I suffer from migraine headaches, without an aura, and drugs I have been prescribed have not helped me. I heard Botox injections can help; do they really offer relief? How long does the effect last? Are they expensive? T.R., Cape Town, South Africa

Prof. Tamir Ben-Hur, head of neurology at Hadassah University Medical Center  in Jerusalem’s Ein Kerem, answers:

It has been quite controversial whether Botox injections help migraine, but additional studies in recent years have pushed the pendulum in favor of this treatment. The degree and duration of response are highly variable between patients, and the drug is quite expensive. We offer this mode of therapy to selected patients who did not respond to various preventive medications, and as a limited trial, which can be continued only in those who showed sufficient response to the Botox injections.

Veteran Israeli pharmacist and pharmaceutical consultant Howard Rice replies:                                                               

Since 2010, Botox has been approved by the US Food and Drug Administration for the treatment of chronic migraine, that is, those suffering from such headaches for more than 15 days per month. The botulinum toxin is injected around the nerves involved in migraine; this then blocks the receptors that cause the pain. This may entail 20 to 30 injections.

Such injections are a preventative treatment. The effect may require more than one course of injections, and then if lasts for about three months. Quite often, however, the condition first worse before it gets better. The success of such a treatment is about 50%.

There is no reason why Botox could not be used for migraine without aura (seeing sparks of light), since the treatment is to block the pain. It can in fact be used for any chronic headache, but it will not be effective if you have fewer than 15 days per month migraine or cluster or other types of headaches.

The price will vary from country to country. You will need about 1,500 units of Botox for a treatment. In the US the treatment is about $800-$1m500, in the UK about £400-800 and in Israel 2500 New Israeli Shekels.

My advice, therefore, is first ask yourself if this is what you want and if other treatments are of use, and then ask a physician who has the experience where and how much to inject. Then then the check the price.

Remember that migraine can also come about after triggering the episodes with wine, cheese, spicy foods and sometimes chocolate. Check these out if you yourself are causing these episodes. I hope this will be of help to you.

I am a 34-year-old woman and very ticklish when somebody suddenly touches me in sensitive places, even just my hand. I was wondering why I don’t feel ticklish when I touch my own hand or other parts of my body. Z.B., Dublin, Ireland.

Judy Siegel-Itzkovich replies:

An interesting study on this question has just been published in Proceedings of the [US] National Academy of Sciences (PNAS).

Our brains seem to reduce sensory perception from an area of our skin when we touch it ourselves, wrote researchers at Linköping University in Sweden. The finding increases our understanding of how the brain distinguishes between being touched by another person and self-touch.

We don’t wonder about our concept of “self” all the time, but the ability to distinguish between self and others is extremely important, they wrote. During the first period of life, newborn children develop an understanding of where their own body ends mainly through being touched by those who care for them.

Problems with the self-concept, such as the ability to recognize one’s own actions, are common in several psychiatric disorders. Most people cannot tickle themselves, but some patients with schizophrenia can, suggesting that their brain interprets sensory perceptions from their own body differently. They have shown that the brain reduces the processing of the sensory perception when it comes from self-touch.

The skin contains sensory receptors that react to touch, pressure, heat and cold. Information about touch is transmitted from these to the spinal cord and on to the brain, where the perception is processed in several steps in different regions of the brain. The researchers

They carried out several experiments in which healthy volunteers lay in a functional magnetic resonance instrument (fMRI), which recorded images of their brain activity. The participants were requested to stroke their arm slowly with their own hand or were told that a researcher would stroke their arm in a similar manner. The researchers investigated how these types of touch were linked to activity in different parts of the brain.

“We saw a very clear difference between being touched by someone else and self-touch. In the latter case, activity in several parts of the brain was reduced. We can see evidence that this difference arises as early as in the spinal cord, before the perceptions are processed in the brain,” wrote principal author Rebecca Böhme, a postdoctoral student in the  clinical and experimental medicine department and the Center for Social and Affective Neuroscience at the Swedish university.

The results are compatible with a theory in brain research that suggests that the brain attempts to predict the sensory consequences of everything we do. This means that it does not attach as much importance to sensory perceptions that are caused by our own bodies, since the information from these is expected. In one of the experiments, the participant’s arm was touched with filaments of different thickness, while the arm was simultaneously stroked either by the participant or by another person.

The researchers showed that the ability to experience simultaneous sensory perceptions was weakened when the participants stroked their own arms. Maybe this phenomenon can explain why we, for example, rub our arm when we bump it against a table.

In the case of the visual system, research has shown that processing of visual impressions occurs as early as in the retina of the eye, and it would be interesting to look in more detail into how the brain modulates the processing of tactile perceptions at the level of the spinal cord, concluded Böhme.

If you want an Israeli expert to answer your medical questions, write to Breaking Israel News health and science senior reporter Judy Siegel-Itzkovich at judy@israel365.com with your initials, age, gender and place of residence and details of the medical condition, if any.