There are many concerning aspects to having epilepsy, and one of the most upsetting is its impact on the memory. Epileptic seizures interrupt brain function, and as a result they interfere with the memory process. Seizures may also cause physical damage to the parts of the brain that are tasked with storing or retrieving memories. (Oxford Academic)
What is Epilepsy?
People have varying degrees of understanding about epilepsy and the seizures that come with this central nervous system disorder. People who have epilepsy suffer from abnormal brain activities that lead to outcomes that vary, but which are all generally described as seizures. Though most people understand a seizure as an acute episode called tonic clonic and characterized by twitching and uncontrollable body movements, a seizure can be as mild as a loss of awareness. People may simply think that a person with epilepsy is simply daydreaming, while their staring blankly into space is actually what is known as an absence seizure in midstream. Once a person has two seizures, they receive an epilepsy diagnosis, even though they may never have another episode: others may suffer with constant and violent symptoms. (Centers for Disease Control and Prevention)
Though epilepsy is treatable, it is not curable. People diagnosed with the condition may only experience it fleetingly while others require lifelong treatment and may even require surgery to address significant and frequent seizures. Some children diagnosed with epilepsy outgrow the condition before they reach adulthood. A thorough workup of the disease will try to determine whether the condition is a result of genetics or of a brain injury of some type. Identifying the source of the condition and the specific epilepsy syndrome is essential to obtaining proper treatment. (Epilepsy Foundation of Greater Chicago)
The Brain and Seizures
Seizures occur in the brain as a result of complex chemical changes in nerve cells. In some cases the cells may engage in too little activity while in other cases they become overly excited and active. No matter what the circumstance, the result is an imbalance and a surge of electrical activity that leads to a seizure. (American Association of Neurological Surgeons)
A seizure is not a disease: rather it is a symptom of a problem within the brain. As is true of symptoms of other conditions, seizures can be mild or severe. An individual having a seizure may not even realize what is happening to them, and those around them may also be unaware. In other cases, seizures are extremely obvious, and can be frightening to observe. The difference in intensity and experience is largely a result of the part of the brain that is involved, and the same is true of a seizure’s potential impact on memory. The more frequently seizures occur, the more likely they are to cause memory problems, and the area of the brain that is involved will determine the type of memory problems a person is likely to experience.
Focal vs. Generalized Seizures
When a person experiences generalized seizures, the entire brain is impacted. By contrast, focal seizures impact a specific part of the brain. It is possible to have both focal and generalized seizures, and understanding the physiology of the brain and what its various parts do will help to understand the impact that a focal seizure can have on memory.
Both the left and right side of the brain have four lobes, referred to as the occipital lobe, the parietal lobe, the temporal lobe and the frontal lobe. People who experience memory problems following epileptic seizures are most often afflicted with seizures in the temporal or frontal lobes. (Mayo Clinic) This is because the left temporal lobe is responsible for creating and retrieving verbal memories such as facts and names, and the right temporal lobe is responsible for creating and retrieving visual memories like recognizing a person’s face or a route to a familiar place. Remembering to do something in the future, like a task or going to an appointment, is controlled by the frontal lobe. Damage to these areas of the brain will have a direct effect on the abilities of these essential memory functions. (Learning and Memory)
Though damage to the brain caused by seizures can cause long-term memory problems, some of the memory lapses that people experience are what is known as “post ictal confusion.” This is a temporary loss of memory. For those who have extremely mild symptoms, post ictal confusion may be the first indication that the person is suffering from seizures. In addition to having a hard time with memory, post ictal confusion is also characterized by extreme exhaustion and an overwhelming sense of needing sleep.
Is The Problem Memory, or Attention?
Though people who have epilepsy may feel that their memory is suffering, there are many who question whether the problem is one of storage and retrieval, or whether the problem may actually be a reduction of attentional speed or information processing. Studies have linked epilepsy directly to a reduction in the amount of information that can be processed in a given period of time, and this deficit has a direct impact on the ability to form memory. When a key element (or elements) of new information are missed because it is being delivered faster than it can be processed, it also cannot be absorbed. Epilepsy can also make an individual more distractible or more easily overwhelmed. Not actually taking information in may be experienced or interpreted incorrectly as a failure of memory. (Epilepsy Foundation)
Is the Problem Memory, or Retrieval Speed?
Similarly, people with epilepsy may have properly encoded and stored information in their memory, but may have slowed retrieval as a result of either damage done to the brain or simple slowing of the retrieval process that has been associated with epilepsy. These individuals will be asked to respond to a question and be unable to do so in the moment and then come up with the answer a short time later. This may be a function of slowed processing speed or of the brain having gotten distracted, as is also common among those diagnosed with epilepsy.
Retrieval of memories can also be complicated by a need for greater context that is common among those diagnosed with the condition. Though isolated episodes can be hard to retrieve, providing greater context or relationships for retrieval may be necessary in order for the memory to be evoked.
Epilepsy Drugs and Memory
In addition to the physical damage caused by epileptic seizures and the impact that the disease itself can have on brain function, it is also important to remember that many of the drugs that are prescribed to prevent epileptic seizures may have an impact on memory. These anti-epileptic drugs may create challenges for your ability to concentrate or may simply make you too drowsy to be able to properly encode information in our short-term memory, and therefore to learn and later retrieve new information. (WebMD)