Value of gadolinium-diethylene-triamine pentaacetic acid dynamics in magnetic resonance imaging of acute myocardial infarction with occluded and reperfused coronary arteries after thrombolysis

The use of the paramagnetic contrast agent gadolinium-diethylene-triamine pentaacetic acid (DTPA) was evaluated in magnetic resonance imaging (MRI) of 18 patients with an acute myocardial infarction after thrombolysis. The patency of the infarct-related vessel was assessed by coronary angiography. At 58 +/- 9 hours after infarction MRI was performed before and after bolus injection of 0.1 mmol/kg gadolinium-DTPA. Myocardial signal intensities were measured using a circumferential profile. Normal and infarcted myocardium showed a maximum signal intensity enhancement of 35 and 66%, respectively. Signal intensity of infarcted relative to normal myocardium (I/N) increased from 1.06 +/- 0.16 before to a maximum of 1.39 +/- 0.13 after gadolinium-DTPA (p less than 0.001), whereas the contrast between normal myocardium and a pseudo-infarct region in 2 healthy volunteers did not change. Between patients with reperfused infarct-related vessels and occluded vessels without collaterals, maximum I/N did not differ. However, observing I/N as a function of time after injection of gadolinium-DTPA, the reperfusion group differed from the occlusion group on images acquired directly after injection (1.29 +/- 0.10 vs 1.14 +/- 0.05, p less than 0.02). Thus, gadolinium-DTPA enhanced the visualization of acute myocardial infarction on relatively longitudinal (T1)-weighted MR images and its dynamics seem of potential value for the noninvasive assessment of coronary artery reperfusion after thrombolysis.     

Hypothalamic activation in trigeminal autonomic cephalgia: functional imaging of an atypical case

We report headache induced BOLD changes in an atypical case of trigeminal autonomic cephalgia (TAC). A 68-year-old patient was imaged using fMRI during three attacks of a periorbital head-pain with a average duration of 3 min. During the attacks, left sided conjunctival injection, rhinorrhea, lacrimation, facial sweating and hypersalivation were apparent. These attacks were usually partly responsive to oxygen administration but otherwise refractory to any drug. The patient described either attacks with a duration of one minute or less or longer attacks persisting for maximum of 20 min with headaches occurring up to 100 times a day. When considering the symptoms, frequency, duration and therapeutic response of the patient's headache, no clear-cut classification to one of the subtypes of trigeminal autonomic cephalgias (cluster headache, paroxysmal hemicrania, SUNCT) or trigeminal neuralgia was possible. The cerebral activation pattern was similar but not identical to those previously observed in cluster headache and SUNCT with a prominent activation in the hypothalamic grey matter. This case study underlines the conceptual value of the term TAC for the group of headaches focusing around the trigeminal-autonomic reflex. Our results emphasize the importance of the hypothalamus as key region in the pathophysiology of this entity.     

Fractures of the shaft of the femur treated with a single AO plate

During a ten-year period 37 femoral diaphyseal fractures were treated by a solitary AO (Arbeitsgemeinschaft für Osteosynthesefragen [Association for the Study of Problems of Internal Fixation]) plate. Thirty fractures united following the internal stabilization. The seven that received an autogenous cancellous bone graft with the plate united. Twenty nongrafted fractures that stabilized in the first week resulted in one nonunion and four delayed unions. Ten nongrafted fractures were stabilized more than one week following injury resulting in one delayed union and one nonunion. Two femurs united after the addition of a bone graft without disturbing the previously applied plate in the fifth month after initial stabilization. A new plate and bone graft produced union in the remaining five. Higher union rates have been reported with the intramedullary nail. A plate rather than an intramedullary nail is the preferred implant in fractures that are either comminuted or infraisthmal or in the presence of a femoral prosthetic stem.