I found this site after looking for something to help with the headaches that one member on another site I use was getting because of her Dissociative Identity Disorder. Hope it comes in handy for someone else.
MPD & Headaches by Sara Lambert
The single most common neurological symptom reported in MPD is headache. (Frank Putnam) Suffering frequent headaches is so typical an experience for multiples that it is one of the major clues psychologists look for when diagnosing MPD. Most multiples report that their headaches are extremely painful, often to the point of being literally blinding. Medication seldom works to relieve the pressure or pain. There are some different explanations for why multiples get more headaches than the general population.
Life can be very stressful for multiples. In addition to normal daily problems, you have to deal with post-traumatic stress arising from your abuse history. Other stresses specific to multiples include lost time, waking up in the middle of situations and having to appear as if you know what is going on, and trying to find ways to continue functioning when all you want is to hide under your bed forever. All of this can leave your nerves ragged and muscles bunched up in tension. It can also drain you of emotional strength. Headaches are a natural result.
Considerable physical stress is also a consequence of having a dissociative disorder as you use your physical senses to contain and come to terms with your psychological disabilities and "strange" experiences. Take derealization, for example: a common occurrence of dissociative misperception wherein the world seems distorted or two-dimensional. The effort to focus your vision all the time can cause eye strain and, subsequently, acute headache. On top of this, it can be incredibly distressing, frustrating, and frightening to experience episodes of derealization. The emotional toll is enough in itself to cause headache. But it doesn't end there because, in addition to the physical effects of trying to deal with dissociative misperceptions, and the emotional effects of it, most dissociators also fight hard to hold everything together and look "normal" to the outside world. This can be exhausting, especially when selves are struggling to get out. As the brain works furiously to manage all these layers of stress, the dissociator develops a worsening headache.
To ease stress headaches, find what works best for you to decrease swollen, tense muscles. This is different for everyone - some prefer ice whereas others need to stand in a warm shower. Massage can be helpful. Music is soothing but, for some people, the noise simply adds another layer of stimulus onto the load the brain is already having to deal with. Some find the only thing they can do to help the pain is sleep. This works by giving your body a chance to rest and revitalize. There are also a number of self-hypnotic techniques you can use to let the stress and pain go. As dissociators are highly hypnotizable, these techniques can be particularly effective. You can create any hypnotic scenario you want from your own imagination. For example, fill your mind with a gentle, soothing color that washes the pain away.
Multiples are very prone to pressure-type headaches caused by too much incoming stimulus. This barrage of psychic "noise" includes things which impact on all our senses and overwhelm them. It may come from inside - for example, too many alter selves standing near the front of consciousness. The noise may also come from outside - too much sound, too many bright colors that blur in front of your eyes. There are two probable reasons why multiples are overly sensitive to external stimuli - because of their chronic abuse experiences, multiples have developed a hyper-alertness which means they are constantly aware of everything around them incase danger is lurking - and because they have so many different "eyes" perceiving the world around them, often simultaneously. As one survivor put it, "Sometimes things have too much meaning. It's as if we're all looking at something at the same time, and our different perceptions get jumbled-up and become too much to cope with, and then our head feels as if it's going to explode. And of course we all have separate feelings and opinions for what we see. It can be unbearable. There are so many eyes/minds, but only one sensory system to process everything. Even just a walk down the city street can leave us with a crippling (but somehow painless) headache."
To help ease headaches cause by over stimulation, ask inside for everyone to step back and give you some space and quiet. Explain that it is more effective for them to tell you about their experiences when you have time and energy to listen properly. Alternatively, they may like to write their thoughts/feelings in a journal if they can't wait. Some multiples find it helpful to carry pen and paper around with them for this purpose. There are ways to achieve ventilation of some of the noise - deep breathing exercises are good for this, and again you can use a number of self-hypnotic techniques, such as picturing a steam-valve on the side of your neck. If you find it overwhelming to go out in public surrounded by "noise pollution", you could try wearing a walkman that playing peaceful, soothing music which blocks out the other noise.
Switching from one alter self to another causes headache mainly when there is some kind of conflict between the selves for control. The solution to this is better communication and cooperation within your system. When there is a disagreement about who should be "out", many selves may be happy to accept a third party to take the out position as act as a mediator so both voices can be heard through her. Often this third party is an automaton self who has few sensitivities of her own, and so is not disturbed by being a channel through which others can communicate. Another suggestion is that, instead of coming completely out, the two selves stand in a place on the edge of inside, where they can be heard without a complete switch having to occur. Most people find that, as their co-consciousness increases, struggles for control (and the consequent headaches) cease to be a problem. There are some multiples who experience headache or other symptoms, such as nausea or dizziness, with even the most uncomplicated and unconflicted switches. This is usually the case for those who are early in their healing process, or whose dissociative barriers are profound. It is not surprising when you consider the physiological changes that happen when a multiple switches between alter selves. It has been proven that selves have their own unique pattern of brainwaves. Furthermore, everyone has at different ages a different biochemistry and mental capacity - thus the switch from adult to child is going to be more physiologically complex than between two adults.
When alters have disputes between themselves at a subconscious level, or when one is seething because of some anxiety they have, the tension often emerges in the form of headache. In this way, the person who is out may have a migraine without being aware that it is being caused by a stroppy teenager who is figuratively stomping around inside because she is angry about something. Alter selves are also notorious for sending headaches to the front person as a kind of message. This headache can be seen as a kind of acting out. In cases like these, pain-killing medication is of no use, because there is no actual physiological problem - the pain results from emotional disturbance. It is necessary to get the selves talking to you about what is going on for them. If they are willing to do this, there is a better chance they will get their needs met than if they simply radiate wordless feelings and pain.
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