Name: Azetukalner (XEN1101) in Focal onset seizures: Diagnosis
Published: 2026-09-21T21:41:53-04:00

Product information and disease description Place of product in therapy Disease description

Diagnosis

7 evidence topics · 5 sources

Role and yield of routine electroencephalography

“The electroencephalogram (EEG) is the most direct measure of electrical brain activity and the most specific test for the evaluation of epilepsy” (opens the source at this quote in a new tab)
“Patients most commonly receive a 20 min routine EEG recorded from 19 scalp electrodes placed according to the 10–20 electrode placement.” (opens the source at this quote in a new tab)
“Studies show that the initial routine EEG fails to record IEDs in approximately 47–50% of epileptic patients.” (opens the source at this quote in a new tab)
“To improve the yield of EEG, subsequent EEG recording should include sleep deprivation, sleep recording, prolonged hyperventilation, optimized light stimulation, addition of an inferior temporal electrode chain, extended EEG duration, and continuous video-EEG monitoring, all measures known to activate IEDs.” (opens the source at this quote in a new tab)

Role of magnetic resonance imaging

“Similarly, magnetic resonance imaging (MRI) has become the gold standard imaging technique for identifying epileptogenic structural brain abnormalities.” (opens the source at this quote in a new tab)

Classification of focal seizures by state of consciousness

“Focal seizures and those of unknown origin are further classified by the patient’s state of consciousness (impaired or preserved) during the seizure, defined operationally through clinical assessment of awareness and responsiveness.” (opens the source at this quote in a new tab)
“If the state of consciousness is undetermined, the seizure is classified under the parent term, that is, the main seizure class (focal seizure or seizure of unknown origin).” (opens the source at this quote in a new tab)
“Consciousness is used as a classifier instead of awareness, with consciousness operationally defined by awareness and responsiveness.” (opens the source at this quote in a new tab)

Consistency of ictal onset in focal seizures

“For each seizure type, ictal onset is consistent from one seizure to another, with preferential propagation patterns that may involve the contralateral hemisphere.” (opens the source at this quote in a new tab)

Review of the diagnosis when seizures continue

“Review the diagnosis of epilepsy if seizures continue despite an optimal dose of a first-line antiseizure medication.” (opens the source at this quote in a new tab)

Assessments that trigger referral to a tertiary epilepsy service

“further assessment and treatment approaches are indicated, such as: video electroencephalogram (EEG) telemetry, neuropsychology or neuropsychiatry, specialised neuroimaging, specialised treatments (for example, medication that can only be prescribed by a tertiary epilepsy service or a ketogenic diet), epilepsy surgery or vagus nerve stimulation” (opens the source at this quote in a new tab)

Investigations used to classify seizure type and epilepsy type

“Classification of seizure type and epilepsy type both take into account the results of investigations such as electroencephalography (EEG) and neuroimaging studies together with other studies exploring the underlying etiology of the epilepsy.” (opens the source at this quote in a new tab)