Introduction
Several clinicians has reported that for many patients, a diagnosis of epilepsy occurs months to years after an initial seizure. An epilepsy diagnostic delay is not only concerning but comes with significant consequences. This blog will discuss the prevalence, possible reasons for an epilspy diagnostic delay and proposed solutions to minimize delays.
Prevalence of an Epilepsy Diagnostic Delay
Findings from several studies indicate that almost half (40-50%) of patients do not seek medical attention after a first seizure. Specifically, a delay of approximately 9 months (Firkin, 2015) to 16 months (Gasparini et al., 2013) is documented. In a recent review that averaged results from many studies, on average, 38% of patients delayed in seeking medical help with approximately 16% of patients waiting a year or more (Alessi 2021).
Parviainen et al., (2020), in a retrospective study (assessing previously recorded clinical data),found that out of 177 patients prior to diagnosis, 45% had 3-10 seizures and 5% experienced 50-100 seizures. In this analysis, the average time from first seizure to diagnosis was 50 months. The greatest extent of delay occurred in patients 18-30 years of age. The second greatest extent occurred in those 30-50 years of age. It is clear that the delay in epileptic diagnosis is real and prominent.
Explanation for the Epilepsy Diagnosis Delay
Scientist offer several explanations to explain an epilepsy diagnostic delay. In general, a delay has been attributed to:
a) lack of medical care availability,
b) lack of awareness of the seizure and
c) medical attention but lack of a diagnosis (Parvianen et al., 2020).
Lack of Access to Medical Care
Firstly, several studies discount the lack of medical availability studies as a viable explanation. This is because the countries conducting these studies are ones with free medical care for all (Gasparini et al., 2013; Firkin, 2015). However, this factor may still be important in countries with limited access to medical care.
Lack of Awareness to a Seizure
Secondly, lack of awareness of a seizure is a reasonable explanation. Scientists postulate that activation of brain tissue around the seizure lesion impairs consciousness or memory of the seizure. Additionally, brief or what is termed as non disruptive seizures (absence seizures, monoclonic jerks) do not attract attention from those nearby and hence are missed by an observer. Thus, the patient and bystander do not recognize the symptoms of a seizure. However, this is not a full explanation since even those with a convulsive seizure (with temporary loss of consciousness), clearly an obvious event, often delay in seeking medical help (Gasparini et al., 2013).
Medical Attention without a Diagnosis
Thirdly, patients with seizures may seek medical advice but if classically accepted diagnostic criteria are not met, these patients are unlikely to get a diagnosis of epilepsy. A diagnosis of epilepsy depends on a detailed history of seizures by the patient and if possible by an observer (usually a family member or friend). Absent this, the physician relies on the presence of brain lesions detected with an MRI, CAT scan or seizure activity with an EEG. A twenty minute EEG rarely picks up a seizure. The MRI/CAT scans detect precipitants of a seizure such as tumors and stroke but not subtle neurological abnormalities. Not surprisingly, seizures in patients with a tumor or stoke have the least extent of diagnostic delay (Yang et al., 2022).
Lack of diagnostic data promotes uncertainty. Hence, physicians are reluctant to declare a diagnosis of epilepsy. Adding to this is the possibility of a false positive, albeit with a 5% occurrence (Oto et al.,2017). Conditions such as cardiogenic syncope (enlarged heart providing insufficient blood to the brain) and psychogenic non epileptic seizure (caused by psychological stress) which appear as seizures but are not cases of epilepsy, contribute to uncertainly in a diagnosis of actual epilepsy.
Another explanation not offered in scientific journals is the social consequence of an epilepsy diagnosis which revokes the driver’s license for 6 months to several years depending on the state. This brings possible repercussion for both work and every day living.
Thus current explanations for diagnostic delay are a) an inability to recognize the symptoms of a seizure by patient and observer, b) the absence of tangible evidence of a seizure (EEG, MRI, CAT, history), and c) possibly, serious concern for changes in living/working conditions.
Proposed Solutions to Minimize Delay
There are several proposed solutions. One suggestion is to emphasize to physicians that it is better to proceed with an uncertain diagnosis. But, at the same time, acknowledge the need for continual review (Oto et al., 2017) . This is difficult in practice because a false positive would subject the patient to unnecessary medication and state laws prohibiting patients with epilepsy from driving, as noted above.
A second suggestion is to better educate both physicians and the public in general, on the symptomatology of a seizure. If the patient cannot remember the seizure, it is important that an observer provide an accurate observation. Education of the public on early warning signs of a heart attack and some cancers have met with success.
A third suggestion is to invest in improved diagnostics. Results of a recent clinical trial showed the benefit of smart phone videography as elevating the predictive value of an epileptic seizure and distinguishing between epileptic and non epileptic seizures (Tatum et al., 2020). This might become a reasonable point of education. Genetic testing has become of increasing value and has success in the identification of a genetic mutation(s) in approximately 50% of epilepsies (Striano and Minassian, 2020). Additionally, several neuroinflammatory biomarkers such as High-Mobility Group Box 1 (see Blog 19) are highly intertwined with epilepsy and are currently investigated as meaningful adjuncts to diagnosis of epilepsy. Additional work would be appropriate.
Conclusions
Nearly half of all individuals who experience a seizure receive a diagnosis of epilepsy after a considerable delay of months to years. This is distressing to clinicians who understand the need for early disease treatment. Currently, epileptic diagnostic delay is only partially understood. Some explanations are memory of a seizure is near impossible, bystanders do not understand seizure symptoms and physicians are reluctant to give a diagnosis if classical signs e.g. abnormal EEG are lacking. Education of seizure symptoms for physicians and public as well as development of meaningful diagnostic tools are desperately needed.
References (pubmed)
1. Firkin AL, Marco DJT, Saya S, et al. Epilepsia 2015;56:1534–41. 2. Gasparini S, Ferlazzo E, Beghi E, et al. Family history and frontal lobe seizures predict long-term remission in newly diagnosed cryptogenic focal epilepsy. Epilepsy Res 2013;107:101–108. 3. Alessi N, Perucca P, McIntosh AM. Missed, mistaken, stalled: identifying components of delay to diagnosis in epilepsy. Epilepsia 2021;62:1494–504. 4. Parviainen L, Kälviäinen R, Jutila L. Impact of diagnostic delay on seizure outcome in newly diagnosed focal epilepsy. Epilepsia Open. 2020 Dec 8;5(4):605-610. 5. Yang M, Tan KM, Carney, et al. Diagnostic delay in focal epilepsy: Association with brain pathology and age. Seizure. 2022 Mar;96:121-127. 6. Oto MM. The misdiagnosis of epilepsy: appraising risks and managing uncertainty. Seizure. 2017;44:143–6. 7. Tatum WO, Hirsch LJ, Gelfand MA et al. Assessment of the Predictive Value of Outpatient Smartphone Videos for Diagnosis of Epileptic Seizures. JAMA Neurol. 2020 May 1;77(5):593-600. 8. Striano P, Minassian BA. From Genetic Testing to Precision Medicine in Epilepsy Neurotherapeutics. 2020 Apr;17(2):609-615.