Navigated resection of giant intracranial meningiomas based on intraoperative 3D ultrasound

Background

Surgical resection of giant meningiomas may pose different challenges. Normal brain tissue is often compressed to the limit and is vulnerable to further traction. In addition, severe intraoperative bleeding may be a problem as many giant meningiomas are vascularised with deep feeding vessels entering from the skull base. Neuronavigation based on preoperative imaging can be of limited use as there may be extensive brain shifts during surgery.

Method

We have retrospectively evaluated navigated resection based on intraoperative 3D ultrasound in a series of 15 giant meningiomas with a diameter of more than 5 cm. A pre- and postoperative MRI was preformed in all patients. Preoperative and postoperative neurological function was assessed.

Findings

We were able to safely perform ultrasound-guided intracapsular gross total resection of tumour tissue in all patients. Twelve out of 15 patients were radically operated (Simpson grade I and II). Major feeding arteries and adjacent normal arteries could be identified by ultrasound power Doppler angiography. In one patient we were not able to indentify important venous structures. All patients experienced postoperative improvement of their symptoms. Postoperative MRIs did not reveal significant ischemic changes in adjacent normal brain tissue. The mean duration of hospitalisation after surgery was 4.9 days.

Conclusion

We present a method of ultrasound-guided resection of giant meningiomas. The method enables image-guided resection through narrow approaches that minimise traction. Power Doppler angiography allows the identification of feeding vessels that may be coagulated to limit bleeding. Likewise, normal arteries can be avoided during surgery. The tumour capsule is often surprisingly easy to remove from the arachnoid membrane after gross intracapsular tumour reduction.     

Integration of Carbon Nanotubes in Microsystems: Local Growth and Electrical Properties of Contacts

Carbon nanotubes (CNTs) have been directly grown onto a silicon microsystem by a local synthesis method. This method has potential for wafer-level complimentary metal-oxide-semiconductor (CMOS) transistor-compatible integration of CNTs into more complex Si microsystems; enabling, e.g., gas sensors at low cost. In this work, we demonstrate that the characteristics of CNTs grown on specific locations can be changed by tuning the synthesis conditions. We also investigate the role of the contact between CNTs and the Si microsystem; observing a large influence on the electrical characteristics of our devices. Different contact modes can render either an ohmic or Schottky-like rectifying characteristics.     

Adhesive capsulitis: one sonographic-guided injection of 20 mg triamcinolon into the rotator interval

The aim of this study was to establish a method for injecting corticosteroid into the rotator interval under sonographic guidance and to measure the effect on function, pain and range of motion after 4 and 12 weeks. This study involved a multicenter cohort trial and carried out at outpatient clinics of the physical medicine and rehabilitation departments in Oslo and Porsgrunn, Norway. 39 patients with adhesive capsulitis lasting between 3 and 12 months. Sonographic-guided corticosteroid and lidocaine injection into the rotator interval medial to the biceps tendon using 20 mg triamcinolon hexacetat and 3 ml 20 mg/ml xylocain. Change in the shoulder pain and disability index score (SPADI) after 12 weeks. The change in SPADI was 42 points (95 % confidence interval, 33–51). Changes in the secondary outcomes shoved highly statistically significant increase in active and passive range of motion. One ultrasound-guided corticosteroid injection into the rotator interval seems to give significant improvement in SPADI and active range of motion after 12 weeks. The protocol was evaluated by the research faculty at Oslo university hospital, dept of physical medicine. The study was regarded as regular clinical procedure as injections with triamcinolon already is standard treatment. No trial registration was obtained but the protocol presented the local ethics committee without comments.     

Subjective improvement in patients with psoriatic arthritis after short-term oral treatment with seal oil. A pilot study with double blind comparison to soy oil

OBJECTIVE: To investigate effects of short-term oral treatment with seal oil in patients with psoriatic arthritis (PsA). METHODS: Forty-three patients with polyarticular PsA were randomized to receive oral treatment for 2 weeks with either seal oil or soy oil in a double blind controlled trial. Clinical and biochemical variables were assessed at baseline, after treatment, and 4 weeks post-treatment. Patients were allowed to continue nonsteroidal antiinflammatory drugs (NSAID) and disease modifying antirheumatic drugs (DMARD) during the study. RESULTS: Forty patients completed the study, 20 in each treatment group. Patients in the seal oil group reported a significant improvement in global assessment of the disease 4 weeks post- treatment (p < 0.01), and both groups showed a trend toward improvement in tender joint count, but the differences between the groups were not significant. There was a fall in the ratio of n-6 to n-3 fatty acids and in arachidonic acid (AA) to eicosapentaenoic acid (EPA) in serum after treatment with seal oil (p < 0.01). Twenty-one percent of all patients had elevated values of calprotectin in feces suggestive of asymptomatic colitis. CONCLUSION: Treatment with seal oil was followed by a modest improvement in patient's global assessment of the disease and a trend towards a decrease in number of tender joints. There was a shift in fatty acid composition in serum toward a putative antiinflammatory profile. Oral treatment with seal oil may have NSAID-like effects in PsA.     

Malnutrition after vascular surgery: are patients with chronic renal failure at increased risk?

BACKGROUND: The deleterious effects of perioperative malnutrition on recovery after general surgery are established. Since the effects of perioperative malnutrition on recovery after vascular surgery are not known, we examined the effects of nutritional status, and risk factors predictive of malnutrition, on outcome after vascular surgery. METHODS: The records of all open index vascular cases (abdominal aortic aneurysm [AAA] repair, carotid endarterectomy [CEA], lower extremity bypass) performed at the Veterans Affairs (VA) Connecticut between July 2004 and June 2005 were reviewed. The primary outcome was mortality; secondary outcomes included infection and nutritional risk index (NRI) scores. RESULTS: Sixty-eight open vascular cases were performed during the study period. Nutritional depletion developed in 55% of patients and was more likely in patients undergoing AAA (85%) or bypass (77%) than CEA (30%; P = .0005). Patients who developed malnutrition had similar mortality as patients who did not develop postoperative malnutrition (6.1% vs. 3.7%; P = .68); however, malnourished patients had higher rates of postoperative infection (24.2% vs. 3.7%; P = .03). Chronic renal failure was the only patient-associated risk factor predictive of postoperative nutritional depletion (odds ratio 5.9, confidence interval 1.0 to 33.6; P = .04). CONCLUSIONS: Patients undergoing major open vascular surgery have high rates of postoperative malnutrition, with patients undergoing AAA repair having the highest rates of postoperative malnutrition and infection. Patients with chronic renal failure undergoing vascular surgery are associated with increased risk for postoperative malnutrition and may be a group to target for perioperative risk factor modification and nutritional supplementation.     

Intraoperative navigated 3-dimensional ultrasound angiography in tumor surgery

BACKGROUND: Avoiding damage to blood vessels is often the concern of the neurosurgeon during tumor surgery. Using angiographic image data in neuronavigation may be useful in cases where vascular anatomy is of special interest. Since 2003, we have routinely used 3D ultrasound angiography in tumor surgery, and between January 2003 and May 2005, 62 patients with different tumors have been operated using intraoperative 3D ultrasound angiography in neuronavigation. METHODS: An ultrasound-based neuronavigation system was used. In addition to 3D ultrasound tissue image data, 3D ultrasound angiography (power Doppler) image data were acquired at different stages of the operation. The value and role of navigated 3D ultrasound angiography as judged by the surgeon were recorded. RESULTS: We found that intraoperative ultrasound angiography was easy to acquire and interpret, and that image quality was sufficient for neuronavigation. In 26 of 62 cases, ultrasound angiography was found to be helpful by visualizing hidden vessels adjacent to and inside the tumor, facilitating tailored approaches and safe biopsy sampling. CONCLUSIONS: Intraoperative 3D ultrasound angiography is straightforward to use, image quality is sufficient for image guidance, and it adds valuable information about hidden vessels, increasing safety and facilitating tailored approaches. Furthermore, with updated 3D ultrasound angiography imaging, accuracy of neuronavigation may be maintained in cases of brain shift.     

Dichotic listening reveals functional specificity in prefrontal cortex: an fMRI study

The present study used fMRI to investigate the relationship between stimulus presentation mode and attentional instruction in a free-report dichotic listening (DL) task with consonant-vowel (CV) syllables. Binaural and dichotic CV syllables were randomly presented to the subjects during four different instructional conditions: a passive listening instruction and three active instructions where subjects listened to both ears, right ear and left ear, respectively. The results showed that dichotic presentations activated areas in the superior temporal gyrus, middle and inferior frontal gyrus and the cingulate cortex to a larger extent than binaural presentations. Moreover, the results showed that increase of activation in these areas was differentially dependent on presentation mode and attentional instruction. Thus, it seems that speech perception, as studied with the DL procedure, involves a cortical network extending beyond primary speech perception areas in the brain, also including prefrontal cortex.     

Brain activation measured with fMRI during a mental arithmetic task in schizophrenia and major depression

OBJECTIVE: The authors used functional magnetic resonance imaging (fMRI) to investigate brain activation in patients with schizophrenia and major depression while they performed two tasks-a vigilance task and a mental arithmetic task-that differed in cognitive complexity. METHOD: In the vigilance task, the participants had to press a response button whenever a specific number was seen on a screen inside the MR scanner. In the mental arithmetic task, the participants had to add two consecutive numbers and press the response button whenever the sum was 10. fMRI was performed with a 1.5-T MR scanner. Twelve patients with recurrent nonpsychotic unipolar major depression, 12 patients with schizophrenia, and 12 healthy comparison subjects were included in the study. RESULTS: Performance data showed that the patients were impaired relative to the comparison subjects and showed no difference in performance between the patient groups. The patients with schizophrenia, but not those with major depression, had less activation in prefrontal brain regions, relative to the comparison participants. However, subtracting brain activation during the vigilance task from activation during the mental arithmetic task showed that the schizophrenia patients had activation in parietal areas. CONCLUSIONS: A double dissociation of parietal and frontal lobe activation was found for the schizophrenia patients and the depression patients. The greater parietal lobe activation in the patients with schizophrenia may reflect a compensatory strategy for the failure to recruit cognitive processes that involve frontal lobe areas when solving a mental arithmetic task.