Seizures manifest in a variety of ways. Accurate description of such seizures can be very valuable in achieving a diagnosis of epilepsy.
Epilepsy is the most common serious neurological disorder with an incidence of around 50 cases per 100,000 population. Most people will recognise the tonic/clonic seizure as an epileptic fit. This is the sudden onset of unconsciousness, the body becoming stiff, then being overtaken by jerking movements
However seizures can take different forms, some of which may not be recognised as an epileptic seizure. Depending on the part of the brain affected seizures can vary from the tonic/clonic described above to those which have solely psychological or emotional effects.
What is Epilepsy?
Epilepsy is defined as having recurrent seizures (fits). A seizure is caused by a burst of abnormal electrical activity which disrupts the normal functioning of the brain. This disruption may affect the whole brain or just part of it. No one knows quite why this occurs but it is known what predisposes people to seizures. Certain types of brain damage, from a problem birth, infections or head injury can give rise to epilepsy. More rarely, arteriovenous malformations or brain tumours may be implicated. Quite often there is no known reason.
As suggested earlier seizures can vary from being very obvious to the onlooker, to the imperceptible. And sufferers who experience very localised seizures may not realise that they have epilepsy, especially if the seizure involves some loss of awareness.
When witnessing someone having a possible seizure it's important to try and remember details of the occurrence. This is particularly important when observing someone who has never had a seizure before since such witness information is invaluable in helping doctors make a diagnosis.
Seizures involving Muscles
If the seizure affects a large part of the brain then the generalised tonic/clonic seizure occurs. In addition to the stiffness and jerking as described earlier, sufferers can occasionally lose control of bowel and bladder. Occasionally they may injure themselves from colliding with surrounding objects. When the seizure has passed they have no knowledge of it and may often feel very tired. Most of the time these seizures only last seconds or minutes at most. Very occasionally one seizure can be followed immediately by a series of others. This can be fatal and requires urgent medical attention.
If the electrical discharge affects only a part of the brain then a partial seizure occurs. This will only affect a group of muscles leading to, for example, twitching of the arm or leg or perhaps just the eyelid.
Absence Attacks
These occur mainly in children. The sufferer becomes momentarily unconscious and may appear to an onlooker as if they are daydreaming. As it normally lasts a very short time it can easily be missed or mistaken as someone not concentrating.
Seizures involving the Emotions
Called temporal lobe epilepsy these seizures may not be noticed by an onlooker at all. They do not involve loss of consciousness although sufferers may less aware of their surroundings than normal. Because the seizure originates in areas of the brain involved with memory and emotion, it manifests as odd feelings like deja vu. One sufferer has described ordinary objects like a chair taking on 'special meaning'. People with this type of epilepsy may hear voices or smell odours that are not actually present.
This article information is for information only. If you have any concerns or queries regarding epilepsy please consult a health professional.
Resources
Tutorials in Differential Diagnosis. Beck et al. Elsevier 2003
