Epilepsy

• What is Epilepsy
• Statistics on Epilepsy
• Risk Factors for Epilepsy
• Progression of Epilepsy
• Symptoms of Epilepsy
• Clinical Examination of Epilepsy
• How is Epilepsy Diagnosed?
• Prognosis of Epilepsy
• How is Epilepsy Treated?
• Epilepsy References

What is Epilepsy

Epilepsy is the continuing tendency of a person to have seizures. An epileptic seizure is caused by an abnormal electrical discharge from a group of nerve cells in the brain. There are many different types of epilepsy and many different causes of epilepsy. Adult onset seizures are almost always caused by a structural problem within the brain. Epileptic seizures can be classified as partial or generalized, simple or complex. In partial epileptic seizures the seizure activity is restricted to a local area in the brain, whereas in generalized seizures a larger area and both sides of the brain are affected, such that the fitting normally associated with epileptic seizures can occur. A partial epileptic seizure can evolve into a generalised epileptic seizure. A simple epileptic seizure is one where there is no loss of consciousness. In a complex epileptic seizure there may be loss of awareness.

Statistics on Epilepsy

Epilepsy is one of the most common serious neurological (brain) condition. Around 10-12% of people will have a seizure during their lifetime, and 3-4% of people will be diagnosed with epilepsy at some point. The causes of epilepsy are often different through age.

Risk Factors for Epilepsy

Conditions which increase the likelihood of developing epilepsy include:

• Stroke or other cerebrovascular disease
• Cerebral tumours
• Alcohol abuse or withdrawal
• Severe head trauma
• Family history of epilepsy: 30% of people with epilepsy will have a first degree relative with a history of seizures
• Previous brain surgery
• Infections of the brain or central nervous system
• Abnormalities of nervous system development

Precipitating factors that may cause a seizure to occur include:

• Psychological or physical stress
• Sleep deprivation
• Hormonal changes associated with the menstrual cycle
• Lights or a flickering television may provoke an attack in susceptible patients
• Exposure to toxic substances, such as alcohol
• Certain medications can provoke epileptic fits in people with a natural tendency to have seizures

Progression of Epilepsy

People who have epilepsy have seizures intermittently and may be asymptomatic for months to years between seizures.

How is Epilepsy Diagnosed?

• Blood tests may be performed to look for potential causes for seizures. These may include a full blood count, liver function tests, and toxin screens.
• Not all patients on anticonvulsant medications need to have their blood anticonvulsant levels checked. Sometimes it can be useful for efficacy, sometimes to see if the patient is taking the medication.
• EEG: this test looks at the electrical activity of the brain. It will be abnormal during a seizure and so may help diagnose epilepsy; however, it is usually normal between seizures in people with epilepsy.
• CT/MRI of the head – to exclude the possibility of an underlying cause such as a brain tumour
• Other investigations may be available in specialist epilepsy centres. These may be particularly useful if surgery is being considered as a treatment option.

Prognosis of Epilepsy

With the use of anticonvulsant medications about 70% of people with epilepsy can have their epilepsy well controlled. Up to 60% of people can have good control without experiencing significant medication side-effects. Patients with epilepsy have an increased risk of developing depression, anxiety, and psychosis. Approximately 20% of epilepsy patients develop depression, and a higher suicide rate compared to the general population has also been noted in patients with epilepsy. There is a 2-3 fold increase in the risk of death in a patient with epilepsy when compared to the general population. Some of this increased risk is probably due to the underlying causes of epilepsy such as cerebral tumours or strokes. However, a very small percentage of patients die from a syndrome known as sudden unexpected death in epileptic patients (SUDEP). The cause of SUDEP is unknown.

With regards to pregnancy in epilepsy, some reduction in fertility has been noted in epileptic populations. This is probably due to a number of factors – for example, a third of women with epilepsy have ovarian abnormalities (e.g. not ovulating regularly, polycystic ovarian syndrome). In addition, the risk of birth defects in pregnant women taking anticonvulsants is higher than the general population. Therefore counselling prior to becoming pregnant is crucial. If drug therapy is continued during pregnancy, use of the lowest possible dose of a single, first-line drug is recommended. Folic acid supplements are also recommended. Despite drug treatment, seizures may persist in 20 – 35% of cases of epilepsy. These patients may benefit from review of medications, attention to treatment compliance, and consideration of surgical options.

How is Epilepsy Treated?

Management of epilepsy will involve the treatment of underlying conditions that could be causing the epileptic seizures, avoidance of triggering factors, use of antiepileptic medications, surgical treatment options, and addressing the emotional issues that face a patient with epilepsy.

Anti-epileptic prescription drugs

Most doctors will recommend antiepileptic medications after a patient has had two or more seizures. Many antiepileptic medications have unwanted side effects. In patients who do not respond to medical management, surgical treatment for certain types of epilepsy may be an option. The choice of anti-epileptic medication depends on seizure type and patient factors. Primary generalised tonic-clonic seizures:

• Primary generalised tonic-clonic seizures: sodium valproate and lamotrigine are first-line treatments. Alternatives include topiramate (Topamax), phenytoin and carbamazepine.
• Partial seizures (including complex partial and secondarily generalised seizures): carbamazepine, phenytoin and sodium valproate are first-line. New drugs such as topiramate (Topamax), levetiracetam and gabapentin may also be used. Pregabalin (Lyrica) is another new drug, also used in the management of neuropathic pain, which has been shown to be highly effective as an adjunctive (additional) treatment in the management of partial-onset epilepsy.
• Absence seizures: sodium valproate and ethosuximide are first-line treatments.

General advice includes:

• Avoid swimming alone.
• Avoid dangerous sports such as rock climbing.
• Take showers rather than baths. Be supervised or leave the door unlocked when taking a bath.
• Patients should be informed of restricted driving conditions – most are able to drive a car for private use after 1 year seizure-free, either off or on prescription drugs, according to Australian guidelines.

Pregnancy and antiepileptics

Antiepileptic medicines can cause birth defects in pregnancy. Your specialist will assess the risk and benefit of the medicines you are on to make the decision. The risk increases with the number of antiepileptic medicines taken. Phenytoin, valproate, carbamezepine and lamotrigine are all pregnancy Category D. Facial malformations, cardiac defects and fingers and nail deformities may occur with several antiepileptic drugs, in particular phenytoin (Dilantin), valproate (Epilim), carbamazepine (Tegretol) and lamotrigine (Lamictal). There is also an increased risk of spina bifida with valproate and, to a lesser extent, with carbamazepine. Topiramate is pregnancy category D because of the results of animal studies. There are no studies using Topiramate (Topamax) in pregnant women. Levetiracetam is category C.

Your specialist will assess the risks and benefits and ensure that you are given the best treatment. He may recommend you use your medication at the lowest effective dose and also start folic acid supplementation (usually 5 mg/day) four weeks prior to and continue for 12 weeks after conception. Please seek your doctor’s advice if you are pregnant or planning to become pregnant.

 

Article kindly reviewed by:

Associate Professor Karl Ng MB BS (Hons I) FRCP FRACP PhD CCT Clinical Neurophysiology (UK) Consultant Neurologist – Sydney North Neurology and Neurophysiology (download referral form and map); Conjoint Associate Professor – Sydney Medical School, University of Sydney; and Editorial Advisory Board Member of the Virtual Neuro Centre.

 

Epilepsy References

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2. Hurst JW (ed). Medicine for the Practicing Physician (4th edition). Norwalk, CT: Appleton and Lange; 1996. Book
3. Kumar P, Clark M (eds). Clinical Medicine (5th edition). Edinburgh: WB Saunders Company; 2002. Book
4. Longmore M, Wilkinson I, Torok E. Oxford Handbook of Clinical Medicine (5th edition). Oxford: Oxford University Press; 2001. Book
5. D’Souza W. Epilepsy video [online]. Perth, WA: Virtual Medical Centre; 14 August 2007 [cited 14 August 2007]. Available from: [URL Link]
6. Brodie MJ. Pregabalin as adjunctive therapy for partial seizures. Epilepsia. 2004; 45(Suppl 6): 19-27. Available from: [Abstract | Full text]
7. Anticonvulsants [online]. Adelaide, SA: Australian Medicines Handbook; January 2007 [cited 22 August 2007]. Available from: [URL Link]
8. Dilantin [online]. St Leonards, NSW: MIMS Online; 2007 [cited 22 August 2007]. Available from: [URL Link]
9. Epilim [online]. St Leonards, NSW: MIMS Online; 2007 [cited 22 August 2007]. Available from: [URL Link]
10. Tegretol [online]. St Leonards, NSW: MIMS Online; 2007 [cited 22 August 2007]. Available from: [URL Link]
11. Lamictal [online]. St Leonards, NSW: MIMS Online; 2007 [cited 22 August 2007]. Available from: [URL Link]
12. Topamax [online]. St Leonards, NSW: MIMS Online; 2007 [cited 22 August 2007]. Available from: [URL Link]