Idiopathic spinal cord herniation: consideration of its pathogenesis based on the histopathology of the dura mater.

INTRODUCTION: We present a patient with idiopathic spinal cord herniation (ISCH) whose dura mater was histopathologically examined to elucidate its pathogenesis. CASE REPORT: A 33-year-old previously healthy man presented with progressive walking difficulty, spasticity of the right lower leg, and hyperesthesia below the right chest. Neuroimaging revealed right ventral displacement of the spinal cord at T5-6. The diagnosis was ISCH and he underwent release of the herniation from the ventral dural opening. Dural biopsy at the edge of the ventral opening and in the dorsal durotomy was performed. Postoperatively, his gait was improved. Histopathological examination of the ventral dural specimen showed non-specific degeneration, i.e., loose arrangements of collagen fibers, edematous changes, minor inflammatory cell infiltration, and angiogenesis. The specimen from the dorsal durotomy was normal. CONCLUSION: It is unclear whether the observed degeneration besides the ventral opening was the primary cause of ISCH or reflected secondary changes resulting from cumulative damage due to pulsation of the herniated spinal cord. However, the degeneration limited to the ventral opening suggests that ISCH was a local event in an individual with a normal dural theca.

[False Aneurysm Formation at the Origin of the M2 Segment of the Middle Cerebral Artery Following a Blunt Head Trauma:A Case Report].

A 43-year-old man fell from a 1m-high truck loading platform and sustained an injury in the occiput. On admission, he was alert and neurologically intact. Computed tomography(CT)showed hemorrhage in the right sylvian fissure and parenchyma adjacent to the sphenoid wing. Magnetic resonance angiography detected no abnormalities. The course was uneventful for 11 days. However, on the 12th day, he spontaneously manifested with stupor. CT and CT angiography revealed expansion of the hemorrhage and an aneurysm arising from the origin of the M2 segment of the right middle cerebral artery. After superficial temporal artery to middle cerebral artery bypass, the aneurysm, a reddish pulsatile mass, was removed from the origin of the torn M2 segment, and the laceration was sutured. The histological diagnosis was false aneurysm. He recovered and was discharged 4 months after the trauma. Traumatic cerebral aneurysms are rare in the proximal segment of the middle cerebral artery. However, they should be distinguished from nontraumatic true aneurysms in the same region and treated as false aneurysms, which are major and critical traumatic aneurysms, for favorable outcomes.

PDGFRA gene rearrangements are frequent genetic events in PDGFRA-amplified glioblastomas.

Gene rearrangement in the form of an intragenic deletion is the primary mechanism of oncogenic mutation of the epidermal growth factor receptor (EGFR) gene in gliomas. However, the incidence of platelet-derived growth factor receptor-α (PDGFRA) gene rearrangement in these tumors is unknown. We investigated the PDGFRA locus in PDGFRA-amplified gliomas and identified two rearrangements, including the first case of a gene fusion between kinase insert domain receptor (KDR) (VEGFRII) and the PDGFRA gene, and six cases of PDGFRA(Δ8, 9), an intragenic deletion rearrangement. The PDGFRA(Δ8, 9) mutant was common, being present in 40% of the glioblastoma multiformes (GBMs) with PDGFRA amplification. Tumors with these two types of PDGFRA rearrangement displayed histologic features of oligodendroglioma, and the gene products of both rearrangements showed constitutively elevated tyrosine kinase activity and transforming potential that was reversed by PDGFR blockade. These results suggest the possibility that these PDGFRA mutants behave as oncogenes in this subset of gliomas, and that the prevalence of such rearrangements may have been considerably underestimated.

[Formation of a Subcutaneous Amputation Neuroma after Incomplete Endoscopic Carpal Tunnel Release Resulting in Complex Regional Pain Syndrome:A Case Report].

This 64-year-old woman had undergone endoscopic carpal tunnel release(ECTR)for right carpal tunnel syndrome 16 months earlier. Thereafter, she reported persistent dysesthesia in the thumb and index finger, developed burning pain in the middle and ring finger, paleness, coldness, and edema of the hand, a decreased range in hand motion, and a painful subcutaneous nodule just distal to the portal in the forearm. Based on physical, radiological, and electrophysiological studies, the diagnosis was incomplete carpal tunnel release associated with complex regional pain syndrome(CRPS). At open revision surgery, the carpal tunnel was released completely and the nodule was removed. Symptoms other than hypesthesia in the middle and ring fingers improved. Pathologically, the nodule was an amputation neuroma. Her CRPS was attributed to ECTR complications; i.e., persistence of median nerve compression and the formation of an amputation neuroma in the palmar cutaneous branch of the ulnar nerve at the portal. Surgeons must be aware that ECTR, a less invasive technique, may result in serious complications including CRPS.

Sacral myolipoma with symptomatic contraction of the conus at standing on tiptoe.

INTRODUCTION: We present a case with spinal myolipoma that was unique in its anatomical composition and symptomatology. CASE REPORT: An 18-year-old male presented with urinary retention and buttock pain exacerbated by standing on tiptoe underwent untethering of the low-set conus associated with a sacral fatty tract. Electrical stimulation of the spinal roots beside the upper conus induced anomalous caudal movement of the conus and contraction of the gastrocnemius muscle. In the lower conus, an ectopic muscle bridging the conus and dura was found, and the tissue contracted upon electrical stimulation. The histopathological diagnosis was myolipoma involving mature striated muscle and fat cells. Postoperatively his buttock pain was relieved immediately, but urinary retention persisted. CONCLUSION: We posit that his buttock pain, exacerbated by standing on tiptoe, was due to traction of the conus by contraction of the ectopic muscle that was aberrantly innervated from the sacral spinal roots.

[Differentiation between a thoracic spinal intramedullary lipoma and an intramedulary hematoma on fast spin-echo MRI scans: a case report].

We describe differentiation of a spinal intramedullary lipoma from an intramedullary hematoma on magnetic resonance images (MRI) with fast spin-echo (FSE) sequences. A 60-year-old man with dysesthesia in the legs and gait disturbance, was suspected of having myelopathy at a middle thoracic lesion. MRI with FSE sequences revealed an intramedullary lesion at T7 to T8. On the basis of hyperintensity on both T1-and T2-weighted images and a perilesional hypointense rim on T2-weighted images we made a diagnosis of subacute hematoma and planned observation. However, computed tomography for associated vertebral degeneration revealed a hypodense area (-97 Hounsfield units) in the region corresponding to the lesion depicted by MRI. We revised our diagnosis to an intramedullary lipoma and debulked the lesion. The lipoma was surrounded by a thick whitish capsule. Histopathologically, the capsule contained mature fat tissue and abundant collagen. The initial diagnosis was mainly attributable to specific FSE characteristics, i. e., the depiction of fat tissue as hyperintense on both T1-and T2-weighted images. Conventional spin-echo MRI depicts fat tissue as hyperintense on T1-and as hypointense on T2-weighted images. Other factors contributing to our initial diagnosis were MRI findings suggestive of an intramedullary hematoma, i. e., the intrinsic location of the lesion and the perilesional hypointense rim on T2-weighted images ascribable to collagen present in the capsule. The accurate diagnosis of an intramedullary lipoma on FSE requires correct interpretation of the signal, which is different from the signal on conventional spin-echo MRI.

Signal intensity changes for the middle cerebral artery on 3-dimensional time-of-flight magnetic resonance angiography indicate acute hemodynamic changes after carotid endarterectomy.

BACKGROUND: For 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA), the signal intensity (SI) loss depends on the flow velocity. In this study, we aimed to evaluate whether 3D-TOF-MRA could be used as an alternative to single-photon emission computed tomography (SPECT) for assessing the increase in the regional cerebral blood flow (rCBF) after carotid endarterectomy (CEA). To do this, we compared the SI of the middle cerebral artery (MCA) on magnetic resonance angiography (MRA) and the rCBF on SPECT. METHODS: We enrolled 30 patients with internal carotid artery stenosis. SPECT and MRA were performed before and 3-4 days after CEA. rCBF was assessed using SPECT, and the SI of the MCA was assessed using single-slab 3D-TOF-MRA. Regions of interest were placed in the bilateral middle M1 portions of the MCA on MRA, and their mean SI was measured. The increase ratio of the rCBF on SPECT and the increase ratio of the SI of the MCA on MRA were calculated using the formula: (post-CEA ipsilateral/post-CEA contralateral)/(pre-CEA ipsilateral/pre-CEA contralateral). RESULTS: A significant correlation was observed between the increase ratio of the rCBF on SPECT and the increase ratio of the SI of the MCA on MRA (r=.894, y=.4863+.5184x, P<.001). All values obtained by MRA were greater than or equal to the SPECT values, indicating that MRA tends to overestimate the post-CEA rCBF increase. CONCLUSION: Because MRA identified increased rCBF after CEA, we recommend that patients first be screened using MRA.

Hyperplasia of Arachnoid Trabecular Cells: A Hitherto Undescribed Lesion Observed in the Setting of Neurofibromatosis Type 1.

Central nervous system manifestations, a variety of benign and malignant tumors as well as non-neoplastic abnormalities, are found in over 70% of neurofibromatosis type 1 (NF1) patients. Herein, we report hitherto undescribed space-occupying lesions in the setting of NF1. We aimed to clarify their characteristics, especially whether they represent neoplastic or non-neoplastic (hyperplastic) lesions. All 3 cases were preoperatively assessed as non-neoplastic; 2 and 1 cases were suspected to be arachnoid cysts and dilation of subarachnoid space, respectively. However, all lesions were revealed to be whitish jelly-like masses by operation, and the histology composed of spindle cells resembling arachnoid trabecular cells with moderate cellularity and cellular uniformity gave an impression that these lesions may be neoplastic. In contrast, electron microscopic analysis showed that the characteristics of these cells were compatible with those of normal arachnoid trabecular cells. Furthermore, whole-exome sequencing and array comparative genomic hybridization did not show any obvious alterations suggestive of their neoplastic nature. DNA methylation analysis demonstrated that these lesions were epigenetically distinct not only from meningiomas but also from normal healthy meninges. In conclusion, considering the clinicopathologic aspects of the present lesions and the results of the molecular analysis that failed to suggest their neoplastic nature, they may represent previously unrecognized rare hyperplasia of arachnoid trabecular cells, which may be associated with NF1.

Fatal Fungal Aneurysm Rupture Due to Aspergillosis after Craniopharyngioma Removal via Endoscopic Endonasal Surgery: Case Report and Comparison with Seven Reported Patients.

There has been a noted increase in the incidence of intracranial aspergillosis; this is often attributed to the wider use of antibiotics, corticosteroids, and immunosuppressants. Fungal cerebral aneurysms due to aspergillosis after neurosurgery remain extremely rare; in fact, only seven cases have been reported in the literature. In this study, we present a patient with an Aspergillus aneurysm that elicited subarachnoid hemorrhage after endoscopic endonasal surgery (EES) for craniopharyngioma. A 70-year-old woman with recurrent craniopharyngioma and steroid treatment underwent uneventful EES. On the 5th postoperative day, she suffered subarachnoid hemorrhage. As per her computed tomography angiography findings, an aneurysm was detected on the left internal carotid artery (ICA). Subsequent digital subtraction angiography showed occlusion of the ICA and an irregularly shaped wall. The diagnosis was pseudoaneurysm. We then performed craniotomy to place a left high-flow bypass and to trap the pseudoaneurysm. Despite continuous intensive care, she died on the 25th postoperative day of a huge, left cerebral infarct. The final diagnosis was made at autopsy; it revealed destruction of the ICA and Aspergillus invasion of the vessel wall, confirming the presence of a true fungal aneurysm. Perioperatively, patients with potential immunosuppression must be carefully managed. Advanced age is a risk factor. As surgery via the paranasal sinuses raises the risk for aspergillosis, fungal infection must be ruled out in patients whose postoperative course is deemed concerning.

Linear fractures occult on skull radiographs: a pitfall at radiological screening for mild head injury.

BACKGROUND: Skull radiography is widely used to screen for fractures in patients with mild head injury. However, the clear depiction of a fracture requires a gap in the skull separated by the fracture that is wide enough to allow the passage of x-rays. We studied atypical linear fractures that were not visualized clearly, because a specific anatomical configuration hampered the passage of x-rays. METHODS: We retrospectively evaluated 278 patients with mild head injuries who had undergone routine skull radiography (anteroposterior and lateral views) and head computed tomography (CT). We found that some patients negative for linear fracture on skull radiographs were positive on bone window CT scans. RESULTS: Of the 278 patients aged between 2 months and 66 years, 8 (2.9%) manifested a linear fracture on CT scans that presented as a cross section of the fracture oblique to the direction of the x-rays. Four of the 8 developed acute epidural hematoma; 2 of these patients underwent craniotomy. CONCLUSIONS: Radiographic study returned false-negative results, because x-rays were absorbed by the double-layered skull along fractures whose cross section was oblique to the direction of the x-rays. The evaluation of head injury by radiography only may miss these fractures and their undetected presence may result in sequelae such as intracranial hematoma.

Effectiveness of interferon-beta therapy for recurrent glioblastoma: a case report.

AIMS AND BACKGROUND: Glioblastoma has a poor prognosis, with few therapeutic options if it recurs. We report a case in which we were able to inhibit the growth of a recurrent glioblastoma by weekly single-dose administration of interferon-beta. CASE REPORT: A patient with recurrent glioblastoma after radiation and chemotherapy was treated with nimustine and interferon-beta. After 2 cycles of nimustine, the patient's leukocyte, neutrophil, and platelet counts showed grade 4 toxicity according to the National Cancer Institute's Common Toxicity Criteria. The patient was treated with a weekly single dose of interferon-beta at 6 x 10(6) IU. The tumor showed no remarkable changes after 18 months, and the patient's Karnofsky performance status remained at 50%. CONCLUSIONS: The administration of interferon-beta produced long-term control in one case of glioblastoma and may be an effective therapy.

Utility of intraoperative fluorescent diagnosis of residual hemangioblastoma using 5-aminolevulinic acid.

Hemangioblastoma is a benign tumor of the cerebellum, and treatment involves surgical excision, both as the initial treatment and also in case of recurrence. Recurrence of hemangioblastoma can be local due to incomplete resection or can be distant and separate from the tumor resection region. Local recurrence can largely be avoided by verifying for any residual tumor intraoperatively before closure. In this study, we used intraoperative fluorescent diagnosis using 5-aminolevulinic acid (5-ALA) to verify the presence of a residual tumor during surgical resection. Nine patients with hemangioblastoma were given 1 g of 5-ALA orally before surgery, and a laser beam of 405 nm was focused on the tumor during resective surgery. Fluorescence of protoporphyrin IX (PPIX) was observed in the core of tumor in all the cases. Fluorescence of PPIX was observed in the peritumoral cyst wall in two patients after tumor resection, and in both of them fluorescent parts of PPIX were resected and histological examination showed tumor cells. Usually, there are no tumor cells in the peritumoral cyst of a hemangioblastoma, yet hemangioblastomas may sometimes recur from an unresected cyst wall. It is thus necessary to excise an infiltrating cyst of tumor cells to prevent recurrence. Intraoperative fluorescent diagnosis using 5-ALA is a useful method to discern whether tumor cells are present in the peritumoral cyst wall of a hemangioblastoma.

Effect of Compound Muscle Action Potential After Peripheral Nerve Stimulation Normalization on Anesthetic Fade of Intraoperative Transcranial Motor-Evoked Potential.

PURPOSE: Anesthetic fade refers to the time-dependent decrease in the amplitude of the intraoperative motor-evoked potential. It is thought to be caused by the accumulation of propofol. The authors examined whether normalization by the compound muscle action potential (CMAP) after peripheral nerve stimulation could compensate for anesthetic fade. METHODS: In 1,842 muscles in 578 surgeries, which did not exhibit a motor-neurologic change after the operation, the motor-evoked potential amplitude was normalized by the CMAP amplitude after peripheral nerve stimulation, and the CMAP amplitude and operation times were analyzed. RESULTS: The amplitudes of both motor-evoked potential and CMAP increased over time after peripheral nerve stimulation because of the disappearance of muscle-relaxant action. Especially, after peripheral nerve stimulation, CMAP significantly increased from the beginning to the end of the operation. Anesthetic fade in transcranial motor-evoked potential monitoring seemed to occur at more than 235 minutes of surgery based on the results of a receiver operating characteristic analysis of the operation time and relative amplitudes. Although the mean amplitude without CMAP normalization at more than 235 minutes was significantly lower than that at less than 235 minutes, the mean amplitude with normalization by CMAP after peripheral nerve stimulation at more than 235 minutes was not significantly different from that at less than 235 minutes. CONCLUSIONS: Compound muscle action potential after peripheral nerve stimulation normalization was able to avoid the effect of anesthetic fade. Anesthetic fade was seemed to be caused by a decrease in synaptic transmission at the neuromuscular junction because of propofol accumulation by this result.

[Effect of Chai-ling-tang (Sairei-to) for methotrexate concentration degradation delay by methotrexate high-dose therapy].

When methotrexate (MTX) salvage chemotherapy is performed for primary brain malignant lymphoma, use of leucovonrin rescue must often be extended due to delays in the degradation of blood concentration. We examined whether delay in MTX blood concentration degradation could be prevented by chai-ling-tang (Sairei-to) which has diuretic action. In the five cases examined were MTX blood concentration 72 hours after MTX administration was more than 1 x 10(-7) M. A single dose of 3 g of chai-ling-tang was administered three times on the day the MTX salvage chemotherapy was subsequently performed. MTX blood concentration at 72 hours post MTX administration and subsequent chai-ling-tang administration was less than 1 x 10(-7) M in all five cases. In addition, urea nitrogen and creatinine levels in serum increased and creatinine clearance decreased following MTX administration, however these changes induced by MTX administration were reduced by chai-ling-tang administration. Chai-ling-tang was effective in preventing an MTX deferent delay in MTX high-dose therapy by improving renal blood flow.

Proteomics of tumor-specific proteins in cerebrospinal fluid of patients with astrocytoma: usefulness of gelsolin protein.

Changes in cerebrospinal fluid (CSF) composition have been shown to accurately reflect pathological processes in the CNS, and are potential indicators of abnormal CNS states, such as tumor growth. To detect biomarkers in high-grade astrocytomas, the differential expression of proteins in the cerebrospinal fluid was analyzed from two cases each of diffuse astrocytoma (grade II), and glioblastoma (grade IV) using agarose 2-D gel electrophoresis (2-DE). It was found that the expression of gelsolin protein decreased with histological grade. To examine whether gelsolin is a useful indicator of tumor aggressiveness or patient outcome, its expression was further studied on immunohistochemistry in 41 formalin-fixed and paraffin-embedded astrocytomas. The positive cell rate of gelsolin in tumors was 59.4% in grade II, 30.0% in grade III and 29.4% in grade IV, respectively. Gelsolin expression was significantly lower in high-grade astrocytomas (grade III or IV) than in low-grade astrocytomas (grade II; P < 0.05). Moreover, in astrocytomas the overall survival of patients in the low-expression group was significantly poorer than in the high expression group (P < 0.05). These data suggest that gelsolin is a prognostic factor in astrocytoma.

Brachial plexopathy due to massive swelling of the neck associated with craniotomy in the park bench position.

BACKGROUND: During prolonged neurosurgical procedures, anesthetized patients are at risk for position-related complications. We report a rare combination of neck swelling and brachial plexopathy as operative position-related complications. CASE DESCRIPTION: This 56-year-old woman was placed in the left park bench position for removal of a tentorial meningioma in the right posterior fossa. At 2 hours after the 10-hour procedure, her left neck began to swell with progression during the next 10 hours to involve the face on the same side and the face and neck on the opposite side. Computed tomography showed swelling of the muscles and deep soft tissue primarily on the left. No brain edema was observed. She was conservatively treated with orotracheal intubation, placed in the head-up position, and received anticoagulants. Her swelling subsided by the 20th postoperative day; however, she manifested weakness in the proximal muscles of the left upper extremity. Magnetic resonance imaging revealed swelling of the brachial plexus on the left; electrophysiologic studies were compatible with damage to the upper trunk of the brachial plexus. She was discharged 2 months after surgery with improved weakness. CONCLUSION: Possible pathologic mechanisms are kinking of the jugular vein due to extremely flexed neck position during surgery and associated delayed swelling of the neck and brachial plexus. The cerebral venous return may have been maintained by anastomosis between the internal jugular and the vertebral venous system. To prevent such complications, we must take great care of the anesthetized patients when placed in the forced neck position.

Spinal cord tethering by aberrant nerve root in myelomeningocele: case report.

INTRODUCTION: A 2,796-gram male baby was born at 40 weeks gestation by vaginal delivery. Soon after, he was admitted at our department for treatment of a dorsal appendage. RESULTS AND DISCUSSION: Magnetic resonance (MR) imaging showed a low-position spinal cord, skin-covered myelomeningocele, syringomyelia, and a tethered cord. Resection of the caudal appendage and tethering tissue was performed 22 days after birth under electrophysiological monitoring. Histopathological examination of the caudal appendage that was covered with skin revealed the presence of spinal cord tissue and peripheral nerve tissue. The string-like tethering tissue that extended from the spinal cord to the caudalis was a nerve root, and there was fiberization of the caudalis. The syringomyelia was improved at postoperative MR imaging. To our knowledge, there is no report of a similar case in the literature. We report rare combination of myelomeningocele and spinal cord tethering by aberrant nerve root with thoracic syringomyelia.