Temporal lobe seizure Health Article

Definition

This type of seizure involves a temporary movement disturbance that often involves a change in a person's behavior, unusual sensations, or various other symptoms. It arises from abnormal electrical activity in the temporal lobe on one or both sides of the brain.

Alternative Names

TLE; Seizure - temporal lobe

Causes, incidence, and risk factors

A seizure is an episode of abnormal electrical activity in the brain that can involve loss of consciousness or reduction of consciousness, involuntary movements, and overwhelming sensations.

Temporal lobe seizures can affect people of any age, and can occur as a single episode or can be repeated as part of a chronic (ongoing) condition. (See seizure disorder).

Information in the brain is transmitted from nerve cell to nerve cell by an electrochemical process. Certain patterns of electrical activity can cause seizures, which are episodes during which electrical signals spread in abnormal patterns within the brain. This process can be detected by an electroencephalograph (EEG).

Given the right conditions (such as exposure to certain drugs, high fever, or electrical stimulation), anyone can have a seizure.

Temporal lobe seizures commonly result from damage to specific areas in the temporal lobe of the brain. This damage includes scarring, called mesial temporal sclerosis. Causes can include traumatic injury, infection, damage to a portion of the temporal lobe due to lack of oxygen, brain tumors, genetic syndromes, and lesions of any sort.

Because the temporal lobe is involved in processing emotion and sensations, seizures in this area may begin with feelings of fear, feelings of joy (sometimes with religious associations and the sensation of a "presence"), recall of certain music, or smells and other unusual symptoms.

Symptoms

The early warning symptoms (called an aura) include:

• Abnormal sensations
• Epigastric sensations ("a funny feeling in my gut," "stomach rising")
• Hallucinations or illusions (vision, smells, tastes, or other sensory illusions)
• Sensation of deja vu, recalled emotions or memories
• Sudden, intense emotion not related to anything occurring at the time

During the seizure:

• Consciousness maintained during the seizure (partial)
• Consciousness reduced or lost during the seizure (partial complex)

Movement disturbances include:

• Abnormal mouth behaviors
  • Lip smacking
  • Chewing or swallowing without cause
  • Profuse salivation "slobbering"
• Abnormal head movements
  • Forced turning of the head
  • Forced turning of the eyes
  • Usually in the direction opposite of the location of the brain lesion
• Repetitive movements, such as picking at clothing
• Rhythmic muscle contraction and relaxation (rare) -- affecting one side of the body, one arm, leg, part of face, or other isolated area

Abnormal sensations include:

• Numbness, tingling, crawling sensation
• Occurring in only one part of the body or spreading
• Preceding motor symptoms
• Sensory hallucinations (visual, hearing, touch, etc.)

Autonomic symptoms include:

• Abdominal pain or discomfort
• Nausea
• Sweating
• Flushed face
• Dilated pupils (eyes)
• Rapid heart rate/pulse

Other symptoms include:

• Changes in vision, speech, thought, awareness, personality
• Loss of memory (amnesia) regarding events around the seizure (partial complex seizure)

Signs and tests

Diagnosis of temporal lobe seizure is suspected primarily on the basis of the symptoms presented and the results of tests. Diagnosis may include a complete physical examination, including a detailed neuromuscular examination, which may or may not be normal.

• An EEG (electroencephalograph, recording of the brain's electrical activity) shows characteristic changes confirming partial (focal) seizures, and may show the focus (location of the cause).
• A head CT scan or a cranial MRI may show the location and extent of the lesion.
• A lumbar puncture may be necessary if there is suspicion of an infection causing the seizure.