top of page
Background.jpg

The Challenge of Diagnosing Frontal Lobe Seizures vs. PNES

  • Writer: Jamie Thomsen
    Jamie Thomsen
  • Aug 13
  • 3 min read

Brain diagram with frontal lobe highlighted from EpilepsyDiagnosis.org.
Brain diagram with frontal lobe highlighted from EpilepsyDiagnosis.org.

Did you know that even with advanced tools like EEG monitoring, it can still be difficult to distinguish between frontal lobe seizures and Psychogenic Non-Epileptic Seizures (PNES)? While both conditions can present with dramatic symptoms, their origins—and therefore their treatments—are quite different.


Understanding the Basics


Frontal lobe seizures are neurological in nature, caused by abnormal electrical activity in the brain's frontal region. PNES, on the other hand, stem from psychological factors such as trauma, stress, or underlying mental health conditions. Despite these vastly different causes, the symptoms can often appear strikingly similar.


One of the most confusing similarities is the level of awareness during an event. Patients with frontal lobe seizures often maintain full or near-full awareness. Interestingly, many individuals experiencing PNES also retain awareness during their episodes. This can lead to misconceptions—even among healthcare professionals—especially when a person quickly returns to baseline without the postictal confusion typically seen in generalized seizures.


Motor Movements: A Closer Look


Frontal lobe seizures often involve unusual, hyper motor behaviors. These can include thrashing, pelvic thrusting, or loud vocalizations, which can be alarming to witnesses. PNES can also involve similar motor manifestations—sometimes nearly indistinguishable. However, there are subtle differences:

  • Frontal lobe seizures: Usually very brief (less than 30 seconds), sudden in onset, and often stereotyped in pattern.

  • PNES: Typically longer in duration (1–5 minutes or more), with movements that may build up gradually and lack consistency.


These nuances are critical in forming an accurate diagnosis.


What Triggers These Events?


Triggers can offer additional clues. Frontal lobe seizures may be brought on by sleep deprivation, flashing lights (especially in photosensitive epilepsy), or general stress. PNES episodes are more commonly linked to emotional distress, interpersonal conflict, or past trauma. Patients with PNES often have a history of psychiatric conditions or abuse, which needs to be taken into consideration during assessment.


Because both types of events can be stress-induced, relying on clinical observation alone can lead to misdiagnosis. That’s where video EEG monitoring becomes invaluable.


EEG: The Diagnostic Gold Standard


Video EEG monitoring is the most reliable tool for distinguishing between frontal lobe seizures and PNES. During a PNES episode, the EEG will typically appear normal, showing no signs of epileptiform activity. In contrast, a seizure originating from the frontal lobe should show abnormal brain activity—though detecting this can be tricky due to the depth and complexity of the frontal lobe’s structure.


Moreover, interictal EEGs (recordings taken between seizures) may not always capture abnormalities in frontal lobe epilepsy, further complicating diagnosis.


Treatment Approaches Differ


Treatment must align with the correct diagnosis:

  • Frontal lobe seizures are managed with anti-seizure medications (ASMs), which aim to control the abnormal electrical activity.

  • PNES does not respond to ASMs, since it is not a neurological disorder. Instead, treatment often includes psychotherapy, trauma-informed therapy, and Cognitive Behavioral Therapy (CBT).


In some cases, patients may suffer from both types of episodes. Subtle or atypical focal seizures might be misinterpreted as psychiatric in nature, delaying proper treatment. Long-term video EEG monitoring in an epilepsy monitoring unit (EMU) can be critical in these cases, offering patients and providers a clearer understanding of what’s happening—and how best to address it.


In Summary


The overlap between frontal lobe seizures and PNES can lead to diagnostic challenges—but with the right tools, careful observation, and multidisciplinary collaboration, it's possible to untangle the symptoms and provide effective, personalized treatment. Early and accurate diagnosis not only improves outcomes but also reduces the emotional toll on patients and their families.


Don’t forget to take a look back at some of our earlier posts:


Resources:




bottom of page