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
CCC Neurocritical Care Series
Emergencies: Brain Herniation, Eclampsia, Elevated ICP, Status Epilepticus, Status Epilepticus in Paeds
DDx: Acute Non-Traumatic Weakness, Bulbar Dysfunction, Coma, Coma-like Syndromes, Delayed Awakening, Hearing Loss in ICU, ICU acquired Weakness, Post-Op Confusion, Pseudocoma, Pupillary Abnormalities
Neurology: Anti-NMDA Encephalitis, Basilar Artery Occlusion, Central Diabetes Insipidus, Cerebral Oedema, Cerebral Venous Sinus Thrombosis, Cervical (Carotid / Vertebral) Artery Dissections, Delirium, GBS vs CIP, GBS vs MG vs MND, Guillain-Barre Syndrome, Horner’s Syndrome, Hypoxic Brain Injury, Intracerebral Haemorrhage (ICH), Myasthenia Gravis, Non-convulsive Status Epilepticus, Post-Hypoxic Myoclonus, PRES, Stroke Thrombolysis, Transverse Myelitis, Watershed Infarcts, Wernicke’s Encephalopathy
Neurosurgery: Cerebral Salt Wasting, Decompressive Craniectomy, Decompressive Craniectomy for Malignant MCA Syndrome, Intracerebral Haemorrhage (ICH)
— SCI: Anatomy and Syndromes, Acute Traumatic Spinal Cord Injury, C-Spine Assessment, C-Spine Fractures, Spinal Cord Infarction, Syndomes,
— SAH: Acute management, Coiling vs Clipping, Complications, Grading Systems, Literature Summaries, ICU Management, Monitoring, Overview, Prognostication, Vasospasm
— TBI: Assessment, Base of skull fracture, Brain Impact Apnoea, Cerebral Perfusion Pressure (CPP), DI in TBI, Elevated ICP, Limitations of CT, Lund Concept, Management, Moderate Head Injury, Monitoring, Overview, Paediatric TBI, Polyuria incl. CSW, Prognosis, Seizures, Temperature
ID in NeuroCrit. Care: Aseptic Meningitis, Bacterial Meningitis, Botulism, Cryptococcosis, Encephalitis, HSV Encephalitis, Meningococcaemia, Spinal Epidural Abscess
Equipment/Investigations: BIS Monitoring, Codman ICP Monitor, Continuous EEG, CSF Analysis, CT Head, CT Head Interpretation, EEG, Extradural ICP Monitors, External Ventricular Drain (EVD), Evoked Potentials, Jugular Bulb Oxygen Saturation, MRI Head, MRI and the Critically Ill, Train of Four (TOF), Transcranial Doppler
Pharmacology: Desmopressin, Hypertonic Saline, Levetiracetam (Keppra), Mannitol, Midazolam, Sedation in ICU, Thiopentone
MISC: Brainstem Rules of 4, Cognitive Impairment in Critically Ill, Eye Movements in Coma, Examination of the Unconscious Patient, Glasgow Coma Scale (GCS), Hiccoughs, Myopathy vs Neuropathy, Neurology Literature Summaries, NSx Literature Summaries, Occulocephalic and occulovestibular reflexes, Prognosis after Cardiac Arrest, SIADH vs Cerebral Salt Wasting, Sleep in ICU
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
