My recent trip to Pennsylvania was both enlightening and focusing in my quest for answers to the questions related to headshaking syndrome.
The first day I went to New Bolton Center where I met with Dr. Jill Beech, Professor of Medicine, Dr.Rose Nolen-Watson, and Dr. Pamela Wilkins. Dr. Beech has been very supportive to me over the past 2 years in giving me advice and recommendations on treatments for headshaking.
We were in agreement on:
Headshaking syndrome has similarities with trigeminal neuralgia and headaches in humans.
The symptoms of nasal congestion, rhinnorehea and eye tearing could be a parasympathetic response. The horses may have cluster headaches with allergies also.
One way to eliminate that allergies may be the cause of the headshaking is to try the low-dose, long-term steroids. If they work, then allergies may play a role, if not, the cause is likely from some other source.
Photophobia goes along with various types of headaches and may be related to the severity or level of the headshaking as to whether it is present or not.
Most headshakers become afflicted with headshaking year round with changes in severity. The periods of lessened severity makes it difficult to evaluate treatments.
Dexamethasone does have the side effect of laminitis but, even with low-dosing, long- term treatment, it rarely seen.

We developed three goals for me to pursue:
MRIs are the best way to find out what is going on in the heads of headshakers. Therefore I will spend time finding funding, practitioners interested in performing MRIs on these horses and headshakers to use for evaluation.
The fact that the dexamethasone pulsing worked so well for my horse makes it a good study to continue to work on. The hypothesis being that high dose dexamethasone for 4 days every 28 days (pulsing) will eliminate the symptoms of headshaking. I will need to write a protocol, find horses for the study and funding. I need to find a select population and maintain a controlled environment. The Center agreed to help with as much of this as they can.
To hold an annual convention for headshaking syndrome in conjunction with one of the larger veterinary conventions such as the NAVC held in February in Orlando.

The second day I met Dr. Judith Shoemaker of Always Helpful Veterinary Services. Her philosophy is to balance the body so it can heal itself. I became interested in meeting her when I found out that cranial electrotherapy stimulation has been proven to be successful with cluster headaches. There is a company that has developed a horse version of this called the Happy Halter. Dr. Shoemaker has used this successfully on headshakers. She gave me a demonstration on her own horse. The horse, which was obviously tense to begin with, began to relax within minutes of applying the device with her bottom lip hanging and her eyes almost closed, This halter has an accumulative effect, the more it is used the better the effect. Then she tried it on me and the effect was euphoric and very relaxing.
We had a telephone conference with Chip Fischer and discussed putting together a study for the device. He agreed that a MRI would be informative especially where the device can be used and followed up with a MRI. Again, we will need funding and participants.
I am heading to Australia to check out a device called the Senar that also works by electro stimulation but through the skin on specific areas. It was developed in Russia for the space program (there are no hospitals in space) and is used in Australia and Europe.

I am thrilled that there are some hopeful treatments for headshakers and will keep the information coming!

Best to all,
Pam