An epileptic seizure can be defined as a sudden synchronous discharge of cerebral neurons causing symptoms or signs that are apparent either to the patient or to an observer.
This may be characterised by periodic loss of consciousness with/without convulsions. It is important to be able to identify a seizure, due to there being many different presentations. Seizures can be either focal, generalised, or of unknown origin.
These different types of seizures are characterised by different presentations and level of consciousness. There are many causes of epilepsy and the pharmacological treatment thereof should be aimed at monotherapy, however if seizure control is not sufficient, dual therapy is recommended.
Status epilepticus is a medical emergency and should be managed in a clinical working environment.
CAUSES OF EPILEPSY
- Primary generalised epilepsy (e.g. juvenile myoclonic epilepsy)
- Developmental (e.g. neuronal migration abnormalities, contact dysplasia)
- Vascular (e.g. cerebral infarction, arteriovenous malformation, venous sinus thrombosis)
- Infectious (e.g. viral encephalitis, meningitis, cerebral tuberculosis, HIV, cerebral toxoplasmosis, neurocysticercosis)
- Immune (e.g. NMDA receptor antibody and potassium channel antibody encephalitis)
- Genetic (e.g. channelopathies)
- Metabolic abnormalities (e.g. hyponatraemia, hypocalcaemia)
- Neurodegenerative disorders (e.g. Alzheimer’s disease)
- Medications (e.g. cyclosporin, lidocaine, quinolones, tricyclic antidepressants, antipsychotics, lithium, stimulant recreational drugs such as cocaine)
- Hippocampal sclerosis
- Brain trauma and surgery
- Intracranial mass legions (e.g. tumours)
- Alcohol withdrawal
TRIGGERS FOR EPILEPSY
- Specific time of day or night
- Sleep deprivation (e.g. being overtired, not sleeping well, not getting enough sleep)
- At times of fevers or other illnesses
- Flashing bright lights or patterns
- Alcohol or recreational drug use
- Associated with menstrual cycle or other hormonal changes
- Not eating well, low blood sugar
- Specific foods, excess caffeine, or other products that may aggravate seizures
- Use of certain medications (e.g. diphenhydramine)
HOW TO RECOGNISE A SEIZURE
When dealing with epilepsy, it’s important to recognise a seizure for both the PWE as well as the onlooker. One can then strategise what the next step is. Seizure types can be divided into three different groups: those of focal onset; generalised onset, and unknown onset.
HOW YOU CAN HELP
Protect the person from injury by removing harmful objects. Cushion the head. Do not restrict movement or put anything in the mouth. Help breathing by putting the person in the “rescue position” (e.g. the body is placed sideways, with the head pulled upwards to open the airways and the top leg pulled up and out to stabilise the person).
Stay with him/her until fully recovered. Talk quietly to reassure him/her. The person may be unaware of the seizure. As people’s seizures vary, so do recovery times. This can be from seconds to minutes. Medical help is usually not necessary, but should be sought if:
- Repetitive seizures occur without the regaining of consciousness in between.
- The seizure shows no sign of stopping after a few minutes.
- There is a physical injury during the seizure.
A diagnosis of epilepsy is made after the occurrence of two or more unprovoked, clearly witnessed, or described seizures within a 12-month period. According to Epilepsy SA, the diagnosis of epilepsy is largely clinical, therefore an accurate description of the seizures and the circumstances in which they occur is most important.
These descriptions will probably be provided by friends or relatives who have witnessed the seizure. This will help in the diagnosis and may determine the need for further investigations such as:
- Blood tests which will assist the doctor to assess the general health of the person and eliminate other potential causes of seizures.
- An electroencephalogram (EEG) will measure changes in the brain’s functioning, detected by alterations in electrical activity.
- Computerised tomography (CAT/CT) scan may be taken to determine whether or not there are any structural changes in the brain. It provides cross sectional images (or slices) of the brain.
- The Magnetic Resonance Imaging (MRI) scan may be done by scanning the brain without using X-rays. During the MRI scan the person’s head is surrounded by a magnetic field. Radio frequency waves are produced to stimulate the brain. The energy changes results in the computer images appearing as two-dimensional slices through the brain.
- Positron Emission Tomography (PET) scanning is a non-invasive imaging technique that creates a three-dimensional image of the brain. An EEG recording is taken at the same time. PET scanning is extremely costly and has been largely replaced by the Single Photon Emission Computed Tomography (SPECT) scan.
- SPECT scanning is similar to PET scanning. It uses different radioisotopes which are able to hold the image of the blood flowing through the brain for up to 24 hours.
- It is quite possible that any or all of these investigations will record “normal” results, however, a diagnosis of epilepsy can still be made on the basis of witnessed symptoms.
PHARMACOLOGICAL MANAGEMENT OF EPILEPSY
When a PWE has a seizure, it is important to ensure an open airway by placing the patient in the “rescue position”, remove any false teeth, and, if available, administer oxygen via a face mask.
When medical facilities are available a strong vein needs to be secured since AEDs cause phlebitis. Anti-epileptic drugs (AEDs) are indicated when there is a clinical diagnosis of epilepsy and a substantial risk of recurrent seizures. Some of the following guidelines apply: • Introduce AEDs at the lowest dose possible, then slowly titrate to a higher dose until the seizures are well controlled.
- Aim for monotherapy – 70% of patients will have good seizure control with a single AED.
- If seizures are not well controlled with a single medication therapy, gradually introduce a second therapy while slowly withdrawing the first AED. If the patient is not seizure controlled, combination therapy is indicated.
- Epilepsy is one of the diseases where non-generic (‘brand name’) prescribing is indicated and justified to ensure consistent drug levels.
- Routine drug monitoring of AEDs is not required and should be reserved for assessing compliance and toxicity.
- There are drug-drug interactions between AEDs e.g. sodium valproate and lamotrigine. Newer generation AEDs have fewer drug-drug interactions.
- Phenytoin is no longer considered a first line AED instead it is used for status epilepticus. Levetiracetam is increasingly used in most types of epilepsy.
The emergency treatment is to ensure patients do not harm themselves and their airways remain unobstructed. Drugs are indicated when a clinical diagnosis of recurrent seizures or a substantial risk of recurrence is made. Treatment should be started as monotherapy and changed according to adequate seizure control.
To ensure effective counselling takes place it is essential to know what the information/counseling needs of PWE are, what the preferred dosage forms are, timing and delivery of information/counseling are, and what the outcomes of information giving/
counselling for people with epilepsy should be.
As part of antiepileptic pharmaceutical care, the pharmacist can supplement their advice to the patient with the following:
- Educate patients and others about epilepsy and help to dispel the myths of the past.
- Advise PWE to find a doctor in whom they have confidence and follow his/her advice.
- Encourage PWE to be open with others and try to ignore any negative reactions. This is especially important in a work environment where high risk activities such as climbing of ladders, working on high surface areas, and when working with volatile substances etc. is part of their job description.
- Discourage PWE to allow the fear of having a seizure keep them at home. They should however honour basic rules, e.g. exercising regularly, not to become sleep deprived, take their medications as indicated, avoid unsupervised swimming or bathing, ensuring the bathroom door is always unlocked, showering rather than bathing (and should they bath, to only put a small amount of water into the bath), minimise burn risks by not coming too close to an open fire, etc.
- Stress the importance of safeguarding their surroundings to prevent the occurrence of any unnecessary accidents. PWE should also be able to teach others what to do if they see him/her having a seizure.
- Investing and wearing a Medic Alert identity disc at all times.
- Keeping an identity card containing their name and address and doctor’s name and telephone number in their wallet or purse.
- Informing PWE that should they have an epileptic seizure when withdrawing their AEDs they should stop driving for a while or until they have stabilised.
- Remembering that with the right approach, qualifications, and skills, epilepsy need not be a major barrier to employment.
- Understanding that help is available, through rough their doctor, clinic, hospital, and Epilepsy SA.
Successful drug therapy involves care by a skilled clinician and the active co-operation of the patient. All patients taking anticonvulsants should be counseled extensively by healthcare professionals.