I Can't Come Up with the Right Word...

Adults with partial epilepsy commonly describe difficulties in coming up with words. This is the most frequently reported disturbance of language in people with complex partial seizures. It is also the symptom that has received the most attention in medical and scientific studies. Neuropsychological research has shown that patients with partial epilepsy affecting the left temporal lobe have greater difficulty in naming objects and pictures than patients with seizures originating from other parts of the brain. These individuals also have problems coming up with words to describe things, and may do poorly when asked to think of as many words as possible in a certain category.

Naming difficulties in patients with complex partial seizures often involve an inability to come up with the appropriate word quickly and on cue. Many experience what is described as the "tip-of-the-tongue" phenomenon. They can describe some features of the word, such as what letter it starts with or what words rhyme with it, but are not able to produce the precise word they are searching for. Sometimes they can substitute a similar word or description.

In other situations, they may use an incorrect word. This kind of error in word retrieval is called paraphasia. Two types of paraphasias are common:

• Semantic paraphasia, in which the meaning of the wrong word is related to the meaning of the word that is wanted-for example, using the word "briefcase" for SUITCASE
• Phonemic paraphasia, in which the wrong word and the desired word are related by sound, such as calling a BALL a "tall"

Difficulties in coming up with words may result from a direct disruption of the language zones. Often, however, epilepsy arising in the temporal lobe will affect structures near the inner surface of the lobe (the hippocampus and its connections), causing a more basic disturbance of word retrieval.

A branch of neuropsychological research has been concerned with defining the mechanisms underlying naming disturbance. Some have argued that the disturbance results from being unable to access (retrieve) words. Others feel that the disturbance is caused by faulty storage and representation of word knowledge (semantic representation). Studies in patients with complex partial seizures have supported both theories, as findings have shown problems in both retrieval and semantic representation in people with left temporal lobe epilepsy.