Symptoms, Seizures, and EEG Diagnosis of EMA

When your child is diagnosed with Epilepsy with Myoclonic Absences (EMA), understanding exactly what is happening during a seizure—both physically and electrically—is the first step toward managing the condition. While these seizures can look intense, they follow a very specific pattern that doctors use to differentiate EMA from other, more common types of epilepsy.

The Physical Appearance of an EMA Seizure

A myoclonic absence seizure is defined by two things happening at once: a loss of awareness (the absence) and rhythmic, repetitive muscle jerking (the myoclonus) ^[1].

During a typical seizure, you might notice:

• The “Spaced Out” Look: Your child will stop what they are doing and become unresponsive. This is the absence component ^[2].
• Rhythmic Jerking: You will see rhythmic, clonic-like jerks, most commonly in the arms and shoulders ^[1]. These jerks typically happen about three times per second ^[3].
• Arm Positioning: A unique feature of EMA is tonic abduction—where the arms are not just jerking, but are also being lifted upward and away from the sides of the body ^[4].
• Head and Face Movements: The head may nod rhythmically, and you may see jerking of the chin or the corners of the mouth ^[1].
• Gestural Automatisms: Sometimes, children may perform “fidgety” or complex movements, such as picking at their clothes or making purposeful-looking gestures ^[4]. These are called automatisms and can sometimes make the seizure look like a “focal” seizure (one that starts in just one region), even though EMA involves bilateral brain networks ^[5].

The “Gold Standard”: Video-EEG Diagnosis

To confirm EMA, doctors use prolonged video-EEG when the diagnosis is uncertain. This records your child’s physical movements and brain waves simultaneously. This allows doctors to see if the physical jerks correspond to the electrical spikes in the brain ^[6].

On the EEG, doctors look for:

• Generalized Spike-and-Wave: This is a characteristic electrical pattern that appears across widespread networks on both sides of the brain simultaneously, often around 3-Hz ^[3].
• The Clinical Correlation: In EMA, muscle jerks are heavily correlated to spikes on the EEG, though it is not always a perfect one-to-one lock-step ^[3].
• Duration: These seizures typically last between 10 and 60 seconds ^[4].

In some cases, specialists add EMG (electromyography) sensors to the skin. These sensors measure muscle activity and help the doctor distinguish between different types of jerks, such as positive myoclonus (an active muscle contraction) and negative myoclonus (a brief loss of muscle tone) ^[7].

How EMA Differs from Other Seizures

Because EMA shares features with other conditions, it is often misdiagnosed. The table below highlights the key differences:

Other Seizure Types in EMA

While myoclonic absences are the hallmark of this syndrome, children with EMA may experience other types of seizures as well.

• Generalized Tonic-Clonic Seizures (GTCs): These are convulsive “grand mal” seizures involving full-body stiffening and jerking. Small observational studies suggest they occur in roughly 42% to 75% of children in these cohorts over time ^[10][3].
• Atonic Seizures: These involve a sudden loss of muscle tone, which can cause a “head drop” or a sudden fall ^[11].
• Status Epilepticus: Occasionally, a child may experience a very long seizure or a series of seizures without fully waking up in between, which requires immediate medical attention and rescue medication as prescribed by your doctor ^[11].

Basic Seizure First Aid

No matter what type of seizure your child is having, standard first aid applies:

• Time the event: Note when the seizure starts and stops.
• Protect from injury: Move hard objects away. If they fall, cushion their head.
• Do NOT restrain: Let the seizure run its course.
• Nothing in the mouth: Never put fingers or objects into their mouth.
• Recovery Position: If they have a convulsive (tonic-clonic) seizure, roll them gently onto their side as soon as it is safe to do so to keep the airway clear.