Seizures do not directly cause tics in the way that, say, a brain injury causes paralysis, but the relationship between the two is more tangled than most people realize. Tics and certain seizure types can look strikingly similar on the surface, epilepsy and tic disorders share a statistically unusual degree of overlap, and some anti-seizure medications can actually trigger tics as a side effect. Sorting out which movements are tics and which are seizures matters enormously for treatment, because the drugs used for one condition can worsen the other.
What Tics and Seizures Actually Are
Tics are sudden, repetitive movements or sounds that a person feels driven to perform. They range from simple (eye blinking, shoulder shrugging, throat clearing) to complex (touching objects in a specific pattern, repeating phrases). A hallmark of tics is that most people who have them sense a building urge beforehand, and many can briefly suppress the movement, even if it feels uncomfortable to do so. In a study of children and adolescents with Tourette syndrome, about 37 percent reported these premonitory sensations, and 64 percent were able to suppress their tics at least temporarily.1PubMed. Premonitory sensory phenomena and suppressibility of tics in Tourette syndrome: developmental aspects in children and adolescents That voluntary, if effortful, ability to hold back the movement is one of the clearest differences between a tic and a seizure.
Seizures, by contrast, are bursts of abnormal electrical activity in the brain. The movements they produce are involuntary in a deeper sense: the person cannot suppress them, and in many seizure types the person is not fully conscious during the event. Seizures also come in many varieties, from the dramatic convulsions most people picture to subtle events like brief staring spells, isolated jerks of a limb, or odd repetitive behaviors called automatisms. It is the subtler seizure types that get confused with tics.
When Seizures Get Misdiagnosed as Tics
The most common diagnostic mix-up runs in one direction: certain seizure types look so much like tics that clinicians treat patients for a tic disorder for years before discovering the real cause. Myoclonic epilepsy is a particularly well-known example. Myoclonic seizures produce quick, jerky muscle contractions, often in the shoulders or arms, that can look almost identical to motor tics. One published case described a patient who had been misdiagnosed with a tic disorder and treated for years before video-EEG monitoring finally revealed myoclonic epilepsy as the true diagnosis.2PubMed Central. Photosensitive Epilepsy Syndromes Mimicking Motor Tics The key clue that clinicians had missed was timing: the jerky movements were concentrated in the morning, which is characteristic of juvenile myoclonic epilepsy but unusual for a tic disorder.
Another seizure type that masquerades as tics involves photosensitive epilepsy, particularly a condition called eyelid myoclonia with absences (also known as Jeavons syndrome). This syndrome produces prominent eyelid blinking and upward eye deviation, often triggered by closing the eyes or exposure to bright light. Those rapid eye blinks look nearly identical to the eye-blinking tics that are among the most common presentations in children with Tourette syndrome.2PubMed Central. Photosensitive Epilepsy Syndromes Mimicking Motor Tics A child who blinks excessively in bright environments might be seen by a pediatrician or psychiatrist before anyone considers epilepsy.
Frontal lobe seizures add another layer of confusion. These can produce bizarre, vigorous movements involving the arms, legs, or torso that happen in clusters, sometimes at night. Unlike the stereotypical convulsion, frontal lobe seizures can involve asymmetric postures, cycling leg movements, or thrashing that looks purposeful. Because the person may remain partially aware during these events, clinicians can mistake them for complex motor tics or even a behavioral issue.
Can a Seizure Disorder Actually Produce Tics?
In a stricter sense, some patients with neurological conditions including seizure disorders do develop genuine tics, not just seizure movements that resemble tics. These are called secondary tics, meaning the tics arise from an identifiable brain condition rather than appearing on their own. In a study of 155 patients evaluated for secondary tics and tourettism, about 1.9 percent had tics associated with seizures specifically.3PubMed. Secondary tics and tourettism That is a small number, but it confirms that seizure-related brain changes can, in some cases, give rise to actual tic movements rather than just mimic them.
The mechanism is not fully understood, but the working theory centers on the brain circuits both conditions share. Tics and seizures both involve disrupted signaling in networks that connect the cortex (the brain’s outer layer) with deeper structures like the basal ganglia and thalamus. When seizure activity repeatedly fires through these circuits, it may alter the way they regulate movement, potentially setting the stage for tic-like behaviors to emerge. This shared circuitry also helps explain why the two conditions co-occur more often than chance would predict.
The Surprising Overlap Between Tourette Syndrome and Epilepsy
Children with Tourette syndrome develop epilepsy at dramatically higher rates than the general population. A large population-based study found that children with Tourette syndrome had roughly an 18-fold increased risk of epilepsy compared to matched controls, and that elevated risk persisted even after adjusting for other conditions commonly seen alongside Tourette syndrome, such as ADHD and OCD.4PubMed. Increased risk of epilepsy in children with Tourette syndrome: A population-based case-control study An 18-fold increase is enormous in epidemiological terms. It is not that most children with Tourette syndrome will develop epilepsy, since epilepsy is uncommon to begin with, but the relative risk is far higher than you would expect if the two conditions were unrelated.
This overlap creates real diagnostic challenges. If a child already has a tic disorder and then starts having new or different movements, the natural assumption is that the tics are worsening. But some of those new movements could be seizures. Clinicians who treat tic disorders are generally aware of this trap, but parents and school staff may not be. Any change in the pattern, frequency, or character of movements in a child with known tics, especially if the new movements are not suppressible or the child seems confused afterward, deserves a closer look.
Practical Ways to Tell Them Apart
Several features help distinguish tics from seizures, though no single sign is foolproof on its own. Taken together, they paint a fairly reliable picture.
- Premonitory urge: Most people with tics feel a rising sensation, itch, or tension before the movement happens. Seizures almost never produce this kind of urge. Some seizures do have auras, but those tend to feel like déjà vu, a rising stomach sensation, or a strange taste, not the localized muscular tension that precedes a tic.
- Suppressibility: Tics can usually be held back for seconds to minutes, even though doing so feels uncomfortable. Seizure movements cannot be voluntarily suppressed.
- Awareness during the event: People experiencing tics are fully aware of their surroundings. Many seizure types alter awareness, even briefly. If a person seems “checked out” or confused during the movement, that points toward a seizure.
- Timing patterns: Tics tend to wax and wane over weeks or months and are often worse during stress or excitement. Myoclonic seizures, by contrast, often cluster in the morning shortly after waking. Frontal lobe seizures frequently occur during sleep.
- Post-event recovery: After a tic, a person feels immediately normal. After a seizure, there is often a recovery period (the postictal phase) marked by fatigue, confusion, or headache. In one study comparing people with epileptic seizures to those with non-epileptic events, more than half of epilepsy patients reported postictal fatigue and all had at least one postictal symptom.5PubMed. Postictal symptoms help distinguish patients with epileptic seizures from those with non-epileptic seizures
None of these features works perfectly in isolation. A child too young to describe a premonitory urge, for instance, cannot help you with that criterion. And some seizures, particularly very brief myoclonic jerks, produce no obvious postictal phase. The combination of several features is what makes the distinction reliable.
What Happens During Sleep
Sleep behavior is another area where the two conditions diverge in useful ways. Tics were long assumed to stop during sleep, but polysomnography studies have shown that they actually persist during both REM and non-REM sleep stages.6PubMed Central. Tourette disorder and sleep However, tics during sleep are generally less frequent and less complex than during waking hours. They do not usually wake the person or produce dramatic body movements.
Certain seizure types behave very differently at night. Frontal lobe seizures can produce vigorous, sometimes violent movements during sleep, occasionally causing the person to sit up, thrash, or even fall out of bed. Nocturnal seizures may also cluster at specific sleep stages, particularly during transitions between non-REM stages. If a bed partner or parent observes dramatic nocturnal movements that seem out of proportion to anything the person does while awake, that asymmetry between daytime and nighttime movements is a red flag for a seizure disorder rather than tics alone.
The Role of Video-EEG Monitoring
When the clinical picture is ambiguous, video-EEG monitoring is the gold standard for sorting things out. The patient wears electrodes that continuously record brain electrical activity while a camera simultaneously captures their movements. If a suspicious movement occurs during recording, clinicians can check whether it coincided with abnormal electrical discharges. In a pediatric study using long-term video-EEG monitoring to clarify uncertain diagnoses, tic disorder was identified in about 6.5 percent of children who had been referred for possible epilepsy.7PubMed Central. The Importance of Long-Term Video Electroencephalography Monitoring in the Differential Diagnosis of Epilepsy in Children In other words, a meaningful fraction of children suspected of having seizures turned out to have tics instead.
The reverse also happens. A child with an existing tic diagnosis who undergoes monitoring for worsening symptoms may be found to have seizure activity mixed in with the tics. Video-EEG is particularly valuable for catching myoclonic jerks and absence seizures, which can be so brief and subtle that they are invisible to clinical observation alone. The practical barrier is availability: extended video-EEG monitoring typically requires a hospital stay and is not always easy to arrange, so it tends to be reserved for cases where the stakes of a wrong diagnosis are high.
When Anti-Seizure Medications Cause Tics
One of the more frustrating complications in this space is that some of the very drugs used to treat epilepsy can trigger tics as a side effect. A review of the evidence identified several anti-epileptic drugs linked to tic development, including carbamazepine, lamotrigine, levetiracetam, phenytoin, and phenobarbital, among others.8PubMed. Tics induced by antiepileptic drugs: a pragmatic review The tics these drugs produced tended to involve the face and trunk, and most resolved when the medication was either stopped or reduced in dose. People with a history of reduced impulse control appeared to be at higher risk for developing drug-induced tics than those with a prior tic history, which is somewhat counterintuitive.
Lamotrigine, widely used for both epilepsy and bipolar disorder, has been singled out in several case reports. In one case, a 45-year-old woman developed tics affecting her entire left side after a modest dose increase from 200 mg to 225 mg daily.9PubMed. Lamotrigine Induced Whole Body Tics: A Case Report and Literature Review Earlier reports had noted lamotrigine-induced tics mainly in the head, neck, and shoulders, making this widespread presentation unusual. In a separate series of five patients, discontinuing the offending anticonvulsant led to a decrease in tic frequency across all cases.10PubMed. Anticonvulsant medications: an iatrogenic cause of tic disorders
This creates a clinical Catch-22 for patients who have both epilepsy and a tic disorder. The anti-seizure medication they need could aggravate their tics. Neurologists managing this combination often have to trial multiple drugs, looking for one that controls seizures without making tics worse. It requires careful monitoring and honest communication between the patient and the care team about which symptoms are improving and which are not.
Anti-Seizure Drugs That May Help Tics
The relationship between epilepsy drugs and tics is not entirely adversarial. A handful of anti-seizure medications have been explored as treatments for tic disorders themselves. Levetiracetam was studied in 60 children and adolescents with Tourette syndrome, and all showed improvement on multiple rating scales, with 43 also showing better behavior and school performance.11PubMed. Use of levetiracetam to treat tics in children and adolescents with Tourette syndrome That said, the overall evidence for levetiracetam as a tic treatment is mixed, with other trials showing less consistent results.12PubMed Central. Levetiracetam as an alternative therapy for Tourette syndrome
Topiramate has shown somewhat more consistent promise. In a study of 41 patients with Tourette syndrome treated with topiramate, about three-quarters had moderate to marked improvement in their tics.13PubMed Central. Topiramate in Treatment of Tourette Syndrome The trade-offs included cognitive and language problems in roughly a quarter of patients and mood changes in about 10 percent. Neither levetiracetam nor topiramate is a first-line tic treatment, but for patients who happen to have both epilepsy and a tic disorder, choosing an anti-seizure drug that might also help tics is an appealing strategy when it works.
Reflex Seizures and Sensory Triggers
Tics are often triggered by stress, excitement, fatigue, or specific environmental contexts. Seizures, by contrast, are usually thought of as unprovoked. But a category called reflex seizures blurs this line. Reflex seizures are triggered by specific sensory stimuli, such as flashing lights, particular sounds, or even touching a particular area of the body. In a documented form called rub epilepsy, prolonged rubbing or touching of a specific skin area triggers a seizure that begins with a sensory spread (a jacksonian march) near the touched zone and progresses to tonic muscle contractions on one side of the body.14PubMed Central. Rub epilepsy: a somatosensory evoked reflex epilepsy induced by prolonged cutaneous stimulation
Why does this matter for someone trying to distinguish tics from seizures? Because if a person’s repetitive movements are reliably triggered by a sensory stimulus, both conditions are in the differential. Tics can be triggered by sensory input too, such as the urge to blink that worsens under fluorescent lighting. The distinguishing features remain the same ones described earlier: whether the person can suppress the movement, whether they stay fully conscious, and whether they feel normal immediately afterward. But the presence of a consistent sensory trigger should prompt clinicians to consider reflex epilepsy, especially if the movements are stereotyped (identical every time) and the person cannot voluntarily stop them once they start.
Complex Motor Behaviors in Temporal Lobe Epilepsy
Temporal lobe epilepsy is the most common form of focal epilepsy in adults, and it usually produces automatisms, such as lip smacking, hand fumbling, or repetitive swallowing, that are not easily confused with tics. But a subset of temporal lobe seizures produce more elaborate motor behaviors. In a study of 502 patients with temporal lobe epilepsy, 12 were found to have complex motor behaviors that differed from typical automatisms, involving large movements of the arms or trunk rather than the small, stereotyped gestures usually associated with this seizure type.15PubMed. Complex motor behaviors in temporal lobe epilepsy These movements were often preceded by an aura and followed by more typical automatisms, which suggests they represent an early phase of seizure spread rather than a separate phenomenon. Seven of the 12 patients became seizure-free after surgery, confirming the epileptic origin of the movements.
For the general reader, the takeaway is that seizures can produce a wider variety of movements than most people expect. The classic image of a person shaking on the ground represents only a fraction of what seizures look like. When unusual repetitive movements do not fit neatly into the tic category, and especially when they are accompanied by altered awareness or followed by confusion and fatigue, epilepsy should be on the list of possibilities even if the movements themselves do not look like a “typical” seizure.