Detection of feigned tactile sensory loss using a forced-choice test of tactile discrimination and other measures of tactile sensation

OBJECTIVE: Intentional exaggeration of disability is a risk in work injuries but is hard to reliably detect clinically. This study examined the accuracy of tactile sensory threshold and forced-choice discrimination measures in detecting feigned sensory loss. METHODS: Participants (n = 80) were randomly assigned to one of four sensory loss groups: (1) none; (2) partial; (3) full; or (4) feigned. Sensory data were collected for the upper extremities. RESULTS: Tactile thresholds greater than 0.5 g, discriminability less than 0.50, or forced-choice scores less than 90% were associated with a very low probability of false-positive errors. CONCLUSIONS: Below-chance scores are definitive evidence that the sensory loss is intentionally feigned. Scores beyond cut-offs should raise the clinician's suspicion of malingering if there is no physical basis for sensory loss.     

Assessment of construct validity of the endoscopic sinus surgery simulator

OBJECTIVE: To study the relationship between performance on an endoscopic sinus surgery simulator (ES3) and fundamental perceptual, visuospatial, and psychomotor abilities. DESIGN: Validation study. SETTING: Tertiary care medical center. PARTICIPANTS: Thirty-four medical students and 4 otolaryngology residents voluntarily enrolled. INTERVENTIONS: Subjects performed tasks on the ES3, minimally invasive surgical trainer virtual reality (MIST-VR), pictorial surface orientation (PicSOr), and 3 visuospatial tests (cube comparison, card rotation, and map planning). MAIN OUTCOME MEASURES: The MIST-VR was scored for time, task error, economy of hand movement, economy of diathermy, and total score. Scores were generated for the PicSOr task and visuospatial tests. Scores were correlated with time, accuracy, and total subscore on navigation, injection, and dissection tasks, as well as hazard score and total trial score on the ES3. RESULTS: The PicSOr score was statistically significantly correlated with the hazard score on the ES3 (r = 0.50, P < .001). Cube comparison (r = 0.43, P < .01) and card rotation (r = 0.45, P < .01) scores correlated significantly with the ES3 trial score, as did the MIST-VR total score and the ES3 trial score (r = 0.57, P < .001). In a multiple regression model, the PicSOr, cube comparison, and MIST-VR total scores were statistically significant predictors of ES3 performance (r = 0.63, P < .01). CONCLUSIONS: Scores on the ES3 correlate strongly with scores on previously validated measures of perceptual, visuospatial, and psychomotor performance. The ES3 provides a reliable assessment of factors that are important to the acquisition of minimally invasive surgical skills, demonstrating construct validity.     

Inflammatory pseudotumor of the pituitary: case report

BACKGROUND: Inflammatory pseudotumor of the pituitary is a very rare nonneoplastic lesion. We describe a case of a patient with past history of lymphocytic meningitis. CASE DESCRIPTION: A 32-year-old man presented with polyuria, polydipsia, anorexia, abdominal discomfort, and panhypopituitarism. He had 2 episodes of lymphocytic meningitis in the last two years. Magnetic resonance image (MRI) disclosed a sellar and suprasellar mass with extension to the pituitary stalk. The patient underwent transnasal-transsphenoidal surgery to remove the lesion. Histopathological findings revealed mixed inflammatory cells composed mainly of lymphocytes, macrophages and extensive fibrosis. CONCLUSIONS: Inflammatory pseudotumor of the pituitary, although rare, should be included in the differential diagnosis of a sellar and suprasellar mass.     

Epidemiology and results of liver transplantation for acute liver failure in Chile

Acute liver failure (ALF) is a severe, life-threatening condition associated with a high mortality rate. The objective of this study is to present the experience of a Chilean liver transplant program with orthotopic liver transplantation (OLT) for ALF. All patients with the diagnosis of ALF evaluated in our program between January 1995 and May 2003 were included in the analyses of etiology and outcomes. Candidates for OLT activated on a national waiting list were transplanted with cadaveric or living-related donor (LRD) organs. Twenty-seven patients age 1 to 19 years (median, 7.4 years) were transplanted at a median weight of 30.7 kg including 17 cadaveric and 10 with LRD livers. Most frequent etiologies were hepatitis A in 10 cases (37%) and unknown in 12 (48.1%). One donor experienced superficial phlebitis. Four patients were retransplanted (14.8%). Twenty patients are alive with 1- and 5-year survival rates of 74.1% At a median follow up of 34 months (range = 2 to 120). Seven patients died due to sepsis, multiorganic failure, graft primary nonfunction, intracranial hemorrhage, and intraoperative cardiac arrest. This experience revealed results comparable to international reports, allowing survival of patients destined to die.     

Proton MR spectroscopy in Wernicke encephalopathy

Wernicke encephalopathy is caused by thiamine deficiency. Although the clinical picture has been well established for some time, clinical diagnosis is attained in only 20% of the cases. MR imaging techniques contribute to early diagnosis of Wernicke encephalopathy. We herein report MR imaging and proton MR spectroscopic findings for a patient with clinical and biochemical features consistent with Wernicke encephalopathy. Increased lactate and typical MR imaging findings are discussed in the context of the known pathophysiology of Wernicke encephalopathy.     

New molecular features of cholestatic diseases of the liver

Hepatic uptake and biliary excretion of bile salts and non-bile salt organic anions is mediated by specific transport proteins located at the basolateral and canalicular membranes of hepatocytes. Several hepatobiliary transport systems have been identified and cloned over the past years. This development has facilitated molecular biological and genetic analyses of these transporters in experimental cholestasis and human cholestatic liver diseases. Evidence now exists that decreased or even absent expression of hepatobiliary transport systems may explain impaired transport function resulting in hyperbilirubinemia and cholestasis. This review summarizes the molecular defects in hepatocellular membrane transporters associated with hereditary and acquired forms of cholestatic liver diseases. The increasing information on the molecular regulation of hepatobiliary transport systems should bring new insights into the pathophysiology and treatment of human cholestatic liver diseases.     

Rotator cuff repair in spinal cord injury patients

Previous studies on the treatment of rotator cuff tears in wheelchair-bound patients have concentrated on nonsurgical management. We conducted a retrospective review to determine the effectiveness of surgical repair of rotator cuff tears in spinal cord-injured patients. Five male patients with rotator cuff tears confirmed by physical examination and magnetic resonance imaging underwent rotator cuff repair. Two of eight shoulders were revisions. The patients were evaluated postoperatively with the American Shoulder and Elbow Surgeons Scoring System. These results were compared with preoperative functional assessment. Patients were given a subjective questionnaire to assess their overall experience. Postoperative range of motion improved in 6 of 8 shoulders. Strength was increased in 6 of 8 shoulders. Patients reported satisfaction with the results in 7 of 8 shoulders, and all 5 patients would recommend the procedure to other spinal cord injury patients. At recent follow-up, 7 of 8 shoulders returned to their preinjury level of function. Surgery for spinal cord injury patients with rotator cuff tears can improve their functional capability and autonomy while reducing their pain. Compliance with the demanding postoperative rehabilitation is essential; therefore proper patient selection is crucial for optimal results.     

Acute reversible paraparesis secondary to probable fibrocartilaginous embolism

Fibrocartilagenous embolism (FCE) of the intervertebral disc represents a very rare cause of spinal infarct. Up to now only 33 others cases in human beings have been reported in the literature, most of them diagnosed post mortem. We present a 14-year-old boy who developed acute dorsal back pain after lifting a heavy gate, followed by progressive paraparesis. An MRI of the spine showed a degenerative disc at D10-D11 without compromise of the spinal canal lumen associated with an acute Schmorl's nodule situated in the superior endplate of D11. A week later, a second MRI disclosed an intraxial spinal cord lesion at D7-D8 vertebral level involving the vascular territory of the anterior spinal artery. It also showed an abnormal signal located in the posterior third of the D8 vertebral body. These clinical and neuro-radiological findings are similar to those mentioned in the literature and support the diagnosis of an anterior spinal infarct secondary to a probable fibrocartilaginous embolism. This case highlights the importance of considering this etiology among the causes of spinal cord infarct, especially in young people, and underlines the utility of MRI in its diagnosis in vivo.     

Low doses of topiramate are effective in essential tremor: a report of three cases

We here report on 3 patients with essential tremor, otherwise unresponsive to pharmacological treatment, who greatly benefited from low doses of topiramate (50 mg/d). No side effects were observed and improvement was sustained during a mean of 7 months (range 3-12 months) follow up. Our results suggest that topiramate titration should be performed gradually, so as not to neglect cases responsive to low doses.