ± 3.6% (n = 12). Treatment with 2 mM diazoxide reduced the infarct volume to 20.9 ± 4.8% (n = 13, P < 0.05). Effects of diazoxide were prominent in the cerebral cortex. The protective effect of diazoxide was completely prevented by the pretreatment with 5-hydroxydecanoate (100 mM in 10 μl saline), a selective blocker of mitoKATP channels (n = 6). These results indicate that selective opening of the mitoKATP channel has neuroprotective effects against ischemia-reperfusion injury in the rat brain.

Objective: Meningioma is an extra-axial tumor that forms adhesions toward the brain surface in the course of its growth. Predicting adhesions between the tumor and the brain surface leads to better predictions of surgical results. There are few studies on brain–tumor adhesions or postoperative hemorrhage. This study aimed to assess tumor vascularity of the dura and cerebral surface, and predict surgical outcomes using four-dimensional computed tomography angiography (4D CTA). Patients and methods: Using a dynamic contrast CT, we conducted a retrospective study of 27 patients with convexity (n = 15), falx (n = 6), and parasagittal (n = 6) meningiomas treated in our hospital from January 2016 to September 2018. We set the region of interest on the dural layer and cerebral surface side of meningiomas and calculated the mean CT value in each region. Distribution of blood flow in the tumor was classified into two groups: A, which has a higher CT value of the dural side than that of the brain surface side at every timing, and B, which meets the criteria other than those in group A. Demographic data, preoperative characteristic images, and postoperative complications were compared between the groups. Results: Twelve and 15 patients were classified into groups A and B, respectively. The extent of adhesions against the cerebral cortex in group A was significantly less severe compared with that in group B (p = 0.038). The rate of postoperative hemorrhage occurrence in group B (53%) was significantly higher than that in group A (8%) (p = 0.04). There were no significant differences in the other preoperative characteristic images or perioperative parameters between groups A and B. Conclusion: A 320-row dynamic contrast CT scanner can detect meningiomas with a high probability of severe adhesion toward the brain surface and postoperative intraparenchymal hematoma.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis have specific risks. Therefore, the accurate evaluation and management of each risk factor are important, especially for patients who are at high risk for both CEA and CAS.We report the case of a 77-year-old man with right ICA stenosis that progressed despite optimal medical treatment. In addition, he had several risk factors for both CEA and CAS, including previous cervical radiation therapy, contralateral ICA occlusion, chronic kidney insufficiency, and severe aortic valve stenosis. CEA was performed with priority given to aortic valve stenosis without complications, and the patient was discharged 10 days postoperatively, without neurological sequelae. However, a pericarotid cervical abscess was detected by carotid echo, computed tomography (CT), and magnetic resonance imaging (MRI) 1 month after CEA that required surgical drainage. The infection was thought to be odontogenic because the pathogen was identified as normal oral bacterial flora, and a wound infection was not apparent. Teeth extraction and abscess drainage, in combination with antibiotic therapy, successfully cured the infection without additional complications.Odontogenic cervical abscesses after CEA can occur, especially if the patient is at risk of infection. Therefore, both preoperative and postoperative dental evaluation and management are recommended. As in this case, a cervical abscess can occur without wound infection, and the abscess diagnosis is sometimes difficult from wound inspection alone. Cervical echocardiogram and CT were useful for detecting fluid collection, whereas MRI was useful for qualitatively evaluating the lesion.

Perimedullary arteriovenous fistulas (AVFs) at the craniocervical junction are uncommon, and are often fed by the anterior spinal artery, with only a few cases fed by the intradural vertebral artery (VA). A 55-year-old man presented with a case of perimedullary AVF fed by the VA at the craniocervical junction manifesting as subarachnoid hemorrhage. Left vertebral angiography demonstrated an AVF supplied by branches from the VA. Three-dimensional computed tomography angiography (3D-CTA) revealed that the feeding arteries originated from the VA at the intradural position. Two feeding arteries were coagulated and dissected, followed by coagulation of a small feeder. The draining veins became discolored and shrank. 3D-CTA performed 2 months after the operation revealed disappearance of the AVF. Open surgery was successfully performed for the almost perimedullary AVF at the craniocervical junction, and is considered to be preferable for the treatment of this disease.

A 70-year-old male presented with a plasma cell granuloma extending from the extracranial to the intracranial space. Findings of preoperative magnetic resonance imaging and intraoperative observation indicated that the lesion extended from the temporal muscle to the subarachnoid space, penetrating the frontal bone. The subarachnoid lesion was composed of neutrophils indicating the presence of acute or subacute inflammation. The final diagnosis of the resected tumor was plasma cell granuloma. High levels of antibodies against Epstein-Barr (EB) virus in the cerebrospinal fluid and the immunohistochemical demonstration of EB nuclear antigens in the plasma cell granuloma suggested that EB virus infection was associated with the development of plasma cell granuloma in this patient.

Objective: The aim of this study was to clarify the relationship between ischaemic symptoms during the early postoperative period in patients with moyamoya disease and changes in the cerebellar asymmetry index (AI), a parameter used to quantitatively identify crossed cerebellar diaschisis (CCD). Patients and methods: We analysed the data of 18 patients with moyamoya disease who underwent quantitative IMP-cerebral blood flow SPECT at least once during the follow-up period. Cerebellar AI scores were calculated using the CBF of the cerebellum calculated automatically from multiple slices of SPECT images with automated ROI setup software and categorized and statistically examined according to the presence or absence of ischaemic symptoms. Results: The cerebellar AI calculated from SPECT performed in the patients who presented with ischaemic symptoms was 0.094 ± 0.023 (mean ± SD), which was significantly elevated compared to the value of 0.013 ± 0.025 (mean ± SD) calculated from SPECT performed when the patients did not present with ischaemic symptoms (p < 0.0001). Limiting the time of SPECT to calculate the cerebellar AI to be compared to the acute phase within 2 weeks after surgery did not change this trend, and again, the cerebellar AI was statistically significantly elevated in the presence of ischaemic symptoms (0.094 ± 0.023 (mean ± SD)) compared to the AI in the absence of ischaemic symptoms (0.000081 ± 0.026 (mean ± SD)) (p = 0.0003). In patients who underwent quantitative SPECT in the acute phase during the first postoperative week, the cerebellar AI values calculated from the results of SPECT performed during the preoperative period as well as multiple times during postoperative period were followed over time in each case. The cerebellar AI increased in patients who presented with symptoms of ischaemia postoperatively but then tended to decrease reversibly and approach zero with the disappearance of symptoms of ischaemia. Conclusions: Since the cerebellar AI reflects the symptom of ischaemia in patients with moyamoya disease, especially in the early stage after revascularization surgery, and is a parameter that improves with symptom improvement, it seems to be useful for understanding the state of cerebral blood flow after bypass surgery in patients with moyamoya disease.

Purpose: MR angiography using the silent MR angiography algorithm (silent MRA), which combines arterial spin labeling and an ultrashort time echo, has not been used for the evaluation of cerebral arteriovenous malformations (CAVMs). We aimed to determine the usefulness of silent MRA for the evaluation of CAVMs. Methods: Twenty-nine CAVMs of 28 consecutive patients diagnosed by 4D CT angiography or digital subtraction angiography, who underwent both time-of-flight (TOF) MRA and silent MRA, were enrolled. Two observers independently assessed the TOF-MRA and silent MRA images of CAVMs. Micro AVM was defined as AVM with a nidus diameter less than 10 mm. The detection rate, visualization of the components, and accuracy of Spetzler–Martin grade were evaluated with statistical software R. Results: For all 29 CAVMs, 23 (79%) lesions were detected for TOF-MRA and all for silent MRA. Of 10 micro AVMs, only 4 (40%) lesions were detectable on TOF-MRA and all (100%) on silent MRA. The visibility of the nidus and drainer was significantly better for silent MRA than TOF-MRA (p < 0.001), while there was no significant difference in the feeder between the two sequences. The accuracy rates of the Spetzler–Martin grade for the TOF and silent MRA were 38% (11/29) and 79.3% (23/29), respectively (p < 0.001). Conclusions: Silent MRA is useful for evaluating CAVM components and detecting micro AVM.

低酸素血症が各種の重症度評価指標値に及ぼす影響を検討するため,当院救急部経由で入院した235名のSIRS患者を,低酸素血症の有無で,更に低酸素血症を伴う患者はその原因を急性肺損傷(Acute lung injury,ALI)とそれ以外で分類し,各群の重症度評価に適する指標を各々検討した.ALI患者及びALI以外の低酸素血症病態の予後は,APACHE IIIスコア,不全臓器数では適切に評価し得ず,一方低酸素血症を呈さないSIRS病態の予後評価は両指標値のいずれでも可能であった.低酸素血症を伴うSIRS病態のうち,ALIに対してはPaO2/F1O2比が重症度評価の妥当な指標と思われたが,ALI以外では予後と相関せず,新たな指標値が必要と考えられた

BACKGROUND The authors’ previous cadaveric study reported a new surgical approach that can expose the deep cerebellar hemisphere, cerebellopontine angle, and upper fourth ventricle through dissection of the horizontal fissure of the suboccipital cerebellar hemisphere. Here, the authors present their experience with the first clinical use of the suboccipital trans-horizontal fissure (SOTHF) approach requiring access to the third and upper fourth ventricle lesions, a challenging compartment to access by traditional approaches. OBSERVATIONS In cases 1 and 2, computed tomography demonstrated large hematomas in the left cerebellar hemisphere with extension into the third ventricle and/or the upper fourth ventricle, resulting in obstructive hydrocephalus. Large hematomas in both the cerebellar hemisphere and the upper fourth ventricle were successfully removed via an SOTHF approach alone without external ventricular drainage. Furthermore, the hematoma in the third ventricle was removed through the aqueduct in case 2. Access to the upper fourth ventricle and the third ventricle were intraoperatively verified using a neuronavigation system. The patients immediately regained consciousness, and the result of cerebellar function testing was almost normal after the operation. LESSONS An SOTHF approach can achieve the removal of cerebellar and intraventricular hematomas simultaneously, is a faster and potentially safer method than others, and subsequently allows rapid clinical improvement.

BACKGROUND: Surgical treatment of pathological lesions in the deep cerebellar hemisphere, cerebellopontine angle (CPA), and fourth ventricle of the posterior cranial fossa (PCF) is challenging. Conventional neurosurgical approaches to these lesions are associated with risk of various complications. Mastery of efficient fissure dissection is imperative when approaching deep-seated lesions. The horizontal fissure (HF) is the largest and deepest fissure of the cerebellum. OBJECTIVE: To conduct an anatomical study and introduce a novel suboccipital trans-HF (SOTHF) approach to access lesions of the deep cerebellar hemispheres, CPA, and upper fourth ventricle of the PCF. METHODS: We performed a cadaveric dissection study focusing on anatomical landmarks and surgical feasibility of the SOTHF approach then implemented it in 2 patients with a deep cerebellar hemispheric tumor. RESULTS: Anatomical feasibility of the SOTHF approach was demonstrated and compared with conventional approaches in the cadaveric study. Opening the suboccipital surface of the HF to create medial, intermediate, and lateral surgical corridors provided optimal viewing angles and wide access to the deep cerebellar hemispheres, CPA, and upper fourth ventricle without heavy cerebellar retraction. Sacrificing cerebellar neural structures and complex skull base techniques were not required to obtain adequate exposure. The SOTHF approach was successfully applied without complication in 2 patients with a deep cerebellar hemispheric tumor. CONCLUSION: The HF is an important cerebellar fissure that provides a gateway to deep areas of the PCF. Further studies are needed to define and expand applications of the SOTHF approach.

  We have outlined the modern cadaver surgical training to facilitate safe complex and advanced skull base surgeries. The normal formalin-fixed cadaver head was useful for learning detailed skull base anatomy and histological research by removing the brain. Our fixation method, with the addition of phenol, ethanol, and methanol, was suitable for surgical simulation. To utilize the dissection performed by doctors for the development of surgical skills, it is essential to create an organization within the university.

Background: A combined transpetrosal approach (CTP) is often used for large lesions in the posterior cranial fossa (PCF). Although CTP provides a wide surgical corridor, it has complex and time-consuming bony work of mastoidectomy and cosmetic issues. Here, we describe a simple combined surgical technique to approach the supratentorial region, anterolateral surface of the brainstem, petroclival region, and foramen magnum by drilling only the petrous apex with a combination of retrosigmoid approach (RA). Clinical presentation: A 27-year-old female was referred with extra-axial left cerebellopontine angle space-occupying epidermoid cyst extending to the prepontine cistern, anterior to the basilar artery, superior to the chiasma, and caudally to the foramen magnum. A one-stage surgical procedure using the anterior transpetrosal approach (ATP) and RA was performed after one-piece temporal-suboccipital craniotomy. These two approaches complemented each other well. Near-total removal was achieved. Conclusion: A one-stage surgical procedure using ATP and RA provides the wider viewing and better visualization of the PCF with minimal technical difficulty.

Langerhans cell histiocytosis (LCH) is a disease characterized by the proliferation of Langerhans cells. Most cases of LCH occur in children, although it can be seen in adults as well. We encountered an adult case of LCH. A 44-year-old woman who was diagnosed as diabetes insipidus underwent a magnetic resonance imaging (MRI) of the head which revealed sellar and suprasellar gadolinium-enhanced mass. Prolactin level was high and cabergoline was prescribed. The size of this mass had reduced, so we supposed the tumor was prolactinoma. However, after 4 years of observation, it had increased once again. The biopsy of pituitary stalk lesion was performed via transcranial approach. The histological diagnosis was initially gangliocytoma. The patient complained of back pain after surgery. Three months after the biopsy, a computed tomography (CT) scan revealed multiple osteolytic lesions throughout the entire body. One of the osteolytic lesions of the skull was removed to determine the diagnosis. The pathological examination of the skull led to a diagnosis of LCH. We concluded retrospectively that the lesion of the pituitary stalk was LCH mimicking gangliocytoma though classical pathological findings were not obtained. In conclusion, LCH should be considered as a differential diagnosis in adult cases of diabetes insipidus with hypothalamic–pituitary lesion.

OBJECTIVE The authors report on the anterior transpetrosal approach (ATPA) and the results of surgeries performed over a 33-year period for petroclival tumors, including meningioma, trigeminal schwannoma, chordoma, and epidermoid tumor. They analyze early postoperative neurological changes, surgical complications, and trends over the decades. METHODS A retrospective analysis of 274 surgical cases that had undergone the ATPA from January 1984 to March 2017 was conducted. Data were collected from charts, clinical summaries, operative records, and operative videos. The analyzed parameters included patient diagnosis, tumor size, disease location, operation date, tumor removal rate, pre- and postoperative neurological symptoms (consciousness level, motor and sensory deficits of the limbs, sensory aphasia, and cranial nerve III–VIII injuries), surgical deaths, and radiologically recognized brain injuries after the operation (contusion, infarction, hemorrhage). RESULTS Gross-total resection (GTR) was achieved in 53.5% of the 243 tumors with available data. The GTR rate for meningiomas (148 cases) was 54.1%. Trigeminal schwannomas had a high GTR rate of 87.1%, whereas chordomas had a low GTR rate of 14.3%. The rate of early neurological deterioration immediately after the ATPA, referred to as “early neurological change,” was as follows: consciousness disturbance in 1.9% of cases (5 cases), improvement of hemiparesis in 45.0% of cases but deterioration in 8.1% of cases, sensory aphasia in 2.3% of cases due to temporal lobe injury, improvement of cerebellar symptoms in 39.3% of cases with rare deterioration (1.9% of cases), worsening of preoperative diplopia in 49.4% of patients and rarely improving, improvement of trigeminal symptoms in 19.1% of cases (mostly trigeminal neuralgia) among the 43.7% of patients who had them preoperatively, and deterioration of facial hypesthesia and/or paresthesia in 27.4% of cases. Early neurological deterioration was monitored in 183 patients for 6 months to determine the surgical complications of ATPA. Consciousness disturbance recovered in half of the cases but persisted in 3 (1.5%). Hemiparesis fully recovered in 63.2% of cases, resulting in a complication rate of 3.0%. The most frequent complication was diplopia (36.4%), with a complete remission rate of 26.4%. The second most frequent complication was facial hypesthesia (24.0%), with a recovery rate of 16.1%. Facial nerve palsy improved in 63.0% of cases and had a complication rate of 4.9%. Cerebellar symptoms showed complete recovery in all cases. CONCLUSIONS The ATPA allows the removal of petroclival tumors extending into Meckel’s cave and the middle fossa, making it preferred for dumbbell trigeminal schwannomas and meningiomas. However, the ATPA’s aggressive tumor removal can risk a lower recovery of cranial nerve IV–VI deficits. For benign meningiomas, initial observation with regular follow-up is recommended. Surgery is appropriate for high-growth cases aiming for total removal, accompanied by a thorough explanation of the risks. If the risks are not accepted, subtotal removal can be considered, and radiosurgery is suggested for residual tumor.

OBJECTIVE The anterior transpetrosal approach (ATPA) was initially reported in 1985. The authors' institution has 274 case records of surgery performed with the ATPA during the period from 1984 to 2017. Although many technical advances and modifications in the ATPA have occurred over those 33 years, to the authors' knowledge no articles to date have reported a detailed analysis of variations and complications of the ATPA. In this study, the authors analyzed their patient series to elucidate improvements over time in ATPA methodology while highlighting unresolved problems and evaluating how to avoid surgical complications. METHODS All surgical cases (274 patients) using the ATPA at the authors' institution during the period from 1984 to 2017 were analyzed retrospectively using charts, clinical summaries, operative records, and operative videos. Obtained parameters were patient age and sex, diagnosis, size of tumors, location of disease, operative date, neurological symptoms before and after surgery, radiographically identified brain injury, and other surgical complications. The most common diagnosis was petroclival meningioma (n = 158), followed by trigeminal schwannoma (n = 32), chordoma (n = 25), epidermoid tumor (n = 21), other tumor (n = 27), aneurysm (n = 6), and other (n = 5). RESULTS The original ATPA was performed in 239 cases. In an additional 35 cases, a modified ATPA was performed. Zygomatic osteotomy with ATPA was a common modification that was used in 19 of the 35 cases to decrease retraction damage to the temporal lobe for high-positioned tumors. Brain injury by temporal lobe retraction without venous hemorrhage still occurred in 8 of the 19 cases (3.1%) with surgical death in 1 of these cases (0.4%) of reoperation with sacrifice of the petrosal vein. Symptomatic CSF leak was the most frequent complication noted and was observed in 35 cases (13.5%). In most of these cases the patients were cured by observation or lumbar drain, but in 6 cases (17.1%) reoperation was needed. Facial nerve damage related to surgical approach decreased from 6.2% to 3.5% after 2010; however, the incidence of CSF leaks (13.5%) has not improved. CONCLUSIONS There have been several modifications and advancements made in the ATPA to increase tumor removal and decrease surgical complications. However, complications related to surgical approach occurred, such as venous occlusion-related brain injury and facial nerve damage at pyramid resection. CSF leak remained an unsolved problem related to the ATPA procedures. Preoperative assessment of venous variation of the middle fossa, pneumatization of the temporal bone, and intraoperative monitoring of cranial nerves are important procedures to decrease these complications.