AUTOIMMUNE EPILEPSIES: SIGNS AND SYMPTONS

Seizures and epilepsy can be due to many different causes. Certain hints or "red flags" should raise the possibility of an autoimmune cause. When a person has other prominent neurological symptoms (such as mental or behavioral changes) in addition to seizures, an autoimmune cause should be considered.

Seizure Types

Although seizures of all types can be seen in autoimmune seizure disorders, there are certain seizure types that strongly suggest an immune cause.

Faciobrachial Dystonic Seizures (FBDS)

These are brief, focal seizures that involve contractions of the face and hand.

-- The seizures most commonly affect just one side during an individual event.

-- Some events may first affect one side, then shortly afterwards will occur on the other side.

-- Less commonly, they involve the leg and can lead to falls.

-- In some people, seizures can have isolated involvement of the face or hand.

-- Sometimes only a grimacing facial expression occurs during the seizure without arm or hand movement.

Each seizure is short (1-5 seconds).

They usually do not progress to a generalized (both sides of the brain) seizure.

They can happen several times per day.

There may or may not be a change in awareness during the seizure.

This seizure type typically presents later in life, after age 50.

This seizure type is associated with LGI1 (leucine-rich glioma-inactivated protein 1) antibodies, which are testable with specialized blood tests.

Mental and behavioral changes may occur as well.

Paroxysmal Dizziness Spells (PDS)

These are brief episodes of dizziness lasting seconds, usually occurring many times a day. Typically, there is no loss of awareness. Some people describe a brief “floating” or “out of body” sensation during PDS seizures.

This type of seizure is also associated with LGI1 antibodies. In one study, half of people with LGI1 presented with this type of attack before developing the mental status changes and other seizure types that can occur with this antibody.

Observed and Described Symptoms

Some symptoms found during the initial medical exam or told by the person to their medical provider (called the clinical presentation) should raise the question of an autoimmune cause.

New Onset, Highly Frequent Focal Seizures

Seizures starting relatively later in life and occurring on a nearly daily or more frequent basis should suggest the possibility of an autoimmune cause.

Symptoms Before Seizures Begin

Certain symptoms occurring days or a few weeks before seizures start, such as flu-like symptoms or headaches, should raise the possibility of an autoimmune cause. These are called prodromal symptoms.

In these cases, infectious causes of seizures also should be considered and evaluated before concluding an immune cause.

History and Demographics

The person’s medical and family history provide clues that may suggest an autoimmune cause.

Age

Autoimmune seizures typically start in adulthood and are generally less common in children.

In adult onset seizures, however, other causes, such as stroke, tumors or other brain lesions need to be excluded.

If there is no other known cause for new onset seizures, especially when they are frequent, an autoimmune cause needs to be considered.

Medical History

Having other autoimmune diseases, such as Hashimoto’s thyroiditis and lupus, should raise the possibility of an immune cause of seizures.

Family History

A family history of autoimmune diseases is a risk factor for an immune cause.

Yet the lack of a personal or family history of autoimmunity does not rule out a diagnosis of autoimmune epilepsy.

Response to Treatment

Anti-seizure Medications

Seizures due to autoimmune epilepsy frequently don’t respond well to antiseizure medications. In fact, only 1 out of 8 people with autoimmune seizures will respond to antiseizure medication alone.

Since the reason for seizures in autoimmune epilepsy is inflammation in the brain, treating the inflammation is critical to gain control of the seizures.

An autoimmune cause should be considered in new onset seizures that are not responding to anti-seizure medication.

Summary

Specific features of seizures can suggest an autoimmune cause of epilepsy. In suspicious cases, evaluation to exclude other causes, and specific testing to identify an immune cause, can affect choice of treatment and outcome.