Single epileptic seizures are very common. Almost one in 10 people in the general population has a single epileptic seizure during their life. Epileptic seizures are not a disease, but a symptom of conditions that may disturb the brain such as fever, low blood sugar, severe sleep deprivation, sudden withdrawal of "suppressant†medications, drug side effects or an acute underlying disease of the brain (e.g. stroke).
Although a single epileptic seizure can be a sign of an acute brain disorder, it does not necessarily mean that the sufferer has epilepsy. For example, if you have a single, severe coughing fit it does not mean that you have chronic bronchitis.
The brain is divided into four main regions called lobes, which carry out specific tasks (see figure. 1). The frontal lobe regulates movement, emotional behaviour, speech, and problem-solving. The parietal lobe is involved in touch sensitivity and is also where the perception of spatial structures is stored - it is not commonly affected by epileptic seizures.
The temporal lobe, however, is often where epileptic seizures originate. This lobe is where the memory centre and emotions (anxiety, excitement, etc.) are located, as well as parts of our speech function. The occipital lobe is mainly responsible for processing visual information. Disturbances in this area during epileptic activity are associated with visual symptoms such as sudden flashes of light.
Figure. 1 The four lobes of the brain
The clinical manifestations (signs and symptoms) of epilepsy are varied since an epileptic seizure can arise from any one lobe and spread to the other lobes. However, the disturbance usually follows a more or less standard pattern in each person and generally lasts no longer than 12 minutes. An epileptic seizure can be described as a sudden disturbance in brain function accompanied by activation of parts of the motor system (muscle movements), the sensing and sensory apparatus (hearing, vision), the autonomic functions (cardiovascular system) or the psyche.