Cyclic Vomiting Syndrome

Cyclic vomiting syndrome (CVS) is a condition characterised by recurrent bouts of nausea and vomiting, without the cause being a diagnosable gastrointestinal disorder.

The pathway to diagnosis for parents and their children alike is often a frustrating one with years often passing and many different doctor visits and investigations from onset of symptoms to diagnosis, as initial episodes are passed off to food poisoning, motion sickness, stress, and viral illnesses. It’s usually the parents that pick up patterns:

• similar times of the day or week, or with similar spacing (e.g. wake at 6am every 2 months)
• consistent but seemingly unrelated triggers (car travel, anticipatory anxiety – pre-birthday party/Xmas/big event etc, over/under sleep, stress, hot car)
• No-one else at home or school ever gets this ‘virus’

CVS (like tension-type headache) has struggled to be taken seriously. First described in 1882 ¹  it was seen as an outward expression of an anxiety disorder and an illness, of

‘highly strung, fidgety, nervous children of slight build’ ² 

Far from a ‘nervous disorder’ CVS is more similar to migraine than it is to other gastrointestinal disorders, in that it is a primary disorder of an irritated nervous system, which is just as prevalent and significantly under-diagnosed in adults.

CVS and migraine have a number of similar traits:

• Conditions of periodic and recurrent episodes
• Primary or functional diagnosis – exclusion of ‘medical or pathological’ causes
• They respond to similar medications (serotonin agonists, SNRI’s)
• Up to 80% of childhood CVS sufferers will go on to develop migraine as adults.
• Nausea and/or vomiting is one of the key defining features of migraine. So much so that back in the early 1900’s migraine was often referred to as ‘sick or bilious’ headache. It is commonly thought that nausea and/or vomiting is the natural result of strong pain, but in fact this isn’t the case. Cluster headache sufferers have the most severe pain we are aware of, yet nausea is rarely part of the presentation. Up to 1 in 4 migraineurs will experience nausea as a premonitory symptom – i.e. well before the headaches starts and sometimes up to 2-3 days before pain.

The ‘Nausea’ Centre in the Brainstem

Nausea is controlled by a key area in the dorsal vagal complex of the brainstem named the Solitary nucleus. The lower part of this nucleus receives the vagus nerve impulses coming up from the internal organs, and is involved in control of heart rate, blood pressure and the stomach (i.e. detecting problems). When activated this nucleus can do many different things, including generate the sensation of nausea. If the nausea signals build to a certain threshold we reach the ‘point of no return’ where the solitary nucleus signals a range of other control centres – referred to as ‘central pattern generation’ producing the familiar premonitory symptoms of vomiting – increased heart rate, sweating, swallowing/gulping and then relaxation of the opening (sphincter) of the stomach and abdominal wall contractions to produce emesis (vomiting).

What is interesting is that migraineurs who get nausea in their premonitory phase (i.e. before onset of headache) hav increased activation in the solitary nucleus. Even more interesting is that the small muscles from the top of the neck have the ability to excite (increase activity) or inhibit (decrease activity) of the solitary nucleus. While this seems odd at first, it forms a vital part of our blood pressure control to the head. Engagement of the neck muscles in particular patters tells the brain we are moving against gravity, and this provides a boost (when getting up) or drop (when lowering down) before the baroreceptors in our arteries kick in, to help maintain adequate blood flow to the head.  It is possible that in the face of this increased activity, the brain is receiving conflicting information – instead of changing blood pressure it ‘shunts it off’ to an adjacent area – and nausea is the result.

Whatever the exact mechanism proves to be – one thing is clear. The small muscles under the base of the skull are capable of being responsible in part or wholly for recurrent nausea and vomiting disorders.

watson headache® approach

Regardless of age, severity or the length of time you or your child has been suffering, the Watson Headache® Approach can provide rapid and sustained relief from CVS and its more persistent variant, chronic nausea and vomiting syndrome (CNVS). Treatment is very well tolerated by all ages including children, with the youngest client with CVS being 3 years old – having suffered since 9 months old, every 2 months. On last report she was a healthy, happy 11 year old. As headache isn’t usually part of the problem, there is often no need for deep pressure on the neck which can be painful. The structure we need to push on is quit superficial, and often treatment will only go for a few weeks.

While it doesn’t offer a solution for everyone, getting it checked and treated comes with no side effects (maybe a little tenderness on the point of pressure), but offers the potential for rapid (sometimes immediate) and sustained relief.