Multimodal Presurgical Evaluation of Medically Refractory Focal Epilepsy in Adults: An Update for Radiologists.

Surgery is a potentially curative treatment option for patients with medically refractory focal epilepsy. Advanced neuroimaging modalities often improve surgical outcomes by contributing key information during the highly individualized surgical planning process and intraoperative localization. Hence, neuroradiologists play an integral role in the multidisciplinary management team. In this review, we initially present the conceptual background and practical framework of the presurgical evaluation process, including a description of the surgical treatment approaches used for medically refractory focal epilepsy in adults. This background is followed by an overview of the advanced modalities commonly used during the presurgical workup at level IV epilepsy centers, including diffusion imaging techniques, blood oxygenation level-dependent functional MRI (fMRI), PET, SPECT, and subtraction ictal SPECT, and by introductions to 7-T MRI and electrophysiologic techniques including electroencephalography and magnetoencephalography. We also provide illustrative case examples of multimodal neuroimaging including PET/MRI, PET/MRI-diffusion-tensor imaging (DTI), subtraction ictal SPECT, and image-guided stereotactic planning with fMRI-DTI.

Advancements in Positron Emission Tomography/Magnetic Resonance Imaging and Applications to Diagnostic Challenges in Neuroradiology.

Since the clinical adoption of magnetic resonance (MR) in medical imaging, MR has proven to be a workhorse in diagnostic neuroradiology, with the ability to provide superb anatomic detail as well as additional functional and physiologic data, depending on the techniques utilized. Positron emission tomography/computed tomography has also shown irreplaceable diagnostic value in certain disease processes of the central nervous system by providing molecular and metabolic information through the development of numerous disease-specific PET tracers, many of which can be utilized as a diagnostic technique in and of themselves or can provide a valuable adjunct to information derived from MR. Despite these advances, many challenges still remain in neuroradiology, particularly in malignancy, neurodegenerative disease, epilepsy, and cerebrovascular disease. Through improvements in attenuation correction, motion correction, and PET detectors, combining the 2 modalities of PET and MR through simultaneous imaging has proven feasible and allows for improved spatial and temporal resolution without compromising either of the 2 individual modalities. The complementary information offered by both technologies has provided increased diagnostic accuracy in both research and many clinical applications in neuroradiology.

Efficacy and safety of novel oral anticoagulants in patients with cervical artery dissections.

BACKGROUND: American and European guidelines support antiplatelet agents and anticoagulants as reasonable treatments of cervical artery dissection (CAD), though randomized clinical trials are lacking. The utility of novel oral anticoagulants (NOAC), effective in reducing embolic stroke risk in non-valvular atrial fibrillation (NVAF), has not been reported in patients with CAD. We report on the use, safety, and efficacy of NOACs in the treatment of CAD. METHODS: We retrospectively identified patients diagnosed with CAD at a single academic center between January 2010 and August 2013. Patients were categorized by their antithrombotic treatment at hospital discharge with a NOAC (dabigatran, rivaroxaban, or apixaban), traditional anticoagulant (AC: warfarin or treatment dose low-molecular weight heparin), or antiplatelet agent (AP: aspirin, clopidogrel, or aspirin/extended-release dypyridamole). Using appropriate tests, we compared the baseline medical history, presenting clinical symptoms and initial radiographic characteristics among patients in the 3 treatment groups. We then evaluated for the following outcomes: recurrent stroke, vessel recanalization, and bleeding complications. p values <0.05 were considered significant. RESULTS: Of the 149 included patients (mean age 43.4 years; 63.1% female; 70.5% vertebral artery CAD), 39 (26.2%), 70 (47.0%), and 40 (26.8%) were treated with a NOAC, AC, and AP, respectively. More patients with severe stenosis or occlusion were treated with NOAC than with AC or AP (61.8 vs. 60.0 vs. 22.5%, p = 0.002). Other baseline clinical and radiographic findings, including the presence of acute infarction and hematoma, did not differ between the 3 treatment groups. One hundred and thirty-five (90.6%) patients had clinical follow-up (median time 7.5 months) and 125 (83.9%) had radiographic follow-up (median time 5 months) information. There were 2 recurrent strokes in the NOAC group and 1 in each of the AC and AP groups (p = 0.822). There were more major hemorrhagic events in the AC group (11.4%) compared to the NOAC (0.0%) and AP (2.5%) groups (p = 0.034). Three patients treated with NOAC and none treated with AC or AP had a worsened degree of stenosis on follow-up imaging (8.6 vs. 0.0 vs. 0.0%, p = 0.019). CONCLUSION: Compared to traditional anticoagulants for CAD, treatment with NOACs is associated with similar rates of recurrent stroke, fewer hemorrhagic complications, but greater rates of radiographic worsening. These data suggest that NOACs may be a reasonable alternative in the management of CAD. Prospective validation of these findings is needed.

Radiofrequency ablation of a solitary liver metastasis complicated by colonic perforation.

Radiofrequency ablation is used for the treatment of primary liver malignancies and liver metastases. In this case, the authors performed percutaneous radiofrequency ablation of a solitary esophageal carcinoma metastasis within the left hepatic lobe. Following the procedure, the patient developed a colonic perforation with a large right upper quadrant abscess. Although the abscess nearly resolved after intravenous antibiotics and percutaneous drainage, the patient ultimately developed a colocutaneous fistula that required surgical excision and right hemicolectomy. The risks for developing this complication as well as measures to minimize this risk are discussed.

Examination of selected clinical factors and medication use as risk factors for pneumonia during stroke rehabilitation: a case-control study.

OBJECTIVE: To assess the association of selected clinical factors and specific medication use (proton pump inhibitors, H2 receptor antagonists [H2 blockers], and angiotensin-converting enzyme inhibitors) with presence of pneumonia in patients with stroke undergoing acute inpatient rehabilitation. DESIGN: Matched case-control study in a freestanding urban academic inpatient acute rehabilitation hospital. Participants were 72 stroke survivors, consisting of 36 patients who developed pneumonia during rehabilitation hospitalization individually matched in order of decreasing priority on age, sex, stroke side, depth, and severity with 36 patients with stroke not developing pneumonia. Potential risk factors, including severe dysphagia, dietary interventions, presence of tracheostomy or feeding tube, and specific medications, were assessed for association with pneumonia during rehabilitation using separate univariate and multivariate analyses. Functional change was assessed using the functional independence measure. RESULTS: Although pneumonia was associated with proton pump inhibitors or H2 blockers (odds ratio, 3.3; 95% confidence interval, 1.0-13.7), any feeding tube (odds ratio: 5.0; 95% confidence interval, 1.4-27.0), severe dysphagia (odds ratio: 15.0; 95% confidence interval, 2.3-631), and tracheostomy (odds ratio: 10; 95% confidence interval, 1.4-434.0) on univariate evaluation, none of these individual factors was significantly associated with pneumonia in a multivariate model. Risk factors were found to be highly related to each other. Odds of pneumonia did not significantly decrease with angiotensin-converting enzyme inhibitors (odds ratio: 0.9; 95% confidence interval, 0.2-3.0). Patients with pneumonia had a significantly lower functional independence measure score at discharge. CONCLUSIONS: A reduction in pneumonia was not found with the use of angiotensin-converting enzyme inhibitors. Although tracheostomies, feeding tubes, proton pump inhibitor or H2 blocker use, and the presence of dysphagia were identified as risk factors for pneumonia on univariate analyses, none of these factors demonstrated an independent association with pneumonia on multivariate analyses. It may be more that the underlying impairment, rather than the assessed interventions, may confer greater risk of pneumonia in the poststroke patient.