Differentiating between CAE and JAE

Age at onset of CAE is considered to be 2 to 13 years of age and for Juvenile Absence Epilepsy (JAE) to be 8 to 20 years of age; there is five years of overlap^[1].
Patients with JAE more often have GTCS and more frequently experience seizure-related injuries compared with patients with CAE
Valproate can be considered as the drug of choice in men and lamotrigine as the first drug of choice in women with JAE.
CAE has a good prognosis (most patients will become seizure-free off ASMs^[2], whereas in JAE many patients have poor seizure control and the syndrome may last a long time^[3].

Feature	CAE	JAE
Age at onset
Usual	4–10 years	9-13 yrs
Range	2–13; caution if diagnosing at <4yrs of age	8–20 years; exceptional cases may present in adulthood
Development	Typically normal, but may have learning difficulties or ADHD	Typically normal, but may have learning difficulties or ADHD
Absences
Frequency	At least daily to multiple per day but may be underrecognized by family	less than daily
Duration	Typical duration = 3–20 s	Typical duration = 5–30 s
Impaired awareness	Severe loss of awareness	Less complete impairment of awareness
Other seizure types
Febrile	Occasional	Occasional
Generalized tonic-clonic seizures	Rarely precede or occur during period of frequent absences but may occur later with evolution to other IGE syndrome	May precede and commonly occur during the period of frequent absences
Myoclonic	Prominent myoclonus exclusionary	Prominent myoclonus exclusionary
EEG background	OIRDA in 21%	Normal
Interictal epileptiform discharge
Awake	2.5–4-Hz generalized spike-wave	3–5.5-Hz generalized spike-wave
Asleep	Polyspike and wave may be seen in drowsiness and sleep only
Irregular generalized spike-wave	Uncommon	More common than CAE
Photoparoxysmal response	Rare IPS triggers generalized spike-wave in 15%–21% but does not induce seizures	Rare IPS triggers generalized spike-wave in 25% but does not induce seizures
Hyperventilation induction	87%	87%
ICTAL EEG	Regular 3-Hz (range = 2.5–4 Hz) generalized spikewave; 21% may have absences starting at 2.5-Hz spike-wave, and 43% may have absences starting at 4 Hz; if no generalized spike-wave is seen with hyperventilation for 3 min in an untreated patient, CAE can be excluded Disorganized dischargesa less frequent	Regular 3–5.5-Hz generalized spike-wave If no generalized spike-wave is seen with hyperventilation for 3 min in an untreated patient, JAE can be excluded Disorganized dischargesa 8 times more frequent than CAE
Abbreviations: ADHD, attention-deficit/hyperactivity disorder; CAE, childhood absence epilepsy; EEG, electroencephalogram; IGE, idiopathic generalized epilepsy; IPS, intermittent photic stimulation; JAE, juvenile absence epilepsy; OIRDA, occipital intermittent rhythmic delta activity. a Disorganized discharges are defined as either brief (less than 1 sec and and transient interruptions in ictal rhythm or waveforms of different frequency or morphology during the ictal rhythm.

Tab. 1: CAE and JAE. Updated diagnostic criteria for IGE syndromes determined by the expert consensus opinion of the ILAE's Task Force on Nosology and Definitions (2017-2021) and international external experts outside our Task Force

1. ^a Hirsch E, French J, Scheffer IE, Bogacz A, Alsaadi T, Sperling MR, Abdulla F, Zuberi SM, Trinka E, Specchio N, Somerville E, Samia P, Riney K, Nabbout R, Jain S, Wilmshurst JM, Auvin S, Wiebe S, Perucca E, Moshé SL, Tinuper P, Wirrell EC. ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions. Epilepsia. 2022 Jun;63(6):1475-1499. doi: 10.1111/epi.17236. Epub 2022 May 3.
[PMID: 35503716] [DOI: 10.1111/epi.17236]

2. ^a Morse E, Giblin K, Chung MH, Dohle C, Berg AT, Blumenfeld H. Historical trend toward improved long-term outcome in childhood absence epilepsy. Epilepsy Res. 2019 May;152:7-10. doi: 10.1016/j.eplepsyres.2019.02.013. Epub 2019 Feb 25.
[PMID: 30856420] [PMCID: 6573015] [DOI: 10.1016/j.eplepsyres.2019.02.013]

3. ^a Danhofer P, Brázdil M, Ošlejšková H, Kuba R. Long-term seizure outcome in patients with juvenile absence epilepsy; a retrospective study in a tertiary referral center. Seizure. 2014 Jun;23(6):443-7. doi: 10.1016/j.seizure.2014.03.002. Epub 2014 Mar 12.
[PMID: 24684814] [DOI: 10.1016/j.seizure.2014.03.002]