Comparison of Dynamic (Brush) and Static (Pressure) Mechanical Allodynia in Migraine

Abstract

Allodynia has been described in migraine but has not been fully investigated for the different sensory modalities. The aim of this study was to compare the prevalence of dynamic (brush) and static (pressure) mechanical allodynia in migraine patients and to suggest a practical method of testing them in a clinical setting. Patients with International Headache Society-defined episodic migraine (EM) or with transformed migraine (TM) as defined by Silberstein and Lipton were prospectively recruited from the Jefferson Headache Center out-patient clinic. A questionnaire of migraine features and symptoms of allodynia was administered. Brush allodynia (BA) was tested by cutaneous stimulation with a gauze pad and pressure allodynia (PA) was tested using von Frey hairs (VFH). The prevalence of BA and PA in all patients and in the different subgroups was calculated and correlated with migraine features. We recruited 55 migraine patients. Twenty-five had EM and 30 had TM. BA was present in 18 (32.7±) patients and PA in 18–24 (32.7–43.6±). Allodynia to both brush and pressure was found in 13–17 (23.6–30.9±) patients. If a patient had allodynia to one modality only, it was more likely to be PA than BA. Both BA and PA were more common in patients with TM compared with those with EM [BA 46.7± vs. 16.0±; PA (differences significant for the medium and thick VFHs) 50± vs. 20± and 50± vs. 12±, respectively]. Both types of allodynia were also more common in patients with migraine with aura compared with those with migraine without aura (BA 57.1± vs. 17.6±; PA 57.1–61.9± vs. 17.6–32.7±). There was a positive correlation between allodynia score (as obtained by examination) and allodynia index (as obtained by history) for both BA and PA. The incomplete, although considerable, overlap between BA and PA suggests that allodynia to different sensory modalities is associated with sensitization of different neuronal populations. Because PA was more common than BA, it may be a more sensitive indicator of allodynia in migraine. PA can be tested clinically in a practical and systematic manner.

Allodynia in Cluster Headache

“…However, studies on the prevalence of CA in migraine have shown a remarkable agreement between the results of QST and those obtained by the brush testing with regard to the prevalence of allodynia in these patients [2,3], supporting brush testing as a valid method for the detection of allodynia in a clinical setting.…”

“…Over the past decade, there has been considerable interest in the pathophysiology of this phenomenon in headaches (particularly in migraine) and in its clinical implications [2,3,[5][6][7][8]. CA in migraine is currently thought to result from sensitization of pain-signaling neurons in the trigeminal nucleus caudalis (TNC) that receive input from both intracranial structures and skin [9].…”

“…These include both mechanical (static or dynamic) and thermal stimuli [2,3]. Different types of mechanical allodynia appear to be mediated through input from different types of receptors [1].…”

Allodynia as a complication of migraine: Background and management

“…In a clinic-based study, brush allodynia was present during an attack in 68% of patients with episodic migraine, in 41% of transformed migraine patients between exacerbations, and in 46% with an exacerbation [5]. There is considerable (but incomplete) overlap with pressure allodynia, as measured with Von Frey hairs [6].Central sensitization is thought to be the physiologic process underlying cutaneous allodynia in headache patients. In animal models, it occurs when a strong, nociceptive stimulus sensitizes the second-order neurons of the trigeminal nucleus or dorsal horn.…”

“…In a clinic-based study, brush allodynia was present during an attack in 68% of patients with episodic migraine, in 41% of transformed migraine patients between exacerbations, and in 46% with an exacerbation [5]. There is considerable (but incomplete) overlap with pressure allodynia, as measured with Von Frey hairs [6].…”