Habituation and sensitization in primary headaches

Abstract

The phenomena of habituation and sensitization are considered most useful for studying the neuronal substrates of information processing in the CNS. Both were studied in primary headaches, that are functional disorders of the brain characterized by an abnormal responsivity to any kind of incoming innocuous or painful stimuli and it’s cycling pattern over time (interictal, pre-ictal, ictal). The present review summarizes available data on stimulus responsivity in primary headaches obtained with clinical neurophysiology. In migraine, the majority of electrophysiological studies between attacks have shown that, for a number of different sensory modalities, the brain is characterised by a lack of habituation of evoked responses to repeated stimuli. This abnormal processing of the incoming information reaches its maximum a few days before the beginning of an attack, and normalizes during the attack, at a time when sensitization may also manifest itself. An abnormal rhythmic activity between thalamus and cortex, namely thalamocortical dysrhythmia, may be the pathophysiological mechanism subtending abnormal information processing in migraine. In tension-type headache (TTH), only few signs of deficient habituation were observed only in subgroups of patients. By contrast, using grand-average responses indirect evidence for sensitization has been found in chronic TTH with increased nociceptive specific reflexes and evoked potentials. Generalized increased sensitivity to pain (lower thresholds and increased pain rating) and a dysfunction in supraspinal descending pain control systems may contribute to the development and/or maintenance of central sensitization in chronic TTH. Cluster headache patients are chrarcterized during the bout and on the headache side by a pronounced lack of habituation of the brainstem blink reflex and a general sensitization of pain processing. A better insight into the nature of these ictal/interictal electrophysiological dysfunctions in primary headaches paves the way for novel therapeutic targets and may allow a better understanding of the mode of action of available therapies.

Visual evoked potentials in migraine: Is the “neurophysiological hallmark” concept still valid?

“…Taken together, in contrast with the view expressed in some recent reviews (e.g. Brighina et al, 2009;Coppola et al, 2013a;Coppola et al, 2009;de Tommaso et al, 2014;Magis et al, 2013), the actual evidence suggests that lack of pattern VEP habituation cannot be considered a reliable finding in interictal migraine. In addition, we could neither reproduce lack of habituation with 3.0 rps and 16' checks in the present study, nor with 3.0 rps and 8' and 65' or 1.9 rps and 31' and 62' checks in previous studies (Omland et al, 2013;Sand et al, 2009;Sand et al, 2008).…”

“…Since migraine is hereditary, some authors argue that subjects with first-degree relatives with migraine should not be included in the control group in VEP habituation studies (Coppola et al, 2013a). As far as we know there are no published data showing that first-degree relatives of migraineurs have altered VEP habituation compared to other controls.…”

Fájdalomcsillapító-túlhasználathoz társuló fejfájás

“…Figyelmet érdemel, hogy nemcsak a szerotonerg támadáspontú rohamgyógyszerek (triptánok, illetve ergotszármazékok) esetén írták le ezt a jelenséget, hanem például paracetamol kísérletes adása kapcsán is [37]. Az idegrendszer megváltozott érzékenységére, a környezeti ingerek feldolgozásának zavarára utalnak azok az elektrofi ziológiai vizsgálatok is, amelyek FTTFbetegek körében a habituáció zavarát igazolták [38]. Más vizsgálatok szerint FTTF-betegekben a fájdalom-ingerek repetitív alkalmazása centrális szenzitizációhoz vezet, azaz a fájdalomérzés a központi idegrendszer fáj-dalomfeldolgozó struktúráinak működészavara miatt fokozódik, illetve tartóssá válik [39].…”

The efficiency of pulsed electromagnetic field in refractory migraine headaches: a randomized, single-blinded, placebo-controlled, parallel group

“…However, they return to the normal state after the migraine attack. [10][11][12][13] Evidence indicates that nonpharmacologic treatments can play an important role in controlling RM.…”