Differential Diagnosis: Seizure Disorders and Dissociative Episodes

Reader’s Question

My therapist recently told me she believes she has seen me dissociate in her office. She wonders if I might have some type of a dissociative disorder in addition to my previously diagnosed Bipolar I Disorder and Post-Traumatic Stress Disorder. Since I didn’t know anything about dissociative disorders, I went online to learn more about their symptoms, etc. From what I have read, a dissociative state sounds very much like a petit mal seizure. I do in fact have a seizure disorder. How can a person tell the difference between a seizure and a dissociative episode?

Our Clinical Psychologist’s Reply

There are indeed some distinct similarities in the signs for both some types of seizures and a dissociative disorder. This makes differential diagnosis quite difficult sometimes.

Dissociative Disorders are of various types. Dissociative Amnesia is characterized by an inability to recall important personal information. Dissociative Fugue is characterized by the sudden abandonment of one’s usual life and location, sudden, unexpected travel to a distant place, and sometimes the assumption of a new identity. Depersonalization Disorder is characterized by a subjective sense of being detached from one’s body or mental processes. And Dissociative Identity Disorder (formerly called Multiple Personality Disorder) is characterized by the presence of two or more distinct personality states. A person can also have some features of a dissociative disorder without having one of the recognized full-blown syndromes.

Although it is certainly possible for a person to have both a seizure disorder and a dissociative disorder, one particular seizure type, called an “absence” seizure (also sometimes referred to as a petit mal seizure) is often mistaken for a dissociative disorder, especially Dissociative Amnesia Disorder. During such a seizure, a person can appear to go “blank.” The person might not respond to stimuli around them. They can appear not to hear or to be aware of their surroundings. Also, individuals who have absence seizures will resume normal activity after their seizure as if nothing ever happened, displaying some “amnesia” for the event, as occurs in Dissociative Amnesia Disorder. Depending upon its “complexity” a absence seizure can also be accompanied by some odd motor behaviors such as rapid eye blinking, tasting movements of the mouth, rubbing fingers together, etc. The biggest differences between a Dissociative Amnesia Disorder and an absence seizure are that memory lapses are immediate and more global with seizure disorders, whereas they are primarily for autobiographical information with Dissociative Amnesia Disorder. Also, when dissociative amnesia occurs to material that’s not autobiographical, it’s often possible to identify a circumstance or stressor that likely triggered the episode.

Some of the symptoms of dissociative disorders are also included in the criteria for Post Traumatic Stress Disorder. Therefore, unless there is a compelling reason to do so, and unless there are additional symptoms that are not fully accounted for either by the PTSD and/or the seizure disorder diagnoses, there may in fact be no need to diagnose a separate dissociative disorder. It would be very important, therefore, to carefully review your entire history with your therapist, who might well need to consult with whatever medical practitioner is treating your seizure disorder.