Epilepsy is a brain disorder that is caused by sudden unsynchronized neuron signaling causing symptoms or signs that are either apparent to the person or to an observer. This may be characterized by periodic loss of consciousness with/without convulsions. The term “epileptic” is no longer in use, and is now referred to as “people with epilepsy” (PWE). Seizures can be either focal, generalized or of unknown origin. These different types of seizures are characterized by different presentations and level of consciousness.
It is important to be able to identify a seizure, due to there being many different presentations. 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.
Epilepsy is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures, and by the neurobiological, cognitive, psychological, and social consequences of this condition1. An epileptic seizure can be defined as following: “ … a sudden synchronous discharge of cerebral neurons causing symptoms or signs that are apparent either to the patient or to an observer …”2 it may also be characterized by periodic loss of consciousness with/without convulsions associated with abnormal brain activity1. It is sometimes a chronic, neurological condition with physical risks and psychological and socioeconomic consequences which impair quality of life1.
People with epilepsy (PWE) are encouraged to live an unrestricted life, with special care to be taken when, for example, participating in swimming or mountain climbing. PWE should be provided with advice such as leaving the bathroom door unlocked, taking a shower instead of a bath, avoiding stroke lightning where there is evidence of EEG-epilepsy, avoiding sleep deprivation and the excessive use of alcohol and recreational drugs 2.
Seizures are divided into two main groups by clinical pattern, namely: focal or generalized seizures and the third group being of unknown origin.
A focal seizure is caused by an electrical discharge restricted in a limited part of the cortex and one cerebral hemisphere. This type of seizure can further be characterized according to whether or not there is: (a) an aura; (b) motor features, (c) autonomic presence or (d) loss of awareness/responsiveness2,3. Focal seizures occur due to failure of inhibitory mechanisms causing a secondary generalized seizure2,4.
A generalized seizure occurs when there is simultaneous involvement of both hemispheres, always associated with loss of consciousness/awareness5. Subtypes of generalized seizures include (a) typical absence seizures (Petit Mal), (b) generalized tonic-clonic seizures (Grand Mal), (c) myoclonic and (d) tonic, clonic or atonic seizures2,4.
Unknown seizures occur when there is insufficient evidence to be characterized being focal, generalized or both2,4.
There are many causes of epilepsy and a good understanding of the origin thereof should be established in order to structure the management.
Causes of epilepsy2
|· Primary generalised epilepsy e.g. juvenile myoclonic epilepsy
· Developmental, e.g. neuronal mitigation abnormalities, contact dysplasia
· Vascular, e.g. cerebral infarction, arteriovenous malformation, venous sinus thrombosis
· Infectious, e.g. viral encephalitis, meningitis, cerebral tuberculosis, HIV, cerebral toxoplasmosis, neurosystercosis
· 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
· Hyppocampal sclerosis
· Brain trauma and surgery
· Intracranial mass legions e.g. tumours
· Alcohol withdrawal
Triggers for epilepsy
It is important to understand what the triggers are for an epileptic seizure.
Triggers for an epileptic seizure6
- 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 is important to recognise a seizure i.e. for both the PWE as well as the onlooker. One can then strategize what the next step is.
Seizure types can be divided into three different groups, namely: (a) those of focal onset; (b) generalised onset and (c) unknown onset.
These different groups can further be divided into subset types.
Figure 1, below, summarises the above, whilst Table I, summarises the different kind of seizures, how they present and how best to act on it.
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 SA9, 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 will eliminate other potential causes of seizures;
- An electroencephalogram (EEG) will measure changes in the brain’s functioning, detected by alterations in electrical activity;
- Computerized 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 pheblitis2.
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 apply2:
- 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 that patients do not harm themselves and that their airways remain unobstructed. Drugs used in the treatment of epilepsy are summarised in Table II, below.
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.
Table III, below, indicates drugs used as first line and second line agents.
Withdrawal of AEDs should be considered after a seizure-free period of at least 2-3 years2.
Management of status epilepticus
Status epilepticus is a medical emergency and exists when two seizures follow each other without recovery of consciousness2. When Grand Mal seizures follow one another there is a risk of death due to cardiorespiratory failure2. Precipitating factors include: abrupt withdrawal of AEDs, intercurrent illness/disease, alcohol abuse and poor patient-drug compliance.
Initial treatment of status epilepticus entails the use of intravenous administration of lorazepam or rectal diazepam. Since lorazepam also causes respiratory depression and hypotension, facilties should be geared for resuscitation2. If lorazepam fails to control the seizures an infusion of phenytoin or phenobarbital should be started. Rapid infusion of phenytoin may cause cardias dysrhythmias, ECG monitoring should be done during the infusion2. Paraldehyde, given rectally/intramuscularly is sometimes also used when intravenous entry is complicated or where facilities are restricted (respiratory depression is not common)2. After the patient is stabilised, intravenous treatment is terminated and treatment with regular AEDs should be commenced.
The Epilepsy Foundation of Minnesota developed a free “Seizure First Aide” app (available at efmn.org/app) that can be downloaded onto a mobile phone for assistance with recognizing different types of seizures, knowing what to do, and timing how long the seizure lasts11.
To ensure that effective counselling takes place it is essential to know what the information/counselling needs of PWE are; what the preferred dosage forms are; timing and delivery of information/counselling are and what the outcomes of information giving/counselling for people with epilepsy should be12.
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 a 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 that the bathroom door is always unlocked; showering rather than bathing, and should they bath, to tap only a small amount of water into the bath; minimize burn risks by not coming too close to an open fire etc.;
- Stress the importance of safeguarding their surroundings to prevent the occurrencee of any unnecessary accidents. PWE should also be able to teach others what to do if they see a 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 stabilized;
- Remembering that with the right approach, qualifications and skills, epilepsy need not be a major barrier to employment and
- Understanding that help is available, through 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 counselled extensively by health care professionals.
AUTHOR: Brown L1 and Helberg, EA2
1BPharm, MSc (Pharm) Cum Laude, PhD, Unaffiliated; 2Dip Pharm, MSc (Med), School of Pharmacy, Sefako Makgatho Health Sciences University
Epilepsy is a complex brain signalling disorder that has different presentations, depending on the type of seizure experienced. Seizures are effectively treated with the necessary drugs. Seizure control should be aimed at monotherapy, but when not effectively controlled, dual therapy is indicated. The Pharmacist plays an important role in the dispensing of AEDs and antiepileptic pharmaceutical care.
All correspondence to Dr Liesl Brown: firstname.lastname@example.org
Cell: 082 870 4165
Fax: 086 537 4165