Subclassification of Koos grade 4 vestibular schwannoma: insights into tumor morphology for predicting postoperative facial nerve function

OBJECTIVE

Koos grade 4 vestibular schwannoma (KG4VS) is a large tumor that causes brainstem displacement and is generally considered a candidate for surgery. Few studies have examined the relationship between morphological differences in KG4VS other than tumor size and postoperative facial nerve function. The authors have developed a landmark-based subclassification of KG4VS that provides insights into the morphology of this tumor and can predict the risk of facial nerve injury during microsurgery. The aims of this study were to morphologically verify the validity of this subclassification and to clarify the relationship of the position of the center of the vestibular schwannoma within the cerebellopontine angle (CPA) cistern on preoperative MR images to postoperative facial nerve function in patients who underwent microsurgical resection of a vestibular schwannoma.

METHODS

In this paper, the authors classified KG4VSs into two subtypes according to the position of the center of the KG4VS within the CPA cistern relative to the perpendicular bisector of the porus acusticus internus, which was the landmark for the subclassification. KG4VSs with ventral centers to the landmark were classified as type 4V, and those with dorsal centers as type 4D. The clinical impact of this subclassification on short- and long-term postoperative facial nerve function was analyzed.

RESULTS

In this study, the authors retrospectively reviewed patients with vestibular schwannoma who were treated surgically via a retrosigmoid approach between January 2010 and March 2020. Of the 107 patients with KG4VS who met the inclusion criteria, 45 (42.1%) were classified as having type 4V (KG4VSs with centers ventral to the perpendicular bisector of the porous acusticus internus) and 62 (57.9%) as having type 4D (those with centers dorsal to the perpendicular bisector). Ventral extension to the perpendicular bisector of the porus acusticus internus was significantly greater in the type 4V group than in the type 4D group (p < 0.001), although there was no significant difference in the maximal ventrodorsal diameter. The rate of preservation of favorable facial nerve function (House-Brackmann grades I and II) was significantly lower in the type 4V group than in the type 4D group in terms of both short-term (46.7% vs 85.5%, p < 0.001) and long-term (82.9% vs 96.7%, p = 0.001) outcomes. Type 4V had a significantly negative impact on short-term (OR 7.67, 95% CI 2.90-20.3; p < 0.001) and long-term (OR 6.05, 95% CI 1.04-35.0; p = 0.045) facial nerve function after surgery when age, tumor size, and presence of a fundal fluid cap were taken into account.

CONCLUSIONS

The authors have delineated two different morphological subtypes of KG4VS. This subclassification could predict short- and long-term facial nerve function after microsurgical resection of KG4VS via the retrosigmoid approach. The risk of postoperative facial palsy when attempting total resection is greater for type 4V than for type 4D. This classification into types 4V and 4D could help to predict the risk of facial nerve injury and generate more individualized surgical strategies for KG4VSs with better facial nerve outcomes.

Delayed facial palsy after resection of vestibular schwannoma: does it influence long-term facial nerve functional outcomes?

OBJECTIVE

Delayed facial palsy (DFP) is a common and unique complication after resection of vestibular schwannoma (VS). Few studies have focused on the clinical question of whether patients with DFP can be expected to have the same long-term prognosis in terms of facial nerve function as those without DFP based on their facial nerve function immediately postoperatively. This study aimed to clarify the clinical impact of DFP on the long-term functional status of the facial nerve after VS resection.

METHODS

The authors retrospectively reviewed patients with sporadic VS who were treated surgically via a retrosigmoid approach between January 2002 and March 2020. DFP was defined as de novo deterioration of facial nerve function by a House-Brackmann (HB) grade ≥ I more than 72 hours postoperatively. The incidence of DFP after VS resection and its impact on long-term facial nerve function were analyzed.

RESULTS

DFP developed in 38 (14.3%) of 266 patients who met the inclusion criteria. The median latency until DFP onset postoperatively was 8.5 days. When facial nerve function was normal immediately postoperatively, the rate of preservation of favorable facial nerve function (HB grade I or II) at 24 months postoperatively was 100% for all patients regardless of whether they developed DFP. In contrast, when facial nerve dysfunction was present immediately postoperatively, the rate of preservation of favorable facial nerve function at 24 months postoperatively was significantly lower in patients with DFP than in those without DFP (77.8% vs 100% in patients with HB grade II immediately postoperatively, p = 0.001; 50.0% vs 90.3% in those with HB grade III immediately postoperatively, p = 0.042). DFP development had a significantly negative impact on the long-term functional status of the facial nerve postoperatively when age, tumor size, and HB grade immediately postoperatively were taken into account (OR 0.04, 95% CI 0.01-0.20; p < 0.001).

CONCLUSIONS

DFP can be a minor complication when normal facial nerve function is observed immediately after surgery. However, when facial nerve dysfunction is present immediately after surgery, even if mild, the long-term prognosis for facial nerve function is significantly worse in patients with DFP than in those without DFP.

Intrasellar Chordoma Mimicking Pituitary Macroadenoma with Hyperprolactinemia and Hypopituitarism: Clinical Images with a Surgical Video

A purely intrasellar chordoma is rare among skull base chordomas and is recognized as originating from ectopic embryological notochord located in the sella turcica. In view of its rarity and nonspecific symptoms, clinicians may misdiagnose intrasellar chordoma as pituitary adenoma based on preoperative radiographic images. In this report, we present an intrasellar chordoma that clinically mimicked pituitary macroadenoma with hyperprolactinemia and hypopituitarism and was successfully resected by endoscopic endonasal transsphenoidal surgery. This case demonstrated radiographic features that chordoma should be suspected in sellar lesions. The enlarged sellar with thinned remodeled bone without clival destruction was firstly reminiscent of pituitary adenoma, whereas the very high signal on T2-weighted images and heterogeneous enhancement characteristically suggested chordoma. This rare diagnosis must be considered in the preoperative evaluation of sellar lesions because it can affect how the neurosurgeon prepares for surgery and the surgical goals.

Presence of a fundal fluid cap on preoperative magnetic resonance imaging may predict long-term facial nerve function after resection of vestibular schwannoma via the retrosigmoid approach

OBJECTIVE

Preservation of neurological function is a priority when performing a resection of a vestibular schwannoma (VS). Few studies have examined the radiographic value of a fundal fluid cap—i.e., cerebrospinal fluid in the lateral end of a VS within the internal auditory canal—for prediction of postoperative neurological function. The aim of this study was to clarify whether the presence of a fundal fluid cap on preoperative magnetic resonance images has a clinical impact on facial nerve function after resection of VSs.

METHODS

The presence of a fundal fluid cap and its prognostic impact on long-term postoperative facial nerve function were analyzed.

RESULTS

A fundal fluid cap was present in 102 of 143 patients who underwent resection of sporadic VSs via the retrosigmoid approach. Facial nerve function was acceptable (House-Brackmann grade I–II) immediately after surgery in 82 (80.4%) patients with a fundal fluid cap and in 26 (63.4%) of those without this sign. The preservation rate of facial nerve function increased in a time-dependent manner after surgery in patients with a fundal fluid cap but plateaued by 3 months postoperatively in those without a fundal fluid cap; the difference was statistically significant at 12 months (96.1% vs 82.9%, p = 0.013) and 24 months (97.1% vs 82.9%, p = 0.006) after surgery. The presence of a fundal fluid cap had a significantly positive effect on long-term facial nerve function at 24 months after surgery when tumor size and intraoperative neuromonitoring response were taken into account (OR 5.55, 95% CI 1.12–27.5, p = 0.034).

CONCLUSIONS

Neuromonitoring-guided microsurgery for total resection of VSs is more likely to be successful in terms of preservation of facial nerve function if a fundal fluid cap is present. This preoperative radiographic sign could be helpful when counseling patients and deciding the treatment strategy.

The impact of hormonal dynamics and serum sodium fluctuations on symptomatic vasospasm after subarachnoid hemorrhage

BACKGROUND

Symptomatic vasospasm (SVS) is a major cause of morbidity and mortality in aneurysmal subarachnoid hemorrhage (SAH), and serum sodium frequently decreases before SVS. Serum sodium changes might be regulated by sodium metabolism-related hormones. This multi-institutional prospective cohort study therefore investigated the measurement of sodium metabolism-related hormones to elucidate the pathophysiology of serum sodium changes in SAH.

METHODS

SAH patients were treated with clipping or coiling from September 2017 to August 2020 at five hospitals. The laboratory data of 133 SAH patients were collected over 14 days and correlations between changes in serum sodium, sodium metabolism-related hormones (plasma adrenocorticotropic hormone (ACTH), serum cortisol, plasma arginine vasopressin (AVP)), and SVS were determined. Serum sodium concentrations were measured every day and serum sodium levels >135 mEq/L were maintained until day 14.

RESULTS

Of the 133 patients, 18 developed SVS within 14 days of subarachnoid hemorrhage onset (SVS group) and 115 did not suffer from SVS (non-SVS group). Circulating AVP, ACTH, and cortisol concentrations were significantly higher on day 1 in the SVS group compared with the non-SVS group. Fluctuations in serum sodium in the SVS group were significantly higher than those in the non-SVS group. There were antiparallel fluctuations in serum sodium and potassium from days 2 to 14.

CONCLUSIONS

Elevated levels of ACTH/cortisol and AVP on day 1 may be predictive markers for the occurrence of SVS. Multiple logistic regression analysis showed that serum sodium fluctuations were associated with SVS occurrence. Serum sodium fluctuations were associated with stress-related hormonal dynamics. (249 words).

Symptomatic Intracranial Artery Stenosis Due to an Unknown Embolus Following Cardiac Surgery: A Case Report

Intracranial artery occlusion due to a foreign body is a complication associated with cardiac surgery that is treated by various techniques. However, little is known about appropriate strategies for symptomatic intracranial artery stenosis due to an unknown embolic source. We reported a case of middle cerebral artery (MCA) stenosis after mitral valve repair (MVR) for infective endocarditis (IE). An 80-year-old man presented with right hemiplegia. MR angiography findings were normal, and diffusion-weighted imaging revealed subtle ischemic change in the left MCA territory. The patient was diagnosed with cardioembolic stroke owing to IE and performed MVR. Four days later, he suddenly presented with consciousness disorder and left hemiplegia. Computed tomography (CT) confirmed a very low-density area within the right MCA. MR angiography revealed right MCA stenosis, which corresponded to the low-density area on CT images. Diffusion-weighted imaging revealed new ischemic change in the right MCA territory. Angiography confirmed an irregular stenosis at the right M2 with antegrade blood flow, and the hemiplegia resolved during angiography. Conservative therapy was performed; however, the resting 123 I-IMP-single photon emission CT revealed moderate perfusion defect in the right MCA territory, and transient left hemiplegia appeared every few days. Therefore, 19 days after the initial transient ischemic attack, the patient was performed superficial temporal artery–MCA anastomosis, and the patient responded with a good clinical course without recurrence of the ischemic symptoms. This strategy may be a safe and effective treatment for symptomatic intracranial artery stenosis due to an unknown embolic source.

Acute Occlusion of the Ventriculoperitoneal Shunt Due to Factor XIII Deficiency-related Postoperative Hemorrhage: A Case Report

Coagulation factor XIII (F13) deficiency has been known to be a rare disease with estimated one per two million and one of the possible reasons of postoperative hemorrhage; however, it still remains unpenetrated to physicians. We report a case of acute ventriculoperitoneal (VP) shunt dysfunction due to delayed intraventricular hemorrhage, which could be because of F13 deficiency. The patient was a 48-year-old man with a history of post-meningitis hydrocephalus followed by VP shunt placement. He was found unconscious and transferred to our hospital. A brain CT scan demonstrated shunt malfunction, and he underwent emergency shunt revision. The postoperative course was uneventful except for unexpected neck bruises and continuous minor bleeding from the surgical wound. Three days after surgery, he suddenly became comatose and a CT scan revealed the recurrence of hydrocephalus with newly identified small volume of intraventricular hemorrhage. Emergency shunt revision was performed again. The shunt valve was filled with a hematoma and bloody cerebrospinal fluid was drained from the ventricle. Postoperative blood sample examination demonstrated no abnormal findings but a decreased level of F13 activity, which was thought to be a possible cause of postoperative hemorrhage and the shunt valve hematoma. F13 deficiency causes delayed intracranial hemorrhage 24–48 h after neurological surgery. It can only be diagnosed by checking F13 activity with suspicion. If diagnosed accurately beforehand, unexpected postoperative bleeding can be preventable with proper treatment, such as F13 concentrate and cryoprecipitate. The actual number of the patient with F13 deficiency may be more than estimated ever.

Comparative Evaluation of 3-Dimensional High Definition and 2-Dimensional 4-K Ultra-High Definition Endoscopy Systems in Endonasal Skull Base Surgery

BACKGROUND

The differences between 3-dimensional (3D) high definition (HD) and 2-dimensional (2D) 4-K ultra-HD (4K) endoscopy and their respective advantages remain unclear.

OBJECTIVE

To evaluate the utility of these endoscopy systems in endonasal skull base surgery.

METHODS

Consecutive series of endoscopic endonasal surgeries performed after introduction of 3D/HD and 2D/4K systems (July 2017) were retrospectively evaluated. Sporadic cases treated with either system, or a conventional 2D standard definition (SD) system, during the rental period from March 2016 were also included. Objective comparisons between the systems were made for newly diagnosed Knosp grade 0 to 3 pituitary adenomas. Surgical procedures were divided into nasal, sphenoidal, and intradural phases, and the surgical procedural time was compared for each phase. The time required for and accuracy of suturing the sellar floor dura was also evaluated.

RESULTS

A total of 74 cases were treated with 3D/HD and/or 2D/4K, and 12 cases with 2D/SD. 3D/HD was advantageous in the nasal phase because of its intuitive depth perception. 2D/4K was advantageous in the intradural phase because of its superior image quality. Surgical time of the nasal phase with 3D/HD, and that of the intradural phase with 2D/4K, were significantly shorter than that with 2D/SD. The time required for and accuracy of sellar floor dural suturing showed a trend toward improving in the order of 2D/SD, 2D/4K, and 3D/HD.

CONCLUSION

3D/HD and 2D/4K endoscopy systems have different advantages, which are useful in distinct surgical phases. Understanding the characteristics of endoscopy systems is important for selecting the most appropriate system for distinct surgical situations.

Potential of machine learning to predict early ischemic events after carotid endarterectomy or stenting: a comparison with surgeon predictions

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended for high stroke-risk patients with carotid artery stenosis to reduce ischemic events. However, we often face difficulty in determining the best treatment strategy. We aimed to develop an accurate post-CEA/CAS outcome prediction model using machine learning that will serve as a basis for a new decision support tool for patient-specific treatment planning. Retrospectively collected data from 165 consecutive patients with carotid stenosis underwent CEA or CAS and were divided into training and test samples. The following five machine learning algorithms were tuned, and their predictive performance was evaluated by comparison with surgeon predictions: an artificial neural network, logistic regression, support vector machine, random forest, and extreme gradient boosting (XGBoost). Seventeen clinical factors were introduced into the models. Outcome was defined as any ischemic stroke within 30 days after treatment including asymptomatic diffusion-weighted imaging abnormalities. The XGBoost model performed the best in the evaluation; its sensitivity, specificity, positive predictive value, and accuracy were 31.9%, 94.6%, 47.2%, and 86.2%, respectively. These statistical measures were comparable to those of surgeons. Internal carotid artery peak systolic velocity, low-density lipoprotein cholesterol, and procedure (CEA or CAS) were the most contributing factors according to the XGBoost algorithm. We were able to develop a post-procedural outcome prediction model comparable to surgeons in performance. The accurate outcome prediction model will make it possible to make a more appropriate patient-specific selection of CEA or CAS for the treatment of carotid artery stenosis.

Anatomical variation of the internal carotid artery and its implication to the endoscopic endonasal translacerum approach

BACKGROUND

The endoscopic endonasal trans-lacerum approach (EETLA) is useful in handling skull base tumors around inferior petrous apex (IPA); however, its surgical corridor is exclusively a triangular space (supra-eustachian triangle [SET]), between the internal carotid artery (ICA) and eustachian tube.

METHODS

We investigated correlation between SET size and extent of resection around the IPA (lateral extent of resection [EOR]) through a retrospective analysis of 15 surgeries using EETLA.

RESULTS

Of 15 cases (9 chordomas, 4 chondrosarcomas, and 2 meningiomas), 20 sides of IPA were affected by the tumor. When being restricted to sides with severe lateral tumor extension beyond the midpoint of petrous ICA (10 sides), the SET size was significantly broader in the group with lateral EOR of ≥90% (p value = 0.019).

CONCLUSIONS

The SET size was a powerful index of tumor resectability in EETLA, especially in cases with severe tumor extension. The individual anatomical variations should be considered when determining EETLA application.

Glioma cells require one-carbon metabolism to survive glutamine starvation

Cancer cells optimize nutrient utilization to supply energetic and biosynthetic pathways. This metabolic process also includes redox maintenance and epigenetic regulation through nucleic acid and protein methylation, which enhance tumorigenicity and clinical resistance. However, less is known about how cancer cells exhibit metabolic flexibility to sustain cell growth and survival from nutrient starvation. Here, we find that serine and glycine levels were higher in low-nutrient regions of tumors in glioblastoma multiforme (GBM) patients than they were in other regions. Metabolic and functional studies in GBM cells demonstrated that serine availability and one-carbon metabolism support glioma cell survival following glutamine deprivation. Serine synthesis was mediated through autophagy rather than glycolysis. Gene expression analysis identified upregulation of methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) to regulate one-carbon metabolism. In clinical samples, MTHFD2 expression was highest in the nutrient-poor areas around “pseudopalisading necrosis.” Genetic suppression of MTHFD2 and autophagy inhibition caused tumor cell death and growth inhibition of glioma cells upon glutamine deprivation. These results highlight a critical role for serine-dependent one-carbon metabolism in surviving glutamine starvation and suggest new therapeutic targets for glioma cells adapting to a low-nutrient microenvironment.

[Sellar and Parasellar Inflammatory Lesions with Impaired Visual Function:Clinical Features and Endoscopic Surgical Outcomes of Six Cases]

Accurate diagnosis and treatment of sellar and parasellar inflammatory lesions is difficult. We report six patients with sellar and parasellar inflammatory lesions and impaired visual function, who underwent endonasal endoscopic surgery. These patients included one with aspergillosis, one with hypertrophic pachymeningitis, one patient with abscess, and three with idiopathic granulomatous lesions. Following surgery and medication, visual function improved in patients with aspergillosis, hypertrophic pachymeningitis, and abscess. In patients with idiopathic granulomatous inflammation, visual function improved in one out of three patients. The treatment outcome for sellar and parasellar inflammatory lesions with impaired visual function depends on the surgery as well as on the reaction to postoperative medication. In the present study, the functional prognosis of patients with idiopathic granulomatous lesions was relatively poor when compared with that of patients with other inflammatory lesions.

Submucosal Inferior Turbinectomy to Widen the Surgical Corridor for Endoscopic Endonasal Skull Base Surgery

The nasal cavity is the exclusive surgical corridor for endoscopic endonasal surgery; however, it is sometimes too narrow to allow extensive surgical maneuvering. Here we show the technique of submucosal inferior turbinectomy (SIT) to widen this surgical corridor. Its effectiveness is evaluated quantitatively by comparing pre- and intraoperative magnetic resonance images. Between March 2015 and October 2018, we performed endoscopic endonasal resection of 57 skull base tumors with 3T intraoperative magnetic resonance imaging (iMRI). Among these resections, cases with previous endonasal surgery and cases for which the iMRI did not cover the entire nasal cavity were excluded. Finally, six cases with and 19 cases without SIT were included in the subsequent retrospective analysis. We measured the dimensions of the narrowest area in inferior nasal cavity on pre- and intraoperative coronal plane gadolinium (Gd)-enhanced T1-weighted MR images using dedicated software, and compared them. The incidence rates of postoperative nasal complaints at outpatient clinics were also compared. Considerable widening of the inferior nasal cavity could be achieved with the SIT, which was statistically significant compared with those without the SIT (111.1 ± 56.5% vs. 39.4 ± 59.4%, respectively; P = 0.0093). In terms of the incidence rate of postoperative nasal complaints at 6 months, there was no statistical difference between the groups (33.3% vs. 15.8%, respectively; P = 0.35). SIT is effective for widening the surgical corridor while keeping nasal function and is especially helpful for lower clivus and laterally extended skull base lesions.

A Case of Multi-System Langerhans Cell Histiocytosis with Local Invasion of the Orbital Apex

Langerhans cell histiocytosis (LCH) is characterised by tissue destruction caused by the abnormal proliferation of pathogenic dendritic cells. We report a rare case of multi-system LCH with local invasion of the orbital apex. A 56-year-old woman suffered from a decrease of visual acuity in the left eye caused by central scotoma and the limitation of eye movement in all directions. Magnetic resonance imaging revealed an enhanced lesion in the left orbital apex, suggesting optic nerve compression. She had been diagnosed with eosinophilic granuloma 24 years previously. Two weeks after the current presentation, we admitted the patient for optic canal and orbital apex decompression and subtotal tumour resection. Histopathological analysis confirmed the diagnosis of LCH. Post-surgical treatment with low-dose cytarabine was initiated for the residual tumour. However, it was ceased because of myelosuppression-induced pyelonephritis. After surgery, the central scotoma disappeared on day 5 and eye movement palsy resolved by 6 months. After the cessation of cytarabine, she has received low-dose steroid therapy for 2 years with no recurrence. Early surgical intervention with low-dose steroid therapy can lead to recovery of visual acuity and resolve eye movement palsy in patients with lesions of the orbital apex caused by multi-system LCH.

[Multiple Spinal Intradural and Extradural Syphilis Granuloma Mimicking Lumbar Dumbbell Type Neurinoma:A Case Report]

Spinal intradural and extradural syphilis granuloma is extremely rare. Here, we report a patient with multiple spinal intradural and extradural syphilis granuloma mimicking dumbbell type neurinoma. The patient was a 68-year-old man, who presented with left femoral pain for a month. Magnetic resonance imaging(MRI)revealed a homogeneous enhanced dumbbell-shaped lesion occupying the spinal canal at the level of lumbar 3/4 and developing through the intervertebral foramen. Although initial blood tests revealed that he contracted with the syphilis, we diagnosed dumbbell type neurinoma preoperatively. He underwent partial tumor removal. The tumor adhered tightly to the cauda equina in intraoperative finding. Histopathological diagnosis of the lesion was granulomatous inflammation with the lymphocytic infiltration. Postoperatively, results of the <i>Treponema pallidum</i> hemagglutination(TPHA)test and the rapid plasma regain(RPR)test of cerebrospinal fluid were reactive, so we confirmed syphilis granuloma. He was treated with penicillin G for two weeks from 25 days after surgery. A follow-up MRI of the lumbar spine 51 days after surgery showed a reduction in size of the lumbar spinal tumor compared to the initial findings. Thus, syphilis granuloma should be considered in differential diagnosis of a spinal dumbbell shaped lesion. Penicillin G may be effective for the treatment of syphilis granuloma.

Application of a Minimally Invasive Liposuction Technique for Harvesting Fat during Transsphenoidal Surgery: A Technical Note

Secure reconstruction in transsphenoidal surgery (TSS) is important for the prevention of the major and serious complication of postoperative cerebrospinal fluid (CSF) leak. Although abdominal fat can be safely and effectively used as a reconstruction tissue, harvesting it from the abdominal wall is traumatic and invasive, resulting in cosmetic problems. In this report, we present a method of harvesting abdominal fat using a minimally invasive liposuction technique to avoid cosmetic issues. Since 2016, we have been using fat harvested from the abdominal wall by suctioning with a dedicated syringe for reconstruction after TSS in selected cases. The liquefied fat obtained by the liposuction technique was wrapped with an oxycellulose sheet and changed its form to what we termed “fatty candy”. In this form, the fat maintained its configuration and could be handled almost as easily as a conventional fat graft. In our experienced series, there was no case with wound complication nor postoperative or late-onset CSF leak during a postoperative follow-up of at least 3 months. The fat harvested by this simple and minimally invasive liposuction technique can be expected to provide an autologous graft that is adequate not only for prevention of cosmetic problems but also for prevention of postoperative CSF leak.

Abstract TP532: Decreased Serum Sodium Levels Predict Symptomatic Vasospasm in Patients With Subarachnoid Hemorrhage

Background: Symptomatic vasospasm (SVS) is one of the major causes of morbidity and mortality in patients with subarachnoid hemorrhage (SAH). Hyponatremia and dehydration due to natriuresis after SAH is related to SVS and predicts it. Therefore, nowadays most institutions target to euvolemia and eunatremia in SAH patients to avoid complications. In this study, we retrospectively investigated the predictors of SVS in terms of water and sodium homeostasisunder maintaining euvolemia and eunatremia after SAH. We also analyzed the relationship between hyponatremia and the effect of treatment modality (clipping and endovascular coiling).

Methods: We monitored changes in serum sodium levels, serum osmolarity, daily sodium intake, daily urine volume, and daily water balance during 14 days after SAH. Outcome was assessed using the modified Rankin scale one month after subarachnoid hemorrhage.

Results: Among 105 patients, 29 (27.6%) had SVS. Patients with SVS were older than those without SVS and SVS affected outcome. Serum sodium levels were sequentially significantly decreased within normal range from one day before occurrence of SVS.Among the patients, 67 (63.8%) were treated with surgical clipping and 38 (36.2%) were treated with endovascular coiling. The group with coiling suffered significantly more severe hyponatremia and had less urine volume compared with the clipping group.

Conclusions: SVS occurs more often in older patients and affects outcome. Serum sodium level decrease occurs one day before SVS. This observation may help predict SVS. A further large prospective study is necessary to resolve the detailed relationships among hyponatremia, urine volume, treatment modality and SVS in patients with SAH.

Abstract TP154: Characteristics and Surgical Outcome of Patients With Carotid Stenosis Resistant to Medical Therapy

Background: The recent progress of medical therapy has made the surgical indication for carotid artery stenosis more stringent. Therefore, surgical outcome of patients resistant to medical therapy were compared with those non-resistant to medical therapy.

Methods: Between August 2006 and September 2017, 320 consecutive carotid revascularizations (CEA/CAS) were performed in our institute. Resistant (R) group was defined as patients with crescendo TIA, repeated TIA/infarction despite of medical therapy (n=15) or patients with symptomatic mobile plaque (n=5) (total 18; 2 patients overlapped). Other patients with symptomatic (116) and asymptomatic (186) stenosis were defined as non-resistant (N) group (total 302). Clinical characteristics, magnetic resonance (MR) plaque imaging, plaque pathology, and long-term outcomes with survival analysis were investigated.

Results: 13 CEA and 5 CAS were performed in R group. 181 CEA and 121 CAS were performed in N group. The periprocedural stroke & death rate was higher in R group (1/18 [5.6%]; CEA 0/13, CAS 1/5 [20%]) than in N group (9/302 [3.0%]; CEA 4/181 [2.2%], CAS 5/121 [4.1%]) but no significant difference was observed. Signal intensity ratio of plaque relative to sternocleidomastoid muscle was significantly higher in R group than in N group (1.9 vs 1.5, p = 0.007; Fig. 1A) in MR plaque imaging study, which was consistent with intraplaque hemorrhage in pathological findings of R group. Estimates of the 4-year event rate of primary end point (stroke/death/MI within 30 days, and any ipsilateral stroke thereafter) using competing risk analysis were 18% for R group and 4.5% for N group (P = 0.022; Fig. 1B). ALL recurrence occurred after CAS.

Conclusion: The resistance to medical therapy was likely to be due to severe intraplaque hemorrhage, which might explain relatively poor outcome of CAS in R group. Appropriate indication is critical for good outcome of R group.

Direct Carotid Cavernous Fistula Due to Rupture of a Cavernous Carotid Aneurysm Embedded Within a Prolactinoma After Cabergoline Administration

BACKGROUND

A small number of reports have described subarachnoid hemorrhage resulting from a ruptured aneurysm embedded within a prolactinoma. To the best of our knowledge, no reports have described an embedded carotid cavernous fistula. We report a patient with carotid cavernous fistula secondary to a ruptured internal carotid artery aneurysm embedded within a prolactinoma.

CASE DESCRIPTION

A 61-year-old woman was referred to our hospital with sudden headache, vomiting, and dizziness. Magnetic resonance imaging demonstrated a small acute subdural hematoma, recurrent prolactinoma, and left cavernous carotid aneurysm. Conservative therapy was initiated. Her serum prolactin level at hospitalization was 11,300 μg/L; therefore, we initiated cabergoline therapy. Twenty days after cabergoline administration, she suddenly presented with left conjunctival injection and pulsatile tinnitus. Angiography showed a left direct carotid cavernous fistula with a connection between the cavernous internal carotid artery and the cavernous sinus via the aneurysm and venous congestion. To prevent hemorrhagic stroke, we scheduled staged surgery. First, we urgently performed embolization of the cavernous sinus and fistula. One month later, to prevent aneurysm rerupture, we performed a radical operation with superficial temporal artery-middle cerebral artery double anastomosis with proximal occlusion of the left internal carotid artery at the cervical portion. The patient was discharged 2 weeks after surgery without neurological deficits. Follow-up angiography revealed complete occlusion of the aneurysm 2 months postoperatively.

CONCLUSIONS

An aneurysm embedded within a prolactinoma should be closely observed when cabergoline administration is started.

Poly(meta-phenylene oxides) for the design of a tunable, efficient, and reusable catalytic platform

We present poly(meta-phenylene oxides) as versatile and tunable scaffolds for immobilized catalyst design.

Endoscopic endonasal surgery for pituitary adenomas extending to the oculomotor cistern

BACKGROUND

Extension of a pituitary adenoma to the oculomotor cistern harbors the risk of oculomotor nerve impairment and further extension into the interpeduncular cistern. The role of endoscopic endonasal surgery for those lesions was investigated.

METHODS

The medical records were retrospectively analyzed. Attention was paid to the oculomotor nerve function and removal rate of the tumor within the oculomotor and interpeduncular cisterns.

RESULTS

Six patients were eligible for the study, including 2 with oculomotor nerve palsy. The tumor from the oculomotor and interpeduncular cistern was removed in all except on one side of the case with bilateral tumor extension. The oculomotor nerve palsy demonstrated partial recovery in both cases during the 3-month follow-up.

CONCLUSION

The pituitary adenoma extending to the oculomotor cistern can be removed under the endoscope. Improvement of oculomotor nerve palsy can be achieved, and further tumor extension into the interpeduncular cistern can be prevented.

Perihemorrhagic ischemia occurs in a volume-dependent manner as assessed by multimodal cerebral monitoring in a porcine model of intracerebral hemorrhage

BACKGROUND

Changes in the perihemorrhagic zone (PHZ) of intracerebral hemorrhage (ICH) are variable. Different mechanisms contribute to secondary neuronal injury after ICH. This multimodal monitoring study investigated early changes in the PHZ of ICH.

METHODS

Twenty-four swine were anesthetized, ventilated, and underwent monitoring of vital parameters. Next to an intracranial pressure-probe (ICP), microdialysis (MD), thermodiffusion cerebral blood flow (td-CBF), and oxygen probes (PbrO2) were placed into the gray white matter junction for 12 h of monitoring. ICH was induced using the autologous blood injection model. Pre-defined volumes were 0 ml (sham), 1.5 ml ipsilateral (1.5 ml), 3.0 ml ipsilateral (3.0 ml), and 3.0 ml contralateral (3.0 ml contra).

RESULTS

ICP equally increased in all groups after ICH. In the 3.0 ml group tissue oxygenation decreased to ischemic values of 9 ± 7 mmHg early after 6 h of monitoring. This decrease was associated with a significant perfusion reduction from 36 ± 8 ml/100 g/min to 20 ± 10 ml/100 g/min. MD correlated with a threefold lactate/pyruvate ratio increase. Measurements in all other groups were unchanged.

CONCLUSION

Multimodal monitoring demonstrates volume-dependent changes of tissue oxygenation, blood flow, and ischemic MD markers in the PHZ independent of increased ICP suggesting early moderate ischemia. No evidence was found for the existence of a perihemorrhagic ischemia in the small hematoma groups.

Chronic subdural hematoma associated with moyamoya disease

Chronic subdural hematomas (SDHs) associated with non-operated moyamoya disease are extremely rare. A 68-year-old woman underwent burr-hole surgery for a right SDH, which resolved completely. On day 3, however, the patient suffered cerebral infarction in the right parietal lobe. Cerebral angiography demonstrated total occlusion of the bilateral internal carotid arteries with transdural anastomoses via branches of the right occipital artery and middle meningeal artery, feeding the left parietal cortex. A branch of the right middle meningeal artery passed near the burr hole, but was preserved. The patient was diagnosed of moyamoya disease. We thought that the main cause of chronic SDH might be the disruption of transdural anastomoses. Furthermore, we also hypothesized that we might have coagulated the small vessels of the transdural anastomoses which were undetectable by postoperative angiography, and that cerebral infarction might occur.

Decrease in plasma adiponectin level and increase in adiponectin immunoreactivity in cortex and hippocampus after traumatic brain injury in rats

AIM

Adiponectin plays an important role in the regulation of tissue inflammation. Recently, it has been reported that the plasma adiponectin levels in several acute illnesses decrease periodically, thus indicating that adiponectin may play a role in the inflammatory response in patients with acute illness. However, little is known about the effects of adiponectin following TBI. The aim of the present study was to examine the changes in the plasma adiponectin levels and the immunoreactivity of adiponectin in the brain after TBI.

MATERIAL AND METHODS

Adult male Sprague-Dawley rats were subjected to lateral fluid percussion injury using the Dragonfly device. Plasma adiponectin levels were determined by ELISA kit. Immunohistochemistry and Western blot analysis were performed to assess the immunoreactivity of adiponectin.

RESULTS

The plasma adiponectin levels gradually decreased and were significantly lower at 48 h and 72 h after injury than before injury. Immunohistochemistry and Western blot analysis showed that the adiponectin immunoreactivity was increased in the cerebral cortex at 24 hours after injury and in the hippocampus at 72 hours after injury.

CONCLUSION

Our findings suggest that adiponectin might participate in the pathophysiological process occurring after TBI.

Adiponectin receptor 1 expression is associated with carotid plaque stability

BACKGROUND

Adiponectin is a hormone secreted exclusively by adipose tissue, and is important in the regulation of tissue inflammation and insulin sensitivity. Adiponectin exerts its effects through two cell-surface receptors: Adiponectin receptor 1 (ADR1) and ADR2. However, the relationship between ADR1/2 expression and progression of atherosclerosis or plaque vulnerability remains unclear.

AIMS

To investigate the relationship between ADR1/2 expression and plaque characteristics in patients with carotid artery atherosclerosis.

MATERIALS AND METHODS

Forty-three patients who underwent carotid endarterectomy for treatment of carotid artery stenosis were reviewed. Immunohistochemical staining for ADR1 and ADR2 was performed in the specimens of carotid plaque. The relationships between ADR1/2 expression and clinical characteristics were analyzed statistically.

RESULTS

Plaque was stable in 7 patients and vulnerable in 36 patients. ADR1 expression was considered weak in 29 patients and strong in 14 patients. The formation of vulnerable plaques was significantly correlated with weak ADR1 expression (P < 0.003). ADR2 expression was considered weak in 14 patients and strong in 29 patients. Rates of formation of vulnerable plaque did not differ between patients with weak and strong ADR2 expression.

CONCLUSIONS

Based on previous and the present results, ADR1 may be strongly related to the stabilization of established atherosclerotic plaques via inactivating macrophages. Enhancement of ADR1 expression could serve as a therapeutic target for the prevention of the formation of vulnerable plaque.

Adiponectin and traumatic brain injury

Adiponectin, a circulating adipose-derived hormone regulating inflammation and energy metabolism, has beneficial actions on cardiovascular disorders. Recent studies have suggested that adiponectin might be a potential molecular target for ischemic stroke therapy; however, little is known about the effects of adiponectin on traumatic brain injury. The present study examined the immunoactivity of adiponectin.Adult male Sprague-Dawley rats were subjected to lateral fluid percussion injury using the Dragonfly device. Immuno-histochemical studies showed that the adiponectin expression was increased in the cerebral cortex at 24 h after injury and in the hippocampus at 72 h after injury. Our findings suggest that adiponectin might participate in the pathophysiological process occurring after traumatic brain injury.

Increased xCT expression correlates with tumor invasion and outcome in patients with glioblastomas

BACKGROUND

xCT is a light chain of the cystine/glutamate antiporter system xc. Glutamate that is released by system xc plays an important role in the infiltration of glioblastoma (GBM) cells. Furthermore, increased glutathione synthesis by system xc may protect tumor cells against oxidative stress induced by radiotherapy and chemotherapy.

OBJECTIVE

To investigate whether the levels of xCT expression correlated with infiltrative imaging phenotypes on magnetic resonance imaging and outcomes in patients with GBMs.

METHODS

Forty patients with histologically confirmed primary GBMs were included in the study. Patient charts were retrospectively reviewed for age, sex, Karnofsky Performance Status Scale score, Mini-Mental State Examination score, magnetic resonance imaging features, xCT expression, isocitrate dehydrogenase 1 R132H expression, O-methylguanine-DNA methyltransferase promoter methylation status, type of surgery, progression-free survival, and overall survival.

RESULTS

In invasive margins, xCT expression was weak in 20 patients and strong in 20 patients. A Cox regression model revealed that a Karnofsky Performance Status Scale score less than 60 (hazard ratio [HR]: 4.525; P = .01), partial removal (HR: 2.839; P = .03), and strong xCT expression (HR: 4.134; P < .001) were significantly associated with shorter progression-free survival and that partial removal (HR: 2.865; P = .03), weak isocitrate dehydrogenase 1 R132H expression (HR: 15.729; P = .01), and strong xCT expression (HR: 2.863; P = .04) were significantly associated with shorter overall survival.

CONCLUSION

These findings suggest that xCT is an independent predictive factor in GBMs.

An automatic bone segmentation method based on anatomical structure for the knee joint in MDCT image

The purpose of this study is to propose an automatic segmentation about each bone (the femur, the tibia, the patellar, and fibular) of the knee in MDCT image. The proposed method was applied for six patients (Age 33 ± 13, four males/tew females). The proposed method segmented the knee joint into each bone by using anatomical structure for the knee joint. The experiments calculate matching rate of the manual and the proposed method for evaluating it. As a result, The matching rate of the femur, the tibia, the patellar, and fibula were 95.84 ± 0.57%, 94.12 ± 1.01%, 94.49 ± 0.83%, 86.37 ± 4.28%, respectively. This study concluded that the proposed method is enough to segment the knee bones.

Diffuse light reflectance signals as potential indicators of loss of viability in brain tissue due to hypoxia: charge-coupled-device-based imaging and fiber-based measurement

Brain tissue is highly vulnerable to ischemia/hypoxia, and real-time monitoring of its viability is important. By fiber-based measurements for rat brain, we previously observed a unique triphasic reflectance change (TRC) after a certain period of time after hypoxia. After TRC, rats could not be rescued, suggesting that TRC can be used as an indicator of loss of brain tissue viability. In this study, we investigated this diffuse-reflectance change due to hypoxia in three parts. First, we developed and validated a theoretical method to quantify changes in the absorption and reduced scattering coefficients involved in TRC. Second, we performed charge-coupled-device-based reflectance imaging of the rat brain during hypoxia followed by reoxygenation to examine spatiotemporal characteristics of the reflectance and its correlation with reversibility of brain tissue damage. Third, we made simultaneous imaging and fiber-based measurement of the reflectance for the rat to compare signals obtained by these two modalities. We observed a nontriphasic reflectance change by the imaging, and it was associated with brain tissue viability. We found that TRC measured by the fibers preceded the reflectance-signal change captured by the imaging. This time difference is attributable to the different observation depths in the brain with these two methods.

Effect of decompressive craniectomy on aquaporin-4 expression after lateral fluid percussion injury in rats

Decompressive craniectomy is one therapeutic option for severe traumatic brain injury (TBI), and it has long been used for the treatment of patients with malignant post-traumatic brain edema. A lack of definitive evidence, however, prevents physicians from drawing any conclusions about the effects of decompressive craniectomy for the treatment of TBI. Therefore, the aim of the present study was to investigate the influence of decompressive craniectomy on post-traumatic brain edema formation. The aquaporin-4 (AQP4) water channel is predominantly expressed in astrocytes, and it plays an important role in the regulation of brain water homeostasis. In the present study, we investigated the time course of AQP4 expression and the water content of traumatized cortex following decompressive craniectomy after TBI. Adult male Sprague-Dawley rats (300-400 g) were subjected to lateral fluid percussion injury using the Dragonfly device. The effect of decompressive craniectomy was studied in traumatized rats without craniectomy (closed skull, DC-), and in rats craniectomized immediately after trauma (DC+). AQP4 expression was investigated with a Western blot analysis and immunohistochemistry. Brain edema was measured using the wet weight/dry weight method. At 48 h after TBI, AQP4 expression of the DC- group was significantly increased compared with the DC+ group (p < 0.01). In addition, the cortical water content of the DC- group was significantly increased compared to the DC+ group at the same time point (p < 0.05). The present results suggest that decompressive craniectomy may affect AQP4 expression and reduce brain edema formation after TBI.

Drug delivery observation of hydrophobe ferrofluid and magnetite nanoparticals by SPring-8 synchrotron radiation

In this study, the composite magnetic nanoparticles of coated SiO nano film with about 8 nm size and high saturation magnetization value, were synthesized by liquid phase precipitation method. The magnetic nanoparticles can be dispersed in various liquid media, widely known as magnetic fluids or ferrofluids with both magnetic and liquid properties. The materials been collected great interests and more and more attentions to focus into Drug Delivery System (DDS) as a new technology in this paper. We use the composite nanoparticles to disperse H2O and inject the solutions into rat's in-vivo organs. And, in the experiments by using a strong photon beam of SPring-8 Synchrotron Radiation facility, the distribution stat and the effects of magnetic field as well as drug delivery behaviour of nanoparticles in the rat' kidney are verified by the in-vivo observations.

Site-specific gene transfer into the rat spinal cord by photomechanical waves

Nonviral, site-specific gene delivery to deep tissue is required for gene therapy of a spinal cord injury. However, an efficient method satisfying these requirements has not been established. This study demonstrates efficient and targeted gene transfer into the spinal cord by using photomechanical waves (PMWs), which were generated by irradiating a black laser absorbing rubber with 532-nm nanosecond Nd:YAG laser pulses. After a solution of plasmid DNA coding for enhanced green fluorescent protein (EGFP) or luciferase was intraparenchymally injected into the spinal cord, PMWs were applied to the target site. In the PMW application group, we observed significant EGFP gene expression in the white matter and remarkably high luciferase activity only in the spinal cord segment exposed to the PMWs. We also assessed hind limb movements 24 h after the application of PMWs based on the Basso-Beattie-Bresnahan (BBB) score to evaluate the noninvasiveness of this method. Locomotor evaluation showed no significant decrease in BBB score under optimum laser irradiation conditions. These findings demonstrated that exogenous genes can be efficiently and site-selectively delivered into the spinal cord by applying PMWs without significant locomotive damage.

Multiparametric characterisation of the perihemorrhagic zone in a porcine model of lobar ICH

OBJECTIVES

To describe early perihemorrhagic changes after lobar intracerebral hemorrhage (ICH) using multiparametric neuromonitoring [intracranial pressure (ICP), cerebral blood flow (CBF), tissue oxygenation (PbrO2), microdialysis (MD)].

METHODS

Seven anaesthetized male swine were examined over 12 h. Four cerebral probes were inserted around the ICH (ICP, MD, CBF and PbrO2). A right frontal autologous arterial ICH (1.5 mL) was induced in all animals.

RESULTS

Initial ICH creation was hampered by using a soft 22-G cannula. A modified injection technique with a 90° bent steel cannula (20 G) allowed for an 87.5% success rate in ICH formation. After induction of ICH, ICP significantly increased from 2 mmHg to 9 mmHg. No significant PbrO2 or CBF reduction occurred during the monitoring period. Consequently, microdialysis did not indicate overall mean deterioration in the hematoma group over time. The indicator of ischemia (extracellular lactate) did not increase significantly during the monitoring period. Individual monitoring episodes demonstrated hypoxic episodes with consecutive metabolic derangement. These effects were reversible by optimizing CPP and FiO2.

CONCLUSION

We established a reproducible cortical ICH model using multiparametric neuromonitoring. Subtle changes in ICP were observed. No evidence for the existence of a perihemorrhagic ischemic area was found, hypothetically because of the small hematoma size. Individual animals underwent critical PbrO2 and CBF decreases with consecutive metabolic derangement. The effect of larger hematoma volumes should be evaluated with this setup in future studies to study volume-dependent deterioration.

Light-scattering signal may indicate critical time zone to rescue brain tissue after hypoxia

A light-scattering signal, which is sensitive to cellular/subcellular structural integrity, is a potential indicator of brain tissue viability because metabolic energy is used in part to maintain the structure of cells. We previously observed a unique triphasic scattering change (TSC) at a certain time after oxygen/glucose deprivation for blood-free rat brains; TSC almost coincided with the cerebral adenosine triphosphate (ATP) depletion. We examine whether such TSC can be observed in the presence of blood in vivo, for which transcranial diffuse reflectance measurement is performed for rat brains during hypoxia induced by nitrogen gas inhalation. At a certain time after hypoxia, diffuse reflectance intensity in the near-infrared region changes in three phases, which is shown by spectroscopic analysis to be due to scattering change in the tissue. During hypoxia, rats are reoxygenated at various time points. When the oxygen supply is started before TSC, all rats survive, whereas no rats survive when the oxygen supply is started after TSC. Survival is probabilistic when the oxygen supply is started during TSC, indicating that the period of TSC can be regarded as a critical time zone for rescuing the brain. The results demonstrate that light scattering signal can be an indicator of brain tissue reversibility.

Endoscopic intra-hematomal evacuation of intracerebral hematomas - a suitable technique for patients with coagulopathies

OBJECTIVES

To describe an endoscopic technique to evacuate acute intracerebral hemorrhage (ICH) using the balanced suction-irrigation method in patients with intrinsic or iatrogenic coagulopathies.

METHODS

We report on our early experience with four patients with atypical ICH related to intrinsic and iatrogenic coagulopathies. In all patients, an endoscopic hematoma evacuation was performed using a navigated burrhole approach. The entry site and trajectory were planned according to the long axis of the hematoma.

RESULTS

Every operation was carried out with the aid of neuronavigation. Gross total removal of the hematoma was not intended as first line, especially if eloquent areas could be avoided. Intra-hematomal evacuation leaving minimal hematoma remnants was performed in three of four patients. We report hematoma removal rates of approximately 90%. In all patients, a significant hematoma reduction was achieved, although residues were tolerated to limit neurological damage. No re-hemorrhage was observed.

CONCLUSION

The endoscopic technique with the aid of neuronavigation may be an appropriate method to safely evacuate ICH in the acute stage in patients with intrinsic or iatrogenic coagulopathies.

[Chronic subdural hematoma--recurrence and prevention]

Chronic subdural hematoma is one of the most common disorders observed in routine neurosurgical care. In the vast majority of cases, this disorder is treated by surgical evacuation, which usually yields a good prognosis. However, the recurrence rates after this initial procedure range from approximately 5% to 30%. In this study, we focused on the recurrence rate of chronic subdural hematoma and its prevention. We reviewed the risk factors for recurrence, surgical procedures used, perioperative management, timing of operation, and medical treatment.

Targeted increase in cerebral blood flow by transcranial near-infrared laser irradiation

BACKGROUND AND OBJECTIVE

Brain function is highly dependent on cerebral blood flow (CBF). The precise mechanisms by which blood flow is controlled by NIR laser irradiation on the central nervous system (CNS) have not been elucidated. In this study, we examined the effect of 808 nm laser diode irradiation on CBF in mice.

STUDY DESIGN/MATERIALS AND METHODS

We examined the effect of NIR irradiation on CBF at three different power densities (0.8, 1.6 and 3.2 W/cm(2)) and directly measured nitric oxide (NO) in brain tissue during NIR laser irradiation using an amperometric NO-selective electrode. We also examined the contribution of NO and a neurotransmitter, glutamate, to the regulation of CBF by using a nitric oxide synthase (NOS) inhibitor, N(g)-nitro-L-arginine methyl ester hydrochloride (L-NAME), and an N-methyl-D-aspartate (NMDA) receptor blocker, MK-801, respectively. We examined the change in brain tissue temperature during NIR laser irradiation. We also investigated the protection effect of NIR laser irradiation on transient cerebral ischemia using transient bilateral common carotid artery occlusion (BCCAO) in mice.

RESULTS

We showed that NIR laser irradiation (1.6 W/cm(2) for 15-45 minutes) increased local CBF by 30% compared to that in control mice. NIR laser irradiation also induced a significant increase in cerebral NO concentration. In mice that received L-NAME, NIR laser irradiation did not induce any increase in CBF. Mice administered MK-801 showed an immediate increase but did not show a delayed additional increase in local CBF. The increase in brain tissue temperature induced by laser irradiation was estimated to be as low as 0.8 degrees C at 1.6 W/cm(2), indicating that the heating effect is not a main mechanism of the CBF increase in this condition. Pretreatment with NIR laser irradiation improved residual CBF and reduced the numbers of apoptotic cells in the hippocampus.

CONCLUSION

Our data suggest that NIR laser irradiation is a promising experimental and therapeutic tool in the field of cerebral circulation research.

Revascularization for anterior cerebral artery dissecting aneurysms--three case reports

We describe three rare cases of dissecting aneurysms in the anterior cerebral artery (ACA) treated by surgical reconstruction, and reviewed 79 previously reported cases with the ACA dissecting aneurysm. We found that 35 (77.8%) of 45 patients with ischemic event and 15 (40.5%) of 37 patients with hemorrhagic event were treated conservatively, with 11.4% (4/35 cases) and 13.3% (2/15) risk of bleeding and rebleeding, respectively. Furthermore, half of these patients died. The other 32 patients were treated surgically, and their outcome was favorable, especially after surgical reconstruction. Simultaneous treatment of both hemorrhagic and ischemic events is essential. We recommend early treatment with revascularization for patients with ACA dissection that has hemorrhaged and for patients presenting with signs of clinical deterioration with ischemic event.

"Phosphene": early sign of vascular compression neuropathy of the optic nerve

BACKGROUND

Phosphenes, flashes of light, are a visual phenomenon experienced by patients with ophthalmological disease and normal individuals.

CASE REPORT

We report here a 68-year-old woman in whom phosphenes appeared in the left visual field due to compression of the right optic nerve by an aneurysm of the anterior communicating artery.

RESULTS

The symptom decreased dramatically after clipping of the aneurysm.

CONCLUSION

Phosphenes may be an important early sign of vascular compression neuropathy of the optic nerve.

Hemorrhage from a falx meningioma after internal use of low-dose aspirin

We report a case in which hemorrhage occurred in an asymptomatic falx meningioma known beforehand, after the internal use of low-dose aspirin for 16 months. Our case is the second one in which hemorrhage from a meningioma may have been induced by aspirin prophylaxis. On the other hand, aspirin may have promoted the enlargement of spontaneous hemorrhage from meningioma. Furthermore, inadequate control of hypertension may have been another cause of hemorrhage. Although it is difficult to solely attribute intratumoral hemorrhage to aspirin, we have to be careful when prescribing aspirin for patients who have asymptomatic meningioma.

Up-regulation of L type amino acid transporter 1 after spinal cord injury in rats

BACKGROUND

L-type amino acid transporter 1 (LAT1) is proposed to be a major nutrient transporter at the blood brain barrier. LAT1 requires the heavy chain of 4F2 cell surface antigen (4F2hc) for functional expression.

METHODS

We investigated the expression of this heterodimeric transporter after traumatic spinal cord injury in rat by using immunohistochemical and western blot analyses.

FINDINGS

LAT1 immunoreactivities were up-regulated in the capillary endothelia in close to the injury epicenter 24 hours after injury. It reached a peak at 48 hours after injury, and thereafter decreased. 4F2hc was abundant and unchanged all through the time course after SCI. Western blot analysis under reductive and non-reductive conditions showed that LAT1 and 4F2hc were conjugated as a heterodimeric transporter and the functional regulation was dependent on the light chain, LAT1.

CONCLUSIONS

We suggest that LAT1 may be transiently upregulated as part of the tissue-repair process after traumatic contusion injury in the spinal cord.

Subarachnoid clot distribution in anterior wall saccular aneurysms of the internal carotid artery

Anterior wall aneurysms of the internal carotid artery (AWAICA) are relatively uncommon. We investigated the distribution of the subarachnoid clot on computerized tomography (CT) scans in patients with ruptured AWAICA and compared the findings with those in patients with internal carotid artery aneurysms (ICAA) at other sites. Twenty-six ruptured ICAA patients were included in this study. Four (15.4%) of these had an AWAICA and 22 had an ICAA at other sites. Three of the 4 patients with AWAICA had an ordinary 'saccular type' aneurysm and the other had a 'blood blister-like' aneurysm. In all three patients with a 'saccular type' AWAICA, accumulation of the subarachnoid clot in the olfactory sulcus was noted on CT scan. In the patient with a 'blood blister-like' aneurysm and in 22 patients with ICAA at other sites, there were no specific correlations between focal accumulations of the subarachnoid clot and aneurysm location. The accumulation of subarachnoid clot in the olfactory sulcus on CT scan may suggest a ruptured 'saccular type' AWAICA.

[Bilateral ptosis and upper gaze palsy with pupil sparing caused by midbrain hemorrhage]

The arrangement within the midbrain oculomotor nerve complex and crossed innervation of the superior rectus muscle are not elucidated in humans. A 65-year-old woman visited our hospital complaining of difficulty opening her eyes. Neurological examination revealed bilateral ptosis and impaired supraduction. The pupils prompty constricted to light. Results of CT and MRI demonstrated that there was a hematoma located in the dorsal midbrain tegmentum that spared the rostral mid-brain. It was presumed that the nerves of the superior rectus and levator palpebrae lie in the midbrain tegmentum more dorsally and medially than the others. Furthermore, crossed innervation of the superior rectus muscle can explain that lesions located in the dorsal midbrain tegmentum cause more often impaired supraduction.