Aura (of migraine) – what is it?
Patients with migraine experience many symptoms other than headache. Some of these occur during headache, some occur before and some after the headache has stopped. A peculiar symptom is what is called aura. About a quarter of patients with migraine will experience the aura symptoms. Most commonly, aura occurs just before headache, but can also occur during the early part of headache or sometimes without the headache. These symptoms can involve changes in vision (visual aura), sensations (sensory aura) or strength (motor aura).
The visual aura is the most common and well-studied. Typically, patients will see a zig-zag line starting on one side which moves across in front of their eyes before fading away. The symptoms are quite alarming and patients often and understandably feel anxious and worried when they get for the first time. Along with zig-zag lines, patients may also see sparkling or flashing lights or diamond-shaped small lights (positive symptoms) or dark spots or dark areas in their vision (scotoma). The hallmark of migraine aura is that the symptoms change in shape, size and location. If the symptoms are stationery i.e. flashing small lights or spots which does not change i.e. move or become big or small, they are unlikely to represent migraine aura. The visual disturbance lasts for more than 5 minutes and not more than 60 minutes in a typical patient although some patients may have these symptoms lasting for a longer time.
Sensory aura consists of either a feeling of tingling i.e. pins and needles or numbness i.e. lack of sensation or ‘dead’ feeling. Again the feeling starts in one area of the body and travels slowly i.e. patients are able to note the march of symptoms. For example, if the feeling starts in the hand, it will move up the arm and not involve the entire arm all at the same time.
Speech and language can also be affected causing ‘difficulty getting the right word’ and slurring of words.
Motor aura causing genuine weakness on one side of the body is much rare. Many patients with this type of aura have other members in the family who experience similar symptoms (called familial hemiplegic migraine) although it can also occur without a family history (sporadic hemiplegic migraine). Although feelings of numbness or apparent weakness (‘my arm felt dead as a heavy load and I had difficulty in moving it’) are common, genuine weakness on one side suggestive of hemiplegic migraine is much less common.
So, why do patients get aura? A gentleman called Lashley in the 1940’s was the first to carefully document his visual aura as it happened. After calculating the rate of progression of the visual aura, it was estimated that the corresponding ‘electrical disturbance’ in the back part of the brain (occipital cortex where vision is represented) had to spread at the rate of around 3 mm/minute. Now, when the occipital cortex of animals is stimulated either by a chemical preparation or mechanically, there is a wave of electrical change that does spread at the rate of around 3 mm/minute. There is also some indirect human evidence that such a change may be occurring in patients during aura, although the evidence is not robust. Drugs that are useful for preventing migraine with aura are able to stop this electrical change in experimental animals. Therefore, it is likely that the electrical change that is called cortical spreading depression (CSD) is the cause of migraine aura. The exact mechanisms for CSD are however not understood.
So, how do you treat migraine aura? Unfortunately, there is no treatment proven to be effective during the aura. Fortunately, most aura symptoms last for a short period of time. If you are known to have migraine aura, its best to rest and be safe and wait for the symptoms to pass away. If the aura symptoms are frequent and disturb your life, there are several preventive medications that can be used to reduce the frequency and the duration of the aura attacks.
Migraine aura and stroke – It has been shown that young female patients with migraine aura have a slightly increased risk of having a stroke. This is a small risk but this can increase further if there are other risk factors like smoking, high blood pressure, high cholesterol, and being over-weight. So, it is important that patients stop smoking and get their blood pressure and cholesterol checked and maintain a healthy lifestyle and body weight. Another thing that can increase the chances of stroke in these patients is the use of oestrogen. So, oestrogen should be avoided by young female patients with migraine aura. There are plenty of other hormonal options available for contraception.
To make an appointment for a private consultation with Dr Maniyar, Please call at the following numbers depending on your desired hospital –
1. City of London Medical Center, Tower Hill (London Bridge Hospital branch) – +44(0)20 7234 2009
2. The London Independent Hospital (BMI), Stepney Green, London – 020 7780 2400
3. The Nuffield Brentwood Hospital, Essex – 01277 695695 ‘
Alternatively, you can call Dr Maniyar’s secretary on 07594 994675 to discuss the consultation, rates, conditions etc. Please leave a message if the phone is not answered straightaway and somebody will contact you on the same day. You can also email at email@example.com or contact Dr Maniyar directly at firstname.lastname@example.org