The question of whether migraines can trigger non-epileptic seizures is complex, involving two distinct yet frequently co-occurring neurological conditions. While a migraine headache itself does not cause an epileptic seizure, a substantial clinical overlap often requires careful medical investigation. Chronic headache disorders are associated with seizure-like events that are neurological or psychological in origin. This relationship highlights a shared vulnerability within the brain’s regulatory systems, necessitating a clear distinction between complicated migraine symptoms and a true seizure event.
Understanding Non-Epileptic Seizures
A Non-Epileptic Seizure (NES) describes an event that physically resembles an epileptic seizure (e.g., convulsions or loss of awareness) but lacks the underlying abnormal electrical activity in the brain. These events are divided into physiological causes (like fainting) and psychogenic causes, referred to as Psychogenic Non-Epileptic Seizures (PNES). PNES is a manifestation of Functional Neurological Disorder (FND), resulting from a disturbance in the nervous system’s function.
The fundamental difference lies in the brain’s electrophysiology. Epileptic seizures are caused by sudden, uncontrolled electrical discharges among groups of neurons. In contrast, during PNES, the brain’s electrical activity remains normal, even while the person exhibits dramatic seizure-like movements. Approximately 50% to 60% of patients diagnosed with PNES also report having migraine, suggesting a significant comorbidity.
Migraine Phenomena That Mimic Seizures
The complex neurological processes involved in a migraine attack can produce symptoms that closely mirror those of a focal seizure. The most common example is Migraine with Aura, a temporary neurological disturbance that precedes or accompanies the headache phase. Auras typically involve visual phenomena (e.g., zigzag lines or blind spots) but can also include sensory or motor symptoms easily confused with a seizure.
A specific type called Hemiplegic Migraine involves temporary weakness or paralysis on one side of the body. This motor aura can last for hours or days, and the unilateral weakness can be mistaken for the post-ictal state (Todd’s paralysis) that follows a true epileptic seizure. Some migraine auras also involve non-visual symptoms, such as speech or language difficulties, which are characteristic of focal seizures. These acute neurological symptoms are direct manifestations of the headache disorder, involving transient changes in cortical activity like Cortical Spreading Depression (CSD).
The Functional Link Between Migraines and Seizure Activity
The most frequent connection between migraines and seizure activity is the development of Functional Neurological Disorder (FND), specifically manifesting as PNES. Chronic migraine acts as a significant, long-term stressor on the central nervous system. This chronic stress can lead to central sensitization, which alters brain pathways and increases vulnerability to functional symptoms.
Studies indicate that individuals with migraine and PNES often suffer from more frequent and longer-duration migraine attacks compared to patients without PNES. This suggests a bidirectional relationship where PNES exacerbates the severity and frequency of the underlying migraine disorder. The abnormal neurocircuitry associated with PNES is thought to contribute to this increased central sensitization.
The seizure-like activity of PNES is a physical manifestation of the brain’s response to distress, altered emotional processing, or chronic pain. PNES is a neurological disorder often associated with psychiatric comorbidities like depression and anxiety. Mental stress is a significantly more predominant trigger for headache in patients with co-occurring migraine and PNES. The chronic nature of severe migraine can create the environment that predisposes a person to developing FND, with PNES as the resulting physical symptom.
Diagnostic Approach: Differentiating Seizure Types
The definitive diagnostic tool used to distinguish between epileptic seizures, migraine mimics, and non-epileptic seizures is Video-Electroencephalogram (VEEG) monitoring. This procedure is considered the gold standard and involves continuous monitoring of the patient’s behavior via video camera while simultaneously recording the brain’s electrical activity using an EEG. The goal is to capture one of the patient’s typical events while monitoring is active.
If a seizure-like event is captured on video but the corresponding EEG recording shows no abnormal electrical discharge, the event is definitively classified as a Non-Epileptic Seizure. Conversely, a true epileptic seizure will always correlate with a distinct pattern of hypersynchronous electrical activity on the EEG. Clinical clues observed during the event can also help with differentiation, such as preserved awareness during bilateral motor activity, which suggests PNES. Patient history and detailed witness accounts are also crucial for accurate diagnosis.