Postoperative Epilepsy: A double blind Trial of phenytoin after craniotomy. North et al
The Lancet, Vol 315, Issue 8165, 384-386, Feb 1980
In a double blind trial of phenytoin for the prevention of postoperative epilepsy in craniotomy patients, epilepsy was observed in 7.9% (8/101) of patients treated with phenytoin and in 16.7% (17/102) of those receiving placebo. Therapeutic drug levels were associated with a significant reduction in frequency of seizures. Three quarters of seizures occurred within one month of cranial surgery.
This paper, although historical, gives clear indication of the very real risk of post-operative seizures, which can be disastrous. It also gives some direction to neurosurgeons on how long they need to continue post operative anticonvulsant prophylaxis.
Antiepileptic drugs as prophylaxis for post-craniotomy seizures (Review), Pulman et al
The Cochrane Collaboration, Dec 2012
Authors concluded that there is little evidence to suggest anticonvulsant prophylaxis is either effective or not effective in preventing post-craniotomy seizures. Many studies are limited in their usefulness or applicability due to variety in tumour locations, surgical approaches and pathologies. There is suggestion within this review that prophylaxis has the potential to do harm.
This review may not be of use in producing clinical guidelines, but may be useful support in a court of law and does prompt us to reflect on the side effect profiles of anticonvulsants we may consider using.
Postoperative seizures following the resection of convexity meningiomas: are prophylactic anticonvulsants indicated?
Sughrue et al
J Neurosurg 114: 705-709, 2011
Prophylactic antiepileptic drug therapy in patients undergoing supratentorial meningioma resection: a systematic analysis of efficacy. Komotar et al
J Neurosurg 115:483-490, 2011
There is not evidence easily available from the literature to support the use of anticonvulsant prophylaxis in this group of patients.
A prospective randomised trial of perioperative seizure prophylaxis in patients with intraparenchymal brain tumours.
Wu et al
J Neurosurg 118:873-883,2013
Population- patients with intraparenchymal tumours (biopsy or compelling imaging) with no previous seizures.
Intervention- administration of phenytoin as seizure prophylaxis
Comparison- no prophylaxis
Outcome- trial was closed early after 123 patients as independent analysis demonstrated there was unlikely to be any clinically significant difference between the groups. Seizure rate was 10% in the phenytoin group and 8% in the control group. The phenytoin group experienced significantly more adverse effects.
Postoperative seizure rates are low, which raises concerns about use of a prophylactic agent with side effects. Adverse effects of phenytoin may be more significant in some patient groups.
Levetiracetam compared to phenytoin for the prevention of postoperative seizures after craniotomy for intracranial tumours in patients without epilepsy.
Kern et al
Journal of Clinical Neuroscience 19 (2012) 99-100
Levetericetam is a valid alternative to phenytoin where there is concern about the side effect profile.