Sensory Changes

Reviewed by: HU Medical Review Board | Last reviewed: November 2021

Epilepsy is a neurological disease that causes seizures. Different people have different types of symptoms during their seizures. Some people have sensory changes. This means they have changes in what they see, hear, smell, taste, or feel.1

Examples of sensory changes caused by a seizure include:1

  • Unusual or bad smells
  • Unusual tastes
  • New, strange, or different sounds
  • Problems hearing or deafness
  • Blurry vision or blindness
  • Seeing flashing lights, colors, or patterns
  • Visual hallucinations (seeing things that are not there)
  • Numbness, crawling, or tingling in the body, arms, or legs
  • Out of body sensations
  • Body parts that feel or look different from reality

Sometimes these symptoms happen before another type of seizure. This is called an aura.1

What causes this?

Focal awareness seizures are usually the cause of sensory changes. These used to be called simple partial seizures. Focal seizures are caused by abnormal electrical activity in 1 small part of the brain. These are the most common type of seizures that people with epilepsy have.2

Focal seizures may cause a variety of symptoms. It depends on where in the brain the seizure takes place. For instance, a seizure taking place in the occipital lobe may lead to vision changes. The occipital lobe is located at the back of the brain. When a seizure takes place in the parietal lobe, objects may look bigger or smaller than reality. The parietal lobe is located at the top, back of the head.3

The person remains aware of their surroundings during this type of seizure.2

How are these seizures diagnosed?

Focal seizures may be diagnosed using a test called an (EEG electroencephalogram). An EEG checks electrical activity in the brain. When a person has a seizure, their brain waves (electrical activity) are abnormal. However, EEGs may not be able to record all seizures.

Brain imaging tests such as MRI look at the structure of the brain. These images help the doctor see if there are abnormal areas that may be causing seizures. These test results are combined with a person's medical history and description of seizure events.

It is also important to keep a seizure journal. Loved ones should make a video of sensory symptoms as they happen. This record of what happens, what seems to trigger the seizure, and when they occur will help your doctor diagnose what is going on and create your treatment plan.

How are these seizures treated?

Focal seizures are treated in a variety of ways. There are 3 goals to treating any epilepsy: controlling seizures, avoiding side effects, and improving quality of life. Treatments may include:4

  • Anti-seizure drugs
  • Surgery
  • Lifestyle changes
  • Diet and nutrition
  • Supportive devices such as a service dog or smartwatch

Doctors believe 7 out of 10 people with epilepsy can become seizure-free with treatment. Some people can eventually stop taking anti-seizure medicines.5

Sensory changes are just 1 possible symptom of epilepsy. Others include:

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