A seizure is a group of neurons firing together in an abnormal and uncontrollable fashion, while the term "epilepsy" refers to the tendency to experience recurrent seizures. Seizures can take many different forms and usually involve a loss of consciousness.
The 1990s to present day have been an exciting time for the evaluation and treatment of seizures. The widespread use of MRI has become available giving more detailed images of the brain's architecture than were previously available in a very noninvasive manner. In addition, more than eight new medications, in addition to the older traditional medications, are now available as well as an epilepsy treatment device called a vagal nerve stimulator.
This series of web articles are not designed to be a complete authoritative guide to epilepsy and seizures as entire books are written on this subject. Rather, it is meant to provide a framework for better understanding of seizures and epilepsy for the interested non-physician. It is critical that the physician and patient adopt a "team approach" to choosing the anti-epileptic to minimize side effects that are not desired and potentially treat other diseases (such as obesity) that the patient also has. Go here to read what Dr. Loftus' patients say about his style of care.
Dr. Loftus treats patients over the age of fifteen. Therefore the articles on this website focus on epilepsies encountered in adults rather than those found in infancy and early childhood.
What can cause a seizure?
A seizure is cause for alarm when the patient is not already diagnosed with epilepsy. New-onset seizures need to be evaluated for potential treatable precipitants. The evaluation usually involves an MRI of the brain (or sometimes CT of the brain) to look for mass lesions such as brain tumors, metastatic cancers, or vascular malformations that may cause seizures. Blood work should also be performed to rule out disorders that may cause seizures such as:
- high or low glucose
- high or low sodium
- low calcium
- low magnesium
- thyroid disorders
- misc other disorders
Evidence of infection should be checked with a physical examination and complete blood cell counts. Additional testing is typically ordered depending on the age of the patient and presenting symptoms.
Brain wave testing called EEG (electroencephalogram) can be helpful in attempting to predict who is more likely to have additional seizures after a first seizure as well as to classify the type of seizure. If a phenomenon is recurrent and unclear in nature, then continuous brain wave monitoring may be employed to determine if the behavior is truly a seizure or not. Most importantly, recent medication changes must be taken into account to determine that may be contributing to the seizure occurrence.
The patient’s history will sometimes reveal diseases such as severe head injuries, strokes, or Alzheimer's that may predispose patients to seizures in the future. In increasing numbers, genetics is being identified as a predisposing factor to many disorders including epilepsy.
Although somewhat arbitrary, if no immediate provoking cause is found for the seizure, and more than one seizure occurs, then the patient is said to have epilepsy. The term "arbitrary" is used because many seizures that have a provoking factor such as sleep deprivation are still usually considered epilepsy. From a practical standpoint this has to do with the degree that the immediate provoking cause is sufficient enough to cause the seizure and the degree to which it is found in the typical population. Herpes encephalitis, an infection of the brain itself, causes seizures in a high percentage of persons who have the disease and very few people, if any, have herpes encephalitis without symptoms. Contrast this with being sleep deprived, a situation that most Americans suffer from on a semi-regular occasion and yet very few people have a seizure associated with sleep deprivation.