Cyclic vomiting syndrome (CVS) 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 (symptom free 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 of 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
Affected individuals 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. Stomach acid, bile and, if the vomiting is severe, blood may be vomited. Some with the condition will ingest water to reduce the irritation of bile and acid on the esophagus during emesis. Between episodes, the affected individual is usually normal and healthy otherwise but can be in a weak state of fatigue or experience muscle pain.
Neurapraxia is very common in professional athletes, especially American football players, and is a condition that can and should be treated by a physician. Signs and symptoms
A variety of nerve types can be subjected to neurapraxia and therefore symptoms of the injury range in degree and intensity. Common symptoms of neurapraxia are disturbances in sensation, weakness of muscle, vasomotor and sudomotor paralysis in the region of the affected nerve or nerves, and abnormal sensitivity of the nerve at the point of injury. It has been observed that subjective sensory symptoms include numbness, tingling, and burning sensations at the site of the injury. Objective sensory symptoms are generally minimal in regards to touch, pain, heat, and cold. In cases of motor neuron neurapraxia, symptoms consist of flaccid paralysis of the muscles innervated by the injured nerve or nerves. Symptoms are often transient and only last for a short period of time immediately following the injury. However, in severe cases of neurapraxia, symptoms can persist for weeks or months at a time. Causes
The cause of neurapraxia is a neural lesion which causes a temporary block of nerve conduction without transection of the axon. A conduction block is classified as a 40% reduction in action potential amplitude over a short distance on the nerve, or a 50% reduction for a longer distance on the nerve. In neurapraxia, stimulation to the injured nerve results in a greater reduction in the action potential amplitude on the proximal site of the injury as opposed to the distal site.