Managing Pre-Ictal Auras in Epilepsy Patients
When an epilepsy patient experiences a pre-ictal aura, they should immediately use a handheld magnet to activate additional vagus nerve stimulation (if they have a VNS device) or move to a safe position to prevent injury during the impending seizure. 1
Understanding Epileptic Auras
Auras are the initial manifestations of a seizure that occur before consciousness is lost and for which memory is retained afterward. They represent the conscious phase of partial seizures and can provide a crucial warning window for patients.
- Prevalence: Approximately 64% of patients with generalized epilepsy experience at least one form of aura 1
- Types of auras:
- Viscerosensorial and experiential auras (common in temporal lobe epilepsy) 2
- Fear (common with mesial temporal origin) 2
- Special sensory auras (visual, gustatory, vertiginous - more common in extratemporal epilepsy) 2
- Somatosensory auras (tingling, numbness, electrical sensations) 2
- Rising sensation from abdomen (epigastric aura) 1
- Unusual unpleasant smell 1
Immediate Actions During Pre-Ictal Aura
For patients with VNS devices:
For all epilepsy patients:
- Move to a safe position (lying down on a soft surface away from hazards)
- Alert caregivers if present
- Remove glasses, loosen tight clothing
- Turn to side position if possible to prevent aspiration
Timing Is Critical
The effectiveness of intervention during an aura is highly time-dependent:
- When VNS is delivered within 3 seconds of seizure onset, seizure duration can be reduced from approximately 30 seconds to 5 seconds 1
- If intervention is delayed more than 4 seconds after seizure onset, there may be no observed change in seizure duration 1
Factors Affecting Patient Response During Auras
Research shows that a patient's ability to react during the aura phase is associated with:
- Younger age
- More localized seizure origin
- Better post-operative outcomes in those who undergo epilepsy surgery 3
Common Pitfalls and Caveats
Misidentification of auras: Some patients may confuse other sensations with epileptic auras. True epileptic auras are stereotyped (consistent from episode to episode) 2
Delayed recognition: Patients should be educated to recognize their specific aura pattern and act immediately, as the window for intervention is extremely brief 1
Overreliance on auras: Not all seizures are preceded by auras, and some patients may never experience them 1
Retrograde amnesia: Seizures can cause retrograde amnesia, which might make patients forget they had an aura 4
Confusion with other conditions: Auras must be differentiated from vestibular dysfunction, migraine, stroke, autonomic disturbances, drug effects, and psychiatric disorders 2
Optimizing VNS Parameters for Patients with Auras
For patients with implanted VNS devices:
- Consider higher duty cycles with reduced OFF time (≤1.1 minutes instead of standard 5 minutes) 5
- Optimal frequency range is 20-30 Hz, though higher frequencies (130-180 Hz) may provide greater seizure attenuation 1, 5
- Closed-loop VNS systems that detect heart rate increases (tachycardia) associated with seizure onset can automatically deliver stimulation 1
Long-term Management
- Document all auras and subsequent seizures to identify patterns
- Review and potentially adjust anti-seizure medications
- Consider VNS implantation for patients with persistent seizures despite medication 5
- Educate family members/caregivers about appropriate responses when the patient reports an aura
By recognizing and acting promptly during the pre-ictal aura phase, patients can potentially abort seizures or minimize their severity, significantly improving quality of life and reducing seizure-related injuries.