A Robust Lamb Wave Imaging Approach to Plate-Like Structural Health Monitoring of Materials With Transducer Array Position Errors.

The Lamb-wave-based damage imaging via beamforming techniques, which can visualize the location of damage in the structure intuitively, is one of the most promising methods in the field of structural health monitoring (SHM). However, transducer array position errors are inevitable in practical application, which may lead to serious degradation in imaging performance. In this study, it is shown that the uncertainty of the steering vectors led by the imprecise position of transducers in an array can be suppressed by the doubly constrained robust Capon beamformer (DCRCB). After the unwanted side lobes are restrained by the DCRCB-based coherence factor (CF) weighting, an effective adaptive beamforming damage imaging method robust to transducer position errors is proposed. The numerical simulation and imaging experiment of damage on an aluminum plate are carried out to verify the effectiveness of the proposed algorithm. The results show that the proposed Lamb wave damage imaging method performs better than the reported beamforming ones in literature in terms of resolution, contrast, and robustness to transducer position errors.

Surgical treatment achieves better outcome in severe traumatic pericallosal aneurysm: case report and literature review.

Traumatic pericallosal aneurysm (TPA) is typically seldom yet potentially lethal. Because of its rarity, also complicated by the unpredictable delayed-onset, TPA is more difficult to be diagnosed promptly. Due to the sporadic reports and diverse opinions on the priority of surgical treatment, a consensus about effective management of TPA has not been reached. Here we report a 55 year-old male patient with TPA, who received an emergent craniotomy to clip the pseudoaneurysm and remove the hematoma under intense intracranial pressure (ICP) monitoring. A satisfactory clinical outcome was achieved at a 3-month follow-up. Thereafter, a review was conducted to evaluate the outcomes of different managing modalities.

Microvascular decompression surgery is effective for the laterocollis subtype of spasmodic torticollis: a long-term follow-up result.

BACKGROUND: Spasmodic torticollis (ST) is characterized by sustained, involuntary, and painful spasms of specific muscle (s), which results into abnormal posture of the neck and head. Although various treatments for ST have been introduced, none of them shows absolute effectiveness. Earlier research from our department showed that microvascular decompression (MVD) surgery is effective in the short-term for ST patients with confirmed accessory nerve compression. However, the long-term outcome of MVD remains unknown. METHOD: Twelve ST patients with confirmed accessory nerve compression received MVD surgery of their accessory nerves. We utilized the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) to evaluate the long-term outcome (5.4 ± 0.87 years). RESULTS: The MVD lowered total TWSTRS scores by 42.8 % in all ST patients. This result, however, only counted for moderate relief. Interestingly, we observed that the laterocollis (LC) subtypes of ST (n = 3) obtained a higher TWSTRS score improvement (86.9 ± 6.2 %), compared to that of the non-LC (28.1 ± 12 %) (P =0.0001). Additionally, the disability (92.7 ± 2 %) subscale score in the LC subtypes had the most prominent improvement compared to the pain (88.1 ± 5.1 %) and severity (81.3 ± 10.5 %). CONCLUSIONS: In the cases of confirmed accessory nerve compression, the MVD could be considered as a treatment alternative for ST, especially for the LC subtypes.

[Surgical treatment of hemangioblastoma in medulla oblongata:a report of 12 cases].

OBJECTIVE: To explore the clinical characteristics, diagnostic strategies and surgical techniques of hemangioblastoma (HB) in medulla oblongata. METHODS: The clinical and radiological characteristics, therapeutic processes and outcomes of 12 HB cases treated at our department from 2002 to 2012 were studied by retrospective analysis. RESULTS: Headache, somatic numbness and limb muscle weakness were the major symptoms of oblongata HB. Magnetic resonance imaging before surgery revealed a total of 12 single tumors. Among these tumors, upper (n = 1), middle (n = 7) and lower (n = 4) parts of medulla oblongata were involved. The locations were surface (n = 9) and intramedullary (n = 3). Three tumors had cyst. Digital subtraction angiography (DSA) was performed on 5 cases and it revealed that the main blood supply arteries of tumors were branches of posterior inferior cerebellar artery (PICA) and anterior inferior cerebellar artery (AICA).One case underwent pre-surgical embolism during angiography. Eleven tumors were totally resected and 1 was fulgurized.Symptoms improved (n = 8) and worsened (n = 2). And two patients died. All survivors were followed up for 3 months to 10 years and had a McCormick functional grading of I-II.One case relapsed 7 year later. CONCLUSION: For Cystic HB, small or medium sized substantial HB in middle and lower part of oblongata, surgical removal is often safe and symptoms may be lessened.It can be used as a first-line treatment. For large ( ≥ 3 cm) substantial HB or HB in upper part of oblongata, serious postoperative complications such as respiratory failure, neurogenic pulmonary edema or acute obstructive hydrocephalus may occur. Thus surgical resection should be prudently considered and possible consequences thoroughly discussed with the patients.

Which is the best peri-operative anti-coagulative therapy of transverse sinus stenting for refractory idiopathic intracranial hypertension?

Treatment of refractory idiopathic intracranial hypertension (IIH) is a challenging problem. We reported a refractory IIH patient who manifested with typical intracranial hypertensive symptoms successfully treated with endovascular stent implantation. Pre-operative cerebrospinal fluid (CSF) opening pressure is 36 cmH2O. Cerebral angiography demonstrated a stenotic lesion located at the right transverse sinus (TS). The stenotic TS returned to its normal caliber and the pressure gradient deceased from 36 mmHg to 4 mmHg after the stent placement. The intracranial hypertensive symptoms resolved and one month later, the CSF opening pressure decreased to 14 cmH2O.

Knockdown of ubiquitin-conjugating enzyme E2C/UbcH10 expression by RNA interference inhibits glioma cell proliferation and enhances cell apoptosis in vitro.

PURPOSE: To address the role of ubiquitin-conjugating enzyme, E2C/UbcH10, in astrocytic carcinogenesis. METHODS: Expression pattern of UbcH10 in U251 glioma cells was evaluated by immunohistochemistry and western blot. RNA interference was employed to downregulate UbcH10 expression in U251 cell line. The effect of UbcH10 silencing on cell proliferation was assessed by MTT assay and cell cycle analysis. Cell apoptosis was determined by flow cytometry, TUNEL staining and western blot. RESULTS: Levels of UbcH10 protein were significantly upregulated in U251 cells compared with normal brain tissues. Marked immunoreactivity for UbcH10 was demonstrated in the cytoplasm of U251 glioma cells, especially in the mitotic cells. The growth rate of U251 cells was significantly inhibited by depletion of UbcH10 by short interference RNA. Further, UbcH10 RNAi induced apoptosis through induction of Bax and p53, downregulation of Bcl-2 and G2/M arrest of the cell cycle. CONCLUSION: These data imply that knocking-down UbcH10 protein expression may represent a potential therapeutic option for glioma.

Microvascular decompression of the accessory nerve for treatment of spasmodic torticollis: early results in 12 cases.

PURPOSE: To describe the early effectiveness of microvascular decompression (MVD) for the treatment of spasmodic torticollis (ST). METHODS: Twelve patients with spasmodic torticollis were treated by microvascular decompression of the accessory nerves using a microscopic neurosurgical technique via the retrosigmoid approach. The most common compressing blood vessels were the ipsilateral posterior inferior cerebral artery (PICA) and/or the vertebral artery. The intraoperative monitor was introduced to detect the accessory nerve and to avoid unnecessary damage to the nerve. RESULTS: Ten patients were cured (83%), and the other two (17%) improved with moderate spasms. In most cases, the improvement was noticed 1 week after the operation. No operation-related complications were observed during the follow-up period, which ranged from 2 months to 3 years. CONCLUSIONS: The early effect of MVD for some patients with spasmodic torticollis was satisfactory, but the long-term results need to be assessed further.

[Effects of treatment of spasmodic torticollis by neurovascular decompression, myotomy, and toxin type A: a comparative study].

OBJECTIVE: To compare the effects of treatment of spasmodic torticollis (ST) by neurovascular decompression, myotomy, and botulinum toxin type A and to investigate the mechanism of ST. METHODS: Nine ST patients who failed to respond to other conservative treatment methods underwent neurovascular decompression of accessory nerve. The effect of decompression was compared with that by botulinum toxin in 22 patients and that by myotomy in 13 patients. RESULTS: The symptoms and signs were improved to a certain degree by botulinum toxin treatment at first, but recurred and gradually worsened in several months. None of the 22 patients had reached a real cure by botulinum toxin type A treatment. Four of 13 patients undergoing myotomy improved a lot in the symptoms and 9 improved only a bit. However, weakness in neck movement was found in all patients after myotomy. Neurovascular decompression was performed on 9 patients, 5 of which had botulinum toxin treatment and 1 had undergone myotomy, and found that all of them had severe vascular compression in the accessory nerve. Obvious alleviation of symptoms was achieved 2 - 14 days after the operation in 8 patients, and 3 months later in 1 patient. All of the 9 patients resumed their nonenal work and life 6 months after the operation. No complication, such as nerve damage, infection, hemorrhage, leakage of cerebrospinal fluid, and weakness of neck, was found. CONCLUSIONS: Neurovascular compression may be the most important cause of ST. Microneurovascular decompression is effective for some patients. However, it is still difficult to judge its indication.

[Microsurgical strategies of glioma located in lateral fissure area].

OBJECTIVE: To investigate the microsurgical strategies of glioma located in lateral fissure area. METHODS: The clinical data of 123 patients with glioma located in lateral fissure area confirmed by pathology, 76 males and 47 females, aged 46.2 (4-75), were retrospectively analyzed. The optimal surgical approach and comprehensive therapeutic strategies were selected according to the imaging features and pathological properties of tumors. Resections were performed by the pterion approach in all cases to remove the tumors, navigational orientation was used in 17 cases, and supervision by B mode ultrasonography was used in 12 cases. The branches of middle cerebral artery and fissure vein were protected carefully. The patients with tumors above grade U, confirmed pathologically after resection, underwent chemotherapy ( teniposide + semustine or temozolomide) and radiotherapy that was designated individually according to the pathological grade and distribution of the tumors. Follow-up was conducted by telephone, mail or outpatient department visit on 102 of the 133 patients (82.9%). RESULTS: 82 patients (66.7%) underwent total resection, 18 (14.6%) underwent subtotal resection, 16 (13.0%) underwent major resection, and 7 (5.7%) underwent partial resection. Postoperatively cerebral vasospasm in 8 cases, brief aphasia and reaction clumsily in 4 cases, muscle strength decline in 3 cases, and epilepsy in 1 case, these patients were submitted to symptomatic treatment with progressive improvement of the above-mentioned signs and symptoms. One patient died of malignant intracranial hypertension. The follow-up showed that 97 patients survived over 1 year, the 5-year survival rate was 25.6%, and the average survival time was 21.7 months. CONCLUSION: The lateral fissure area glioma can be treated through proficient microsurgical technique after the anatomic training. It is the key in the surgery on the lateral fissure glioma to protect the main branches of middle cerebral artery, trunk of middle cerebral vein, and important brain functional areas.

A huge occipital osteoblastoma accompanied with aneurysmal bone cyst in the posterior cranial fossa.

Osteoblastoma is an infrequent benign tumor and skull involvement is extremely rare. The occipital bone is much less frequently involved. We report an unusual case of a huge occipital osteoblastoma with aneurysmal bone cyst in the posterior cranial fossa of a 20-year-old young man. MRI scan and CT three-dimensional reconstruction revealed that the tumor (approximately 8.5 cm x 6 cm x 5 cm) occupied nearly half volume of the posterior cranial fossa. The cerebellum, the forth ventricle and brain stem were compressed remarkably and hydrocephalus was noted. The tumor mass was multiloculated cystic and highly vascular. Excessive bleeding occurred during operation and total removal was achieved. The patient was symptom-free and MRI scan revealed no evidence of recrudescence after a follow-up period of 18 months. Pathological examination revealed that the lesion was a benign osteoblastoma with secondary aneurysmal bone cyst (ABC). ABC constitutes a highly vascular lesion while complete surgical resection is often impeded by excessive intraoperative bleeding. Preoperative embolization may reduce the risk. Despite the benign nature of osteoblastoma, local recurrence after incomplete resection is not rare and malignant transformation during recurrence may occur even after adequate surgery. Our case confirms the findings of previous investigators that if osteoblastoma is removed completely, no recurrence is expected even without adjuvant irradiation and chemotherapy.

[Molecular cloning and identify expression of the novel human LNX gene in gliomas].

OBJECTIVE: To clone and identify expression pattern of the novel LNX gene, and characterize its molecular mechanism in all grades of human gliomas. METHODS: From a fetal brain cDNA library, we isolated the novel human LNX gene. The expression pattern of LNX gene in 16 normal tissues was examined by MTC panel (Clontech). Microarray were adopted and hybridized with LNX probes to examine the expression of novel gene in gliomas. Northern hybridization was used for verifying expression of LNX gene in gliomas. Two-hybrid screen in yeast was used to identify human LNX interacting proteins. Pull-down assays and Co-immunoprecipitation were transfected in HEK293 cells according to the lipofectAMINE protocol. RESULTS: We isolated a 3.7 kb cDNA containing an open reading frame (ORF) of 1,899 bp and a putative 632 amino acids protein, which was located on 4q12. cDNA microarray showed LNX was down-regulated in all 18 glioma samples and it was testified by Northern-blot. The MTC panel showed a ubiquitous expression pattern which highly expressed in adult brain, kidney and pancreas, while weak expression in heart, lung, etc. The two-hybrid screen in yeast revealed that LNX interacted with SKIP (Ski interacting protein) via PDZ domains. The co-immunoprecipation suggested that LNX interacted with SKIP in HEK293 cells and could affect the subcellular localization of Numb, which indicated that LNX might function as a molecular anchor that localized Numb to the subcellular site of its interaction with Notch. CONCLUSION: cDNA microarray technology is a powerful technique in screening and locking differentially expressed genes in gliomas, LNX was closely related to human gliomas and suggested playing an important role in gliomas by notch signal approach.