Indocyanine green endoscopic evaluation of pituitary stalk and gland blood flow in craniopharyngiomas.

To assess the use of indocyanine green (ICG) fluorescence endoscopy to evaluate pituitary blood flow in craniopharyngioma resection and its possible impact on intraoperative decisions regarding pituitary stalk processing. Patients with craniopharyngiomas who had undergone transsphenoidal surgery since March 2021, when an ICG endoscope was introduced at the Kagoshima University Hospital, were included in the study. When targeted tumor removal was approaching completion, 10 mg of ICG was administered intravenously to evaluate blood flow in the pituitary stalk and gland. ICG signals and endocrinological status before and after surgery were evaluated retrospectively. Pituitary stalk and gland blood flow were evaluated as positive (++), weakly positive (+), and no signal (-).Ten patients with craniopharyngiomas underwent transsphenoidal surgery using an ICG endoscope (mean age 56.6 ± 14.2 years; 40% male). Among the eight patients in whom the pituitary stalk was preserved, pituitary function with positive signal on the stalk was intact in two. Two other patients with weakly positive stalk and positive pituitary gland signals showed intact function or minimal pituitary dysfunction. Four patients had impairments in more than three axes with poor ICG signals in the stalk or pituitary gland. Two patients underwent pituitary amputation because of high tumor invasion and lack of ICG signal in the stalk after tumor removal, resulting in panhypopituitarism. A negative ICG signal in the pituitary stalk is likely to indicate postoperative pituitary function loss. Craniopharyngioma surgery using ICG endoscopy may be useful for predicting endocrine prognosis and improving tumor outcomes.

Dural sac shrinkage signs on magnetic resonance imaging at the thoracic level in spontaneous intracranial hypotension-its clinical significance.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is secondary to a cerebrospinal fluid leak at the spinal level without obvious causative events. Several signs on brain and cervical spine magnetic resonance (MR) imaging (MRI) have been associated with SIH but can be equivocal or negative. This retrospective study sought to identify characteristic SIH signs on thoracic spinal MRI. METHODS: Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed. RESULTS: The most prevalent findings on T2-weighted MRI at the thoracic level were anterior shift of the spinal cord (96.3%) and dorsal dura mater (81.5%), probably caused by dural sac shrinkage. These dural sac shrinkage signs (DSSS) were frequently accompanied by cerebrospinal fluid collection in the posterior epidural space (77.8%) and a prominent epidural venous plexus (77.8%). These findings disappeared in all six patients who underwent post-EBP spinal MRI. Dural enhancement and brain sagging were minimum or absent on the cranial MR images of seven patients, although DSSS were obvious in these seven patients. For 23 patients with SIH and 28 healthy volunteers, a diagnostic test using thoracic MRI was performed by 13 experts to validate the usefulness of DSSS. The median sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of the DSSS were high (range, 0.913-0.931). CONCLUSIONS: Detection of DSSS on thoracic MRI facilitates an SIH diagnosis without the use of invasive imaging modalities. The DSSS were positive even in patients in whom classic cranial MRI signs for SIH were equivocal or minimal.

CT morphometric analysis of the cervical spinal canal with special reference to the correlation with the vertebral level.

BACKGROUND: Narrowness of the spinal canal is associated with the development of cervical myelopathy. While studies have addressed the sagittal diameter of the cervical spinal canal, few evaluated the correlation between the size of the spinal canal and the vertebral level. We addressed this issue. METHODS: Our retrospective study included 102 patients with cranial or spinal disorders. We examined the correlation between the cervical spinal canal diameter (SCD) at C1 to C7 and the inner anteroposterior diameter (IAPD) of the atlas on CT images. RESULTS: At C1, the SCD was largest, at C4 it was smallest. While there was a strong correlation between the IAPD and the SCD at C1 (r = 0.8), the correlation between the size of the atlas and the SCD at C4 to C7 was weak (r = 0.2-0.3). We divided our patients into a normal group (n = 34, SCD ≥ 12 mm at any levels) and a stenosis group (n = 68, SCD < 12 mm at all levels). The mean SCD at C2 to C7 was significantly larger in the normal group. There was no significant difference between the two groups with respect to the IAPD and the SCD at C1. CONCLUSIONS: The size of the subaxial spine does not necessarily affect the size of the atlas. The pathophysiology of spinal canal stenosis should be considered separately at the C1- and the subaxial level.

Expression of the JAK/STAT signaling pathway in the ligamentum flavum of patients with lumbar spinal canal stenosis.

BACKGROUND: Ligamentum flavum (LF) hypertrophy is an important cause of lumbar spinal canal stenosis (LSS), one of the most common spinal disorders in the elderly. Although many cytokines are reported to be associated with LF hypertrophy, the intracellular signaling system is rarely discussed. The purpose of this study was to identify the JAK/STAT signaling pathway and to examine the role of the JAK/STAT systems in the hypertrophied LF. METHODS: The LF of 10 LSS patients was analyzed and the expression of JAK1, STAT3, phosphorylated (p)-STAT3, and actin was examined by Western blot analysis. The expression of p-STAT3 was also examined by immunostaining and its positive cell ratio was compared between LSS and non-LSS samples. We measured the thickness of the LF on magnetic resonance images and studied the relationship between its thickness and the expression of p-STAT3. RESULTS: JAK1, STAT3, and p-STAT3 were detected in almost all samples by Western blot analysis. Immunoreactivity against p-STAT3 was observed mainly in endothelial- and fibroblast-like cells. The expression of p-STAT3 was significantly higher in LSS than non-LSS samples; it was significantly stronger on the dorsal than the dural side of the LF and positively correlated with the thickness of the LF on the dorsal side. CONCLUSIONS: The JAK/STAT signaling pathway is positively correlated with the thickness of the LF. Our findings suggest that JAK1 and STAT3 molecules are involved in and regulate LF hypertrophy.

Rapid malignant transformation of low-grade astrocytoma in a pregnant woman.

We report rapid malignant transformation of diffuse astrocytoma to glioblastoma during pregnancy in a young woman. A 21-year-old woman was found to have a non-enhancing right frontal lesion, supposed to be a low-grade astrocytoma according to magnetic resonance imaging (MRI) studied for chronic headache. Due to the absence of clinical symptoms, the patient refused further investigations and delivered a baby and then became pregnant with a second baby. At first, she refused the biopsy because she was afraid, although the size of the lesion on MRI was increasing; however, due to repeated persuasion, she underwent a biopsy during the 4th month of her second gestation, with a result of diffuse astrocytoma (WHO grade II). At 1 month after the second delivery and 6 months after the biopsy, MRI revealed further enlargement of the tumor and a heterogeneous kenhancement effect. A gross tumor removal was carried out, and the tumor was histologically diagnosed as glioblastoma (WHO grade IV). This is the quickest ever malignant transformation of diffuse astrocytoma during pregnancy in the published reports.

Improvement in treatment results of glioblastoma over the last three decades and beneficial factors.

BACKGROUND: The purpose of this study is to elucidate the trend of glioblastoma outcome and scrutinize the factors contributing to better outcome over three decades. METHODS: Survival time and the influencing factors were retrospectively analyzed in 223 newly diagnosed primary glioblastoma patients during 1980-2010. Appraised factors included age, sex, tumor site, year of surgery, extent of resections, use of surgery supporting system, Karnofsky Performance Status (KPS), chemotherapy, conventional external beam radiotherapy (EBRT), and CyberKnife stereotactic radiotherapy (CK-SRT) use. RESULTS: The median survival time (MST) in all patients was 13.6 months. The MSTs for 4 periods were 9.8 (1980-1990), 13.7 (1991-2000), 12.9 (2001-2005), and 15.8 months (2006-2010), respectively (p=0.0047). Total resection, subtotal resection, partial resection, and biopsy had MSTs of 31.8, 13.9, 11.4, and 7.0 months, respectively (p<0.0001). Regarding chemotherapy, MSTs of the temozolomide base group and nimustine hydrochloride (ACNU) base group were 16.9 and 14.6 months, respectively, whereas the MST of patients without chemotherapy was only 9.8 months (p<0.0001). The MSTs for 40-Gy EBRT plus CK-SRT and 60-Gy EBRT were 19.1 and 10.7 months, respectively (p<0.0001). But in sub-selected patients, treated during 2001-2010, whose resection rate was total resection or subtotal resection, EBRT was completed and postoperative KPS was greater than or equal to 70, the MST with and without CK-SRT was 26.6 and 18.3 months, respectively (p=0.1529). According to the Cox proportional hazards model, degree of resection, KPS, ACNU use, temozolomide use, bevacizumab use, EBRT dose, and CK-SRT use were good prognostic factors. Use of neuronavigation and use of intraoperative magnetic resonance imaging were related to higher resection rate, but not determined as prognostic factors. CONCLUSIONS: We observed a gradual improvement in glioblastoma outcome, presumably because of improvements in therapeutic modalities for surgery, anticancer agents, and radiation, but the efficacy of CK-SRT remains unclear.

Solitary Cranial Langerhans Cell Histiocytosis: Two case reports.

Langerhans cell histiocytosis (LCH) is a proliferation of Langerhans cells intermixed with inflammatory cells, in particular eosinophils, that may manifest as a unisystem (unifocal or multifocal) or multisystem disease. We describe the clinical and histologic spectrum of LCH of the orbit and skull in our two cases. Both cases had unifocal erosive skull lesions with a history of trauma. Typical histologic features included numerous histiocytes with varying degrees of giant cell formation and scattered eosinophilic granulocytes. The presence of Langerhans cells was confirmed by CD1a and S100 immunohistochemistry. LCH has an excellent prognosis when treated with surgical resection, steroids and radiotherapy or chemotherapy. One of our patients is disease free at 7 year follow-up and one patient had regression of lesion on follow-up.

Thyroid storm induced by TSH-secreting pituitary adenoma: a case report.

Thyroid stimulating hormone-secreting pituitary adenomas (TSHomas) are uncommon tumors of the anterior pituitary gland. Patients with TSHomas may present with hyperthyroidism, but the incidence of thyroid storm due to TSHomas has yet to be determined. We report a rare case of thyroid storm caused by TSHoma in a 54-year-old woman. Preoperatively she had symptoms of excessive sweating and palpitation. Blood tests showed inappropriate secretion of TSH with blood TSH 6.86 µ U/mL, fT3 19.8 pg/mL, and fT4 5.95 ng/dL. Magnetic resonance imaging (MRI) revealed a pituitary tumor with maximum diameter of 13 mm that was extirpated through transsphenoidal route. After operation the patient was stuporous and thyroid storm occurred presenting with hyperthermia, hypertension, and tachycardia. It was well managed with nicardipine, midazolam, steroids, and potassium iodide. Immunohistochemical staining of tumor specimen was positive for TSH and growth hormone (GH). One year after operation, fT3 and fT4 levels were still high. As her tumor was diagnosed to be GH- and TSH-producing adenoma, octreotide injection therapy was started, which normalized thyroid hormone levels. This is the second reported case with thyroid storm due to TSHoma and emphasizes the importance of strategies with interdisciplinary cooperation for prevention of such emergency conditions.

Intraoperative continuous monitoring of facial motor evoked potentials in acoustic neuroma surgery.

The preservation of facial nerve function is one of the primary objectives in acoustic neuroma surgery. We detail our method of continuous intraoperative facial motor evoked potential (MEP) monitoring and present criteria for the preservation of facial nerve function to avoid postoperative facial nerve palsy. Our study population was comprised of 15 patients who did not (group 1), and 20 who did (group 2) undergo facial MEP monitoring during surgery to remove acoustic neuromas. In group 2, we continuously stimulated the facial motor cortex at 5- or 10-s intervals throughout surgery. Electromyograms (EMGs) were recorded from the contralateral orbicularis oculi- and orbicularis oris muscles. Optimal anode and cathode placement was at the facial motor cortex and the vertex, respectively. Postoperative facial palsy occurred in 8 of the 15 group 1 patients; in 2 it improved to grade II at 6 months after the operation. Of the 20 group 2 patients, 7 suffered postoperative facial palsy. At 6 months after the operation, their facial nerve function was normal. At the end of the operation, the ratio of the amplitude of the supramaximal EMG to the amplitude at the dural opening was 39.6 % in patients with- and 94.3 % in patients without transient postoperative facial palsy. Continuous facial MEP monitoring not only alerts to surgical invasion of the facial nerves but also helps to predict postoperative facial nerve function. To preserve a minimum amplitude ratio of 50 %, even transient postoperative facial palsy must be avoided. MEP monitoring is an additional useful modality for facial nerve monitoring during acoustic neuroma surgery.

Efficacy and safety of the pterional keyhole approach for the treatment of anterior circulation aneurysms.

Keyhole surgery is partly replacing the standard pterional approach in patients undergoing surgery to treat aneurysms of the anterior circulation. We describe the pterional keyhole approach for the clipping of anterior circulation aneurysms and discuss the efficacy and safety of our keyhole craniotomy procedure. We treated 103 patients with 111 intracranial aneurysms by surgical clipping via the pterional keyhole approach and retrospectively compared the characteristics and clinical outcomes of the keyhole procedure and the standard pterional approach. We also compared the surgical results of the keyhole approach when the operator was an experienced neurosurgeon or a less experienced neurosurgeon guided by an experienced colleague. All keyhole operations were carried out successfully without enlargement of the craniotomy or a change to a different approach. The outcomes of the keyhole and the standard pterional approach in patients with subarachnoid hemorrhage were not significantly different. Favorable outcomes were obtained in patients with unruptured aneurysms treated by either experienced or less experienced surgeons. The pterional keyhole approach offers the same surgical possibilities as conventional pterional approaches for the treatment of anterior circulation aneurysms. It is safe and simple and yields favorable outcomes even if the operators are less experienced neurosurgeons. Careful patient selection and sufficient opening of the sylvian fissure are the key points for good outcomes and the prevention of intraoperative complications.

A Case of Superficial Siderosis with Elevated Anti-Ro/SSA Antibody.

Superficial siderosis (SS) of the central nervous system is a rare disorder that is caused by chronic or recurrent hemorrhage in the subarachnoid space via a dural defect at the spinal level. The most common clinical features of SS include slow-progressive sensorineural deafness, cerebellar symptoms, and pyramidal tract signs. Considering that SS can present with broad clinical manifestations, for precise diagnosis, this disease must be understood. Anti-Ro/SSA antibodies are commonly detected in patients with Sjögren's syndrome and are utilized as markers for autoimmune diseases. In this report, we present a unique pathological condition in which SS coincided with a positive anti-Ro/SSA antibody test result. During the diagnosis of gait disturbance, an elevation in anti-Ro/SSA antibody was detected, and steroid pulse therapy was initiated as the initial treatment for autoimmune diseases. Head magnetic resonance imaging (MRI) revealed extensive hypointensity as a dark band that surrounded the intracranial basal structures and cerebellar hemispheres. Spinal MRI indicated ventral longitudinal intraspinal fluid collection extending from C7 to T5 as well as a defect in the ventral T2-3 dura mater. Intraoperative visualization revealed that the intradural venous plexus was the source of bleeding that caused the SS. To our knowledge, this report is the first to discuss the presence of anti-Ro/SSA antibodies in patients with SS. The role of anti-Ro/SSA antibodies in the pathophysiology of SS remains unclear; therefore, to confirm a possible association, further research and accumulation of cases are required.

Radiological Analysis of Cerebrospinal Fluid Dynamics at the Craniovertebral Junction Using Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging in Patients with Cervical Spinal Canal Stenosis.

OBJECTIVE: Spondylotic changes in the cervical spine cause degeneration, leading to cervical spinal canal stenosis. This stenotic change can affect cerebrospinal fluid (CSF) dynamics by compressing the dural sac and reducing space in the subarachnoid space. We examined CSF dynamics at the craniovertebral junction (CVJ) using time-spatial labeling inversion pulse magnetic resonance imaging (Time-SLIP MRI) in patients with cervical spinal canal stenosis. METHODS: The maximum longitudinal movement of the CSF at the CVJ was measured as length of motion (LOM) in the Time-SLIP MRI of 56 patients. The sum of ventral and dorsal LOM was defined as the total LOM. Patients were classified into 3 groups depending on their spinal sagittal magnetic resonance imaging findings: control (n = 27, Kang classification grades 0 and 1), stenosis (n = 14, Kang classification grade 2), and severe stenosis (n = 15, Kang classification grade 3). RESULTS: Time-SLIP MRI revealed pulsatile movement of the CSF at the CVJ. The mean total, ventral, and dorsal LOM was 14.2 ± 9, 8.1 ± 5.7, and 3.8 ± 2.9 mm, respectively. The ventral LOM was significantly larger than the dorsal LOM. The total LOM was significantly smaller in the severe stenosis group (6.1 ± 3.4 mm) than in the control (16.0 ± 8.4 mm) or stenosis (11 ± 5.4 mm) groups (P < 0.001, Kruskal-Wallis H-test). In 5 patients, postoperative total LOM was improved after adequate decompression surgery. CONCLUSIONS: This study demonstrates that CSF dynamics at the CVJ are influenced by cervical spinal canal stenosis. Time-SLIP MRI is useful for evaluating CSF dynamics at the CVJ in patients with spinal canal stenosis.

Hypometabolism in the Posteromedial Temporal and Medial Occipital Cortex on Preoperative 2-Deoxy-2-(18F) Fluoro-D-Glucose Positron Emission Tomography Suggests Exacerbation of Visual Field Defects After Surgery for Temporal Lobe Epilepsy: A Retrospective Long-Term Follow-Up Study.

OBJECTIVE: Surgery is a good treatment option for drug-resistant temporal lobe epilepsy (TLE). 2-deoxy-2-(18F) fluoro-D-glucose (FDG) positron emission tomography (PET) is used to detect epileptic foci as hypometabolic lesions in presurgical evaluation. Visual field defects (VFDs) in the contralateral homonymous upper quadrant are common postoperative complications in TLE. This study aimed to quantify VFDs using pattern deviation probability plots (PDPPs) and examine the effect of hypometabolism in FDG-PET on VFDs. METHODS: This study included 40 patients. Both visual fields were assessed using the Humphrey field analyzer preoperatively and 3 months and 2 years postoperatively. PDPPs with <0.5% confidence level counted in the contralateral homonymous upper quadrant. FDG-PET results were compared between groups with (15 patients) and without (24 patients) hypometabolism in the optic radiation. RESULTS: All 40 patients were evaluated by Humphrey field analyzer at 3 months postoperatively and 39 at 2 years postoperatively. The incidence of VFDs 3 months postoperatively was 35/40 (87.5%), and 17/40 (42.5%) patients had severe VFDs. In cases of surgery on the left temporal lobe, ipsilateral eyes appeared to be more significantly affected than contralateral eyes. VFDs were more severe in patients with FDG hypometabolism than in those without hypometabolism in posteromedial temporal and medial occipital cortex (P < 0.01); however, 85% of patients with FDG hypometabolism had a reduced VFD 2 years postoperatively. CONCLUSIONS: PDPP counting is useful for quantifying VFDs. Preoperative dysfunction indicated by preoperative FDG-PET in the posteromedial temporal and medial occipital cortex could enhance VFDs early after TLE surgery.

Bilateral Internal Carotid Artery Hypoplasia with Craniofacial Anomalies: A Case of Suspected Treacher Collins Syndrome.

Internal carotid artery aplasia or hypoplasia above the cervical bifurcation is rare, occurring in less than 0.01% of the general population. Unilateral neurocristopathy complicated by unilateral internal carotid artery agenesis or hypogenesis has been reported, but bilateral internal carotid artery hypoplasia is rare and scarcely reported. Herein, we report a novel case of Treacher Collins syndrome complicated by bilateral internal carotid artery hypoplasia. A 94-year-old woman presented with complaints of headache and vomiting. Computed tomography revealed a subarachnoid hemorrhage and dysplasia of the bilateral zygoma, mandible, and external auditory meatus. The patient had severe hearing loss and visual impairment. Computed tomography angiography revealed bilateral internal carotid artery hypoplasia and multiple aneurysmal changes in the intracranial arteries. We diagnosed the patient with a ruptured anterior inferior cerebellar artery aneurysm and performed coil embolization. The patient's unique facial features were consistent with neurocristopathy, especially Treacher Collins syndrome. Developmental anomalies of neural crest cells can present as vascular abnormalities and craniofacial malformations. Special care is required for endovascular treatment and airway management in cases of neurocristopathy because of the specific craniofacial anomalies.

Favorable prognostic impact of phosphatase and tensin homolog alterations in wild-type isocitrate dehydrogenase and telomerase reverse transcriptase promoter glioblastoma.

Background: Telomerase reverse transcriptase promoter (TERTp) mutations are a biological marker of glioblastoma; however, the prognostic significance of TERTp mutational status is controversial. We evaluated this impact by retrospectively analyzing the outcomes of patients with isocitrate dehydrogenase (IDH)- and TERTp-wild-type glioblastomas. Methods: Using custom next-generation sequencing, we analyzed 208 glioblastoma samples harboring wild-type IDH. Results: TERTp mutations were detected in 143 samples (68.8%). The remaining 65 (31.2%) were TERTp-wild-type. Among the TERTp-wild-type glioblastoma samples, we observed a significant difference in median progression-free survival (18.6 and 11.4 months, respectively) and overall survival (not reached and 15.7 months, respectively) in patients with and without phosphatase and tensin homolog (PTEN) loss and/or mutation. Patients with TERTp-wild-type glioblastomas with PTEN loss and/or mutation were younger and had higher Karnofsky Performance Status scores than those without PTEN loss and/or mutation. We divided the patients with TERTp-wild-type into 3 clusters using unsupervised hierarchical clustering: Good (PTEN and TP53 alterations; lack of CDKN2A/B homozygous deletion and platelet-derived growth factor receptor alpha (PDGFRA) alterations), intermediate (PTEN alterations, CDKN2A/B homozygous deletion, lack of PDGFRA, and TP53 alterations), and poor (PDGFRA and TP53 alterations, CDKN2A/B homozygous deletion, and lack of PTEN alterations) outcomes. Kaplan-Meier survival analysis indicated that these clusters significantly correlated with the overall survival of TERTp-wild-type glioblastoma patients. Conclusions: Here, we report that PTEN loss and/or mutation is the most useful marker for predicting favorable outcomes in patients with IDH- and TERTp-wild-type glioblastomas. The combination of 4 genes, PTEN, TP53, CDKN2A/B, and PDGFRA, is important for the molecular classification and individual prognosis of patients with IDH- and TERTp-wild-type glioblastomas.

Alterations in EGFR and PDGFRA are associated with the localization of contrast-enhancing lesions in glioblastoma.

Background: Glioblastoma (GBM) is a malignant brain tumor, with radiological and genetic heterogeneity. We examined the association between radiological characteristics and driver gene alterations. Methods: We analyzed the driver genes of 124 patients with IDH wild-type GBM with contrast enhancement using magnetic resonance imaging. We used a next-generation sequencing panel to identify mutations in driver genes and matched them with radiological information. Contrast-enhancing lesion localization of GBMs was classified into 4 groups based on their relationship with the subventricular zone (SVZ) and cortex (Ctx). Results: The cohort included 69 men (55.6%) and 55 women (44.4%) with a mean age of 66.4 ±â€…13.3 years. EGFR and PDGFRA alterations were detected in 28.2% and 22.6% of the patients, respectively. Contrast-enhancing lesion touching both the SVZ and Ctx was excluded because it was difficult to determine whether it originated from the SVZ or Ctx. Contrast-enhancing lesions touching the SVZ but not the Ctx had significantly worse overall survival than non-SVZ lesions (441 days vs. 897 days, P = .002). GBM touching only the Ctx had a better prognosis (901 days vs. 473 days, P < .001) than non-Ctx lesions and was associated with EGFR alteration (39.4% vs. 13.2%, P = .015). Multiple contrast lesions were predominant in PDGFRA alteration and RB1-wild type (P = .036 and P = .031, respectively). Conclusions: EGFR alteration was associated with cortical lesions. And PDGFRA alteration correlated with multiple lesions. Our results suggest that clarifying the association between driver genes and tumor localization may be useful in clinical practice, including prognosis prediction.

Clinical presentation and treatment of distal anterior inferior cerebellar artery aneurysms.

Aneurysms located at the distal portion of the anterior inferior cerebellar artery (AICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of nine distal AICA aneurysms in nine patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes seven women and two men. Of their nine aneurysms, eight were ruptured and one was unruptured; six were saccular and three were dissecting aneurysms. The most prevalent location was the meatal loop (n = 5) followed by the postmeatal (n = 3) and premeatal segment (n = 1) of the AICA, suggesting hemodynamic stress as an etiology of these distal AICA aneurysms. Of the nine patients, five presented with angiographic features suggestive of increased hemodynamic stress to the AICA and the common trunk of the posterior inferior cerebellar artery, with vertebral artery stenosis, marked laterality, and a primitive hypoglossal artery. We addressed eight aneurysms (eight patients) surgically; one aneurysm in one patient disappeared in the course of 3 months without surgical treatment. Of the eight surgically treated aneurysms, seven were ruptured and one was unruptured, five were clipped via lateral suboccipital craniotomy, two were trapped via lateral suboccipital craniotomy, and one was embolized. Good outcomes were obtained in six of the eight patients who underwent operation (75 %). We consider increased hemodynamic stress attributable to anatomic variations in the AICA and related posterior circulation to be the predominant contributor to the development of distal AICA aneurysms. Direct clipping and trapping yielded favorable outcomes in our series.

Spinal intradural solitary fibrous tumor/ hemangiopericytoma with intramedullary invasion mimicking a hemangioblastoma.

Background: Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are rare mesenchymal tumors of nonmeningothelial origin that comprises <1% of all central nervous system tumors. Case Description: A 45-year-old male presented with sleep apnea (apnea-hypopnea index was 17.1 events/hour) and dysesthesias of the right upper and lower extremities. The magnetic resonance demonstrated a heterogeneous intradural extra-axial C1 mass with syringobulbia and syringomyelia. The right vertebral angiography revealed a hypervascular mass (i.e., intense tumor staining). With the preoperative diagnosis of a spinal hemangioblastoma, the patient underwent tumor removal. However, intraoperative findings demonstrated that the ventral component of the tumor was intramedullary without a dural attachment. Further, the histological diagnosis was consistent with SFT/HPC (HPC phenotype). The postoperative course was uneventful, and the patient's symptoms and the syrinxes spontaneously regressed. Conclusion: A 45-year-old male presented a rare spinal intradural lesion at C1 appeared to be a spinal hemangioblastoma, but proved to be SFT/HPC (HPC phenotype) with intramedullary invasion.