Page 133 - Migraine, the heart and the brain

Cerebellar function and ischemic brain lesions in migraine
as the pointing paradigm or posturographic measures of sway (1,6), which are potentially open for bias. We don’t believe the contrasting ndings were due to use of different tests. The pointing paradigm resembles the prism paradigm we used in that it also compares motor output of the forelimbs before and after manipulating visual feedback and the posturographic measures of sway were similar to our body-sway test (1,6). Conditioned eyeblink responses measured with the use of electromyography (EMG) (10), can be readily repeated with the more sensitive Magnetic Distance Measurement Technique (MDT) method used in the current study (19). Finally, as we did nd signi cant differences in a relatively small group of FHM1 patients with the same set of tests, we are reassured that the tests we employed were suf ciently sensitive to detect differences. Thus, in contrast to previous ndings (1,7,8,38), our ndings argue against the hypothesis that cerebellar function is altered in the average migraine patient. Moreover the results of our study underline the importance of including unbiased study populations and ensuring that investigators are blinded for clinical diagnosis.
The effect of cerebellar ischaemic lesions on cerebellar function
A conspicuous advantage of our study was that virtually all migraine patients and
controls (275/282; 98%) were subjected to detailed brain MRI as part of the CAMERA-2
study. In total 20/275 (7%) individuals,17 with migraine and three controls, showed
cerebellar ischaemic lesions, eight had an isolated cerebellar ischaemic lesion.
Migraine patients with cerebellar ischaemic lesions performed signi cantly worse 7 on multiple outcomes of the pegboard task including the assembly score, number of
pegs with right hand and number of pegs with both hands. However, outcome parameters of all other cerebellar tests were not affected.
Why we detected de cits only with the pegboard test remains elusive. Possibly the cerebellar ischaemic lesions were accidently selectively localised in the cerebellar lobules involved in pegboard performance, but not the other tests. Such an explanation would be in line with the nding that the patients with impaired pegboard performance all showed larger lesions mainly in the posterior lobules (Supplemental table), which is the cerebellar region presumably responsible for this task (29,31,34). The anterior lobe can also contribute to limb movements (39). However, as indicated by several studies (29,31,34) the ne nger movements, as tested intensely by the pegboard test, rely mainly heavily on the loop between the posterior cerebellum and cerebral cortex. Alternatively, performance of the pegboard task might also depend on cerebral cortical function (29), and the
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