Delayed diagnosis of focal nonmotor seizures represents ‘significant treatment gap’
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Patients with focal nonmotor seizures experienced a delay from first seizure to diagnosis that was 10 times longer than patients with motor seizures at the time of onset, according to findings published in Epilepsia.
“This research was prompted by a clinical observation that many patients with focal epilepsy experience delays to diagnosis,” Jacob Pellinen, MD, assistant professor of neurology at the University of Colorado School of Medicine, told Healio Neurology.
Pellinen and colleagues analyzed time to diagnosis as well as the rate of injuries and motor vehicle accidents among people with focal nonmotor vs. focal motor seizures at the time of epilepsy onset. They conducted a retrospective study using enrollment data from the Human Epilepsy project, a multicenter, multinational study designed to obtain information on response to treatment, biomarkers and comorbidities in participants with newly treated focal epilepsy. The study enrolled participants between 2012 and 2017 across 34 sites in the United States, Canada, Europe and Australia within 4 months of treatment for focal epilepsy.
The researchers examined data from 447 participants, grouped according to initial seizure semiology (focal nonmotor or focal with motor involvement). Demographic characteristics were similar between groups. There were more women than men overall (58.4% vs. 41.6%) and the average age at seizure onset overall was 30 years.
Slightly more than half of patients (n = 246; 55%) had nonmotor seizures at the time of epilepsy onset; 201 participants (45%) had motor seizures at onset. The researchers reported a median number of 219 days from first reported seizure to diagnosis (interquartile range [IQR] = 49-999 days) for all participants in the study. Participants in the nonmotor seizure group (55%) experienced a median delay of 616 days (IQR = 188.3-2,110.3 days), a 10-fold longer delay than the time to diagnosis for participants in the motor seizure group (45%), which was 60 days (IQR = 8-220 days; P < .001). Most patients (n = 181; 90%) in the initial motor seizure group experienced focal to bilateral tonic-clonic seizures; these patients still experienced a significantly shorter median time to diagnosis (38.5 days; IQR = 8.8-500.8 days) compared with patients in the nonmotor seizures group (P < .001).
“Delayed diagnosis has several consequences,” Pellinen said. “First, people's seizures became worse over time — even if they initially only had subtle symptoms, they would often go on to experience generalized convulsions, which frequently led to injuries. Moreover, delayed diagnosis was associated with seizure-related motor vehicle accidents reported by patients in our study, which may have been preventable if patients were diagnosis and started on treatment earlier. This has larger implications, as motor vehicle accidents affect both patients and the communities in which they live.”
The researchers did not observe a significant difference in the number of injuries between patients with initial nonmotor seizures vs. motor seizures or in the severity of injuries (rated as mild, moderate or severe). However, Pellinen and colleagues found that the “vast majority” of injuries in the nonmotor seizures group were in participants who developed motor seizures: 55.1% (92/167) of participants in the nonmotor group who developed motor seizures had an injury compared with 10.1% (8/79) of participants in the nonmotor group who never developed motor seizures and had an injury (P < .001).
Pellinen and colleagues also found that most motor vehicle accidents (82.6%; P < .001) happened in patients with undiagnosed nonmotor seizures. These patients had a similar time to diagnosis as the nonmotor seizures group overall (median time to diagnosis, 654 days; IQR = 164-6,556 days), and a median number of 20 seizures before receiving a diagnosis (IQR = 7-254).
The findings “highlight a treatment gap that is particularly significant in patients who experience nonmotor seizures at epilepsy onset,” according to Pellinen. He noted that focal nonmotor seizures are often overlooked by several groups, including the public, primary care providers and emergency care providers.
“Improving recognition of focal epilepsy, particularly when it manifests as non-motor seizures, will be critical in closing the treatment gap highlighted in our study,” Pellinen said. “Educational initiatives for the public, health care trainees and health care professionals would undoubtedly improve the lives of many people with new-onset focal epilepsy. We are hoping that through our research, we can not only identify problems, but find solutions, and that this will help garner support for educational initiatives.”