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FACT SHEET: Epilepsy (also known as “seizure disorder”) 

Date of Publication: August 7, 2014

Note: Deep brain stimulation (DBS) is addressed in more detail in a dedicated CDHO fact sheet.

Is the initiation of non-invasive dental hygiene procedures* contra-indicated?

  • No, unless:
    • there is the potential for electrical energy transmission or electromagnetic interference (EMI) from dental/dental hygiene equipment that could affect operation or safety of an implanted deep brain stimulation or vagus nerve stimulation (VNS) device. (This would be unusual in the non-invasive procedure setting.)

Is medical consult advised?  

  • No (assuming patient/client is already under medical care for epilepsy, which is well controlled), unless
    • unaddressed complications of, or technical complications with, DBS or VNS therapy are suspected.

Is the initiation of invasive dental hygiene procedures contra-indicated?**

  • No, unless:
    • there is the potential for electrical energy transmission or electromagnetic interference (EMI) from dental/dental hygiene equipment that could affect operation or safety of an implanted DBS or VNS system. Certain activities and equipment are to be avoided; for DBS, refer to deep brain stimulation fact sheet for details.

Is medical consult advised? 

  • See above. Also, medical consult is warranted if there is medication non-compliance.

Is medical clearance required? 

  • Possibly. For example, if: 
    • there is significant risk of seizure. Patient/client should be seizure-free for several months to be considered controlled.
    • the patient/client has an implanted deep brain stimulation or vagus nerve stimulation device, for which there is the potential for equipment-related electrical energy transmission or electromagnetic interference that could affect operation or safety of the DBS or VNS system.

Is antibiotic prophylaxis required?  

  • No.1

Is postponing treatment advised?

  • No (assuming patient/client is already under medical care for epilepsy, which is well controlled and for which there are no anticipated exacerbating factors in the office setting, and assuming there is no pending medical clearance for equipment safety).

Oral management implications

  • Important considerations in the management of epileptic patients/clients are prevention of seizures in the dental chair and preparation for managing seizures if they occur. When a patient/client responds positively to questions about seizures/epilepsy during health history taking, further information should be obtained. Based on the patient/client’s responses, the dental hygienist may choose to postpone treatment to avoid triggering a seizure in the dental chair. 
  • The routine management of epilepsy in the dental/dental hygiene setting involves clarification of the diagnosis and type of epileptic seizures, any known stimuli, warning signs (such as aura), and appropriate management should seizures occur. In addition to medication history, all patients/clients with epilepsy should be asked if they have an implanted neuromodulation device, including VNS2 or DBS3 systems, and details of the device and how it is operated should be recorded.
  • In order to reduce trigger stimuli, the dental hygienist should find out what factors have the potential to exacerbate epileptic seizures in a particular patient/client in order that trigger stimuli can be avoided. The dental hygienist can reduce stress and anxiety by explaining procedures before starting. Bright light should be kept out of the patient/client’s eyes, and dark glasses may assist with this.
  • The dental hygienist should check that the patient/client has taken his/her routine medications, has eaten normally, is not excessively tired, and has not been recently ill before starting treatment. If the patient/client has a VNS device, the accompanying hand-held magnet4 should be made available to the oral health team.5
  • Seizure devices — which are sometimes used in patients/clients who have medication treatment resistant epilepsy — have implications for dental/dental hygiene care. With deep brain stimulation there is the potential for equipment-related electrical energy transmission or electromagnetic interference (EMI) that could affect operation or safety of the implanted DBS system. Similar considerations exist for vagus nerve stimulation therapy, although possibly to a lesser degree for EMI.6
  • As with DBS systems, diathermy is contraindicated in patients/clients with VNS devices. The energy from diathermy can heat the VNS system, causing vagus nerve, vascular, and/or tissue damage. For the same reason, if external defibrillation is required for cardiac arrest, the paddles should be placed as far away from the pulse generator as possible.
  • Noncompliance with treatment regimen (especially the taking of prescribed antiseizure medications) is a significant problem in the medical management of some epileptic patients/clients. The dental hygienist should be alert to this possibility for each patient/client with epilepsy, to inform the decision to proceed or not proceed with a particular dental hygiene appointment, as well as to inform potential medical referral. 
  • Fatigue can trigger seizures, and thus dental hygiene appointments should be considered for early in the day or at other times when seizures are less likely to occur for a specific patient/client.
  • Alcohol can trigger seizures, and thus consumption should be avoided by the patient/client proximate to the dental hygiene appointment.
  • Hormonal changes during an epileptic woman’s reproductive cycle may affect the tendency to have seizures. 
  • When administered with at least 20% oxygen, nitrous oxide sedation is generally not contraindicated for patients/clients with epilepsy. However, local anaesthetics (such as lidocaine) may have pro-convulsant effects, particularly if administered in large amounts or if inadvertently injected intravenously.7
  • Most persons with epilepsy (two out of three) achieve good seizure control with prescribed medication.
  • Despite preventive measures, seizures may still occur in the dental hygiene office. Management should focus on preventing injury and maintaining adequate ventilation.

Management of generalized tonic-clonic (grand mal) seizures is as follows:

  1. Recognize prodrome or aura.
  2. Terminate procedure — remove instruments and dental appliances from patient/client’s mouth.
  3. Activate office emergency team.
  4. Position the patient/client in supine position with legs elevated; lower dental chair and protect patient/client from injury. Turn patient/client to side to minimize aspiration of secretions; do not place anything in the mouth or between teeth.
  5. Time the seizure.
  6. Consider activation of emergency medical services — Call 911 if the seizure lasts longer than 3 to 5 minutes or the patient/client becomes cyanotic from the onset.
  7. Assess and perform basic life support as needed (circulation 🡺 airway 🡺 breathing).
  8. After seizure, reassure patient/client and allow him/her to recover; assess O2 saturation and administer oxygen as needed; monitor vital signs; briefly assess oral cavity for injury to teeth and tissues.
  9. Discharge patient/client to hospital, physician, or home with a responsible adult, depending on post-seizure circumstances.
  • The ongoing medical management of epilepsy is usually based on long-term drug treatment. Phenytoin, carbamazepine, and valproic acid are first-line agents commonly used in the ongoing management of tonic-clonic seizures, whereas drugs of choice for absence seizures included ethosuximide, valproic acid, lamotrigine, and clonazepam. These, and other, antiepileptic drugs (AEDs) may have adverse effects with dental hygiene treatment considerations.
  • For patients/clients being treated with the phenytoin, the frequency of continuing care appointments should take into account the presence and severity of drug-induced gingival enlargement. 
  • Drowsiness is a side effect of some AEDs, particularly phenobarbital.
  • Some drugs prescribed by dentists or physicians can interfere with seizure control because they interact with antiepileptic medications. For example, metronidazole, antifungal agents (e.g., fluconazole) and antibiotics (e.g., erythromycin and clarithromycin) may alter the metabolism of certain antiepileptic drugs.
  • Powered toothbrushes may be too stimulating for some patients/clients and should be recommended only after determining if they can be tolerated.
  • Co-morbid conditions are common in patients/clients with epilepsy, and the dental hygienist should be alert for them.
  • The pulse generator of a vagus nerve stimulation device may interfere with hearing aids operating in the 30 kHz to 100 kHz range. This may be a consideration for hearing impaired healthcare professionals (as well as for other patients/clients and care-givers).
  • Vagus nerve stimulators have motor and sensory effects on the larynx and diaphragm. Long-term vagus nerve stimulation can result in altered breathing patterns, decreased air flow, and increased respiratory effort during sleep. This poses an additional risk factor during recovery from general anaesthesia.

Oral manifestations

  • While epilepsy and seizures themselves do not produce oral changes, accidents resulting from seizures and medications/devices used to treat the condition may result in oral sequelae.
  • Scarring of the lips, buccal mucosa, and the tongue may indicate past injury to the oral cavity due to biting during a seizure. Teeth may be fractured due to forceful biting that often accompanies tonic-clonic seizures. Enzyme-inducing drugs, antiepileptic drugs (e.g., phenytoin, phenobarbital, and carbamazepine) alter the metabolism and clearance of Vitamin D and thus contribute to increased fracture risk via osteopenia and osteomalacia. TMJ dislocation can result from seizure-related trauma.    
  • The most common significant oral complication seen in epileptic patients/clients is gingival hyperplasia, which is associated with the antiepileptic medications phenytoin, phenobarbital, and, more rarely, valproic acid and vigabatrin. Phenytoin alters the metabolism of gingival fibroblasts, resulting in the production of excessive amounts of collagen. Drug-induced gingival hyperplasia occurs in about half of patients/clients on continual phenytoin therapy within 12—24 months of initiation, and it may be disfiguring as well as interfere with mastication and speech. 
  • Ulcerations and glossitis may result from vitamin B-12 or folate deficiency caused by various anti-epileptic drugs.
  • Adverse effects of phenytoin, in addition to gingival hyperplasia, include aphthous ulcers, delayed healing, increased incidence of microbial infection, gingival bleeding, and osteoporosis. More rarely, phenytoin (and some other AEDs, particularly carbamazepine) may trigger Stevens-Johnson syndrome, a serious condition that involves sloughing of the skin and mucous membranes.
  • Xerostomia, stomatitis, and intra-oral petechiae or bleeding (resulting from drug-induced thrombocytopenia) are infrequent adverse effects of carbamazepine. Rash that may involve the oral cavity has been associated with lamotrigine. Valproic acid can cause bone marrow suppression and decrease platelet count, which may occasionally lead to clinically significant bleeding and impair wound healing. Valproic acid can also cause direct bone marrow suppression, which can impair wound healing and increase post-operative bleeding and infections.
  • In patients/clients treated with low intensity VNS, reduced pain thresholds may be present. Trigeminal pain may also occur; such pain is reversible with a decrease in stimulation current intensity. Additionally, altered taste (and smell) perception has been reported.

Related signs and symptoms

  • Epilepsy is a general term for conditions characterized by recurrent seizures. In general, epilepsy is diagnosed after a person has had two or more unprovoked seizures separated by at least 24 hours. There are many kinds of seizures (i.e., paroxysmal changes in central neurologic function), but all involve abnormal electrical activity in the brain that causes discrete episodes of involuntary changes in body movement (e.g., convulsions) or in sensation, awareness, or behaviour. 
  • Epilepsy affects persons of all ages, with a peak incidence of seizures in childhood and old age. The prevalence of epilepsy in Canada approaches 1 per 100 people, with about 360,000 persons affected. Up to 10% of the population will have at least one seizure in a lifetime, and 2% to 4% will experience recurrent seizures at some point. Some children outgrow the disorder, but others will require ongoing medical care. 75% of epilepsy is classified as primary or idiopathic (i.e., no known cause), with the remainder being secondary, due to causes such as birth asphyxia, head injury, or meningitis in children, or cerebrovascular disease or metastatic tumours in older persons.
  • While seizures are required for the diagnosis of epilepsy, not all seizures imply the presence of epilepsy. Seizures do not necessarily indicate epilepsy if they are provoked by a medical condition such as high fever, nervous system infection, electrolyte disturbance, hypoglycemia, alcohol or drug withdrawal, or acute traumatic brain injury (including concussion).  
  • The classification of seizures has evolved over time8. A basic, overarching classification of seizures9 is: focal onset10, generalized onset11, and unknown onset12.
  • While there are many types of seizures, four that are particularly relevant for dental hygienists are: generalized onset tonic-clonic (convulsive or “grand mal”) seizures; generalized onset non-motor (absence or “petit mal”) seizures; focal onset seizures due to temporal lobe epilepsy (TLE); and convulsive status epilepticus (CSE).
  • Generalized onset tonic-clonic seizures have a typically rapid onset but may be preceded by a prolonged prodrome13 (premonition) or, less commonly, a momentary aura14. Associated with tonic and clonic phases of muscular spasm, the patient/client loses consciousness. Defecation and micturition may occur. Cyanosis may be observed during the tonic phase (continuous tension or contraction) lasting for 20—40 seconds. The clonic phase (alternating series of contractions and partial relaxation) may last for several minutes. The patient/client wakes up from the seizure with a severe headache and confusion. Recovery may be quick or the patient/client may be irritable. Most tonic-clonic seizures end within 1 to 2 minutes, but post-ictal signs/ symptoms (i.e., after-effects) may last for much longer.
  • Generalized onset non-motor seizures usually appear between 3 years of age and puberty. They often consist of a transient loss of consciousness, and episodes typically last less than 30 seconds. Upward rolling of the eyes, drooling, rhythmic nodding of the head, and/or slight quivering of the trunk and limb muscles may be observed.
  • Temporal lobe epilepsy is the most common epilepsy syndrome with focal seizures. These seizures are frequently associated with auras of nausea, emotions (such fear or déjà vu), or unusual taste or smell. The seizures themselves entail a brief period of impaired consciousness which may appear as a staring spell, dream-like state, or repeated automatisms. TLE often begins in childhood or adolescence.
  • Convulsive status epilepticus is variously defined, including the following: the active part of a tonic-clonic seizure lasts 5 minutes or longer; a person goes into a second convulsive seizure without recovering consciousness from the first one; or, a person has repeated convulsive seizures for 30 minutes or longer.15 This condition is most frequently caused by an abrupt withdrawal of anticonvulsant medication or an abused substance, but it may also be triggered by infection, neoplasm, or trauma. It is a life-threatening medical emergency, which requires urgent medical intervention.16 
  • Rash is a common side effect of antiepileptic drugs, occurring in 5% to 7% of patients/clients taking phenytoin and 5% to 17% of patients/clients taking carbamazepine.
  • Coarsening of facial features may occur in patients/clients on long-term phenytoin, which is related to increased osteoblast activity.
  • Osteoporosis and increased fracture risk are associated with long-term use of some antiepileptic drugs (e.g., carbamazepine, phenytoin, primidone, and valproic acid). 
  • Epilepsy is generally more severe in persons who have developmental disabilities. Dental hygienists should be alert to potential co-morbid conditions in patients/clients with epilepsy.
  • Persons living with epilepsy — particularly children — often have psychosocial and emotional sequelae of living with a chronic, potentially unpredictable disease.  
  • Parents may interfere with their child’s psychosocial adjustment by being overprotective or having low expectations of the child.

References and sources of more detailed information

Management of generalized tonic-clonic (grand mal) seizures adapted from:
Bowen DM (ed.) and Pieren JA (ed.). Darby and Walsh Dental Hygiene: Theory and Practice (5th edition).  St. Louis: Elsevier Saunders; 2020; citing adaptation from Malamed SF. Medical Emergencies in the Dental Office (7th edition). St. Louis: Elsevier Mosby; 2015 + adapted from Aragon CE and Burneo JG. Understanding the Patient with Epilepsy and Seizures in the Dental Practice. J Can Dent Assoc 2007;73:1 at and Pickett FA and Gurenlian JR.  Preventing Medical Emergencies: Use of the Medical History in Dental Practice (3rd edition).  Baltimore/Philadelphia:  Wolters Kluwer Health; 2015.

Date: July 10, 2014
Revised: January 2, 2020; March 4, 2023


1 Implanted DBS and VNS devices do not typically require antibiotic prophylaxis.
2 Vagal nerve stimulation typically involves a pulse generator implanted below the left collar bone, with an electrode implanted in the left vagus nerve. At recurring intervals, the VNS system sends a mild electrical stimulation to the brain, via the left vagus nerve, affecting the reticular activating system and limbic systems of the brain. This results in reduced seizure activity. When an aura occurs, a specific external magnet — swiped over the vagus nerve stimulator — may also be used to activate the VNS device. VNS is usually used to treat focal (partial) seizures that do not respond to seizure medications.
3 Similar to VNS, DBS is typically used to treat medically refractory focal (partial) seizures.
4 The external magnet can be used to: 1/ initiate vagus nerve stimulation if one senses an impending seizure (via swiping over the stimulator), or 2/ temporarily turn off vagus nerve stimulation, which may be necessary during certain activities such as public speaking, singing, or strenuous exercise/activity, or if there are swallowing problems (via placement over the chest where the pulse generator is implanted; the device reactivates when the magnet is removed). As a further note, the magnet may damage credit cards, mobile phones, computer disks, televisions and other items affected by strong magnetic fields. Care should be taken to keep the magnet away from such items.
5 Some patients/clients with a VNS device may additionally benefit from buccal midazolam (a benzodiazepine), as prescribed by their physician.
6 An evaluation by Roberts (see References section) was conducted on Cavitron ultrasonic scalers, Automix amalgamators, Analytic pulp testers, and Optilux high output curing lights. Under the conditions of the study, they were not found to generate a magnetic field of sufficient magnitude to affect the VNS pulse generator’s normal function. Therefore, some commonly used electrical dental devices are possibly able to be safely used in close proximity to patients/clients with implanted VNS devices. However, the author was careful to state that these findings are not necessarily generalizable to all types of electrical dental devices.
7 Local anaesthetics may also have anticonvulsant effects; intravenous lidocaine has been used to treat status epilepticus, mainly in children.
8 Prior to 2017, it was common to classify seizures into focal (also known as partial) and generalized types, depending on the extent of brain involvement. Focal seizures were noted to be the most common type experienced by persons with epilepsy, occurring when abnormal electrical activity affected only one area of the brain. Focal seizures were further classified as simple (in which the person remained conscious) and complex (in which consciousness was altered or lost). Generalized seizures were noted to involve both sides of the brain, causing alteration or loss of consciousness either briefly or for a longer period of time.
9 classification as per the International League Against Epilepsy (ILAE) 2017 classification system
10 Focal onset seizures are further categorized according to: aware/impaired awareness; motor onset/non-motor onset; and focal to bilateral tonic-clonic. About 60% of patients/clients with epilepsy have focal seizures.
11 Generalized onset seizures are further categorized according to: motor (tonic-clonic or other motor)/non-motor (absence).
12 Unknown onset seizures are further categorized according to: motor (tonic-clonic or other motor)/non-motor) and unclassified.
13 A prodrome is a premonition that occurs hours or days before a seizure. More commonly associated with generalized onset than with focal onset seizures, features include: anxiety, difficulty concentrating, irritability, light-headedness, mood changes, sleep disturbances, and ecstatic feeling (rare).
14 An aura is a sensation that a seizure is imminent. More commonly associated with focal onset than with generalized onset seizures, an aura occurs suddenly, involves feelings of passivity or automatism, is of great intensity, and feels strange.
15 The duration of continuous seizure activity used to define status epilepticus has varied over time, with the recent trend being to shorter definitional time. Practically, once seizures have continued for more than a few minutes, treatment should begin without additional delay.
16 Non-convulsive status epilepticus (NCSE) also requires emergency medical treatment in a hospital, particularly given that NCSE predisposes to convulsive status epilepticus. NCSE is a term used to describe long or repeated absence or focal impaired awareness (complex partial) seizures.

* Includes oral hygiene instruction, fitting a mouth guard, taking an impression, etc.
** Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991. Invasive dental hygiene procedures are scaling teeth and root planing, including curetting surrounding tissue.