Atmospheric effects on the laser-driven avalanche-based remote detection of radiation.

The effect of realistic atmospheric conditions on mid-IR (λ = 3.9 µm) and long-wave-IR (λ = 10 µm) laser-induced avalanche breakdown for the remote detection of radioactive material is examined experimentally and with propagation simulations. Our short-range in-lab mid-IR laser experiments show a correlation between increasing turbulence level and a reduced number of breakdown sites associated with a reduction in the portion of the focal volume above the breakdown threshold. Simulations of propagation through turbulence are in excellent agreement with these measurements and provide code validation. We then simulate propagation through realistic atmospheric turbulence over a long range (0.1-1 km) in the long-wave-IR regime (λ = 10 µm). The avalanche threshold focal volume is found to be robust even in the presence of strong turbulence, only dropping by ∼50% over a propagation length of ∼0.6 km. We also experimentally assess the impact of aerosols on avalanche-based detection, finding that, while background counts increase, a useful signal is extractable even at aerosol concentrations 105 times greater than what is typically observed in atmospheric conditions. Our results show promise for the long-range detection of radioactive sources under realistic atmospheric conditions.

Surgical treatment of transcatheter aortic valve infective endocarditis.

There is growing interest in infections occurring after transcatheter aortic valve implantation (TAVI). The incidence, and clinical and anatomical features suggest many similarities with prosthetic valve endocarditis. The survival of patients with an infected TAVI prosthesis is generally poor; however, only a minority of them (10%) have undergone treatment with surgical explantation of the infected prosthesis. A literature search was performed using online databases. Papers reporting surgical treatment of TAVI prosthesis infections were retrieved, focusing on pre- and intraoperative characteristics and early outcome. Thirty-seven papers ultimately provided information on 107 patients. Their mean ± standard deviation (SD) age was 76 ± 8 years and 72% were male. The mean ± SD time interval between the TAVI procedure and reoperation was 10 ± 10 months. Annular abscess formation was described in 34% of cases and mitral valve involvement in 31%. All patients underwent TAVI prosthesis explantation and surgical aortic valve replacement; concomitant mitral valve replacement was necessary in 22% of cases. Postoperative in-hospital mortality was 28%. Surgical explantation of infected TAVI prostheses was associated with a high postoperative mortality, although these initial experiences included elderly and high-risk patients. Considering the expansion of TAVI procedures towards younger and lower-risk patients, surgical treatment of TAVI endocarditis may represent the best option for a life-saving procedure.

Cryopreservation of autogeneous bone flap in cranial surgical practice: what is the future? A grade B and evidence level 4 meta-analytic study.

AIM: Autogenous bone flap adequately preserved can be used successfully for repair of iatrogenic cranial bone defects because of its biological and economic advantages. The commonly used techniques of bone preservation are freezing at temperature ranging from -16 to -40 inverted exclamation mark C or subcutaneous pocketing. METHODS: We searched on NLM database querying as subject headings "cranioplasty and autologous bone" and found 7 papers meeting our criteria. For every series we considered the frequency of bone resorption and infection and performed statistical analysis by means of contingency tables carrying out for the chi2 test according to Pearson and considering to be statistically significant p(chi2) <0.05 values. RESULTS: Compared series presented no statistically significant difference with regard to frequency of the complications (chi2=6.43 for critical value of 11.07 (k-1=5) (P>0.25) and chi2=5.48 for critical value of 7.81 (k-1=3) (P>0.10) respectively for infection and resorption. CONCLUSION: Although we did not find any significative difference among the frequencies of the complications of the series, it is our opinion that freezing the bone flap is preferable to abdominal pocketing because it needs no double surgical abdominal time and the bone flap frozen is stronger to mechanical loading than fresh flap. Cryopreservation of autologous bone flap should be the standard technique of preservation for delayed cranioplasty but a multicentric prospective trial is advisable to obtain in short time statistically significant results focusing better on the rate of marginal resorption of the bone flap using new cryoprotectant solutions.

Transverse carpal ligament reconstruction with polyesterurethane patch for prevention of recurrence in therapy of failed primary carpal tunnel surgery.

A small group of patients with carpal tunnel syndrome (CTS) can present recurrences and persistent symptoms of CTS after its surgical release. If recurrence is due to scarring between median nerve and surrounding tissue (true recurrence of CTS, transverse carpal ligament [TCL] reconstruction with transposition flap technique is available but it presents poor results: This 48-year-old woman presented a recurrence of CTS 3 months after open standard incision. At operation, a scar was detected that did not permit normal median nerve gliding during wrist movements. External neurolysis restored normal gliding and non-absorbable polyesterurethane patch was used to reconstruct TCL. At 2-year follow-up the patient was in good health and returned to her manual usual job without pain and sensitive and motor deficits. Implantation of unresorbable poliesterurethane patch for TCL reconstruction after external neurolysis appears to be more advantageous than TCL reconstruction with transposition flap technique because it takes little time, causes minimal adhesion formation, does not need of wide incision and provides the same favourable conditions of the transposition flap as mechanical stabilization of the tranverse carpal arch, prevention of bowstringing of the flexor tendons, increase of postoperative grip strength and good protection of the median nerve. However, more cases should be studied before considering TCL reconstruction with poliesterurethane patch as a useful option in secondary surgery of true recurrence of CTS.

Detection of resistance to isoniazid by denaturing gradient-gel electrophoresis DNA sequencing in Mycobacterium tuberculosis clinical isolates.

Isoniazid (INH) resistance was genotypically assessed in 104 (37 INH-susceptible, 67 INH-resistant) genetically unrelated Mycobacterium tuberculosis strains cultured in North Italy. The PCR products of selected regions of the katG gene, the oxyR-ahpC intergenic region, and the inhA regulatory region were analyzed utilizing the double gradient-denaturing gradient gel electrophoresis (DG-DGGE) technique and confirmed by DNA sequencing. Mutations were detected in 61 (91%) of the INH-resistant strains, the relative frequency of the mutations being 65.7% in katG, 23.9% in oxyR-ahpC, and 13.4% in inhA. Previously described alterations, invariably associated with drug resistance, accounted for 95.1% of the mutations. No alterations were found in the INH-susceptible strains. DG-DGGE analysis and DNA sequencing were equally sensitive, but the former is cheaper, easier and more robust. Rapid genotypic assessment of INH resistance by means of the methodology described here could reasonably be used in clinical mycobacteriology laboratories.

Symptomatic subdural hygroma after petroclival meningioma surgery. Case report of a intractable complication.

Although subdural hygroma development after craniotomy or aneurysm surgery is a well-known complication and subdural peritoneal or V-P shunt are commonly successful procedures, there are situations that cannot be treated by available surgical options. We reported a case of a 28-year-old young man who developed a symptomatic subdural hygroma after removal of petroclival meningioma. This hygroma increased in size and became bilateral in spite of implantation of V-P with programmable valve at open pressure variable from 30 to 180 mmH2O, placement of subdural-peritoneal shunt with low-low valve or without valve and external diversion. The occurrence of this case showed that there other factors can play role in hygroma development as disturbance of normal CSF dynamic with shunt of CSF from basal arachnoidal to subdural spaces secondary to surgery and/or slow growth of petroclival meningioma as well as postoperative progressive cerebral atrophy. Actually there are not effective diagnostic tools to detect causes and therefore, there are restricted therapeutic possibilities. This potential and serious complication should be always considered when planning petroclival meningioma surgery because of the severe consequences on functional outcome.

Metastatic breast cancer delayed brachial plexopathy. A brief case report.

Metastatic involvement of brachial plexopathy is a rare condition that is often associated with advanced systemic breast cancer and the role of surgeon appears to be restricted because radio-chemotherapy is better recommended in this setting. We report a case of a 64-year-old woman that presented a very delayed breast cancer metastatic lower trunks lesions without associated radiation injury, treated by surgery. MRI of plexus and CT of chest and axilla are methods of choice in preoperative radiological evaluation. Neurosurgeon effort is restricted to provide pathologic diagnosis (confirm of metastasis), adequate pain control and improvement of neurological function. So that surgical exploration and neurolysis should be performed as soon as possible after appearance of neurological deficits before denervation signs occurs. General surgeon presence should be warranted for more radical removal of remain lymph nodes and metastatic nodal infiltration of adjacent anatomical structures (vessels and so on) when detected by preoperative radiological work-up.

Management of chronic subdural hematoma in patients treated with anticoagulation.

BACKGROUND: The diffusion of the surgical technique of cardiac valve replacement with metallic prostheses, as well as bypass graft in the arterial occlusive disease of the lower extremities, both requiring permanent oral anticoagulation, has increased the number of patients affected by chronic subdural hematoma that can be diagnosed at an earlier stage of this disease with the advent of the CT. METHODS: The records of seven patients with mean GCS = 14.2 and mean clinical grade = 1.85 affected by chronic subdural hematoma and in treatment with anticoagulants were examined retrospectively. All the patients underwent subtemporal craniectomy plus closed drainage or burrhole(s) plus closed drainage after immediate correction of hypocoagulability by administration of vitamin K and fresh frozen plasma and normalization of PA by calcium heparin. RESULTS: Outcome was good for all the patients except one who died because of cerebral herniation due to massive solid subdural hematoma during extracorporeal dialysis. Complications included: intracerebral hemorrhage, solid subdural hematoma, slow brain reexpansion, subdural collection reaccumulation and cerebral embolism. Three patients required re-operation. Mean duration of hospital stay was 18 days with range from 7 to 24 days. CONCLUSIONS: Basing on this retrospective study and the proposed pathophysiology, the guidelines for optimal management of this subgroup of patients are proposed. Recommendations include the immediate correction of hypocoagulability, the appropriate surgical technique and the cautious conversion to oral anticoagulation as well as the appropriate timing of such conversion.

Infections and re-infections in long-term external ventricular drainage. A variation upon a theme.

BACKGROUND: The infection of the external ventricular drainage (EDV) remains the main morbidity and mortality associated with this procedure, in the setting of the treatment of hydrocephalus and its complications, leading to excess of hospitalization with annual economic burden. METHODS. In this 3-year retrospective study we selected and reviewed the records of 15 of 143 patients (mean age 34 years with range from 1 months to 70 years; 12 males and 3 females) undergone to prolonged EVD in the setting of management of hydrocephalus (5 patients because of acute ventricular dilation post-intraventricular hemorrhage or post-hemorrhagic HCP, 8 because of V-P shunt infection, 1 because of post-traumatic HCP and 1 because of shunt malfunction by elevated CSF protein) and developing a shunt infection or one or more superinfection. RESULTS: There was a 26% mortality and a 13% morbidity (1 patient had GOS score of 2, 1 score of 3 and 3 score of 5). The pathogens yielded by CSF culture were normal or transient flora of the patient's skin. The causes of infection were carefully analyzed. CONCLUSIONS: Based on our experience the management of infection in long-term EVD includes: the standardization of the environment of the surgery achieved with a) use of prophylactic antibiotics; b) preparation of the patient and sterile field; c) no touch technique. After implantation of EVD the risk of infection must be minimized by carefully nursing care of EVD, and administration of above prophylactic antibiotics. CSF must be collected for culture and cell count, glucose and protein when clinically indicated. When infection o reinfection is demonstrated by CSF culture then it is advisable to remove the entire hardware and start the antibiotic therapy intravenously and intraventricularly basing on susceptibility tests, CSF penetration of antibiotics, their bactericidal action, toxicity, specificity and cost. Regard to the duration of the therapy, a practical guide is treating for 10-14 days after three consecutive CSF sterile cultures. Thus, convention of EVD to a shunt can be performed within 3 weeks from admission, in the best favourable cases, decreasing the duration of hospital stay and the overall cost of neurosurgical management of the cerebral pathology requiring as therapeutic adjunct and EVD.

Detection of MRI brain contour using isotropic and anisotropic diffusion filter. A comparative study.

Reconstructed brain surface from MRI are still based on either interactive or manual edge detection methods which are time consuming and subjective. In order to overcome such inadequate result, the scale-space technique was applied using isotropic and anisotropic diffusion filter. Isotropic diffusion was not adequate because it did not allow locally adaptive blurring. On the contrary, stopping the anisotropic diffusion process at the best time of diffusion, edge detector provided the true location and morphology of the sulci and gyri. Although some sulci appeared open curves this one didn't have to be considered as failure of anisotropic diffusion because it was related to the resolution of the original MR image. Nevertheless the human vision subjectively made explicit their closure.

[Normal levels of collagen-type-I telopeptide in the first 90 days of life]. / Livelli normali di telopeptide del collagene di tipo I nei primi 90 giorni di vita.

Serum levels of carboxyterminal telopeptide of type I collagen (ICTP), a marker of matrix degradation, were measured by RIA test, on 184 samples of healthy newborns and children aging from 1 (cord blood) to 90 days of life. We found ICTP values about tenfold higher than the adults', with highly significant variations (P < 0.001) in the whole period studied. During the first three months of life serum levels of the bone marker show a progressive increase from 0 to 7 days, they remain unchanged until the 30th day and then decrease until the 45th day, maintaining similar values from the 45th to the 90th day of life. The authors think that the pattern of ICTP in the first week of life is under the influence of the adapting phenomena following delivery, in which catabolic processes are predominant, while in the second period ICTP modifications are related to growing processes and then to bone turnover.

Traumatic chronic subdural hematoma over 80 years. A preliminary prospective study.

Six very elderly patients (mean of age: 85 years with range from 80 to 95 years) with mean GCS = 12 and mean clinical grade = 2.5 affected by traumatic chronic subdural hematoma (CT mean maximum thickness = 2.8 +/- 0.46 cm with midline shift = 1.56 +/- 0.48 cm and absence of homolateral mesencefalic cistern in all case but one) underwent parietal or frontal craniectomy under temporalis muscle and 48-h closed subdural drain. There was no mortality as consequence of the operative procedure. In all the patients but one who died postoperatively from a preoperative midbrain infarction secondary to a transtentorial herniation, there was a progressive and slow clinical improvement in spite of residual markedly persistent fluid collection (CT mean maximum thickness 1.44 +/- 0.19 cm) with mass effect (CT mean midline shift = 0.5 +/- 0.17 cm) due to a some failure of the brain to re-expand. Impairment of hemodynamic reserve should be considered as important cause of failure of the brain re-expansion. Clinical and CT control within two months after discharge from hospital demonstrated further clinical improvement (mean GOS = 4.6) and resolution of subdural residual fluid collection. Basing on these results we recommend do not reoperate persistent subdural fluid collection if there is clinical improvement. The patient can be discharged from hospital or transferred to Geriatric Department where he can be clinically and CT evaluated. Only a clinical deterioration or an increase of residual subdural fluid collection provides clear indication to reoperative surgery.

Infected cerebral hemorrhage by ruptured infectious anterior communicating artery giant aneurysm in a patient with T cell acute lymphoblastic leukemia. Case report.

Although the majority of infectious (bacterial) intracranial aneurysms occur in patients with subacute bacterial endocarditis, septic cerebral embolization and infectious intracranial aneurysm formation can also occur in immunocompromised patients. We report the case of ruptured bacterial aneurysm occurring in a 19 years old man immunocompromised by vigorously treated acute lymphoblastic leukemia. This case confirms very poor prognosis for infectious aneurysms in immunocompromised patient reported in literature, suggesting that a high index of suspicion needs for early diagnosis and that a conservative approach (high dose antibiotic therapy with possible delayed surgery) should be preferred unless intracerebral hemorrhage or abscess with significant mass effect provides a clear indication for operative intervention.

Painful ophthalmoplegia syndrome (spheno-cavernous syndrome) caused by a ruptured posterior communicating artery aneurysm. A brief report.

A case is reported of ruptured posterior communicating artery aneurysm presenting as a painful ophthalmoplegia syndrome (spheno-cavernous syndrome). This case suggests that there is need to carried out immediately neuroradiological studies when a painful ophthalmoplegia appears because of possible underlying intracranial aneurysm. This decisional algorithm should decrease the probability of aneurysmal rebleeding and increase the chance of oculomotor nerve function recovery.

Thallium-201-SPECT and 99Tc-HM-PAO SPECT imaging to study functionally cerebral supratentorial neoplasms: the biological basis of the functional imaging interpretation.

Nineteen patients with histologically diagnosed supratentorial cerebral neoplasms carried out CT and/or MRI, 201T1 SPECT and 99mTc-HM-PAO studies preoperatively. 99mTc-HM-PAO SPECT images revealed information about both tumoral perfusion and intracellular concentration of mediators converting 99mTc-HM-PAO to hydrophilic derivates (glutathione and other yet unknown factors) within viable tumoral cells while 201T1 SPECT images about permeability, extension of tumoral capillary network and viable tumoral cells presence. Basing on the different mechanisms of the tracer uptake, cerebral supratentorial tumors could be distinguished in three groups: 1) cerebral tumors presenting 201T1 very high uptake (201T1 index > 1.5) and homogeneous and high retention of 99mTc-HM-PAO (CBI > or = 1.05) (meningiomas, PRL adenoma); histologically these neoplasms presented very rich neoformed capillary network; 2) cerebral neoplasms with 201T1 high uptake (201T1 index > 1.5) and with inhomogeneous retention of 99Tc-HM-PAO (high grade gliomas amd metastasis); microscopically these tumors presented vascular proliferation, necrosis and high cellularity; 3) cerebral neoplasms characterized by 201T1 low uptake (201T1 index < 1.5) and lower retention of 99Tc-HM-PAO than cerebellum (low grade gliomas); at microscopic examination these neoplasms were characterized by absence of vascular proliferation and necrosis. These results suggest coupled 201T1/99Tc-HM-PAO SPECT is necessary to discriminate intra-axial from extra-axial tumor localization (lacking CT or MRI) and to detect the grade of malignancy of gliomas and tumor cell presence within necrotic areas.

Parietal bone non-secreting solitary myeloma (plasmacytoma) with spread to the epidural space and scalp. Case report.

A case of solitary osteolytic lesion in the parietal bone in an otherwise asymptomatic patient is reported. Skull radiographs showed a radio-lucent lesion with well-defined margins without sclerotic reaction, CT scan demonstrated a mass that markedly enhanced extending from the epidural to the subcutaneous space of the parietal region. The patient underwent surgery and tumor was completely excised. Pathological examination showed tumor to be a plasmacytoma synthesizing kappa chains. Postoperatively the patient received radiotherapy. Four years after treatment there was no sign of local recurrence on CT can and of progression of multiple myeloma on clinical and laboratory studies. Our recommended treatment is that of a complete surgical excision followed by radiation to dose levels of 45-50 Gy. The patients should be followed carefully because of either local recurrence or possible progression to multiple myeloma. Radiotherapy and chemotherapy should started when signs of progression or other significant disease manifestations occur.

Distal posterior inferior cerebellar artery saccular and giant aneurysms: report of two new cases and a comprehensive review of the surgically-treated cases.

Aneurysms of the distal posterior inferior cerebellar artery are rare comprising less than 0.5 to 3% of all aneurysms. The authors report two cases of distal PICA aneurysms: a case of a ruptured saccular aneurysm arising on the tonsillomedullary segment of the PICA and a case of a giant aneurysm arising on junctional site of lateral-medullary and tonsillo-medullary segments. In the first case subarachnoid and intraventricular hemorrhage was diagnosed by CT and four vessel-angiography visualized the aneurysm which was clipped successfully. In the second case MRI was suggestive for posterior fossa giant aneurysm; four vessel angiography confirmed the suspicion, detected distal PICA origin of the giant aneurysm and disclosed the association with a middle cerebral artery saccular aneurysm. Because of lacking of a clippable neck and important perforating vessels to brainstem, the aneurysm was trapped and excised successfully. The literature is exhaustively reviewed. Discussion regarding to distal PICA aneurysm distribution (location, age, sex, multiplicity and associated vascular anomalies), pathophysiology, clinical presentation, neuroradiological findings, surgery and outcome is presented.

Idiopathic middle cerebral artery occlusion in children: report on three cases.

Three cases of middle cerebral artery occlusion in children are reported. The origin of M1 was the site of occlusion in two cases, while occlusion 1 cm after the origin of M1 was found in the third. The possible etiological diagnosis was infectious arteritis in the first two cases, cranial trauma in the third. In no case were serious contralateral motor deficits detected in follow-up examinations. Follow-up digital subtraction angiography showed complete regression of arterial lesions in the second case. The authors conclude that middle cerebral artery occlusion may have a benign clinical course in children; surgical revascularization is indicated only in highly selected cases.

Craniofacial pain and incomplete oculomotor palsy associated with ipsilateral primitive trigeminal artery. Case report.

A case is reported of persistent primitive trigeminal artery associated with recurrent facial pain and noncomitant strabismus by partial ipsilateral oculomotor palsy. Transcranial Doppler disclosed indirectly persistent carotid-basilar anastomosis. CT and angiography allowed complete diagnosis excluding a posterior communicating artery aneurysm, a Tolosa-Hunt syndrome and an ophthalmoplegic migraine. Steroid therapy is recommended treatment. Surgery should be considered when symptoms are intractable to medical therapy.