In medicine, a paroxysm is a sudden and uncontrollable attack. The term paroxysmal attack refers to a disorder that occurs suddenly but resolves quickly. The experience may be nothing to worry about if it occurs only once, but if it occurs again, then veterinary care is recommended. The most important concern initially is to make sure the pet does not hurt themselves during an attack, whether it occurs at home or during exercise.
What is a paroxysmal event?
A paroxysmal event refers to a sudden onset of an abnormal body event that returns to normal within a short time frame. Paroxysmal events can be caused by problems with the nervous system (epileptic seizures, narcolepsy/cataplexy, sudden loss of balance, muscle stiffness, movement disorders…), or by diseases affecting other organs (heart disease causing fainting, or low blood sugar causing weakness and trembling…). In veterinary neurology, epilepsy is the most common and best understood form of paroxysmal event.
What can I do to find out what is wrong?
It is often the case that a patient may appear completely normal when you examine them because you have not witnessed these paroxysmal events. As a result, it is extremely important that the owner is asked to provide a detailed description of the event. The following information should be included:
- When did the owner see the first episode?
- How many times have the episodes happened?
- Do all these episodes look the same?
- What was the pet doing just before these attacks?
- Can the owner trigger or predict one of these attacks?
- How long does each attack last?
- Is the pet normal in between each attack?
- During the attack was the pet:
- Consciousness or unaware of its surroundings?
- Able to follow the owner’s movement with its eyes or did its eyes looked glazed or flickering?
- Stiff, weak, twitching, making running movements, violently shaking or not moving at all?
- Foaming from its mouth, or lose control of its bladder or bowels?
- Pale, blue or pink in its gums?
Using the answers to these questions, you can determine if these paroxysmal events are caused by a neurological condition and what further tests are needed. Video recordings of the pet during one of the attacks can be very helpful. The cause of some paroxysmal events may be a disease such as a stroke, a tumour, or an inflammation in the brain. However, others may be caused by chemical imbalances in the body or abnormal wiring within the nervous system and will not be detected by medical tests. One of the best examples is primary epilepsy (also known as idiopathic epilepsy) in which a diagnosis is made by first recognising the paroxysmal events as being an epileptic seizures and then ruling out any diseases that could be causing them. Among the other paroxysmal events suspected of being caused by chemical imbalance or abnormal neuronal wiring are head bobbing, paroxysmal dystonia, collapsing Cavalier, primary orthostatic tremors, Scottie cramps, narcolepsy/cataplexy, and compulsive or obsessive disorders.
What does it mean if the test results all come back normal?
When investigating many paroxysmal events, it is not uncommon for all test results to be normal. Certain conditions can be diagnosed based on the response to drug therapy if the correct tests have been conducted. In the case of pets with suspected narcolepsy/cataplexy, treating them with the appropriate drug is likely to result in a less frequent and severe attack, indicating the right diagnosis. Unfortunately it may be necessary to use more than one drug for a sufficient length of time before to draw any conclusions can be drawn and this should only be done if you are sufficiently confident of the suspected diagnosis. Before treatment can be started, it is essential to know how often the attacks occur so that any treatment response can be assessed. It may be sensible not to start the animal on any therapeutic trial if these attacks occur infrequently.
What is the prognosis?
In order to answer this question, you will need to perform a lot of tests. In some cases, the underlying cause of attacks can be found, but in others, the attack may settle down or stop without treatment. With time, there is always the risk that the problem will get worse and the attacks will become more severe.