About Focal-Onset Epilepsy

What You Need to Know About Focal-Onset or Partial-Onset Epilepsy:

Unlike generalized epilepsy, which starts in both sides of the brain at the same time, focal-onset epilepsy is a neurological condition that starts on only one side of the brain, resulting in recurring seizures. However, focal-onset seizures can become generalized seizures (affecting both sides of the brain).

There are two main focal seizures:

  • Focal aware seizures
  • Focal impaired awareness seizures

As the term implies, in focal aware seizures, you are fully aware of your surroundings and what is going on around you. In focal impaired awareness seizures, your awareness of your surroundings and even of what’s happening to you might be affected. You may even forget the event occurred.

Both types of focal-onset epilepsy can be categorized as either motor or non-motor, depending on the involvement of muscular activity. In focal motor seizures, you may have repeated movements, jerking, or loss of muscle tone. In focal non-motor seizures, there is no muscular activity, but rather alterations or changes in thinking, sensations, or emotions.

  • Typically, most focal aware seizures can occur anywhere between a few seconds and 2 minutes
  • Most focal impaired seizures can last between 1 and 2 minutes

What Happens After a Focal Seizure?

  • The post-ictus or the time after an epileptic event varies from person to person
  • You may feel confused or tired even days after the event
  • You may be able to resume normal function immediately after an event
  • You may feel like you need to sleep
  • You may feel temporary weakness
  • You may experience temporary, partial or complete paralysis that usually occurs on one side of your body and that may last anywhere between a few minutes and 36 hours (also known as Todd’s paralysis)

Focal-onset epilepsy can be categorized by location or lobe of the brain in which it occurs:

  • Frontal lobe epilepsy
  • Temporal lobe epilepsy
  • Parietal lobe epilepsy
  • Occipital lobe epilepsy

Frontal lobe epilepsy begins in the area behind the forehead. The frontal lobe is responsible for executing movement, planning, and even personality. Frontal lobe seizures are often short and last approximately 30 seconds or less. They also tend to occur at night.

Temporal lobe epilepsy is used to describe recurring seizures that begin in the temporal lobes. Seizures most commonly arise from the temporal lobes. With these types of seizures, you may experience strong emotions, staring, loss of awareness, automatic and repetitive movements, and even experience a particular smell.

Parietal lobe epilepsy occurs in the parietal lobe, also known as the association cortex due to its responsibility for connecting meaning to the brain’s functions. This area of the brain is also responsible for creating visual images and associating a sound with a word, or a sense of touch with a particular object. Parietal lobe epilepsy is highly uncommon. With these types of seizures, you can experience sensory anomalies, such as numbness or electrical sensation, hallucinations and distortions of space.

Occipital lobe epilepsy begins in the area in the back of your head. This area is responsible primarily for vision. Seizures beginning in this area are also uncommon. You may experience flashing bright lights or other visual changes associated with these types of seizures.

This information was summarized using the following two sources:

  1. https://www.hopkinsmedicine.org/health/conditions-and-diseases/epilepsy/focal-epilepsy
  2. https://www.epilepsy.org.uk/info/seizures/focal-seizures