Day # 122: Psychogenic Non-Epileptic Seizures (PNES)
Today we will continue our current theme of psychosomatic disorders as we discuss psychogenic non-epileptic seizures (PNES).
Today's Content Level: Intermediate
PNES = Psychogenic Non-Epileptic Seizures.
These are sudden and involuntary episodes that resemble seizures clinically but are not derived from electrical disturbances. They lack a correlate on electroencephalography (EEG).
Where does PNES belong in the DSM-V? These events are a subtype of functional neurologic disorder (ie, conversion disorder). However, these events can also occur in factitious disorder or malingering. A generally accepted view is that the significant majority of patients with PNES are a subtype of functional neurologic disorder and are given the specifier of "with attacks or seizures". Please see day # 120: Functional Neurologic Disorder for a detailed post about diagnostic criteria, specifiers, common symptoms, epidemiology, clinical pearls, and treatment of FNDs.
Other terms have been used by clinicians and in the research literature and include:
Pseudoseizures (this term is not preferred)
The preferred term for patients and families is psychogenic non-epileptic events (PNEE). 1
EPIDEMIOLOGY / PATHOGENESIS 2
Prevalence = proportion of individuals who have a condition at a particular period of time
Incidence = proportion or rate of individuals who newly develop a condition during a period of time
Incidence estimated to be 1.5-5 per 100,000 per year.
Prevalence estimated to be 2-33 per 100,000 per year.
More common in women, however reported female-to-male ratio differs among studies.
Onset of symptoms most commonly between 20-40 years of age but can also be seen in both children and the elderly.
Risk factors include history of sexual trauma or physical abuse, maladaptive behaviors, and certain comorbid conditions (fibromyalgia, chronic pain, chronic fatigue, somatic symptom disorder, depressive disorders, anxiety disorders, PTSD, personality disorders). A notable risk factors is comorbid neurological disease with similar symptoms and, yes, this also includes a history of actual epileptic seizures. It is estimated that 10-30% of patients with PNES also have comorbid, active epileptic seizures or a history of epilepsy.
FEATURES SUGGESTIVE OF EPILEPTIC VS NON-EPILEPTIC SEIZURES
It can sometimes be difficult to distinguish an epileptic vs non-epileptic seizure by clinical features alone, however there are important differences/clues that can help you. I have summarized these features below.
Epileptic seizures 3
Loss of awareness
Tongue biting or other significant injury
May occur during sleep
Non-Epileptic seizures (PNES) 3, 4
Resistance to anti-epileptic drugs
Emotional triggers - such as stress, conflict, becoming upset, pain, sounds, lights.
Suggestibility / Inducible - episodes tend to occur in the presence of an audience. They may frequently occur in the doctor's office or waiting room or during monitoring. They may be able to be provoked by induction techniques (see diagnosis section below).
Bilateral clonic movements without loss of consciousness - preserved awareness during bilateral motor seizures is highly suggestive of PNES.
*Absence of post-event confusion/lethargy (prompt recovery)* - the notable exception here is a specific type of seizure called absence seizures which are characterized by staring spells with prompt recovery without a post-ictal period.
Variable responsiveness or preserved awareness.
Discontinuous ("stop and go") motor activity; Out of phase movements of extremities.
Complex motor movements such as pelvic thrusting or bicycling or opisthotonic posturing.
Side to side head movements.
Eye closure or eye flutter.
Stuttering, weeping, postictal whispering.
Usually do not occur during sleep.
Physical exam and mental status exam: watch for overly dramatic behavior or suggestibility.
Keep in mind that non-epileptic is not synonymous with psychogenic, since there can be other forms of paroxysmal non-epileptic episodes. This is important to know for your differential diagnosis.
Differential diagnosis includes epilepsy (particularly frontal lobe), convulsive syncope (common), transient ischemic attacks (TIAs), autoimmune encephalitis, paroxysmal movement disorders (ex, dystonia), narcolepsy with cataplexy, complicated migraines, parasomnias, and breath-holding spells and shuddering attacks in children. 1
Labs should be obtained depending on the clinical picture to rule out organic causes of symptoms. A complete metabolic panel, urine drug screen, complete blood count are typically obtained to rule out metabolic or toxic causes. Prolactin and creatine-kinase may have some role if obtained immediately after the event, however the sensitivity/specificity varies and there is debate about the clinical usefulness of this practice. See here and here for a more thorough discussion.
The gold standard tool for diagnosis is an EEG with video monitoring (at least 24 hours, but 3-5 days is preferred). Routine EEG (<1 hour) has very low sensitivity and misdiagnosis of epilepsy is common (PNES accounts for 90% of misdiagnosed epilepsy patients). The diagnostic goal is to record an event/seizure and demonstrate no EEG changes. Verify that the event recorded is representative of that patients typical events. If there are EEG changes, characterize the type of seizure and where it originates. Analysis of the video is as important as the EEG itself because it may show behaviors incompatible with epileptic seizures. Consider induction techniques when diagnosis is uncertain or there are no spontaneous episodes (examples include hyperventilation, photic stimulation, and verbal suggestion).
Video EEG limitations: EEG during PNES can be difficult to interpret, since movements during a PNES event cause rhythmic artifacts on EEG. Some epileptic seizures (partial) can be electrically silent on EEG. Also, the event may not occur during monitoring.
A word of caution about previous abnormal EEG results: If there is a high clinical suspicion of PNES, do not automatically trust previous abnormal EEG results. Obtain and review the actual tracing previously recorded as epileptiform and review with neurology. When reviewed, if high suspicion of PNES, the majority will show over-interpreted normal variants.
Treatment of all functional neurologic disorders, including PNES, is a process that starts with explaining the diagnosis in a way that helps the patient understand and gain confidence in it. This in turn enhances the odds of adherence to and success from therapeutic strategies. Delivering the diagnosis in this way is the most important step of treatment. The diagnosis should be explained clearly as psychological, stress-induced, or caused by emotions. The approach needs to be compassionate but also firm and confident. Patient awareness that events are psychogenic can be therapeutic with one study reporting remission rate close to 40% at 6-12 months in a subset of patients. 1
Be prepared for possible frustration with the diagnosis. Their reaction may be disbelief or anger because of previous organic diagnosis or feeling accused. “Are you accusing me of faking?” “Are you saying I’m crazy”? Unless the patient and their family understand the diagnosis, they will not follow through with treatment
Education: The primary treatment is education about the illness. It should be emphasized that the patients symptoms are real while emphasizing which medical and neurologic conditions have been considered and rule out. The diagnosis of "functional neurologic disorder" and/or "psychogenic non-epileptic events" should be clearly shared. Explain how the diagnosis was made by demonstrating relevant clinical findings. Consider providing written materials explaining the diagnosis or referring the patient to neurosymptoms.org.
General approach: Team-based approach with primary care, neurology, and behavioral health. There should be regularly scheduled visits to one primary care physician with a focus on reassurance, acknowledging health fears, education about coping, and limiting unnecessary tests/referrals. Educate and empathically acknowledge that real symptoms can be present even in the absence of other disease. It is often best to address psychological issues slowly, and patients may initially resist referral to a mental health professional. The main goal of treatment is to improve patients functional status and coping rather than elimination of symptoms.
Psychotherapy: Cognitive behavioral therapy (CBT) is first-line psychological treatment. CBT and other psychotherapies designed for FNDs include components such as education, skills in gaining control of symptoms, recognizing triggers, cognitive restructuring of dysfunctional beliefs, modification of maladaptive behaviors associated with symptoms, and widening therapy to other aspects of interpersonal functioning. Other psychological treatments with emerging evidence includes hypnotherapy, relaxation techniques, psychodynamic psychotherapy, family therapy, and group therapy.
Pharmacotherapy: There are no specific PNES treatments. Comorbid anxiety and depressive disorders should be treated with selective serotonin reuptake inhibitors (SSRIs) or other appropriate psychotropic medications (see treatment of depression; treatment of anxiety). Improvement of FNDs to any pharmacological treatment can occur because of positive effects on mood, coexisting disease, or placebo response.
Next lesson we will discuss factitious disorder and malingering. If you want more learning resources then check out our recommended resources page.
Resources for today's post include: Pocket Psychiatry, DSMV-5, and the articles referenced in the text.
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