TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Progress in the management of patients with medically intractable epilepsy is impeded because we do not fully understand why pharmacoresistance happens and how it can be predicted. The presence of multiple seizures prior to medical treatment has been suggested as a potential predictor of poor outcome. In the present study, we used an animal model of temporal lobe epilepsy to investigate whether pharmacoresistant rats differ in seizure frequency from pharmacoresponsive animals.', 'Epilepsy with spontaneous recurrent seizures (SRS) was induced by status epilepticus. Frequency of SRS was determined by video/EEG (electroencephalography) monitoring in a total of 33 epileptic rats before onset of treatment with phenobarbital (PB).', 'Thirteen (39%) rats did not respond to treatment with PB. Before treatment with PB, average seizure frequency in PB nonresponders was significantly higher than seizure frequency in responders, which, however, was due to six nonresponders that exhibited > 3 seizures per day. Such high seizure frequency was not observed in responders, demonstrating that high seizure frequency predicts pharmacoresistance in this model, but does not occur in all nonresponders.\Question: Is high seizure frequency prior to antiepileptic treatment a predictor of pharmacoresistant epilepsy in a rat model of temporal lobe epilepsy?

SOLUTION: The data from this study are in line with clinical experience that the frequency of seizures in the early phase of epilepsy is a dominant risk factor that predicts refractoriness. However, resistance to treatment also occurred in rats that did not differ in seizure frequency from responders, indicating that disease severity alone is not sufficient to explain antiepileptic drug (AED) resistance. These data provide further evidence that epilepsy models are useful in the search for predictors and mechanisms of pharmacoresistance.

PROBLEM: Context: Readout-segmented echo planar imaging (rs-EPI) significantly reduces susceptibility artifacts in diffusion-weighted imaging (DWI) of the breast compared to single-shot EPI but is limited by longer scan times. To compensate for this, we tested a new simultaneous multi-slice (SMS) acquisition for accelerated rs-EPI.', 'After approval by the local ethics committee, eight healthy female volunteers (age, 38.9 ± 13.1 years) underwent breast MRI at 3T. Conventional as well as two-fold (2× SMS) and three-fold (3× SMS) slice-accelerated rs-EPI sequences were acquired at b-values of 50 and 800 s/mm(2). Two independent readers analyzed the apparent diffusion coefficient (ADC) in fibroglandular breast parenchyma. The signal-to-noise ratio (SNR) was estimated based on the subtraction method. ADC and SNR were compared between sequences by using the Friedman test.', 'The acquisition time was 4:21 min for conventional rs-EPI, 2:35 min for 2× SMS rs-EPI and 1:44 min for 3× SMS rs-EPI. ADC values were similar in all sequences (mean values 1.62 × 10(-3)mm(2)/s, p=0.99). Mean SNR was 27.7-29.6, and no significant differences were found among the sequences (p=0.83).\Question: Do simultaneous multi-slice readout-segmented echo planar imaging for accelerated diffusion-weighted imaging of the breast?

SOLUTION: SMS rs-EPI yields similar ADC values and SNR compared to conventional rs-EPI at markedly reduced scan time. Thus, SMS excitation increases the clinical applicability of rs-EPI for DWI of the breast.

PROBLEM: Context: International registries for acute type A aortic dissection (TAAD) demonstrate stagnant operative mortality rates in excess of 20% and stroke rates of 9% to 25%, with little global emphasis on stroke reduction or carotid involvement. Cerebral malperfusion with TAAD has been linked to poorer outcome. We hypothesize that concomitant carotid dissection or complex dissection flaps in the arch play a major role in stroke development and that aggressive reconstruction of the arch and carotid arteries can improve neurologic outcomes in TAAD.', 'A standardized protocol focused on expedient care, neurocerebral protection, and common carotid and total arch reconstruction was developed for 264\xa0consecutive TAADs. Arch and complete carotid replacement was based on arch dissection anatomy, carotid involvement, or an intraarch tear. Neurocerebral monitoring with continuous electroencephalogram/somatosensory evoked potentials was used in all cases.', 'The postoperative stroke and hospital mortality rates were 3.4% and 9.1%, and stroke rates by extent of arch replacement were 4%, 3%, and 0% for hemiarch, total arch, and total arch with complete carotid replacement, respectively. An intraoperative change in the electroencephalogram/somatosensory evoked potentials was strongly predictive of stroke and had a negative predictive value of 98.2%.\Question: Does aggressive Aortic Arch and Carotid Replacement Strategy for Type A Aortic Dissection improve Neurologic Outcomes?

SOLUTION:
An algorithmic approach to TAAD including (1) rapid transport-to-incision-to-cardiopulmonary bypass established centrally, (2) neurocerebral monitoring, (3) liberal use of total arch replacement for clearly defined indications (and hemiarch for all others), and (4) common carotid arterial replacement for concomitant carotid dissections significantly improves outcomes.