Persistent migraine aura: new cases, a literature review, and ideas about pathophysiology.

BACKGROUND: Persistent migraine aura without infarction (PMA) is a rare condition that is defined as an aura that lasts longer than 1 week in absence of infarction. Two types of PMA have been distinguished, notably persistent primary visual disturbance (PPVD) and typical aura (TA). OBJECTIVES: This case-based review article describes four new cases of PMA as well as reviews all cases reported, trying to identify relevant associations, in particular with respect to functional investigations. METHODS: We performed a systematic literature search, extending from the period when it was first described (1991) to March 2014. We included all case descriptions of which criteria for PMA formulated in the International Classification of Headache Disorders, second edition, were met. In addition, we described four new cases. RESULTS: We identified 47 cases of PMA, 27 PMA-PPVD and 19 PMA-TA. In one case, there was not enough information to define the type of PMA. The mean age of onset was 30 years, varying from 7 to 74 years. The duration of symptoms varied from 9 days to 28 years. Besides a longer duration in symptoms in the PMA-PPVD group, we could not identify any differences between these groups. Some authors report occipital hypoactivity on Tc99m-hexamethylpropylene amine oxime -single-photon emission computed tomography (Tc99m-HMPAO-SPECT) or fluorodeoxyglucose-positron emission tomography (FDG-PET) in PMA cases, but data are inconsistent. Multiple drugs have been used for the treatment of PMA, usually with little effect. Lamotrigine seems to be the most effective drug. CONCLUSION: Despite the fact that 47 cases of PMA have been reviewed in this paper, many questions remain. The cases that have been described so far show inconsistent data with respect to the results of functional studies as well as treatment effects. The pathophysiology of PMA is still largely a matter of conjecture.

Clinical and Radiological Outcomes of Intracranial Aneurysm Clipping Aided by Transit Time Flowmetry.

BACKGROUND: Since the International Subarachnoid Aneurysm Trial, coiling has been favored over clipping for intracranial aneurysms, resulting in selection of increasingly complex aneurysm configurations for clipping. We present the outcomes of clipping of aneurysms not suitable for coiling, with transit time flowmetry technology to aid monitoring of intraoperative flow. METHODS: All consecutive patients surgically treated for intracranial aneurysms were included. We assessed intraoperative arterial blood flow in relation to postoperative ischemia and unfavorable outcome (modified Rankin Scale score 3-6), along with radiological occlusion rate, at 6 months and 1 year after surgery. RESULTS: Mortality at 1 year was 7.9%, with a 21.6% rate of an unfavorable outcome. Almost all (96.1%) of patients with unruptured aneurysms had an favorable outcome at 1 year, compared with 71.9% of patients with aneurysmal subarachnoid hemorrhage. Postoperative computed tomography imaging showed an 86.7% occlusion rate and a 7.5% rate of clip-related ischemia. Flow <40% of baseline significantly predicted clip-related ischemia (odds ratio [OR], 5.14; 95% confidence interval [CI], 1.41-8.4; P = 0.012). Clip reposition aided by transit time flowmetry resulted in restored flow >50% above baseline flow in 85.7% of aneurysms. Less than 50% flow from baseline was an independent predictor of unfavorable outcome (OR, 3.85; 95% CI, 1.6-9.0; P = 0.001), along other risk factors. CONCLUSION: In this study of clinical and radiological outcomes of surgically treated cerebral aneurysms not suitable for unassisted coiling, we showed positive results for these challenging aneurysms, aided by transit time flowmetry as a valuable tool, providingquantitative measurements of arterial blood flow to help achieve optimal clip placement and minimizing aneurysm residuals that may be sites of rebleeding. Adequate flow, defined as ≥50% of baseline, greatly reduces the risk of unfavorable outcome.

Repeatability and reproducibility of relative cerebral blood volume measurement of recurrent glioma in a multicentre trial setting.

BACKGROUND: Measurement of relative cerebral blood volume (rCBV) with dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) is used extensively for brain tumour diagnosis and follow-up. The aim of this pilot study was to assess the robustness of rCBV measurement in patients with enhancing recurrent glioma in a European multicentre trial setting. METHODS: We included pre-treatment postcontrast T1 weighted (T1w) and DSC scans of 20 patients with recurrent glioma from 2 European Organisation for Research and Treatment of Cancer trials (26101 and 26091). Three reviewers independently placed a fixed circular region of interest of 70 mm2 in the tumour area of highest rCBV (rCBVmax). To calculate the normalised rCBVmax (nrCBVmax), three ROIs were placed in the anterior, middle and posterior centrum semiovale normal-appearing white matter of the contralateral hemisphere. After several months, each observer repeated the assessments blinded for initial findings. Repeatability and reproducibility were estimated with a mixed model. Each measurement was also classified according to 4 clinically meaningful categories. RESULTS: Three patients were post hoc excluded from analysis because of lack of enhancing tumour. The mean nrCBVmax repeatability was 49.5%, and reproducibility was 5.5%. In 14 of 17 patients, at least 2 reviewers classified the patient into the same category. CONCLUSIONS: Our results indicate that a well-established review process needs to be applied upfront to assess perfusion in a multicentre trial setting. While awaiting further validation, we propose as a strategy to measure rCBV in the context of recurrent glioma trials to use two central reviewers and an adjudicator in case of disagreement.