Optimal visuotactile integration for velocity discrimination of self-hand movements.

Illusory hand movements can be elicited by a textured disk or a visual pattern rotating under one's hand, while proprioceptive inputs convey immobility information (Blanchard C, Roll R, Roll JP, Kavounoudias A. PLoS One 8: e62475, 2013). Here, we investigated whether visuotactile integration can optimize velocity discrimination of illusory hand movements in line with Bayesian predictions. We induced illusory movements in 15 volunteers by visual and/or tactile stimulation delivered at six angular velocities. Participants had to compare hand illusion velocities with a 5°/s hand reference movement in an alternative forced choice paradigm. Results showed that the discrimination threshold decreased in the visuotactile condition compared with unimodal (visual or tactile) conditions, reflecting better bimodal discrimination. The perceptual strength (gain) of the illusions also increased: the stimulation required to give rise to a 5°/s illusory movement was slower in the visuotactile condition compared with each of the two unimodal conditions. The maximum likelihood estimation model satisfactorily predicted the improved discrimination threshold but not the increase in gain. When we added a zero-centered prior, reflecting immobility information, the Bayesian model did actually predict the gain increase but systematically overestimated it. Interestingly, the predicted gains better fit the visuotactile performances when a proprioceptive noise was generated by covibrating antagonist wrist muscles. These findings show that kinesthetic information of visual and tactile origins is optimally integrated to improve velocity discrimination of self-hand movements. However, a Bayesian model alone could not fully describe the illusory phenomenon pointing to the crucial importance of the omnipresent muscle proprioceptive cues with respect to other sensory cues for kinesthesia.

The interaction between N-category and N-ratio as a new tool to improve lymph node metastasis staging in gastric cancer: results of a single cancer center in Brazil.

BACKGROUND: Depth of tumor invasion (T-category) and the number of metastatic lymph nodes (N-category) are the most important prognostic factors in patients with gastric cancer. Recently, the ratio between metastatic and dissected lymph nodes (N-ratio) has been established as one. The aim of this study is to evaluate the impact of N-ratio and its interaction with N-category as a prognostic factor in gastric cancer. METHODS: This was a retrospective study in which we reviewed clinical and pathological data of 165 patients who had undergone curative surgery at our institution through a 9-year period. The exclusion criteria included metastases, gastric stump tumors and gastrectomy with less than 15 lymph nodes dissected. RESULTS: The median age of the patients was 63 years and most of them were male. Total gastrectomy was the most common procedure and 92.1% of the patients had a D2-lymphadenectomy. Their 5-year overall survival was 57.7%. T-category, N-category, extended gastrectomy, and N-ratio were prognostic factors in overall and disease-free survival in accordance with univariate analysis. In accordance with TNM staging, N1 patients who have had NR1 had 5-year survival in 75.5% whereas in the NR2 group only 33% of the cases had 5-year survival. In the multivariate analysis, the interaction between N-category and N-ratio was an independent prognostic factor. CONCLUSION: Our findings confirmed the role of N-ratio as prognostic factor of survival in patients with gastric cancer surgically treated with at least 15 lymph nodes dissected. The relationship between N-category and N-ratio is a better predictor than lymph node metastasis staging.

Clinical and pathologic prognostic factors for curative resection for pancreatic cancer.

BACKGROUND: Pancreatic cancer is the fifth leading cause of cancer-related deaths in the world. Operative resection is the only therapeutic option with curative potential for this disease. OBJECTIVE: The aim of the present study was to correlate clinical and pathologic parameters with survival in patients submitted to pancreatic resection for pancreatic adenocarcinoma. METHODS: Surgical resection with curative intent (R0 and R1 resections) was performed in 65 pancreatic cancer patients between 1990 and 2006. The overall results of surgical treatment were retrospectively analyzed and compared with the clinicopathologic features of these patients. RESULTS: Pylorus-preserving pancreatoduodenectomy was performed in 37 patients (56.9%), classic resection in 35.4%, distal pancreatectomy in 4.6% and total pancreatectomy in 3.6%. The inhospital mortality was 5% (three patients). Postoperative complications occurred in 28 patients (43%). Mean survival and five-year survival rate after curative resection were 27 months and 9.0%, respectively. Sex, TNM stage, tumor differentiation, neural invasion, tumor size and involvement of resection margin were significant prognostic factors on univariate analysis. Multivariate analysis showed tumor differentiation and neural invasion as prognostic factors. CONCLUSION: Patients with pancreatic cancer, even those with poor prognostic factors should be given the opportunity of surgical resection with curative intent.

Modified pharyngogastrostomy by a stapler technique.

Pharyngolaryngoesophagectomy is the gold standard treatment for the majority of larynx, pharynx and cervical esophagus advanced tumours. Reconstruction of these pharyngoesophageal defects is complex, and implicates additional time, morbity and mortality to the procedure. Gastric pull up and pharyngogastrostomy with hand sewing technique is the commonest way of doing it. The authors describe a modified technique to execute it using a stapler device.

'Benign focal epilepsy in infancy with vertex spikes and waves during sleep'. Delineation of the syndrome and recalling as 'benign infantile focal epilepsy with midline spikes and waves during sleep' (BIMSE).

PURPOSE: To better delineate the electroclinical features of infants who presented with focal seizures and typical midline sleep EEG abnormalities with a benign outcome. We discuss the significance of the typical EEG marker in non-epileptic patients. METHODS: Patients were selected from a group of epileptic subjects with seizure onset less than 3 years we observed from 1st November 1990 and 31st December 2003. Inclusion criteria were the presence of typical sleep EEG marker and focal seizures with benign outcome. Cases with less than 18 month follow-up period were excluded from this study. RESULTS: There were 19 patients (12 males, 7 females). Pre-, peri- and post-natal personal history was negative in all patients. Psychomotor development was normal, both before and after seizure onset. Neuroradiological investigations gave normal results. Seizure manifestations were typical, characterized by cyanosis, staring and rare lateralizing signs, of short duration. Age at onset was comprised between 4 and 30 months. The typical EEG marker, a spike followed by a bell-shaped slow-wave, localized in the midline regions, was present in all subjects only during sleep. All had a favorable outcome and the overwhelming majority of the patients were not treated. CONCLUSIONS: Our patients have an homogeneous electroclinical picture to constitute a new epileptic syndrome not included in the ILAE classification. We propose to call it 'benign focal epilepsy in infancy with midline spikes and waves during sleep' (BIMSE).

Efficacy of levetiracetam in pharmacoresistant continuous spikes and waves during slow sleep.

OBJECTIVE: To evaluate the efficacy of levetiracetam (LEV) in continuous spikes and waves during slow sleep (CSWS). Despite first description dates back to 1971, no agreement exists about CSWS treatment. The condition is rare and controlled clinical trials are very difficult to perform, so the reports about efficacy of different drugs are anecdotal. PATIENTS AND METHODS: We introduced LEV in three children affected by symptomatic focal epilepsy and pharmacoresistant CSWS and evaluated clinical, neuropsychological and electroencephalographic outcome. RESULTS: Two cases responded completely, one case showed only a mild reduction of spikes and waves during slow sleep. CONCLUSION: Even if our report is anecdotal, LEV expands the spectrum of antiepileptic drugs that can be used for the treatment of CSWS. LEV efficacy should be confirmed in larger series.

Pancreatic head tumors with portal vein involvement: an alternative surgical approach.

BACKGROUND/AIMS: One of the determining factors for the unresectability of pancreatic head tumors is the involvement of the portal venous system. Recent reports show that the resection of tumors with portal vein involvement has similar results to lesions with same stage without portal vein invasion. The aim of this study is to present a technique that allows the resection of portal vein segments without the use of grafts and with a shorter period of intraoperative venous occlusion. METHODOLOGY: Fifteen patients with pancreatic head tumors and portal vein involvement were submitted to pancreaticoduodenectomy according to this technique. The main feature of the technique is starting the pancreatic dissection at the posterior aspect of the head of the pancreas. The superior mesenteric artery is completely dissected from the pancreatic tissues leaving the section of the pancreas and the resection of the portal vein to the last step. RESULTS: Portal vein flow occlusion did not exceed 10 minutes. There were no major postoperative complications or mortality. CONCLUSIONS: This maneuver allows an easier resection of the mobilized portal vein with a shorter period of venous clamping and reconstruction without the need of venous graft.

Insulinoma: diagnostic strategies and surgical treatment. A 22-year experience.

BACKGROUND/AIMS: The efficacy of preoperative localization methods and the results of the surgical treatment of insulinoma were studied. METHODOLOGY: Fifty-nine patients referred for surgical treatment were studied and the results of the diagnostic tools for tumor localization were compared with findings at surgical intervention. The influence of the type of surgical procedure in the immediate and late postoperative course was also studied. RESULTS: Ultrasonography had a sensitivity of 30%, computed tomography 25%, angiography 54%, portal vein sampling 94%, endoscopic ultrasonography 27% and magnetic resonance 17%. Intraoperative palpation localized 98.2% of the tumors and by the addition of intraoperative echography, all lesions were identified. In 55 patients with benign lesions, 22 enucleations, 25 distal pancreatectomies, 7 pancreatectomies plus enucleation and one duodenopancreatectomy were performed. Malignant tumors were treated by pancreatic resection, postoperative hepatic artery embolization and systemic chemotherapy. There was no postoperative mortality. Pancreatic fistula was the most common complication. Three patients who underwent distal pancreatectomy developed late diabetes (9.3%). CONCLUSIONS: Extensive preoperative investigation, mainly with invasive methods, is not indicated and by combining intraoperative palpation and echography most of the cases can be adequately dealt with. Preservation of pancreatic tissue with enucleation and preservation of the spleen are the best choice for treatment of benign insulinomas.

Seckel's syndrome and malformations of cortical development: report of three new cases and review of the literature.

Seckel's syndrome is a rare form of primordial dwarfism, characterized by peculiar facial appearance. In the past, this condition was overdiagnosed, and most attention was given to the facial and skeletal features to define more precise diagnostic criteria. The presence of mental retardation and neurologic signs is one of the peculiar features of this syndrome, but only recently were rare cases of malformation of cortical development described, as documented by magnetic resonance imaging (MRI). Here, we present three new cases of Seckel's syndrome showing different malformations of cortical development (one gyral hypoplasia, one macrogyria and partial corpus callosum agenesis, and one bilateral opercular macrogyria). We hypothesize that the different types of clinical expression of our patients could be explained by different malformation of cortical development types. We think that MRI studies could be performed in malformative syndromes because of the possible correlations between type and extent of the lesion and the clinical picture of any individual case.

A clinical spectrum of the myoclonic manifestations associated with typical absences in childhood absence epilepsy. A video-polygraphic study.

We investigated the electroclinical features of 12 patients with childhood absence epilepsy (CAE), presenting with typical absence seizures associated with myoclonic manifestations of the face or neck. All patients underwent repeated and prolonged split-screen video-polygraphic EEG recordings. The polygraphic recordings and clinical correlations of the absence seizures were analysed. All patients presented with multi-quotidian, typical absence seizures. During the absences, the patients could show mild, rhythmic, myoclonic jerks involving facial areas (eyebrows, nostrils, perioral region, chin) or neck muscles (sternocleidomastoideus), with the same frequency as the spike-wave complexes. Polygraphic tracings demonstrated that the myoclonias were correlated to the spike component. Clinically, all patients showed a benign course, with complete seizure control under antiepileptic treatment. In the follow-up, 7 patients withdrew from treatment without relapse. We conclude that all our patients showed an electroclinical picture consistent with CAE. The occurrence of myoclonic manifestations of the face or neck associated with the absences did not influence the benign course of their disease. The electroclinical features observed in our group of patients differentiates our cases both from epilepsy with myoclonic absences and from absences with perioral myoclonia (with Video).

Benign partial epilepsies of adolescence: a report of 37 new cases.

PURPOSE: To delineate the electroclinical features of patients with partial seizures in adolescence with a benign outcome. METHODS: Patients were recruited in five different Italian epilepsy centers. Patients were selected among those with partial seizures between ages 11 and 17 years. We excluded benign childhood epilepsies, those with neurologic or mental deficits, and those with neuroradiologically documented lesions. We also excluded patients with less than 3 years' follow-up or who were still receiving antiepileptic therapy. RESULTS: There were 37 (22 male, 15 female) patients. Seizures started at the mean age of 14.5 years (range, 11-16.11). Two main electroclinical patterns emerged: 16 of 37 patients had somatomotor seizures frequently associated with focal theta discharges involving the centroparietal regions. Ten of 37 patients showed versive seizures and interictal spiking involving the posterior regions. A third group had clinical characteristics resembling the cases described by Loiseau. All had a favorable outcome. CONCLUSIONS: This relevant multicenter study further confirms the existence of benign partial epilepsies with onset during adolescence.

Alternative technique of laparoscopic hepaticojejunostomy for advanced pancreatic head cancer.

Only 20% of patients with pancreatic cancer can undergo curative resection. Therefore, palliative treatment of pancreatic cancer assumes the utmost clinical importance. The aim of the palliative treatment of pancreatic head carcinoma is to relieve the jaundice and/or duodenal obstruction. Endoscopic or transparietal decompression of the obstructed bile duct can be accomplished in most cases, but the durability of these techniques is not as great as that of a surgically created bypass. On the other hand, hepaticojejunostomy carries higher morbidity and mortality rates than the former nonsurgical methods. In order to promote long lasting palliation with low morbidity and mortality rates, minimally invasive techniques of biliary and gastric bypass have been described. However, laparoscopic Roux-en-Y hepaticojejunostomy seems to be a complex surgical procedure. With an aim to simplify the construction of a laparoscopic hepaticojejunostomy, the authors suggest an alternative technique.

Hepatic adenoma and focal nodular hyperplasia: differential diagnosis and treatment.

The diagnosis of benign hepatic tumors as hepatic adenoma (HA) and focal nodular hyperplasia (FNH) remains a challenge for clinicians and surgeons. The importance of differentiating between these lesions is based on the fact that HA must be surgically resected and FNH can be only observed. A series of 23 female patients with benign liver tumors (13 FNH, 10 HA) were evaluated, and a radiologic diagnostic algorithm was employed with the aim of establishing preoperative criteria for the differential diagnosis. All patients were submitted to surgical biopsy or hepatic resection to confirm the diagnosis. Based only on clinical and laboratory data, distinction was not possible. According to the investigative algorithm, the diagnosis was correct in 82.6% of the cases; but even with the development of imaging methods, which were used in combination, the differentiation was not possible in four patients. For FNH cases scintigraphy presented a sensitivity of 38.4% and specificity of 100%, whereas for HA the sensitivity reached 60% and specificity 85.7%. Magnetic resonance imaging, employed when scintigraphic findings were not typical, presented sensitivities of 71.4% and 80% and specificities of 100% and 100% for FNH and HA, respectively. Preoperative diagnosis of FNH was possible in 10 of 13 (76.9%) patients and was confirmed by histology in all of them. In one case, FNH was misdiagnosed as HA. The diagnosis of HA was possible in 9 of 10 (90%) adenoma cases. Surgical biopsy remains the best method for the differential diagnosis between HA and FNH and must be performed in all doubtful cases. Surgical resection is the treatment of choice for all patients with adenoma and can be performed safely. With the evolution of imaging methods it seems that the preoperative diagnosis of FNH may be considered reliable, thereby avoiding unnecessary surgical resection.

[Laparoscopic treatment of common bile duct lithiasis]. / Tratamento laparoscópico de coledocolitíase.

With the advances of videolaparoscopic surgery, this approach had become the treatment of choice for cholelithiasis. However, about 5% to 10% may present common bile duct lithiasis. Most surgeons have still difficulties to deal with this situation and do prefer resolve with open surgery or with further endoscopic approach. We present a case of a 60-year-old man, with 18 months history of right upper quadrant pain, weight loss and jaundice. He was referred with diagnostic of pancreatic cancer. Laboratory investigation showed increased bilirubin (10 mg/dL), alkaline phosphatase and GGT. Abdominal ultrasound showed atrophic gallbladder with dilated intra and extrahepatic biliary tree. Computerized tomography scan disclosed enlarged biliary tree with 3 cm stone in the distal common bile duct. The patient underwent a laparoscopic cholecystectomy followed by choledochotomy and retrieval of the large stone. A latero-lateral choledochoduodenum anastomosis was then performed to decompress the biliary tree. The patient had an uneventful recovery being discharged at the 6th postoperative day. Laparoscopic management of choledocholithiasis is feasible in many patients, specially those with dilated biliary tree. The retrieval of stones may be followed by biliary drainage with T-tube. In some elderly patients with chronically dilated common bile duct, as in the present case, a choledochoduodenal anastomosis is the procedure of choice.

Surgical treatment of cicatricial biliary strictures.

BACKGROUND/AIMS: Cicatricial biliary strictures are usually associated with high morbidity and mortality rates, frequently related to technical difficulties of their surgical repair, mainly in hilar lesions. Interference with bile duct blood supply during surgical attempts for correction is a major factor for unsuccessful results. The aim of this study is to evaluate, after an extended follow-up period, the results obtained with a modified technique for surgical correction of cicatricial biliary strictures. METHODOLOGY: The medical records of 57 patients surgically treated for cicatricial biliary strictures between January 1984 and July 1995 were reviewed and the immediate and long term results retrospectively analyzed. Patients consisted of 46 females and 11 males. The average age was 43 years. The etiology of the biliary lesion was: cholecystectomy alone (23); cholecystectomy with duct exploration (8); T tube CBD drainage (6); Biliary-enteric anastomosis stricture (16); choledochoplasty (2) and trauma (2). In 28 cases (49.1%) the stricture was located in the upper third of the bile duct, in 28 (49.1%) in the middle third and in one case (1.7%) it was low. All patients were submitted to longitudinal Roux-en-Y hepaticojejunostomy with mucosa apposition after dissection of the anterior aspect of the biliary tract. No transanastomotic stents were used. RESULTS: Ten patients (17.5%) presented 11 postoperative complications: biliary fistula (4), duodenal fistula (1), wound infection (5), and acute pancreatitis (1). Average hospital stay was 11 days and there were no postoperative mortalities. The follow-up study was possible in 54 patients and ranged from one to ten years, with an average of 2.9 years. Four patients of 28 (14%) with hilar lesions developed stricture recurrence and cholangitis episodes, whereas no patients bearing lesions below the biliary junction had such complications. CONCLUSION: Roux-en-Y hepaticojejunostomy with mucosa apposition without transanastomotic stent performed after minimal dissection of the biliary duct, thus avoiding major interference with the bile duct blood supply, is a safe and efficient method for the surgical repair of cicatricial biliary strictures. Using this technique excellent results can be obtained in the lesions below the biliary junction and acceptable results may be achieved in patients with hilar lesions.

[Surgical treatment of insulinoma: study of 59 cases]. / Tratamento cirúrgico dos insulinomas--Estudo de 59 casos.

UNLABELLED: After establishing the diagnosis of an insulinoma the next step is its localization in order to perform the most suitable management approach. PURPOSE: To evaluate the methods used for the diagnosis of insulinoma and the localization of its site as well as the results of the surgical treatment. METHODS: Fifty nine consecutive patients with pancreatic insulinomas were studied. The discriminative power of the preoperative investigations in the localization of insulinomas was analysed. Special attention was focused to the intra operative methods of tumor localizations. The early and late results of the surgical treatment were also investigated. RESULTS: There were 55 benign cases and 4 malignant tumors. Preoperative localization was attempted by using ultrasonography (positive in 28.1%) CT imaging (positive in 25%), selective arteriography (positive in 54.1%), endoscopic ultrasonography (positive in 27.2%) and assay of portal plasma insulin levels (positive in 94.4%). In 54/55 cases (98.2%) the tumors were identified intraoperatively by palpation. By addition of intraoperative ultrasonography all lesions were identified and successfully removed without mortality. Five patients had multiple endocrine neoplasias all with multiple lesions in the pancreas. In patients with benign lesions 29 enucleations and 32 resections were performed. Pancreatic fistulas were the most common complication (29/59). Excluding the patients with malignant lesions the recovery rate was 98.1%. Three patients who underwent corporo caudal pancreactectomy developed diabetes. CONCLUSIONS: The preoperative localization is not necessary, since a combination of palpation and intraoperative ultrasonography can deal with most cases. Enucleation when possible is the best choice for benign lesions.

[Laparoscopic cholecystectomy in a patient with sickle-cell anemia]. / Colecistectomia laparoscópica em paciente portador de anemia falciforme.

Laparoscopic cholecystectomy has recently become a popular alternative to traditional laparotomy and cholecystectomy in the management of patients with gallbladder disease. Elective surgical treatment of cholelithiasis in patients with sickle cell anemia has been followed by frequent postoperative complications. We present a case of elective laparoscopic cholecystectomy in a patient with sickle cell anemia followed by severe postoperative complications related to the hematological disease.