AANS(1995, 2000) and AAPM&R(1998) Practice Parameters
• Recognize effects of AEDs on recovery, compliance • Lack of efficacy in prevention of late PTS • Option: Phenytoin, carbamazepine may prevent early PTS in high risk TBI; early PTS treatment does not prevent late PTS or improve outcome • Standard: Prophylactic anticonvulsants not
Multi-center study rationale
• What is natural history late PTS with new guidelines? • CT scan findings not incorporated into risk factor profile in previous studies • Civilian gunshot wounds may be different from military shrapnel wounds-> seizure risk • Follow-up mechanisms already in place through TBI Model Systems grants:
Hypotheses: multi-center, prospective study
• < 20% mod-severe TBI -> late PTS by 2 years • 1st year incidence > 2nd year • GCS injury severity will predict late PTS • Intracranial lesions by CT scan predict late PTS • Dural penetration predict late PTS
Consumer Feedback early 1990’s: Anticonvulsants (AED)
• No Standard of care: AEDs continued indefinitely • MDs reluctant to discontinue medications, especially prescribed by another MD • Memory problems and compliance • Drug side effects: ataxia, rashes, periodontal care, hair growth or loss, slowed thinking • Cost of medications, laboratory tests
Posttraumatic Seizure (PTS) Risk and Management in TBI: Objectives
Guidelines for PTS prophylaxis: AANS, AAPMR Predict PTS risk based on clinical presentation Analyze treatment strategies for individuals with late PTS from case study
Posttraumatic Seizure (PTS) definition
• Temporary brain dysfunction with excessive, hypersynchronous discharge of cortical neurons • Immediate: first 24 hours post injury • Early PTS: first 7 days • Late PTS: after one week
• Trauma centers: Denver, Richmond, Detroit, San Jose • > 16 yo, not pregnant, no previous seizure, stroke, tumor, intracranial surgery; AEDs < 1 mo post TBI • CT lesions during first week post TBI • SAH or intraventricular hemorrhage • cerebral contusion • epidural or subdural hematoma
Traditional Risk Factors for late PTS
• Penetrating shrapnel injuries, military: 53% over 15 years (Salazar, 1985) • Coma > 3 weeks: 25% (Guidice, 1987) • Early PTS->late PTS: 17-33%, age related in some studies • Intracranial hematoma: Epidural, 22%; subdural or intracerebral, 45% (Jennetcurrent unprovoked seizures • TBI accounts for 5-20% symptomatic epilepsy in general population • Early PTS -> 3-15% adults, 10-15% children; 17-33% develop late PTS, adults > children • Late PTS -> 86% recurrent seizures in 2 yrs (Haltiner et al, 1997)