Post-Traumatic Seizures
Reviewed and revised 10 October 2014
OVERVIEW
- Post-Traumatic Seizures (PTS) occur in ~ 15% of patients with blunt severe TBI
- higher risk in children
- most occur within 48 hours
- most studies suggest that compliance with BTF guidelines (see below) regarding PTS prophylaxis is poor, most likely reflecting the paucity of evidence
CLASSIFICATION
- immediate seizure, <24 h (1-4% of TBI)
- early seizure, <7 days (4-25% of TBI)
- late seizure, > 7 days (9-42% of TBI)
RISK FACTORS FOR POST-TRAUMATIC SEIZURES
From BTF guidelines:
- GCS<10
- Cortical contusion
- Depressed skull fracture
- Subdural, epidural or intracerebral haematoma
- Penetrating head wound
- Seizure within 24 hours of injury
IMPLICATIONS
- an ‘impact seizure’ at the time of TBI is often benign
- PTS can contribute to secondary injury:
— increased metabolism
— increased neurotransmitter release
— increased intracranial pressure - potential for longterm sequelae:
— abnormal cognition and behaviour
— adverse effects on employment and recreation
PROPHYLAXIS
Overview
- Anti-epileptic drugs (AEDs) prevent early seizures (NNT = 10, Cochrane Review) but have no impact on outcome or mortality
- AEDs in the acute phase of TBI (first 7 days) do not reduce the incidence of PTS in the longterm and are not recommended for this purpose
- AEDs can have significant side-effects
Indications for AEDs
- clinical or EEG evidence of post-traumatic seizures
- high-risk of post-traumatic seizures (controversial; BTF guidelines suggest the presence of at least 1 risk factor)
Phenytoin is the first line agent (BTF Guidelines)
- proven efficacy in partial and generalized seizures
- loading dose 15–20 mg/kg over 30 min followed by 100 mg IV three times daily for 7 days titrated to plasma levels
— phenytoin cannot be given enterally at the same time as enteral nutrition - a second AED can be instituted if seizures persist
Levetiracetam may be an appropriate alternative
- 20mg/kg IV followed by 1000mg q12h for 7 days
- Szaflarski et al, 2010: a ‘single-blinded’ RCT of 53 patients compared levetiracetam and phenytoin, found that phenytoin associated with
— worsening neurologic function (GOSE at 6 months)
— more frequent adverse drug events
References and Links
Journal articles
- Bratton SL, et al. Guidelines for the Management of Severe Traumatic Brain Injury, 3rd edition: Antiseizure prophylaxis. Journal of Neurotrauma 2007;24(S1):S82-S86
- Khan AA, Banerjee A. The role of prophylactic anticonvulsants in moderate to severe head injury. Int J Emerg Med. 2010 Jul 22;3(3):187-91. PMC2926870
- Szaflarski JP et al. Prospective, randomized, single blinded comparative trial of intravenous levetiracetam versus phenytoin for seizure prophylaxis. Neurocrit Care 2010;12:165-172. PMID: 19898966
- Temkin NR. Risk factors for posttraumatic seizures in adults. Epilepsia 2003;44 (Suppl 10):18-20.
- Temkin NR, Dikmen SS, Wilensky AJ, Keihm J, Chabal S, Winn HR. A randomized, double-blind study of phenytoin for the prevention of post-traumatic seizures. N Engl J Med 1990;323:497-502. PMID: 2115976
- Thompson K, Pohlmann-Eden B, Campbell LA. Pharmacological treatments for preventing epilepsy following traumatic head injury (Protocol). Cochrane Database of Systematic Reviews 2012, Issue 6. Art. [Free Full Text – protocol only is published as of 10/10/2014]
FOAM and web resources
- EM PharmD — Post traumatic seizure prophylaxis – Phenytoin and PTS Part 2 (2013)
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC