Since the invention of arterial spin labeling (ASL) it has been acknowledged that ASL does not allow reliable detection of a white matter (WM) perfusion signal. However, recent developments such as pseudo-continuous labeling and background suppression have improved the quality. The goal of this research was to study the ability of these newer ASL sequences to detect WM perfusion signal. Background suppressed pseudo-continuous ASL was implemented at 3T with multislice 2D readout after 1525 ms. In five volunteers it was shown that 10 min scanning resulted in significant perfusion signal in 70% of WM voxels. Increasing the labeling and delay time did not lead to a higher percentage. In 27 normal volunteers it was found that 35 averages are necessary to detect significant WM signal, but 150 averages are needed to detect signal in the deep WM. Finally, it was shown in a patient with a cerebral arteriovenous malformation that pseudo-continuous ASL enabled the depiction of hypointense WM perfusion signal, although dynamic susceptibility contrast MRI showed that this region was merely showing delayed arrival of contrast agent than hypoperfusion. It can be concluded that, except within the deep WM, ASL is sensitive enough to detect WM perfusion signal and perfusion deficits. Magn Reson Med 62:165-173, 2009.

Intra-and multicenter reproducibility of currently used arterial spin labeling (ASL) methods were assessed at three imaging centers in the Netherlands, equipped with Philips 3TMR scanners. Six healthy participants were scanned twice at each site. The imaging protocol consisted of continuous ASL (CASL), pseudo-continuous ASL (p-CASL) with and without background suppression, pulsed ASL (PASL) with single and multiple inversion times (TIs), and selective ASL for segmentation. Reproducibility was expressed in terms of the coefficient of repeatability and the repeatability index. Voxelwise analysis of variance was performed, yielding brain maps that reflected regional variability. Intra-and multicenter reproducibility were comparable for all methods, except for single TI PASL, with better intracenter reproducibility (F-test of equality of two variances, P < 0.05). Pseudocontinuous ASL and multi TI PASL varied least between sites. Variability maps of all methods showed most variability near brain-feeding arteries within sessions and in gray matter between sessions. On the basis of the results of this study, one could consider the use of reference values in clinical routine, with whole-brain p-CASL perfusion varying < 20% over repeated measurements within the same individuals considered to be normal. Knowledge on regional variability allows for the use of perfusion-weighted images in the assessment of local cerebral pathology.

Botox is widely used in chronic migraine although efficacy in studies was only modest and likely confounded by unblinding. In a randomised, double-blind, placebo-controlled trial, Pijpers et al. show that Botox affords no additional benefit over acute withdrawal in patients with chronic migraine and medication overuse.

BackgroundThe outcome measures most frequently used in studies on the effectiveness of migraine treatment are whether the patient is free of pain, nausea, and free of photophobia/phonophobia within two hours. However, no patient-centred outcome measures are available. Therefore, we performed an online Delphi procedure to compile a list of outcome measures deemed most important to migraine patients.MethodsFrom a large database of migraine patients, we randomly selected 150 males and 150 females patients. We asked the open-ended question: ‘If a new medicine was developed for migraine attacks, what would you wish the effect of this medication to be?’ In the second and third rounds, we presented the answers of the first round and asked the patients to rate the importance of each item.ResultsThe initial response rate was 56% (n = 169). In the subsequent rounds the response rates were 90% (n = 152), and 97% (n = 147), respectively. Patients wanted their attack medication to treat the headache within 30 min, to prevent the attack from getting worse, to ensure they could function properly within 1 h, and prevent the recurrence of symptoms during the same day.ConclusionsThe currently used outcome measures in migraine research do not sufficiently reflect the wishes of patients. Patients want the medication to work faster, to take away pain at an earlier stage, to make them able to function properly quickly, and to prevent recurrence. These aspects should be considered in future evaluation of new attack medication for migraine.

Flow-territory mapping by MR imaging ASL noninvasively provides a unique insight into the distribution of cerebral perfusion. The introduction of planning-free vessel-encoded pCASL made flow-territory mapping feasible for clinical use, though lack of individual planning could impede reproducibility of this technique. We assessed the reproducibility of planning-free vessel-encoded pCASL in patients and controls. Results indicated that planning-free vessel-encoded pCASL is a reproducible method that could assist in clinical decision-making.