Susie Morris, MD, MA. Assistant professor of psychiatry and forensic psychiatrist, UCLA. Los Angeles, CA.
Dr. Morris has no financial relationships with companies related to this material.
The nurses ask you to see a patient whom they believe is having a seizure. You rush to the patient’s room to find her moaning with her eyes closed. Her entire body is shaking, and her movements include pelvic thrusting and arching of her back. You order a dose of intramuscular lorazepam, and she stops moving briefly while the injection is administered. The movements resume for five more minutes, and then the patient sits up and asks for water. The nurses tell you they don’t feel comfortable keeping this patient on the psych unit and want her transferred to the medical floor.
Psychogenic nonepileptic seizures (PNES) are paroxysmal events that look like seizures but are not associated with EEG changes. They are also known as psychogenic seizures, dissociative seizures, functional seizures, and nonepileptic seizures. An older term, “pseudoseizure,” is no longer in favor as it implies the seizures are feigned. We now know these seizures are not volitional, and the DSM-5-TR classifies PNES as a functional neurologic disorder (conversion disorder). If you’ve had patients with PNES on your unit, you know their seizure-like episodes take up considerable amounts of time and effort and can be quite distressing to staff and other patients.
The etiology remains unclear, but psychosocial stressors seem to trigger PNES in certain individuals. Patients often have a history of childhood trauma, PTSD, depression, or personality disorders. Additionally, 30% have a developmental disability (Duncan R and Oto M, Epilepsy Behavior 2008;12(1):183). Most patients are female and typically first exhibit symptoms in their 20s. The incidence is unclear, but 20%–40% of patients with refractory seizures are eventually found to have PNES (Huff JS and Murr N. Seizure. In: StatPearls. StatPearls Publishing; 2022). Conversely, 5%–22% of people with PNES also have epileptic seizures for which they need treatment (Duncan R and Oto M, Neurology 2008;71(13):1000–1005)
Typical features and diagnosis
Most cases of PNES resemble tonic-clonic seizures: Patients shake, roll from side to side, and exhibit pelvic thrusting and arching of their backs. These episodes can be dramatic and alarming. If the patient is on your psychiatric unit, you might think they need to be transferred to the medical floor. However, there are clues that can help you distinguish PNES from epileptic seizures.
Emotional vocalizations, like crying or screaming, are common with PNES (see “Differences Between PNES and Epileptic Seizures” table). Patients typically thrash their head and trunk from side to side and keep their eyes tightly closed, in contrast to patients with epileptic seizures. In fact, eye closure predicts PNES in 95% of cases (Chung SS et al, Neurology 2006;66(11):1730–1731). Additional features of PNES include asynchronous movement of limbs and the absence of a post-ictal period. Epileptic seizures are usually brief (less than two minutes), while PNES can last much longer. “Psychogenic status epilepticus” refers to PNES episodes that last 20 minutes or more and can be mistaken for status epilepticus.
Behaviors like tongue-biting and incontinence do not generally help in making the diagnosis. While they are more commonly observed in epileptic seizures, nearly one-third of PNES episodes will present with these behaviors (Reuber M et al, Ann Neurol 2003;53(3):305–311).
A minority of patients with PNES don’t demonstrate convulsive features but instead have a “swoon” version of PNES, with minimal movement and nonresponsiveness. This variant is more likely to occur in public places, like a doctor’s waiting room (Benbadis SR, Epilepsy Behav 2005;6(2):264–265).
Can you conclusively make the diagnosis of PNES if your patient exhibits all the classic features? No—epileptic seizures can be mistaken for PNES, so patients should undergo a full neurologic workup for epilepsy. The gold standard for diagnosis of PNES is long-term video-EEG monitoring (also known as EEG telemetry).
PNES is a diagnosis of exclusion. Other conditions to keep in your differential diagnosis include absence seizures, partial complex seizures, syncope, movement disorders, and sleep disorders (eg, narcolepsy and restless legs syndrome).
Once you have determined that your patient’s symptoms represent PNES, what do you do next? First and foremost, inform your patient about the diagnosis in a respectful, nonjudgmental manner, acknowledging the distress they feel from their condition. This simple intervention will often put an end to a patient’s PNES episodes! Disclosure of the PNES diagnosis resolves symptoms in 17%–40% of patients (Duncan R et al, Epilepsy Behav 2020;102:106667). I reassure patients that their test results are normal and tell them that their symptoms are, indeed, real, but do not represent traditional “seizures.” I also explain how our bodies sometimes translate trauma and mental distress into physical symptoms.
Another important step is to treat co-occurring psychiatric diagnoses, like depression, anxiety, and personality disorders. Psychotherapy—in particular, cognitive behavioral therapy (CBT)—can be effective in treating or reducing PNES episodes (Goldstein LH et al, Lancet Psychiatry 2020;7(6):491–505).
And lastly, discontinue antiepileptic medications in individuals who do not need them. This step can be tricky, as some people with PNES also have epileptic seizures. But if the workup confirms your patient does not have epileptic seizures, there’s no reason to expose them to unnecessary treatment. Failure to correctly identify PNES can lead to large administrations of benzodiazepines, respiratory depression, and even death (Reuber M et al, Neurology 2004;62(5):834–835).
What’s the prognosis?
Unfortunately, about 60% of individuals with PNES will continue to have seizures despite interventions, although treatment helps reduce the frequency. It’s not unusual for these patients to remain on psychiatric units for extended periods as their improvement can be slow. Certain demographic factors, including higher education and younger age of symptom onset, portend a more favorable prognosis (Reuber et al, 2003).
You provide an in-service to educate the psych unit staff about PNES. You educate the patient about her symptoms, treat her underlying depression, and encourage her to join a support group, where she works on overcoming maladaptive communication skills. She tells you that she now realizes that she can stop impending episodes by writing in her journal. She feels ready to return home.
Carlat Verdict: To identify PNES, look for clues: emotional vocalizations (eg, crying, screaming), closed eyes, thrashing of the head and trunk, and an absence of post-ictal confusion. The gold standard for diagnosis is video-EEG. PNES episodes will often resolve or lessen when patients learn about their diagnosis. Discontinue unnecessary antiepileptic medications, treat co-occurring psychiatric disorders, and refer patients for therapy, like CBT, to help reduce the frequency of events. Remember that some patients with PNES also have epilepsy.
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