Health news blog

The first phase (aura) of a migraine attack is vasoconstriction of the intracranial circulation. To prevent any possibility of damage to the brain due to cerebral ischemia, the attack should be aborted before this phase but, once the first symptoms appear, vasoconstriction has already started. Occasionally people may get (prodromal) feelings the day before warning of an impending attack; these are sometimes related to gastric upsets, e.g. some people feel hungry, and eating sugar may abort the attack. In the majority of cases, the aim is to stop the headache coming and to prevent nausea and vomiting.

Pain itself has an effect on the cerebral vasculature; even mild pain causes activation in the area of brain representing the painful area of the body and there is a slight increase in blood flow in that region. As pain increases, there is a more generalized increase in blood flow through the whole brain, caused by vasodilatation which in turn causes more pain. This cycle can be stopped by altering the appreciation of pain by means of analgesic (pain-killing) drugs; the feedback can also be broken by sedation using tranquillizing drugs such as Valium. Vasodilatation can be reversed using a short-acting vasoconstricting substance.

Nausea and vomiting are not only disturbing in themselves but they also upset and prevent the administration of remedies by mouth. These symptoms are partly due to chemical transmitter acting on the ‘vomiting centre’ of the brain and partly due to the stomach becoming sluggish in its action (hypotonic). This means that the contents of the stomach, including tablets, do not readily pass down into the small intestine where most foods and medicines are absorbed. The reason why tablets taken during an attack of migraine do not help may be because they do not get into the blood stream. Sufferers often say: ‘nothing helps the attacks; I just have to lie quietly in a darkened room and wait for it all to pass’.

Although the migrainous aura need not be very troublesome in itself, if it can be stopped, the full-blown attack may be prevented.

Most sufferers prefer to lie down during an acute attack. This is partly because it is difficult to function or concentrate as well during this time and also because lying down provides some relief of headache and nausea. Because light and sound are upsetting, a quiet darkened room is preferred.

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