Antiepileptic drugs for the primary and secondary prevention of seizures after subarachnoid haemorrhage

The purpose of this review was to examine whether the routine use of antiepileptic medication in preventing epileptic seizures following subarachnoid haemorrhage can be justified. This includes patients who have not yet had a seizure (primary prevention) and those who have already had one (secondary prevention).

Epileptic seizures are caused by abnormal, rhythmic discharges of nerve cells within the brain leading to involuntary changes in body movement or function, sensation, awareness, or behaviour. Following a subarachnoid haemorrhage seizures can occur in up to 25% of patients, triggered by nerve cell damage caused by the blood itself, the formation of scar tissue, and swelling around the site of bleeding. Recurrent uncontrolled seizures can cause considerable morbidity and mortality, preventing neurological recovery and reducing quality of life. Conversely, side effects of antiepileptic medication include diarrhoea, nausea and vomiting, drowsiness, dizziness, agitation, tremor, confusion and skin rash. These need to be considered when prescribing antiepileptic medication, as the medication itself may hinder neurological recovery and rehabilitation.

To date there have been no randomised controlled trials comparing antiepileptic drugs with placebo following subarachnoid haemorrhage. Some retrospective studies have suggested worse outcomes in patients on higher doses and a longer duration of antiepileptic treatment, as explained in the review, but they do not provide the strength of evidence required for their use as a routine recommendation.

Currently, there is insufficient evidence to justify the routine use of antiepileptic medication for the primary and secondary prevention of seizures after subarachnoid haemorrhage, and a double blind randomised controlled trial comparing antiepileptic medication with placebo would help to clarify this important question.

Authors' conclusions: 

There was no evidence to support or refute the use of antiepileptic drugs for the primary or secondary prevention of seizures related to subarachnoid haemorrhage. Well-designed randomised controlled trials are urgently needed to guide clinical practice.

Read the full abstract...

Subarachnoid haemorrhage may result in seizures both acutely and in the longer term. The use of antiepileptic drugs (AEDs) in the primary and secondary prevention of seizures after subarachnoid haemorrhage is uncertain, and there is currently no consensus on treatment.


To assess the effects of AEDs for the primary and secondary prevention of seizures after subarachnoid haemorrhage.

Search strategy: 

We searched the Cochrane Epilepsy Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 1) in The Cochrane Library, and MEDLINE (1946 to 12th March 2013). We checked the reference lists of articles retrieved from these searches.

Selection criteria: 

We considered all randomised and quasi-randomised controlled trials in which patients were assigned to a treatment (one or more AEDs) or placebo.

Data collection and analysis: 

Two review authors (RM and JK) independently screened and assessed the methodological quality of the studies. If studies were included, one author extracted the data and the other checked it.

Main results: 

No relevant studies were found.