Seizures and convulsions for first responders – August 2015
Seizures, convulsions, first responder, pre-hospital, emergency, ambulance, paramedic
A seizure is a transient episode of abnormal and chaotic electrical activity within the brain. The brain is made up of nerve cells that begin and pass on electrical transmissions to other brain cells and parts of the body. These control the normal functions within the body including touch, feel, movements, heart beat, blood vessels, breathing, the gastrointestinal system and other organs.
Seizures occur within the brain and so cannot be seen without a device known as an electroencephalograph or EEG. However the parts of the body controlled by the affected part of the brain can sometimes be observed behaving abnormally. Much of the brain mass is responsible for conscious thought and body movements. As such when this part of the brain is involved, movement and thought might be visibly affected.
The most common seizure presentation involves loss of consciousness of the patient followed by uncontrolled motor function of the limbs. The limb movement is called a convulsion. It might be violent shaking, subtle tremor or even rigid stiffness. A seizure is not less brain function. It is in fact increased but uncontrolled. A seizure can occur without a convulsion being seen. Again it depends on the part of the brain that is affected. Convulsion activity is sometimes referred to as ‘having a fit’.
There are many reasons seizures occur. Some have a clear cause. Some are medical whilst others are traumatic. Some are easily managed and pose little problem. Others can be very problematic. Some will be very predictable allowing the person to vary their life around them. Others will be first time and without any warning.
Seizure causes can be divided loosely into three different sub-groups. There are those that follow some structural change or injury inside the brain, those that involve something outside of and separate to the brain and those that involve temporary changes in normal brain activity.
Structural causes of seizure include medical causes such as stroke or brain tumour and traumatic causes from head injury. These can interfere with normal production and passing of electrical impulses within the brain.
The brain is an organ protected within the skull. There is a down side to this as anything that causes the size of the brain to increase will cause the brain to be literally squeezed inside the skull. This can have an adverse impact on the functions of the brain. A tumour growing inside the skull can cause this. Onset of seizures may be the first sign of a tumour. Tumours may cause occasional or frequent seizures and can continue even after surgery to remove them.
Stroke causes part of the brain to be damaged following interruption of normal blood supply to some cells. Some brain cells can die. This can cause disruptions to the normal passing of electrical messages from one part of the brain to others and can cause seizures. This can happen in acute stroke or in the longer term following the stroke.
Just as parts of the brain can be damaged or die in stroke, they can too in head trauma. Trauma to the head can damage some cells immediately. Other cells can be damaged from bleeding within the skull or swelling of the brain. Similar to stroke this can interfere with normal electrical impulses in the brain leading to seizures.
Not all seizures follow some structural change or injury in the brain. Seizures can be triggered by events originating outside the brain including fever and infection, oxygen starvation, cardiac arrest, drug overdose, metabolic abnormalities and pregnancy.
Infections that directly affect the brain such as meningitis can cause seizures. This may be due to the bacteria or virus itself or complications of the immune response such as inflammation in the brain. This can happen at any age.
A common association between infection and seizures is the febrile convulsion that affects children. This form of seizure is caused by the inability of young children to be able to manage sharp rises in body temperature. This part of the child’s brain is not yet developed in some young children. Typically it occurs in children less than a few years of age. These seizures do not continue through to later life or go on to become epilepsy.
The brain must receive oxygen for normal function and survival. If deprived of oxygen loss of consciousness occurs. For short periods this can cause a seizure to occur as the patient deteriorates. It is critical to recognise this is the cause of a seizure as it must be corrected immediately before permanent brain damage can occur. Acute breathing difficulty or airway obstruction may be such causes.
Similar to oxygen starvation a seizure can occur if the pulse suddenly stops. The sudden stop of blood supply to the brain causes loss of consciousness. In the first minute after cardiac arrest a seizure may occur with this. This can be sudden and without warning. It is essential to identify if a seizure is caused by loss of pulse as the only means of treating it is to manage the cardiac arrest. A correct primary survey will allow for this.
Both prescription and illicit drugs can cause seizures. Cocaine and other stimulant drugs such as amphetamine can. Some mental health drugs including some antidepressants can also. The seizure may be caused by the direct action of the drug or by the side effects such as interruption to breathing or pulse. Withdrawal from drugs and alcohol can also cause seizures. This can include both illicit and prescriptive drugs where some dependence has been established.
The brain needs two essential elements to function – oxygen and glucose. Just as absence of oxygen can cause a seizure so too can glucose absence. Hypoglycaemia can cause a seizure. Management of the low blood sugar is important to stop this seizure. Any time a patient is found having a seizure the blood sugar should be assessed as soon as practicable, particularly if there is no history of seizure activity or if there is a history of blood sugar disorder.
Changes in the amount of sodium and calcium in the blood can also cause seizures to occur but this will be very difficult to recognise by pre-hospital responders.
Very uncommonly the pregnant woman can have a rise in blood pressure and elevated protein in the blood. Likely this will have been noted by the antenatal doctor and will be known to the patient. This is known as pre-eclampsia. It is important to note high blood pressure when you examine the pregnant woman, particularly in the latter months of gestation. When severe the problem can disturb the blood flowing through the brain and lead to seizures occurring. This is known as eclampsia and is particularly serious.
Not all seizures will have a detectable reason for occurring that can be identified and managed. Sometimes the seizure will occur in an otherwise normal functioning brain. There is no structural change within the brain nor is there some other problem within the body that is causing it. The seizure may spontaneously appear without warning then disappear soon afterward. This is a common form of seizure with the best known type being epilepsy.
With epilepsy the chaotic electrical activity in the brain begins spontaneously and can present in a number of ways depending on the part of the brain affected. Many patients are born with this problem. Some manage it well in life being only occasionally troubled. Others take medications that limit how often seizures occur. One of the reasons seizures continue to occur is patients failing to take medications as prescribed. A few people will have major problems so that even with medication, seizures can sometimes even occur multiple times every day.
Seizure types: Seizures present in various ways. They can involve only a small part of the brain or they can be generalised and involve the whole brain. As the seizure occurs it may cause loss of consciousness or it may have no impact on consciousness at all. The seizure may be short in duration or it may last for many hours and pose great difficulty in stopping it.
A seizure can start in one part of the brain and remain limited to that part. The observable effects of this partial seizure will also be limited to the part of the body controlled by that brain part. This may include the eyes, face, one arm or one side of the body. Focal seizure means that it has one focal point in the brain.
Generalised seizure is arguably the best known form of seizure. It involves the whole of the brain and so is ‘generalised’ instead of with one focus. It may start as a partial seizure or as a generalised seizure. Twitching and jerking convulsion movements of the face, arms and legs may be seen. There is no real purpose to these movements and they can change and range between strong movements to barely noticeable.
This sort of seizure was once known as grand mal seizure. More recently it has become called tonic/clonic seizure. The tonic part is a sudden stiffening of muscles all over the body including those of breathing. This may force the patient to cry out, a common first clue that there is a problem. The clonic part is the more vigorous body movements that follow immediately after. This may stop quickly or gradually slow. Mostly they stop by themselves within a few minutes.
Not all generalised seizures cause convulsions. Absence seizures, once known as petit mal seizures, involve vacant staring of the patient. This can be observed in young children in particular and sometimes not be recognised for what it is.
In all cases it is important to note and document clearly what the seizure looks like as it may provide important clues to where the problem is coming from. Similarly, if the seizure has stopped it will be important to get a history from those who did witness it.
Consciousness is frequently lost during seizures. When loss of consciousness occurs this is known as a complex seizure. If consciousness is not lost the seizure is a simple one. Partial seizures may be simple or complex. Similarly generalised seizures may be simple or complex.
Almost all seizures will last for between a few seconds to a few minutes. Infrequently some fail to stop by themselves. This is called continuous seizures. Whilst one short seizure might not even be considered an emergency and just a part of normal life by some, the seizure that will not stop is an emergency. This has previously been called status epilepticus.
Recurrent seizures are where the seizures do stop each time but keep returning a short time after. This can clearly become quite a problem for any person.
When a seizure does not stop it will cause a number of problems for the patient. Some are direct and some indirect.
Continuous seizure activity means excess electrical activity of part or all of the brain. The direct complications happen to those brain cells doing this excessive work. Just as would happen to an overworked muscle, the brain cells become less efficient and burn up more oxygen and energy than they can receive. Excess lactic acid builds up that can damage or destroy brain cells if too severe or prolonged.
Indirect complications include the results of the convulsion. Respiratory muscles can initially spasm and stop breathing. This will not last long and breathing will again return. Seizures can last for hours so breathing must still continue. However it will likely not be sufficient to allow for the increased brain activity so will not be much help with the increased need for oxygen. This will be compounded by the loss of normal airway reflexes putting the patient at risk of airway obstruction. A generalised seizure causing major convulsion activity can produce a lot of body heat too and this can be problematic for the brain if it goes on too long.
Assess carefully for seizure activity. The patient may be unconscious but not actually seizing. It may be difficult to tell if the seizure has stopped or still continues with much less visible convulsion activity. Seizing may be obvious with violent limb jerking movements visible. It may be subtle and have to be carefully looked for. Look at the eyes for eye rolling, pulled in one direction or twitching. Assess the arms and legs for stiffness or jerking movements. Less obvious seizure activity might only include twitching of the hands or the face.
More commonly though the patient may be beginning to return to normal consciousness and show signs of normal movement or awareness returning.
Some patients can have ongoing problems with seizures that cannot be managed with their own daily medication. These people can have an emergency plan for this. This includes anticonvulsant medication similar to that used by paramedics. Drugs that can be administered into the rectum or the nose of the patient can be kept at the patient’s home for carers to deliver.
First responders may find these medications have already been administered. Where this is the case it will be important to evaluate if the drug has worked and if the seizure has been stopped. It will also be important to look for problem side effects such as shallow breathing. In some cases the medication will not yet have been administered. Where this is the case enquire of the carer why not. Assistance can be offered to the carer to now administer their drug as long as the patient remains seizing.
Febrile convulsion in children is a common ambulance call. These may be alarming for parents to watch and reassurance is needed. However the appearance and management of the febrile convulsion in children is not much different to any other seizure.
One difference will be the fever and the infective illness causing it. Many seizure patients will generate extra body heat from the convulsion activity. Temperature during febrile convulsion will often exceed 38°C. Fever is considered part of the helpful immune response and is only a problematic if excessive. Up to 40°C or so is acceptable though the child may feel irritable.
Administration of paracetamol to reduce fever was considered normal but this is no longer routinely advised. Only encourage the parents to administer paracetamol if the child is particularly restless or in pain or if the temperature is too high. Typically this will be above 40°C. Similarly placing the patient in a tepid bath to reduce body temperature is no longer recommended unless the temperature is similarly too high. The child must not be cooled too much as this can cause shivering. The child should never be left unattended in a bath.
The child will has an underlying illness that will complicate assessment. Not only will the vital signs be changed by the seizure but also by the illness. There may already be a faster pulse rate or breathing. The child may also have a sore ear or throat, runny nose or other infection. The fever may even have been caused by a very recent immunization.
A most important point about febrile convulsion is that the cause of infection must be identified. Though most will be relatively harmless, such as ear, nose or throat infection, the most worrying cause of fever will be infections that affect the brain such as meningococcal infections. Medical examination of all febrile convulsions is important to identification of cause.
Most seizures stop within a few minutes without any intervention needed. When they stop there are two common outcomes. The patient may show a return to consciousness and normal behaviour. Alternatively they may stay unconscious and not show either seizure activity or return of consciousness.
The medical term for seizure is ‘ictus’. The period after a seizure is referred to as the ‘post-ictal’ state. This period can be as short as a few minutes but may last for thirty minutes or more. Initially it may be difficult to tell if the seizure has completely stopped. Within a few minutes this should become more apparent. Typically the patient post seizure may appear as if they want to sleep. They may try to pull their arms under the head or body and curl in a ball. They may push those touching them away trying to be left alone.
Verbal communication may be limited early and may be little more than incomprehensible groaning or inappropriate. Early conversation may be confused. The patient may be slightly fearful or agitated for a few minutes but eventually there will be a progressive return to normal conscious state. The patient may not realise they have had a seizure so will have to be reassured everything is okay. They may not even be aware of who you are.
Uncommonly some patients will be neither continuously seizing nor recovering in a post-ictal state. The patient may appear to be simply unconscious when assessed. This can occur for a number of reasons.
The patient may have very subtle seizure activity not enough to be seen as clonic jerking movements. Close examination may demonstrate subtle signs such as stiffness in the limbs, twitching of the eyes or even twitching of fingers or toes.
The seizure activity may have stopped and the patient simply has a long recovery time and has not begun to show signs of recovery yet.
The patient may be under the effects of medication provided by others to stop the seizure. This might include diazepam (valium) or midazolam given by family, carers or paramedics. These drugs can work well after the seizure has stopped delaying recovery.
Jeff Kenneally www.prehemt.com
Jeff is the author of the 2014 – 2016 Ambulance Victoria First Responder clinical practice protocols and accompanying education program.