From the Guidelines
Testing for psychogenic seizures requires a comprehensive approach, with the gold standard diagnostic test being video-electroencephalogram (video-EEG) monitoring, as it allows clinicians to observe the physical manifestations of the seizure while confirming the absence of epileptiform activity in the brain 1.
Diagnostic Approach
The diagnostic process for psychogenic seizures involves several steps, including:
- A thorough neurological examination to rule out any underlying neurological conditions
- A detailed medical history to identify any potential triggers or contributing factors
- Psychological assessment to evaluate for any underlying psychological conditions, such as anxiety or depression
- Video-EEG monitoring to capture and analyze seizure events
Diagnostic Tools
Additional diagnostic tools that may be used include:
- Serum prolactin levels measured within 10-20 minutes after a seizure event to help differentiate between epileptic and psychogenic seizures
- Neuropsychological testing to evaluate cognitive function and identify any potential deficits
- Screening for trauma history or psychiatric conditions, as psychogenic seizures often coexist with these conditions
Importance of Sensitivity
It's essential to approach diagnosis with sensitivity, as psychogenic seizures represent real, involuntary events requiring appropriate treatment, typically involving psychological therapies like cognitive behavioral therapy rather than antiepileptic medications 1.
Limitations of Other Tests
Other tests, such as MRI and CT scans, are not recommended for routine evaluation of patients with syncope or psychogenic seizures, as they are unlikely to provide diagnostic information and may expose patients to unnecessary radiation and costs 1.
From the Research
Testing for Psychogenic Seizures
To test for psychogenic seizures, also known as psychogenic nonepileptic seizures (PNES), several methods can be employed:
- Video-electroencephalographic (EEG) monitoring: This is considered the most effective way to distinguish PNES from epileptic seizures 2, 3, 4, 5.
- Suggestive seizure induction (SSI): This can be used in conjunction with video-EEG monitoring to support a high level of diagnostic certainty 4.
- Clinical evaluation: A comprehensive clinical evaluation, including psychiatric and psychological assessment, can contribute to the correct diagnosis of PNES 5.
- Video analysis: In some cases, experienced epileptologists can predict the diagnosis of PNES based on video recordings alone, although this is not always reliable 6.
Diagnostic Criteria
The diagnosis of PNES is typically based on a combination of the following:
- The presence of a seizure-like event without any corresponding epileptiform activity on EEG
- The presence of psychological or psychiatric co-morbidities, such as anxiety, depression, or personality disorders 2, 5
- The presence of typical PNES semiology, such as closed eyelids, rapid tremor, or asynchronous limb movement 5
Limitations and Challenges
The diagnosis of PNES can be challenging, and some patients may not receive the diagnosis well 2. Additionally, the use of suggestive seizure induction may not be effective in all cases, and some patients may have a low seizure frequency, making it difficult to capture a spontaneous event on video-EEG monitoring 4.