Utility of the scalp-recorded ictal EEG in childhood epilepsy
H Yoshinaga1, J Hattori, H Ohta
1Department of Child Neurology, Okayama University Medical School, Shikatacho 2-5-1 Okayama, Japan 7008558. magenta@md.okayama-u.ac.jp
Insights
Scalp-recorded ictal electroencephalograms (EEGs) are highly useful for diagnosing childhood epilepsy, confirming seizure types, and identifying previously unrecognized seizure disorders. These recordings aid significantly in classifying and treating epilepsy, especially complex partial seizures (CPS).
Area of Science:
- Neurology
- Pediatrics
- Clinical Neurophysiology
Background:
- Childhood epilepsy diagnosis can be challenging, often requiring precise seizure type classification for effective management.
- Scalp-recorded electroencephalograms (EEGs) are a cornerstone in epilepsy diagnosis, but the utility of ictal recordings (during a seizure) in children needs further evaluation.
Observation:
- A study analyzed 259 seizures in 183 pediatric patients over six years.
- Ictal EEGs were categorized by diagnostic usefulness: confirming diagnosis (101 seizures), aiding classification (101 seizures), correcting misclassifications (37 seizures), and revealing new seizure types (20 seizures).
- Specifically, 11 nonepileptic seizures were misdiagnosed as epileptic, and complex partial seizures (CPS) were frequently involved in misclassifications.
Findings:
- Ictal EEGs confirmed or aided seizure classification in 202 out of 259 instances.
- The recordings corrected misdiagnoses in 37 cases and identified previously undocumented seizure types in 20 cases, including myoclonic and absence seizures.
- Ictal EEGs proved crucial for diagnosing CPS, particularly in 11 patients with normal interictal EEG findings.
Implications:
- Scalp-recorded ictal EEGs are invaluable for accurate diagnosis and classification of epilepsy in children.
- These recordings assist in uncovering unsuspected seizure types and refining treatment strategies.
- Ictal EEG is particularly beneficial for diagnosing complex partial seizures in pediatric populations.
Purpose:
To evaluate the usefulness of the scalp-recorded ictal EEGs in diagnosing childhood epilepsy.
Methods:
We analyzed the ictal EEGs of 259 seizures in 183 patients who visited the department of child neurology, Okayama University Medical School, during the past 6 years.
Results:
We divided all seizures into the following four categories, according to the diagnostic usefulness of ictal EEGs in determining the seizure type: 1. (a) Ictal EEGs confirmed the diagnosis of the seizure type based on seizure symptoms (101 seizures); (b) Ictal EEGs aided in the classification of the seizure type based on the seizure symptoms (101 seizures); (c) Ictal EEGs corrected errors in the classification (37 seizures); and (d) Ictal EEGs revealed previously unreported/undocumented seizure type (20 seizures). 2. Of the 37 misdiagnosed seizures (group C), 11 were nonepileptic seizures misdiagnosed as epileptic seizures, eight were complex partial seizures (CPS) misdiagnosed as the other seizure types, and 10 were other seizure types misdiagnosed as CPSs. 3. Of the 20 previously unreported/undocumented seizures (group D), nine were myoclonic seizures, five were absence seizures, five were CPS, and one was tonic spasms. 4. Seventy-two patients had CPS. Among them, 11 patients showed no epileptic spikes in their interictal EEG recordings. Therefore, ictal recordings confirmed the diagnosis of epilepsy.
Conclusions:
Ictal EEG recording is a very useful diagnostic tool not only for determining seizure types, but also for uncovering the existence of the unsuspected seizure types. It supplies the physician with useful information for the classification and the treatment of epilepsy. In particular, ictal EEGs are useful in diagnosing patients with CPS.
