DDS Clients with Epilepsy
Prepared by Robert B. Duckrow, M.D.
To provide guidance for persons who provide support for people with intellectual disability who have epilepsy (seizure disorder). Additional guidelines are provided people receive supported living supports and services.
This advisory applies to all individuals of the department regardless of the facility or region in which they are served.
The department recognizes the special need to work with facilities which it does not fund or license to ensure the thorough understanding and implementation of medical advisories.
Intellectual disability can accompany inherent (genetic) brain dysfunction or acquired brain injury. Seizures, defined as transient episodes of altered behavior or awareness caused by the abnormal synchronous activity of brain cells, are a common expression of brain dysfunction and frequently accompany intellectual disability and cerebral palsy. When seizures recur as the result of permanent brain dysfunction the condition is called epilepsy. While the prevalence of epilepsy in the general population is 4 to 8 per 1000, the risk is increased 10-fold by either mental retardation or cerebral palsy and 50-fold if both conditions are present. Accordingly, the diagnosis and therapy of epilepsy will be major concern of those who care for people with cognitive and physical disabilities.
II. Goals of Neurological Care
The neurological care of DDS individuals with epilepsy should strive to optimize quality of life by minimizing the impact of seizures on the cognitive and functional abilities on the individual. The care of a new individual with a prior diagnosis of epilepsy or an established client who develops seizures should begin with a neurological evaluation. The goals of this evaluation should be
- to confirm the diagnosis,
- to determine its cause, and
- to develop an epilepsy care plan.
The basic elements of the epilepsy care plan should include
- characterization of seizure type(s),
- development of a seizure response protocol, and
- formulation of an anticonvulsant treatment program.
Participants in this process should include the client, the individual's family, the interdisciplinary care team, the primary care physician, and a consulting neurologist.
III. Confirm the Diagnosis of Epilepsy
Not all transient spells of altered behavior or awareness are seizures, and isolated seizures do not necessarily imply a diagnosis of epilepsy. When dealing with a new individual with established spells or an established individual with new spells, the first step is to assure the accuracy of the diagnosis. To make an accurate diagnosis the physician must have a complete description of what occurs during a spell.
Seizures can occur in response to provocative factors attending acute physiological stress and may not represent a continuing disorder of brain function that would require further treatment. Non-epileptic spells can follow fainting, or be caused by trauma, metabolic disturbance, or medicines. Behavioral episodes can occur that mimic epileptic seizures.
Because individuals may be unconscious or unaware of their spells, it is important that a clear description of witnessed events be communicated to the evaluating physician. Caregivers who witness new spells should write down their observations using simple common words, avoiding medical jargon that could be misinterpreted. Video-taped documentation of unusual behaviors or spells is invaluable, although appropriate permission should be obtained before recordings are made.
During the initial neurological evaluation, or if the individual's care is being transferred to a new neurologist, all effort should be made to provide documented historical information relevant to the understanding of the epilepsy. This would include:
- what is known of the individual's gestation, labor and delivery,
- the presence of post-natal injury or infection,
- subsequent illness during infancy or adolescence, and/or
- a family history of epilepsy.
There should also be documentation of the circumstances surrounding the onset of the epilepsy, including
- a description of initial seizures and
- the results of any early diagnostic testing, such as lumbar puncture (spinal tap), electroencephalography (EEG), or brain imaging (CT scan or MRI).
In cases of established epilepsy, it is helpful to provide a synopsis of the course of the disorder, including seizure frequency, changes in seizure type, and the beneficial or toxic effects of specific anticonvulsant medicines.
In the course of an evaluation, additional testing may be indicated to confirm the diagnosis and to determine a cause. Epileptic seizures can be differentiated from non-epileptic spells such as fainting or behavioral episodes using 24-hour ambulatory EEG monitoring or continuous (inpatient) EEG/Video monitoring to record brain electrical activity during a habitual spell.
IV. Determine the Cause
Epilepsy is the symptomatic expression of brain dysfunction, and the rational therapy of epilepsy should be directed by knowledge of the underlying cause of that dysfunction. However, the cause of brain dysfunction in the majority of people with individual disability is seldom completely understood. Nevertheless, an attempt should be made to determine the cause of the epilepsy, if only to improve communication between health care providers. In some cases, the resulting information can influence or improve the treatment of the disorder.
Although the history is the most important element of the diagnostic process, the results of prior laboratory tests are also helpful. These can include:
- blood chemistry measurements,
- cerebrospinal fluid analysis (lumbar puncture),
- electroencephalography (EEG),
- brain imaging (CT scan or MRI), and/or
- continuous EEG/Video monitoring.
V. Create a Care Plan
The basic elements of the epilepsy care plan are as follows:
- the definition of seizure type(s),
- the development of a seizure response protocol, and
- the formulation of an anticonvulsant treatment program.
VI. Define the Seizure
Different people may have seizures with markedly different clinical manifestations, and individuals may have multiple seizure types. Once the diagnosis of epilepsy is verified, management depends on the accurate recognition of individual seizures to allow immediate response and to assess control by establishing the event frequency. Although physicians characterize seizures with an international classification scheme, schemes are subject to revision, and poorly defined jargon can interfere with care. The care team should participate in defining a person's seizures and agreeing on common terms for their description.
Observations made during witnessed seizures should be discussed and condensed into a seizure description that is individualized for each person. This description should use common words rather than medical jargon. A shortened name can also be developed that may include elements of the international classification of seizures (Appendix I.). The condensed description should include generally agreed upon upper limits for quantitative aspects of the should include generally agreed upon upper limits for quantitative aspects of the event, such as maximum duration or usual cluster frequency, so that variations can be recognized, recorded, and acted on. After the condensed description and seizure name are approve by a physician, they should be incorporated into a seizure record.
VII. Develop a Seizure Response Protocol
A seizure occurrence should trigger a pre-established response. The response protocol should be developed by the care team with the goals of reducing the likelihood of injury during a seizure and the assessment of the effects of a seizure when it ends. The response should be individualized and can be expected to vary widely between individuals. It is possible that some seizures will require as little response as documenting the occurrence , while other seizures will prompt immediate medical evaluation.
In people with intellectual disability, the primary seizure-related risks are physical injury and aspiration pneumonia. Most seizures are self-limited by their nature, and the immediate care of the person during seizure should be directed toward preventing injury or aspiration.
A. Risks Associated with Specific Seizures Types
1.. Brief myoclonic, tonic, or atonic seizures
These types of seizures can cause falls or throw the person to the ground. The resulting lacerations or fractures can be difficult to avoid.
Helmets can be used to prevent injury to the face or skull. Restricting the person to a chair or bed can prevent injury, but the resulting immobility is detrimental to overall health and should only be used if all else fails. (If the use of such restraint is being considered, review by the department's Program Review and Human Rights Committees and approval by the training school or regional director is required prior to implementation.)
2.. Tonic-clonic seizures
Tonic-clonic seizures also cause falls, but a greater concern is aspiration and resulting pneumonia. If possible, the person should be turned on his/her side to allow secretions to drain until a cough reflex has returned. Attempts to prevent tongue-biting by placing objects in the mouth should be avoided, as only further injury to the mouth can result. Afterwards, limbs and joints can be examined to detect fractures or dislocations.
3. Partial seizures
These seizures seldom cause injury. However, some clients will wander during or after their partial seizures and should be diverted from walking into traffic or stumbling down stairs.
B. Response for seizures of longer duration and/or increased clusters
If a seizure continues beyond its usual duration or they cluster in number beyond the usual count, additional medical treatment may be required either on site or after transport to a local hospital emergency room. The threshold for this action will vary considerably from person to person, and should be established with reference to the past history of such activity and in consultation with the neurologist. It is possible that short-term increases in established antiepileptic drug doses or the administration of a short-acting agent will abort such activity, but the institution of such a treatment program should be made carefully after the natural history and response to medication are well understood.
1. Seizure occurrence should be recorded to document the natural history of the epilepsy and to assess the efficacy of anticonvulsant medications. The seizure record should include the following:
- seizure type,
- time of onset,
- duration of the active phase, and
- any differences between the observed seizure and the established seizure pattern for the particular client.
2. Seizure records should accompany clients on physician visits. (See Appendix II)
VIII. Establish an Antiepileptic Drug Treatment Program
Antiepileptic medicines reduce seizure frequency and can eliminate seizures in 40 to 80% of patients. However, people with intellectual disability are the least likely to have complete seizure control and are the most likely to require the use of multiple antiepileptic medicines at higher doses. Sedation and other adverse effects will be more common and more disabling.
Treatment decisions should consider the positive and negative effects of antiepileptic drug use. The desire for complete seizure control should be balanced with optimization of overall function.
Therapy with a single antiepileptic drug (monotherapy) is preferred over multiple antiepileptic drugs (polytherapy) if at all possible. The dose of the single antiepileptic drug should be increased until it is effective or until side-effects appear. If ineffective, monotherapy with an alternative antiepileptic drug should be considered before polytherapy is used. While the addition of a second antiepileptic drug can improve seizure control in 10% of patients, it will cause adverse effects in 90%. When possible, the choice of antiepileptic drug should be directed by the specific epilepsy syndrome. It is recognized that in people with mental retardation, secondary generalized epilepsy may predominate and the no specific antiepileptic drug may offer a clear advantage. However, it is clear that barbiturates (phenobarbital, primidone, mephobarbital) are more sedating.
Factors to be considered when choosing or using an antiepileptic drug include the pharmacokinetics of absorption, distribution, and elimination. For example, the oral suspension form of phenytoin (Dilantin) has low solubility and incomplete but rapid absorption. Absorption is further reduced by feeding solutions. If delivered by gastric tube, continuous feedings should be suspended before and after each dose, and doses should be given twice a day. On the other hand, sustained-release phenytoin (Dilantin Kapseals) has slow absorption and a half-life of more than 24 hours, making once-a-day dosing an advantage for people in supported living, where compliance or the effect of missed doses may be an issue.
IX. Enzyme Induction and Medication Interactions
Carbamazepine, phenytoin, phenobarbital, and primidone increase the activity of liver enzymes (induction) and result in decreased serum levels of antiepileptic drugs and other medications that are metabolized by the liver. This can reduce the effectiveness of medicines such as theophylline, oral contraceptives, warfarin, and haloperidal. Some medications inhibit the metabolism of anticonvulsants producing increased levels and toxic symptoms. Erythromycin, isoniazid, propoxyphene, diltiazem, verapamil, and cimetidine can increase carbamazepine levels. Chloramphenicol, sulfonamides, isoniazid, disulfiram, and cimetidine can increase phenytoin levels. Methylphenidate, propoxyphene and valproic acid can increase phenobarbital level. Cimetidine, erythromycin, and phenothiazines can increase valproate levels. (See Table, Appendix IV.)
Antiepileptic medication interactions are common and the actual effect of combining medications will be difficult to predict. In general, if there is a clear need for the use of a new medication, it should be used according to its' indications. Antiepileptic drug levels can subsequently be measured to test for major changes in pharmacokinetics caused by drug interaction. However, when suitable equivalent alternatives are available they should be used, as would be the case for erythromycin, propoxyphene (Darvon) or cimetidine (Tagamet).
X. Role of Serum Levels and Blood Tests
Antiepileptic drug blood levels are obtained to determine if the oral dose is adequate or to explain the cause of toxic symptoms, especially if polytherapy if used. When possible, blood should be sampled just prior to administration of the morning dose.
Serum levels commonly are obtained
- after new anticonvulsants are instituted,
- if there is an unexpected change in seizure frequency, or
- when signs or symptoms of toxicity appear.
The same indications would hold for blood work designed to screen for metabolic or hematological changes that accompany antiepileptic drug use.
Routine blood testing at intervals less than one year should be avoided, unless it is known that a client has a specific sensitivity to a given agent. For example, hyponatremia is not uncommon with the use of carbamazepine, and more frequent monitoring could be justified by a past history of marked variation in serum sodium levels. In contrast, antiepileptic medicines commonly increase plasma gamma glutamyl transferase (GGT) and repeated measurements are seldom helpful. In healthy individuals, the cost-effectiveness of any routine blood chemistry measurement is seriously questioned. This opinion must be tempered by the presence of higher co-morbidity in people with mental retardation who have epilepsy.
XI. Follow-up Examination
Individuals with intellectual disability who have complete control of their epilepsy with a single antiepileptic drug should be evaluated by a neurologist once every two years.
Individuals on polytherapy or those with incomplete seizure control should be seen at least once a year, or more frequently as specified by the neurologist.
XII. Discontinuing Antiepileptic Drug Therapy
Antiepileptic medications can be withdrawn when there are
- two years of complete seizure control,
- a normal neurological examination,
- a normal electroencephalogram (EEG), and
- normal brain imaging studies (CT or MRI).
By definition, people with intellectual disability do not meet these criteria. However, antiepileptic drug withdrawal can be considered if seizures have been a single type and have been easy to control with one anticonvulsant for 3 to 5 years.
The EEG can aid in the decision, with the presence of clear epileptiform activity before antiepileptic drug withdrawal or the return of epileptiform activity after withdrawal being a relative, but not absolute, contraindication. The best candidates for anticonvulsant withdrawal are those cases where the diagnosis of epilepsy may have been incorrect from the start.
GUIDELINES FOR PEOPLE RECEIVING SUPPORTED LIVING SUPPORTS AND SERVICES
I. Level of surveillance
Individuals who live independently with support should be monitored at intervals appropriate to the frequency and severity of their seizures. The plan for neurological care should follow the basic guidelines. The frequency of monitoring visits should be determined by the health care team and may vary with fluctuations in the person's condition.
Monitors of individuals receiving supported living services should assist in the
- maintenance of the seizure record,
- evaluation of the impact of continuing seizures, and
- aid medication compliance.
II. Seizure record
Monitors should be aware of a person's established seizure type or types. A dialogue between the person and the monitor should be established that allows recognition and recording of seizure occurrence. The person with mental retardation should be encouraged to mark seizure occurrence on a seizure calendar that can be maintained with the aid of the monitor.
When multiple seizure types are present, the monitor should assist the individual in distinguishing between types and recording them appropriately.
The monitor should be aware of the person's usual seizure frequency so that variances can be reported to the responsible nurse or physician. Seizure calendars should be taken on doctor visits.
III. Response to seizures
Monitors should be aware of the usual impact of individual seizures on the person's function. Unexplained burns, bruises, cuts, or respiratory infection should be correlated with changes in seizure frequency
If seizures are responsible for injury, and improvement in seizure activity is not expected, a change of level of care should be considered.
Monitors should evaluate the person's compliance with prescribed antiepileptic medication use. Each person should be encouraged to learn to identify each of his or her medications and know the dosing schedule.
Compliance can be estimated by pill counts (the number remaining in a bottle should approximate the number of prescribed minus the daily dose, times the number of days since the last refill). Poor compliance should be reported and can be supported by measuring antiepileptic drug levels. Medication compliance an be improved by
- encouragement and education,
- short-term increases in the frequency of monitoring visits,
- pill dispensing boxes,
- simplification of antiepileptic drug dosing schedules, and/or
- changing to longer acting antiepileptic drug preparations.
Individuals with child bearing potential should be aware that antiepileptic drug use has been associated with a small but measurable increase in the risk of birth defects. This risk can be minimized by the use of antiepileptic drug monotherapy. This risk can also be reduced by folic acid supplements taken in the months before planned conception.
Antiepileptic medications that induce liver enzymes (phenytoin, carbamazepine, phenobarbital, and others) can reduce the efficacy of oral contraceptive pills. Intermenstrual breakthrough bleeding can be an indication that higher-dose estrogen preparations may be needed to prevent conception.