From the Guidelines
Epilepsy is diagnosed based on the International League Against Epilepsy (ILAE) criteria, which defines epilepsy as having at least two unprovoked seizures occurring more than 24 hours apart, one unprovoked seizure with a probability of further seizures similar to the general recurrence risk after two unprovoked seizures, or a diagnosis of an epilepsy syndrome. The diagnostic process for epilepsy involves a comprehensive evaluation, including a detailed medical history and neurological examination, as well as diagnostic tests such as electroencephalogram (EEG) and neuroimaging studies like MRI, as noted in the context of seizure diagnosis and management 1. Key points to consider in the diagnosis of epilepsy include:
- The ILAE classification of seizures, which was last revised in 2017, categorizes seizures as focal onset, generalized onset, or unknown onset 1
- Focal seizures can be further characterized by having motor onset or nonmotor onset symptoms and can also be characterized by being aware or having impaired awareness 1
- Generalized seizures are further subdivided into tonic-clonic, other motor, or nonmotor (absence) 1
- Certain types of seizure disorders are likely to be associated with structural brain lesions, including tumors, infection, infarction, traumatic brain injury (TBI), vascular malformations, developmental abnormalities, and seizure-associated brain pathology 1 Given the complexity of epilepsy diagnosis and the importance of accurate diagnosis for guiding treatment, diagnosis should be made by a neurologist, ideally one specializing in epilepsy, particularly for complex cases or when seizures prove difficult to control with initial medication, as this ensures the best possible outcome in terms of morbidity, mortality, and quality of life.
From the Research
Diagnostic Criteria for Epilepsy
The diagnostic criteria for epilepsy involve a multifaceted approach, including a careful history, diagnostic evaluation, and prompt referral to an epilepsy specialist 2. The evaluation of a patient presenting with a seizure involves excluding an underlying neurologic or medical condition, classifying the seizure type, and determining if the patient has epilepsy 3.
Key Points in Diagnosis
- A careful history is essential to confirm the diagnosis and to identify previously unrecognized seizures that would change the diagnosis to one of epilepsy 4.
- Diagnostic evaluation includes EEG and brain imaging 2.
- Screening for mental health conditions and neurocognitive testing should also be considered 2.
- The physical examination plays a crucial role in the initial clinical evaluation, although to a lesser extent than the clinical history 4.
Classification of Seizure Type
- Classification of seizure type is critical in determining the diagnosis and treatment of epilepsy 3.
- Seizures can be classified as focal onset seizures or generalized onset seizures 5.
- Accurate classification of seizure type is essential for selecting the appropriate treatment and for prognostication 3.
Importance of Accurate Diagnosis
- Accurate diagnosis of epilepsy is crucial for selecting the appropriate treatment and for prognostication 3.
- Proper treatment requires accurate diagnosis of the epilepsy type and syndrome, and the use of a medication that is effective and without adverse effects 3.
- Most patients can achieve complete seizure control with medication, but if medication is unsuccessful, surgical treatment can be an option 3.