Paroxystic events

A paroxysm is a sudden uncontrollable attack and in people is often applied to events like a ‘fit of giggles’. In animals a paroxystic attack is more serious and describes a disorder that starts suddenly but also resolves quickly. A one-off event like this may be nothing to worry about but if the experience is repeated you should contact your veterinarian immediately for advice. Attacks may occur at home or at exercise and the most important concern initially is to make sure your pet cannot hurt themselves during the attack. There are many causes of these attacks and your veterinarian will need to investigate further in order to find out what is causing the attacks so that appropriate treatment can be given if any exist for this type of attack.

©Douglas McCallum

A paroxystic event is a non-specific term used to define an abnormal event of the body with an abrupt onset and an equally sudden return to normal. A paroxystic event can relate to a problem in the nervous system (epileptic seizure, narcolepsy/cataplexy, sudden loss of balance, muscle stiffness or weakness, movement disorder…) or a disease in other organs (heart disease causing fainting, or weakness and trembling caused by low blood sugar levels…). Epileptic seizures are the most common and certainly best understood type of paroxystic event in veterinary neurology.

In most cases, your veterinarian will not witness these paroxystic events and very often will not be able to detect anything wrong when they examine your pet. It is therefore really important for you to be able to give a detailed description of the event. This should include the following information:

• When did you see the first episode?
• How many times have the episodes happened?
• Do all these episodes look the same?
• What was your pet doing just before these attacks?
• Can you trigger or predict one of these attacks?
• How long does each attack last?
• Is your pet normal in between each attack?

During the attack was your pet:

• Conscious or unaware of its surroundings?
• Able to follow your 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?

The information from these questions may help your veterinarian to determine if these paroxystic events are related to a neurological problem or not and this will determine what other tests are needed. If you are able to take a video of your pet during one of the attacks it can be very useful to your veterinarian. While some paroxystic events can be the symptom of a disease such as a stroke, a tumor or an inflammation in the brain, others can be caused by chemical imbalances in the body or abnormal wiring in the nervous system and therefore may not show up on any test. One of the best examples is primary epilepsy (also known as idiopathic epilepsy) in which a diagnosis is made by first recognizing the paroxystic events as being an epileptic seizures and then ruling out any diseases that could be causing them. Compared to dogs, epileptic seizures in cats are often not ‘typical’ (generalized with loss of consciousness, foaming from the mouth, urination, defecation and severe twitching of the limbs). More than half of epileptic seizures in cats are ‘paratial seizures’, eg twitching of one side of the face, twitching of one limb and, in some cases, transient abnormal behavior.

It is not unusual for all test results to come back normal when investigating many paroxystic events. If the correct tests have been done response to drug therapy can be used to make a diagnosis of certain conditions. For example a pet can be treated with the appropriate drug for suspected narcolepsy/cataplexy and if the frequency and severity of these attacks is reduced it is likely that the correct diagnosis was made. Unfortunately it may be necessary to use more than one drug for a sufficient length of time before any conclusions can be drawn and this should only be done if your veterinarian is sufficiently confident of the suspected diagnosis. It is important that you know how often the attacks are occurring before treatment is started so that any response to treatment can be assessed.  If these attacks are occurring very infrequently, your veterinarian may decide not to start your animal on any therapeutic trial and just monitor the frequency.

Unfortunately your veterinarian will not be able to answer this question without performing a lot of tests. Some conditions causing attacks can be treated, in other cases it may not be possible to find an underlying cause but the attacks may settle down or stop without treatment. Sadly there is always a risk that the problem may be more serious and the attacks will get worse with time.