Nonmotor Seizures in Adolescents Missed in ED: How to Ask the Right Questions

Early diagnosis and treatment of epilepsy is intrinsic to the prevention of worse disease outcomes, developmental delays, and seizure-related injuries and deaths.^1,2

The results of a recently published study in Neurology indicate that nonmotor seizures are rarely recognized in adolescents presenting to the emergency department (ED), which can lead to delays in diagnosis and treatment within this patient population.³

Study Findings

Researchers of a retrospective analysis of enrollment data from the Human Epilepsy Project aimed to assess the recognition rate of motor vs nonmotor seizures in 83 adolescents aged 12 to 18 who had focal epilepsy and were evaluated in pediatric and non-pediatric EDs.³

At the time of presentation to the ED, 70% of all patients lacked an epilepsy diagnosis. Although most patients (90%) visited the ED for motor seizures, many also had a history of nonmotor seizures (38%).³

Compared with motor seizures, nonmotor seizures were less likely to be correctly identified (81% vs 33%; P =.008). Nonmotor seizures were also often misattributed to causes such as anxiety, dehydration, and gastrointestinal complaints.³

In patients presenting with first-time motor seizures who also had a history of nonmotor seizures, the history of nonmotor seizures went unrecognized. Compared with the rate of recognition of nonmotor seizure history among adolescents, the rate of recognition among adults is greater, but still low (23%).³ 

“Our study highlights a critical need for physicians to inquire about the symptoms of nonmotor seizures, even when the presenting seizure is motor. Future interventions should focus on improving nonmotor seizure recognition for this population in EDs,” the researchers concluded.³

Clinical Implications

The failure to recognize a history of nonmotor seizures can lead to diagnostic delays, as clinicians may consider the motor seizure to be a first-lifetime seizure rather than 1 of many seizures, which would prompt an epilepsy diagnosis and initiation of antiseizure medication.

“We have seen this result in another tonic-clonic seizure occurring in close succession to the first after the person has been discharged from the ED, and this second tonic-clonic seizure has led to injuries in some cases,” explained study co-author Jacqueline French, MD, professor in the department of neurology at NYU Grossman School of Medicine and Comprehensive Epilepsy Center and director of The Epilepsy Study Consortium (TESC).

According to Dr French, “Failure to recognize nonmotor seizures leads to unnecessary delays in the initiation of therapy. This is particularly important, because once therapy is initiated, it is quite likely to be effective.”

“While the failure to recognize nonmotor seizures can also occur in the outpatient clinic and other settings, most individuals experiencing a tonic-clonic seizure will present to the ED, so the ED serves as an opportunity to address this issue,” she continued.

Although the study did not divulge why the recognition of nonmotor seizures was less common among adolescents vs adults, Dr French suggested that the discrepancy may be attributable to adolescents having a greater difficulty describing the symptoms of nonmotor seizures, or that the ED staff may be more likely to discount reports of nonmotor events in adolescents.

According to the study data, many of the participants with a history of nonmotor seizures had previously described their symptoms in similar ways, including hearing voices, auditory disturbances, episodes of “aura,” feelings of tingling or numbness, and feelings of fear or anxiety. These symptoms “conceivably could have been elicited with a thorough review of systems that included a nonmotor line of questioning,” the researchers noted.

Asking the Right Questions

To accurately recognize a history of nonmotor seizures in patients presenting with what may at first appear to be a single motor seizure incident, Dr French and her colleagues emphasized the importance of thorough history taking and asking 2 key questions:

1. Did you feel anything at the beginning of the seizure, and if so, have you ever felt the same thing before? and,
2. Before today, have you had any feelings (ie, feeling scared, anxious, or worried, or having a sudden thought out of nowhere or a déjà vu moment) that come on suddenly for no reason and last fewer than 5 minutes?³

According to a 2022 qualitative study based on interviews with 10 physicians, the following 5 characteristics may help identify seizures:

• Unprovoked symptoms with a sudden onset;
• Short-lasting symptoms;
• Strange or difficult-to-describe symptoms;
• Highly stereotyped symptoms; and,
• Postictal symptoms.⁴

Clinicians may ask patients about any other short-lasting, stereotyped episodes they may have experienced, Dr French explained. An affirmative response “should prompt discussion about starting an antiseizure medication or urgent discussion with, or referral to a neurologist, depending on what is described,” she advised.

In line with the current findings, previous research has found substantially longer diagnostic delays in individuals with initial nonmotor seizures.⁵ In addition to delays in treatment initiation, delayed diagnosis adds unnecessary stress to the parents and families of children with epilepsy.³ Improving rates of accurate and timely diagnosis in these patients will require ongoing education of ED physicians, as well as further research dedicated to the exploration of the frequency of unrecognized nonmotor seizures in the ED and related consequences.