From the Guidelines
Diagnosing psychogenic seizures requires a comprehensive approach combining video-EEG monitoring, clinical observation, and psychological assessment, with the gold standard being video-EEG monitoring, as it captures typical events while simultaneously recording brain activity, showing normal brain wave patterns during the seizure-like episodes 1. To diagnose psychogenic seizures, clinicians should look for specific features that differentiate them from epileptic seizures, including:
- Gradual onset and cessation
- Asynchronous limb movements
- Side-to-side head movements
- Closed eyes during the event
- Variable patterns between episodes A thorough medical history and neurological examination are essential, with attention to psychological factors, trauma history, and comorbid psychiatric conditions like anxiety, depression, or PTSD. Some key historical clues during the attack can help differentiate psychogenic seizures from other conditions, such as:
- Duration of loss of consciousness (LOC) >1 minute, which is more likely to be an epileptic seizure or psychogenic non-epileptic seizures (PNES) than syncope
- Duration of LOC >5 minutes, which is more likely to be psychogenic pseudosyncope (PPS) or PNES
- Presence of pelvic thrusting, which is more commonly seen in PNES, but can also be seen in frontal lobe seizures
- Repeated waxing and waning in intensity and changes in nature of movement, which is characteristic of PNES 1. Psychological testing using instruments such as the Minnesota Multiphasic Personality Inventory (MMPI) may support the diagnosis, and serum prolactin levels measured shortly after an event can sometimes help differentiate, as they typically rise after epileptic seizures but not after psychogenic ones. The diagnosis of psychogenic seizures should be delivered compassionately, emphasizing that these events are real and involuntary, not fabricated, and treatment typically involves a multidisciplinary approach including psychotherapy, psychiatric care for underlying conditions, and education about the nature of the disorder 1.
From the Research
Diagnostic Techniques for Psychogenic Seizures
- Psychogenic nonepileptic seizures (NES) can be diagnosed using a multidisciplinary team approach, involving a neurologist, psychologist or psychiatrist, and support staff 2
- Video-electroencephalographic (EEG) monitoring is a valuable tool in diagnosing NES, as it can capture the seizure and help distinguish it from epileptic seizures 2, 3, 4, 5
- Semiology with video EEG (vEEG) remains the most valuable tool to determine the diagnosis of PNES 5
- Induction techniques, especially when coupled with vEEG, can lead to a captured event, which then confirms the diagnosis 5
Clinical Factors and Diagnostic Tests
- Clinical factors such as semiology, psychiatric comorbidities, medical comorbidities, and psychological traits can be helpful in establishing the diagnosis of PNES 5
- Diagnostic tests such as EEG, psychometric and neuropsychological measures, prolactin level, clinical neuroimaging, and autonomic testing can support the diagnosis of PNES 5
- Postevent prolactin level and personality assessment can support the diagnosis but need to be carefully contextualized with other clinical factors 5
Challenges in Diagnosing Psychogenic Seizures
- Psychogenic NES can pose difficult diagnostic problems, and their diagnosis relies on a multidisciplinary evaluation 2, 4
- Motor characteristics previously considered to distinguish psychogenic seizures can be infrequent, and slow, subtle writhing or in-phase limb movements can be mistaken for status epilepticus 3
- Unresponsive behavior in the absence of motor manifestations is a common ictal presentation of psychogenic seizures 3