Some characteristics which may distinguish PNES from epileptic seizures include gradual onset, out-of-phase limb movement (in which left and right extremities jerk asynchronously or in opposite directions, as opposed to rhythmically and simultaneously as in epileptic seizures), closed eyes, high memory recall, and lack of post-ictal confusion.
Unlike epilepsy, many PNES patients presenting with total unresponsiveness still retain some form of conscious response, including the natural behavior to protect oneself from harm.
This is often reflected by a lack of tongue-biting, urinary and/or fecal incontinence, fall-related trauma, or accidental burns, all of which are significantly less common in PNES than in epileptic seizures.
[6][7] Other means of determining consciousness include dropping a patient's hand above the nasopharyngeal lead; the natural response is to prevent it from falling.
An epileptic seizure lasting longer than five minutes is considered a life-threatening medical emergency, which is not a risk in PNES.
[16] Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements, and occurrence during sleep.
[20] Laboratory testing can detect rising blood levels of serum prolactin if samples are taken in the right time window after most tonic-clonic or complex partial epileptic seizures.
[23] This therapy focuses on the idea that PNES are caused by a learned physical reaction or habit the body develops, similar to a reflex.
[23] In the cognitive behavioral therapy for adults with dissociative seizures (CODES) trial, the largest regarding CBT treatment for PNES though found no significant reduction in monthly episodes compared to the control arm at 12 months, however there were significant improvements on a number of secondary outcomes, such as psychosocial functioning, and self-rated and clinician-rated global change.
[26] The prevalence for PNES is estimated to make up 5–20% of outpatient epilepsy clinics; 75–80% of these diagnoses are given to female patients and 83% are to individuals between 15 and 35 years old.
The etiology of FND was historically explained in the context of psychoanalytic theory as a physical manifestation of psychological distress and repressed trauma.
[34] Although "pseudoseizures" remains a common term for PNES episodes in the medical field, many patients dislike it due to associated stigma and implications of malingering.