Cyclic vomiting syndrome


Cyclic vomiting syndrome is a chronic functional condition of unknown pathogenesis. CVS is characterized as recurring episodes lasting a single day to multiple weeks. Each episode is divided into four phases: inter-episodic, prodrome, vomiting, and recovery. Inter-episodic phase, is characterized as no discernible symptoms, normal everyday activities can occur, and this phase typically lasts one week to one month. The prodrome phase is known as the pre-emetic phase, characterized by the initial feeling an approaching episode, still able to keep down oral medication. Emetic or vomiting phase is characterized as intense persistent nausea, and repeated vomiting typically lasting hours to days. Recovery phase is typically the phase where vomiting ceases, nausea diminishes or is absent, and appetite returns. This syndrome is most commonly seen in children usually between ages 3 and 7, however adult diagnosis is quite common. This disorder is thought to be closely related to migraines and family history of migraines.

Signs and symptoms

Sufferers may vomit or retch 6–12 times in an hour and an episode may last from a few hours to over three weeks and in some cases months, with a median episode duration of 41 hours. Acid, bile and, if the vomiting is severe, blood may be vomited. Some sufferers will ingest water to reduce the irritation of bile and acid on the esophagus during emesis. Between episodes, the sufferer is usually normal and healthy otherwise but can be in a weak state of fatigue or experience muscle pain. In approximately half of cases the attacks, or episodes, occur in a time-related manner. Each attack is stereotypical; that is, in any given individual, the timing, frequency and severity of attacks is similar. Some sufferers experience episodes that progressively get worse when left untreated, occurring more frequently with reduced symptom free phase.
Episodes may happen every few days, every few weeks or every few months, for some happening at common uniform times typically mornings. For other sufferers, there is not a pattern in time that can be recognized. Some sufferers have a warning of an episodic attack; they may experience a prodrome, usually intense nausea and pallor, heightened sensitivity, especially to light, though sensitivity to smell, sound, pressure, and temperature, as well as oncoming muscle pain and fatigue, are also reported by some patients. The majority of sufferers can identify triggers that may precede an attack. The most common are various foods, infections, menstruation, extreme physical exertion, lack of sleep, and psychological stresses, both positive and negative.
A sufferer may also be light-sensitive, sound-sensitive or, less frequently, temperature- or pressure-sensitive during an attack. Some sufferers also have a strong urge to bathe in warm or cold water. Some sufferers experience insomnia, diarrhea, hot and cold flashes, and excessive sweating before an episode. Some sufferers report that they experience a restless sensation or stinging pain along the spine, hands, and feet followed by weakness in both legs. Some of these symptoms may be due to dehydration or hypokalemia from excessive vomiting, rather than the underlying cause of CVS.

Genetics

There is no known genetic pathogenesis for CVS. Recent studies suggest many affected individuals have a family history of related conditions, such as migraines, psychiatric disorders and gastrointestinal disorders. Inheritance is thought to be maternal, a possible genetic mitochondrial inheritance. Adolescents show higher possible mitochondrial inheritance and maternal inheritance than found in adults. Single base-pair and DNA rearrangements in the mitochondrial DNA have been associated with these traits.

Diagnosis

The cause of CVS has not been determined and there are no diagnostic tests for CVS. Several other medical conditions, such as cannabinoid hyperemesis syndrome, can mimic the same symptoms, and it is important to rule these out. If all other possible causes have been excluded, a diagnosis of CVS using Rome criteria by a physician may be appropriate.
Once formal investigations to rule out gastrointestinal or other causes have been conducted, these tests do not need to be repeated in the event of future episodes.

Diagnostic criteria

Although there are differences between early-onset CVS and late-onset CVS, there are established criteria to aid in diagnosis of CVS, namely:
  1. A history of three or more periods of intense, acute nausea and unremitting vomiting, as well as pain in some cases, lasting hours to days and even weeks or months
  2. Intervening symptom-free or reduced-symptom intervals, lasting weeks to months
  3. There are repeated cycles of periods with intense/acute nausea, with or without vomiting, with or without severe pain, followed by periods of reduced symptoms, followed by gradual increase in CVS symptoms until it peaks.
  4. Exclusion of metabolic, gastrointestinal, genitourinary or central nervous system structural or biochemical disease, e.g., individuals with specific physical causes

    Treatment

Treatment for cyclic vomiting syndrome depends on the evident phase of the disorder.
Because the symptoms of CVS are similar to those of the disease well-identified as "abdominal migraine," prophylactic migraine medications, such as topiramate and amitriptyline, have seen recent success in treatment for the prodrome, and vomiting, phases, reducing the duration, severity, and frequency of episodes.
Therapeutic treatment for the prodromal phase, characterized by the anticipation of an episode, consists of sumatriptan an anti-migraine medication, anti-inflammatory drugs to reduce abdominal pain, and possible anti-emetic drugs. These options may be helpful in preventing an episode or reducing the severity of an attack.
The most common therapeutic strategies for those already in the vomiting phase are maintenance of salt balance by appropriate intravenous fluids and, in some cases, sedation. Having vomited for a long period prior to attending a hospital, patients are typically severely dehydrated. For a number of patients, potent anti-emetic drugs such as ondansetron or granisetron, and dronabinol may be helpful in either preventing an attack, aborting an attack, or reducing the severity of an attack. Many patients seek comfort during episodes by taking prolonged showers and baths typically quite hot. The use of a heating pad may also help reduce abdominal pain.
Lifestyle changes may be recommended, such as extended rest, reduction of stress, frequent small meals, abstain from fasting, and possibly cessation of cannabis use. A diet change may be recommended avoid food allergens, eliminating trigger foods such as chocolates, cheese, beer, and red wine.
Some patients experience relief from inhaled isopropyl alcohol.

Prognosis

Fitzpatrick et al. identified 41 children with CVS. The mean age of the sample was 6 years at the onset of the syndrome, 8 years at first diagnosis, and 13 years at follow-up. As many as 39% of the children had resolution of symptoms immediately or within weeks of the diagnosis. Vomiting had resolved at the time of follow-up in 61% of the sample. Many children, including those in the remitted group, continued to have somatic symptoms such as headaches and abdominal pain.
Most children who have this disorder miss on average 24 school days a year. The frequency of episodes is higher for some people during times of excitement. Charitable organizations to support sufferers and their families and to promote knowledge of CVS exist in several countries.
Complications can include dehydration, cavities, or an esophageal tear.

Epidemiology

The average age at onset is 3–7 years, with described cases as young as 6 days and as old as 73 years. Typical delay in diagnosis from onset of symptoms is 3 years. Females show a slight predominance over males.
One study found that 3 in 100,000 five-year-olds are diagnosed with the condition. Two studies on childhood CVS suggest nearly 2% of school-age children may have CVS.

History

Cyclic vomiting syndrome was first described in France by Swiss physician Henri Clermond Lombard and first described in the English language by pediatrician Samuel Gee in 1882.
It has been suggested that Charles Darwin's adult illnesses may have been due to this syndrome.