Magnetic resonance imaging of the normal pituitary gland using ultrashort TE (UTE) pulse sequences (REV 1.0)

Introduction The purpose of this study was to examine the normal pituitary gland in male subjects with ultrashort echo time (TE) pulse sequences, describe its appearance and measure its signal intensity before and after contrast enhancement. Methods Eleven male volunteers (mean age 57.1 years; range 36–81 years) were examined with a fat-suppressed ultrashort TE (= 0.08 ms) pulse sequence. The studies were repeated after the administration of intravenous gadodiamide. The MR scans were examined for gland morphology and signal intensity before and after enhancement. Endocrinological evaluation included baseline pituitary function tests and a glucagon stimulatory test to assess pituitary cortisol and growth hormone reserve. Results High signal intensity was observed in the anterior pituitary relative to the brain in nine of the 11 subjects. These regions involved the whole of the anterior pituitary in three subjects, were localised to one side in two examples and were seen inferiorly in three subjects. Signal intensities relative to the brain increased with age, with a peak around the sixth or seventh decade and decreasing thereafter. Overall, the pituitary function tests were considered to be within normal limits and did not correlate with pituitary gland signal intensity. Conclusion The anterior pituitary shows increased signal intensity in normal subjects when examined with T₁-weighted ultrashort TE pulse sequences. The cause of this increased intensity is unknown, but fibrosis and iron deposition are possible candidates. The variation in signal intensity with age followed the temporal pattern of iron content observed at post mortem. No relationship with endocrine status was observed.     

Hormone inactive parathyroid cyst: rare differential diagnosis in the evaluation of cervical cysts

Parathyroid cysts are a very rare disease entity. Hormone activity is uncommon and they usually present without any clinical symptoms. The differential diagnosis of cystic neck masses should nevertheless include parathyroid cysts as surgical therapy can be very effective. We report the case of a 57-year-old patient presenting to our department with a hormone inactive parathyroid cyst. Final diagnosis was achieved eventually after histological examination of the resected specimen, which is the reason for evaluating the current data for preoperative management of this disease entity in this case report.     

Differential Effect of Ketamine and Lidocaine on Spontaneous and Mechanical Evoked Pain in Patients with Nerve Injury Pain

Background: The mechanisms underlying neuropathic pain are incompletely understood. Targeting specific molecular mechanisms in the pain signaling system may assist in understanding key features in neuropathic pains such as allodynia. This study examined the effect of systemically administered ketamine, an N-methyl-d-aspartate receptor antagonist and lidocaine, a sodium channel blocker, on spontaneous pain, brush-evoked pain, and pinprick-evoked pain in patients with nerve injury pain.

Methods: Twenty patients participated in two randomized, double-blinded, placebo-controlled, crossover experiments in which they, on four different days, received a 30-minute intravenous infusion of ketamine (0.24 mg/kg), lidocaine (5 mg/kg), or saline. Ongoing pain, pain evoked by brush and repetitive pinprick stimuli, and acetone was measured before, during, and after infusion.

Results: Ketamine significantly reduced ongoing pain and evoked pain to brush and pinprick, whereas lidocaine only reduced evoked pain to repetitive pinprick stimuli. In individual patients, there was no correlation between the pain-relieving effect of lidocaine and ketamine on ongoing or mechanically evoked pains.     

Use of aprotinin in cardiac surgery: effectiveness and safety in a population-based study

Objective: The effectiveness and safety of aprotinin use in cardiac surgery have been questioned. More data reflecting everyday clinical practice from large-scale, unselected populations are needed. We compared the effectiveness and safety of aprotinin in cardiac surgery with those of tranexamic acid in a follow-up study using the population-based Danish health-care databases. Methods: We identified a total of 3535 patients who underwent cardiac surgery at the Aarhus University Hospital, Skejby, between 1 January 2003 and 31 December 2006; of these, 635 patients were treated with aprotinin and 2900 with tranexamic acid. We used propensity score matching to match aprotinin-treated patients with tranexamic-acid-treated patients in a 1:1 ratio, followed by Poisson regression analysis to compute relative risks (RRs). Results: Patients treated with aprotinin had more severe preoperative risk profiles than the tranexamic-acid-treated patients. The rates of postoperative drainage and transfusion of red blood cells were similar in the two groups, whereas the aprotinin group received plasma (adjusted RR = 1.39; 95% confidence interval (CI): 1.15–1.68) and platelets (adjusted RR = 1.47; 95% CI: 1.19–1.81) more frequently than the tranexamic acid group. There were no statistically significant differences in risks of re-operation due to bleeding (adjusted RR = 1.22; 95% CI: 0.84–1.78), 30-day mortality (adjusted RR = 1.03; 95% CI: 0.69–1.54), acute myocardial infarction (adjusted RR = 1.06; 95% CI: 0.69–1.64), stroke (adjusted RR = 1.36; 95% CI: 0.75–2.44) or composite major event (adjusted RR = 1.14; 95% CI: 0.87–1.50) between the two groups. However, patients who received aprotinin had an increased risk of postoperative dialysis (adjusted RR = 1.76; 95% CI: 1.15–2.70). Conclusions: Aprotinin treatment was associated with an increased use of plasma and platelet transfusion and an increased risk for postoperative dialysis, but not with other adverse outcomes, including short-term mortality.     

Intravenous Lidocaine Relieves Spinal Cord Injury Pain: A Randomized Controlled Trial

Background: Neuropathic pain in spinal cord injury is a common challenging therapeutic condition. The current study examines the analgesic effect of the sodium channel blocker lidocaine on neuropathic pain in patients with spinal cord injury and the predictive role of concomitant evoked pain on pain relief with lidocaine.

Methods: Twenty-four spinal cord injury patients with neuropathic pain at or below the level of injury were randomized and completed a double-blind crossover trial of 5 mg/kg lidocaine and placebo infused over 30 min. Twelve patients reported evoked pain, and 12 patients had no evoked pain. Spontaneous and evoked pains were assessed using a visual analog scale and quantitative sensory testing.

Results: Lidocaine significantly reduced spontaneous pain in all patients (P < 0.01) and in each of the two groups with (P < 0.01) and without (P = 0.048) evoked pain, with no difference in number of responders (pain reduction >= 33%) between the patients with (n = 6) and without (n = 5) evoked pain. Lidocaine significantly relieved both at-level and below-level neuropathic pain and decreased brush-evoked dysesthesia but not cold allodynia, pinprick hyperalgesia, or pain evoked by repetitive pinprick.