Epilepsy treatment, electroencephalography, evoked potentials

The sleep laboratory is associated with this department and offers the entire spectrum of modern examinations as well as corresponding consultations and treatments. In the field of epileptology, there is a strategic partnership with the Center for Epilepsy in Zurich. Sleep Medicine is part of the Interdisciplinary Center for Sleep Medicine at the USZ and, from 2012, a partner of a clinical research focus at the University of Zurich.

First aid for epileptic seizures

An epileptic seizure usually subsides on its own. It is important to keep calm as a support person and ensure that the person affected does not injure themselves. Simple basic rules should be observed.

During the seizure:

• Keep calm.
• Avoid injuries, clear pointed or sharp objects out of the way.
• Place a soft object (pillow or piece of clothing) under the head to protect it.
• Loosen constricting clothing if necessary.
• Do not put anything in your mouth, even if the person concerned has bitten their tongue.
• Do not block the affected person’s movements as long as there is no risk of injury.

After the seizure:

• Place the victim in the recovery position.
• Continue to observe the person concerned.

An emergency doctor should be called if:

• the seizure occurs for the first time,
• the seizure lasts longer than five minutes,
• an unusually high number of seizures occur within a short period of time,
• the person concerned is confused or unresponsive for an unusually long time and
• the person concerned is injured or is no longer breathing.

You can find more information about first aid for epileptic seizures in the flyer from the Swiss Epilepsy League.

Therapy for epilepsy

A single epileptic seizure does not necessarily need to be treated. In the case of very rare or very mild seizures, we carefully consider whether and which therapy is suitable.

Epilepsy cannot be cured, but therapy can alleviate or prevent the symptoms. Most people with epilepsy take medication – so-called antiepileptic drugs (also known as anticonvulsants) – to prevent seizures. If drug therapy does not achieve the desired success, there are other treatment options.

Antiepileptic drugs: Medication to prevent a seizure

Numerous medications from different groups of active ingredients are available for treatment. Which medication we prescribe depends on how well you tolerate the medication, the type of epilepsy and whether you have any concomitant illnesses. If therapy with a single preparation does not have a lasting effect, we prescribe a medication from a different group of active ingredients or combine different medications.

Discontinue antiepileptic drugs

At every consultation, our doctors critically scrutinize whether drug treatment is still necessary. Many people with epilepsy require long-term treatment. In some cases, however, a discontinuation attempt can be discussed if the patient has been seizure-free for a longer period of time.

Such a decision, including the advantages and disadvantages, will be discussed in detail with you by the doctor responsible. Medication is then usually discontinued gradually, under regular medical supervision and in compliance with precautionary measures (e.g. refraining from driving and activities involving a risk of injury).

Epilepsy surgery: when antiepileptic drugs are not enough

Neurosurgical intervention can be useful if at least two attempts at treatment with different antiepileptic drugs fail to stop the seizures permanently.

Various surgical procedures are available:

• Surgery: The area of the brain that triggers the focal seizures is surgically removed. Surgery is associated with risks and can only be performed in well-chosen cases. The area of the brain causing the seizures must be clearly localizable. This area should not be located in an area of the brain that is responsible for important functions such as vision or speech. In the case of genetic or generalized epilepsies, such an operation is not usually effective. We therefore weigh up very carefully whether an operation is an option.
• Deep brain stimulation: In this stimulation procedure, a battery-powered “brain pacemaker” that emits electrical impulses is implanted under the skin. The pacemaker is connected to contacts that are implanted in a deep region of the brain. It is said to influence the activity of nerve cells and reduce their overactivity.
• Vagus nerve stimulation: In this stimulation procedure, a battery-operated “brain pacemaker” is also implanted under the skin. The pacemaker is connected to the vagus nerve in the neck area. It is intended to reduce the overactivity of nerve cells.

Treatment of epilepsy during pregnancy

Pregnancy does not lead to a worsening of epilepsy. Many of our patients have had a safe pregnancy and given birth to healthy children under our care. For women with epilepsy, however, pregnancy should be planned early on with an expert and accompanied by specialists.

Women with epilepsy should be advised by experts right from the start of family planning. First and foremost, the epilepsy should be adequately treated so that dangerous seizures do not occur during pregnancy. On the other hand, antiepileptic drugs should be adjusted to the lowest possible but sufficiently effective dose. This process takes time and should therefore be planned well in advance.

For women of childbearing age who are taking antiepileptic drugs, we recommend taking folic acid (vitamin B9). Folic acid is a vitamin that can reduce the risk of fetal malformations. This should be done before the pregnancy arrives.

The main danger posed by some antiepileptic drugs is the risk of fetal malformations. Depending on the substance, this risk is 2 to 3 times higher compared to an approx. 1-1.5% risk in untreated women with epilepsy. The most common malformations under antiepileptic medication include malformations of the nervous system, cardiac septum, cleft palate and cleft lip. The following malformation rates were described for the individual active substances: non-exposed 1-1.5%, lamotrigine 2-3%, levetiracetam 2-3%, oxcarbazepine 2-3%, carbamazepine 3-5.5%, topiramate 4-5%, phenytoin 3-6.5%, phenobarbital 5.5-6.5%, valproic acid 9-10%.

In general, the risk of malformation is lower with treatment with only one antiepileptic drug than with treatment with several antiepileptic drugs at the same time. Medications with a comparatively favorable risk of fetal malformations include lamotrigine and levetiracetam; medium risk for carbamazepine and oxcarbazepine; increased risk for phenobarbital and topiramate; high risk for valproic acid. The effects of valproic acid, phenobarbital, carbamazepine (more than 700 mg per day) and possibly also lamotrigine (more than 300 mg per day) are dose-dependent. Valproic acid also carries the risk of childhood problems with speech and IQ, which are dose-dependent.

In summary, adequate but generally low-dose antiepileptic treatment with an active substance with a favorable profile and the intake of folic acid are recommended. During pregnancy, it is advisable to check the blood levels of your medication every month or so, as the blood levels of many medications can drop significantly and it may be necessary to increase the dose.

Electroencephalography (EEG)

We offer electrophysiological services for clinics and institutes of the USZ, external hospitals and practicing physicians, including

• the conventional scalp EEG
• the EEG after monitored sleep deprivation
• Telemetric EEG and long-term behavioral monitoring
• the electrophysiological monitoring of coma patients, pentothal coma treatments and patients with status epilepticus (waking room area, intensive care area)

Evoked potentials (EP; visual, somatosensory, acoustic)

We offer the following examinations:

• visual evoked potentials (VEP) to assess the optic nerve and the visual pathway, for example in the diagnosis of optic neuritis in multiple sclerosis.
• acoustically evoked potentials to assess the auditory pathway from the inner ear to the brain stem and auditory cortex.
• somatic evoked potentials (SEP, also SSEP for somatosensory evoked potentials) for the assessment of the peripheral sensory nerves and the central somatosensory pathway.