E-360 Edition 22: Focal Seizures

Home > E-360 Edition 22: Focal Seizures


What type of seizures do you have? There are many terms used for focal seizures; some people use the term “petit mal” whilst others say partial or even absence seizures. There have been recent changes to seizure naming and organisation and these non-convulsive seizures are now called focal seizures. It can be confusing to say the least. Here we will discuss focal seizures.

Old terms

Probably the oldest terms for seizures that are still incorrectly used are grand mal and petit mal. They are French terms meaning great sickness and little sickness and usually refer to convulsive seizure or non-convulsive seizure.

We then moved on to partial seizures which were sometimes used to refer to any minor or non-convulsive seizure. Partial seizures were split up into simple partial seizure and complex partial seizure. Simple partial seizures were also sometimes called an aura because there was complete awareness for the seizure. Complex partial meant the person lost or had impaired awareness and often became disorientated or confused and had behavioural changes.

New terms

Seizures are now divided into groups depending on:

  • where they start in the brain
  • whether or not a person’s awareness is impaired
  • whether or not seizures involve movement

Depending on where they start, seizures are described as either focal onset, generalised onset or unknown onset.

Focal onset seizures

The most recent changes have now called the petit mal or partial seizures, focal onset seizures.

Focal onset seizures are seizures that start in one small area or one hemisphere of the brain.

There are a few subgroups of focal onset seizures. They include:

  1. Focal Aware Seizures

In these seizures the person is conscious (aware and alert) and will usually know that something is happening and will remember the seizure afterwards. Sometimes they may not be able to move or communicate during the seizure, but they are aware of what is happening.

Focal aware seizures usually last less than two minutes and are distinguished by the symptoms that are seen or felt. They can be further divided into:

  • Focal sensory seizure– numbness, tingling or burning sensation in a region of the body, unusual smell or taste, dizziness, feeling hot or cold
  • Focal motor seizure – jerking of a limb, twitching of the face, weakness or paralysis of a muscle group
  • Focal autonomic seizure – blushing, pallor, heart-rate changes or palpitations, nausea
  • Focal emotional seizure – changes in mood or emotion such as fear, panic, laughing, crying
  • Focal cognitive seizure – unable to speak, speech difficulty, déjà vu, visual hallucinations, hearing sounds
  • Focal behaviour arrest seizure – the person just “freezes” and appear unable to move or talk

Remember the person knows these focal aware seizures are happening and may not even regard them as a seizure, but as a warning of an impending seizure. What causes these symptoms though is seizure activity in a small region of the brain.

When a focal aware seizure ends, the person usually continues doing whatever activity they were doing before it started. This type of seizure can also develop into a stronger seizure with impaired awareness or loss of consciousness (focal impaired awareness and/or tonic clonic seizures)

Quite often people think they just have focal aware seizures, but there often can be a loss of awareness without the person realising until an eyewitness describes to them what their behaviour was during the seizure.

  1. Focal Impaired Awareness Seizures – these are often simply called focal seizures.

Awareness during a seizure is described as the person being fully aware of themself and their environment throughout the seizure, even if they are immobile. If awareness is impaired at any point during the seizure, the seizure is then called a focal impaired awareness seizure. The degree of loss of awareness may vary.

In these seizures the person’s awareness is diminished, and they may be confused, may or may not be able to hear you, and will not fully understand what you say or be able to respond to you. Often, they lose memory for some or all the seizure.

These seizures typically last from 1 to 2 minutes but the post-seizure period can last several minutes.), Symptoms vary but can include; blank staring or confusion, chewing or lip smacking, picking at clothes, fumbling, repetitive movements, unusual vocalisation, becoming unaware of surroundings, and wandering. Sometimes these seizures are very subtle and not recognised as a seizure, and other times they are mistaken for intoxication or psychiatric illness. This seizure type may be preceded by a focal aware seizure (previously referred to as an aura or warning)

Afterward, the person may be tired or confused for about 5 – 15 minutes and may need to rest and not be able to return to normal function for hours.

Sometimes these seizures can spread to the other side (hemisphere) of brain and develop into a tonic clonic seizure.

The most common focal seizures arise from the temporal and frontal lobes. Sometimes people are told they have temporal lobe epilepsy or frontal lobe epilepsy. These are correct, more specific terms to describe the type of epilepsy.

Because focal seizures arise from a small part of the brain, if they are not successfully controlled by medication, then surgical removal of the seizure focus is possibly an option.

It’s not unusual for someone not to know the type of seizure or epilepsy they have. Often seizures are diagnosed based on descriptions of what an eyewitness has seen. These descriptions may not be fully complete, or one can’t tell where a seizure begins from this information.

Unfortunately, focal seizures can quite often be misunderstood or mistaken for other events. Diagnosis can take some time if this happens.