By Dissociative State we mean the patient’s mind is so preoccupied that they are unaware of what they are doing at the time, and have complete amnesia for the episode. The distracting factor is usually a traumatic memory. A person would be aware enough not to hurt themselves, but nobody knows what actions they perform at the time, because they are invariably alone. Anyone else present would likely cause them to “snap out of it.”
Essentially, a person comes for care because they “lost time.” They experienced a period of amnesia they can’t account for; maybe multiple episodes. There are many variants of Dissociative Disorder, some include what is sometimes referred to as “multiple personality disorder;” that’s not what we’re describing here.
It’s impossible for a clinician to distinguish an unwitnessed psychiatric Dissociative episode from a Complex-Partial Seizure, given that both include amnesia for the event. Since there are no tests to diagnose the former, we try to rule out the latter, by doing:
- an MRI, looking for a possible brain tumor. Seizures of any kind most often occur on their own, without tumors. So no tumor doesn’t prove anything, but the presence of one would reinforce the likelihood it was a seizure; AND
- An electroencephalogram (EEG) looking for abnormal brain waves suggesting predisposition to seizures.
Since Complex-Partial Seizures may come from abnormalities deep in the brain, sometimes a regular EEG is false-negative. So we refer to Neurology to rule out the possibility (see link).
Here’s the best example I’ve seen personally (also described in Passing Out – Full Text). A friend who’d been working abroad during a civil war, and was having episodes of amnesia, visited San Francisco, I ordered an EEG and MRI to rule out Seizure (both were normal). A consulting Neurologist said there was no way to distinguish between the 2 conditions, leaned toward the latter since tests were normal & war is tough. But I knew her situation abroad, which wasn’t particularly traumatic or dangerous. It was only weeks later, before flying to Chicago, that she confided she was traveling to confront a brother who’d molested her in childhood. Diagnosis: Dissociative Episodes.