Seizure: Symptoms, Causes

Brief overview

  • Description: Involuntary event with convulsive or jerking movements, possibly with loss of consciousness.
  • Causes: Usually epilepsy, sometimes with a specific trigger (such as increased intracranial pressure, hypoglycemia, encephalitis), but usually without; more rarely non-epileptic seizures such as febrile convulsions in children or seizures as a result of a stroke.
  • Treatment: First aid measures (such as head protection, recovery position), emergency medical treatment if necessary, long-term treatment of the underlying disease (e.g. with anticonvulsants)
  • When to see a doctor? In the event of a first seizure, prolonged seizures (over 3 minutes) or repeated seizures within a short period of time: call an emergency doctor!
  • Diagnostics: Patient interview (medical history), electroencephalography (EEG), computer tomography (CT) or magnetic resonance imaging (MRI), blood and urine tests, cerebrospinal fluid puncture if necessary

What is a seizure?

A seizure is usually a sudden, involuntary event with convulsive or twitching movements. Depending on the type of seizure, the person affected may lose consciousness. Sometimes a seizure has all three of these characteristics, sometimes not.

Around 5 percent of people will have a seizure at some point in their lives.

During a cerebral seizure (= originating in the brain), however, all order is lost, so that certain groups of nerve cells suddenly discharge simultaneously and transmit their uncoordinated signals synchronously. They infect downstream nerve cells, so to speak. Metaphorically speaking, a seizure can also be described as a “thunderstorm in the brain”.

Seizure: symptoms

A seizure is characterized by various symptoms that differ depending on the type and severity of the seizure:

  • Involuntary, convulsive or twitching movements
  • Tingling or numbness
  • Loss of consciousness

A seizure is usually over in less than two minutes; sometimes it only lasts a few seconds. After prolonged, generalized seizures, those affected often feel exhausted and need to rest and sleep.

Seizure: causes

The most common cause of seizures is epilepsy. However, not every seizure is caused by an epileptic disorder.

There are also seizures that are not due to a neurological disorder in the brain, but have psychological causes (such as an extreme stress situation). Doctors refer to this as a psychogenic seizure.

Epileptic seizures

This is to be distinguished from symptomatic epilepsy, in which the epileptic seizures have known triggers. These include

  • Brain injuries: As a result of such injuries, scar tissue forms in the brain, which in turn triggers an increase in seizures.
  • Circulatory disorders: Disturbed blood flow to the brain (such as in the case of a stroke) occasionally results in epileptic seizures.
  • Tumors or inflammation: Sometimes epileptic seizures are a symptom of a brain tumor or an inflammation of the brain or meninges (encephalitis, meningitis).
  • Increased intracranial pressure: Increased pressure in the brain (e.g. as a result of an injury) may promote seizures.
  • Metabolic disorders: Sometimes low blood sugar (hypoglycemia) can be identified as a seizure trigger.
  • Oxygen deficiency: If there is a prolonged lack of oxygen (hypoxia), the body is undersupplied at a certain point, which sometimes triggers a seizure in the brain.
  • Visual stimuli: In some people, for example, strobe lights in discos or flickering lights in video games trigger a seizure.
  • Poisoning: Sometimes medications such as tricyclic antidepressants provoke a seizure.
  • Drugs and alcohol: When an alcoholic goes through withdrawal, for example, seizures occasionally occur.

Seizure – but no epilepsy

Some people suffer a seizure but do not have epilepsy. Such non-epileptic seizures are therefore not due to an increased susceptibility of the neurons to seizures – rather, they are caused by a reversible disorder in the brain or another condition that irritates the brain, such as:

  • head injury
  • stroke
  • infection
  • medication
  • drugs
  • in children: Fever (febrile convulsion)

Other diseases and disorders that sometimes lead to muscle cramps must be distinguished from seizures. For example, a tetanus infection (tetanus) causes muscle cramps all over the body.

Seizures in children and babies

Seizures are not uncommon in infants. For parents, such an event is initially a shock. In most cases, however, the cause is harmless.

Febrile infections, for example, trigger seizures. These seizures are usually only brief and leave no lasting damage. However, epilepsy, brain damage during birth and metabolic disorders also sometimes cause seizures in babies.

Read the article “Seizures in children and babies” to find out how seizures manifest themselves in very young children and how best to react to them.

Seizure: What to do?

First aid for a seizure

If you see someone having a seizure, stay calm – even if such a full-body convulsion is often a frightening sight. The seizure usually stops on its own within a few minutes. The following recommendations also apply:

  • Remove dangerous objects that are close to the person having the cramp so that they do not injure themselves.
  • Protect the head (e.g. with a pillow).
  • Do not hold the person affected.
  • Do not put any objects in the mouth as a chock (e.g. spoons) – there is a risk of injury and the patient may inhale or swallow the object.
  • Secure the airway by turning the patient into the prone or stable side position.
  • Call an ambulance if the seizure lasts longer than three minutes.

It is best to stop the time in order to actually assess how long the seizure has lasted. In emergency situations, the sense of time quickly gets out of joint.

Medical treatment for a seizure

In the case of seizures, the doctor tries to treat the cause. For example, if hypoglycemia has triggered the seizure, the patient will be given glucose (usually as an infusion). If possible, the doctor will also initiate treatment for the cause of the low blood sugar level – in this case often diabetes mellitus.

  • Anticonvulsant medication (called anticonvulsants or antiepileptics)
  • Avoidance of possible triggers (such as excessive alcohol consumption, lack of sleep)
  • Surgical intervention on the brain if necessary (less common)

Seizure: when to see a doctor?

After a first seizure – whether in childhood or adulthood – it is always advisable to see a doctor. This is the only way to clarify possible causes and diagnose any underlying illnesses. The specialist responsible for seizures is a neurologist.

Sometimes those affected do not even realize that they are having or have just had a seizure, for example in the case of absences. Outsiders who do notice are best advised to make this clear.

When to call an ambulance in the event of a seizure?

If you observe a seizure in another person, it is not absolutely necessary to call an ambulance: If you know that the patient is already being treated for seizures and the seizure stops on its own after a short time, medical assistance is usually not necessary.

In the following cases, however, it is always advisable to call a doctor:

  • When a seizure occurs for the first time
  • If a seizure lasts longer than three minutes (risk of so-called status epilepticus)
  • If several seizures occur within 30 minutes

If one of the bystanders has a cell phone or other camera to hand, it is very useful in this case to film the seizure: a video on which the doctor can see the movements and face of the person having the seizure is very helpful for the diagnosis.

How dangerous is a seizure?

Single seizures are usually not dangerous and will pass by themselves. However, an epileptic seizure that lasts longer than five minutes (status epilepticus) is life-threatening. This requires immediate medical treatment.

In principle, it is also dangerous if someone has a seizure in an unsafe situation – for example at the wheel of a car, when working on a roof or with a chainsaw. Epileptics should take this to heart, even if it has been some time since their last seizure.

Seizure: examinations and diagnosis

First of all, the doctor clarifies whether a seizure has actually occurred. To do this, he first rules out other causes that cause similar symptoms. If the patient has actually had a seizure, the cause must be clarified and treatment initiated if necessary.

A precise description of the symptoms – either by the patient themselves or by relatives – is already very helpful. The doctor will also ask questions such as

  • How long did the seizure last?
  • How quickly did you / did the patient recover after the seizure?
  • Are there any factors that could have triggered the seizure (noises, flashing light, etc.)?
  • Is there a pre-existing or underlying condition (e.g. brain infection) or a recent head injury?
  • Do you / does the patient consume drugs such as alcohol? Is withdrawal currently taking place?

Electroencephalography (EEG) is then used to measure and record the patient’s brain waves in order to detect any abnormalities. The doctor may also try to provoke a seizure during the measurement – for example by using certain light stimuli or by deliberately causing the patient to hyperventilate.

An EEG can also be recorded over a longer period of time. It is also possible to film the patient during this time (video EEG monitoring) so that the doctor can see exactly what happens during a (possible) further seizure.

In order to identify possible causes of seizures, the doctor may use computer tomography (CT) or magnetic resonance imaging (MRI) to produce detailed cross-sectional images of the brain. It may be possible to identify structural changes (such as those caused by a stroke or tumor) that cause seizures.

Further examinations may be indicated. These include taking and analyzing a sample of cerebrospinal fluid (lumbar puncture) if an infection of the brain is suspected as the cause of seizures.