Migraine's Premonitory Phase: What Can We Learn From It?
Migraine's Premonitory Phase: What Can We Learn From It?
Given what is beginning to be unraveled concerning the premonitory phase, it is apposite to make a clear statement about what is meant, in definition terms, by the premonitory phase. The ICHD-III-beta mentions in the main text that a premonitory phase may exist in patients, and says it can begin hours or days beforehand. In the definition of terms, it states that premonitory symptoms begin 2–48 hours prior to an attack, being prior to aura in migraine with aura and prior to pain in migraine without aura. This definition is at best unusable. If premonitory symptoms precede an attack, then they must not be part of an attack and since premonitory means forewarning (Oxford English Dictionary on-line), of what is the warning a predictor? Moreover, what is the period of 2 hours before aura or pain begins to be called? The clinical data when prospectively collected show there is no 2-hour gap between the end of premonitory symptoms and the beginning of pain. Indeed, the neuroimaging data show activation of the same brainstem regions, such as the dorsolateral pons in the premonitory and pain phase proper. Given aura can start before pain, with pain or after pain, and its physiology is so different, it cannot itself be regarded as canonically premonitory. We submit, and consider that others have tacitly and intuitively considered, that the premonitory phase is any portion of the migraine attack prior to the commencement of headache. We consider the premonitory phase part of a migraine attack in its totality. The remaining complexity is how to regard the neck discomfort or stiffness often reported before head pain as such commences. We would suggest that it is considered as premonitory until there are further data. We urge the International Headache Society Classification Committee to resolve this definition anomaly prior to the completion of the beta round.
Defining the Premonitory Phase
Given what is beginning to be unraveled concerning the premonitory phase, it is apposite to make a clear statement about what is meant, in definition terms, by the premonitory phase. The ICHD-III-beta mentions in the main text that a premonitory phase may exist in patients, and says it can begin hours or days beforehand. In the definition of terms, it states that premonitory symptoms begin 2–48 hours prior to an attack, being prior to aura in migraine with aura and prior to pain in migraine without aura. This definition is at best unusable. If premonitory symptoms precede an attack, then they must not be part of an attack and since premonitory means forewarning (Oxford English Dictionary on-line), of what is the warning a predictor? Moreover, what is the period of 2 hours before aura or pain begins to be called? The clinical data when prospectively collected show there is no 2-hour gap between the end of premonitory symptoms and the beginning of pain. Indeed, the neuroimaging data show activation of the same brainstem regions, such as the dorsolateral pons in the premonitory and pain phase proper. Given aura can start before pain, with pain or after pain, and its physiology is so different, it cannot itself be regarded as canonically premonitory. We submit, and consider that others have tacitly and intuitively considered, that the premonitory phase is any portion of the migraine attack prior to the commencement of headache. We consider the premonitory phase part of a migraine attack in its totality. The remaining complexity is how to regard the neck discomfort or stiffness often reported before head pain as such commences. We would suggest that it is considered as premonitory until there are further data. We urge the International Headache Society Classification Committee to resolve this definition anomaly prior to the completion of the beta round.
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