The Epidemiology of Posttraumatic Epilepsy

Epidemiology of Traumatic Brain Injury

Traumatic brain injury (TBI) is an important contributor to morbidity and mortality, and results in reduced quality of life and lifespan.^[1] An estimated 1.7 million traumatic brain injuries occur annually in the United States;^[2] 1.2 million traumatic brain injuries occur annually in the European Union (including Iceland, Norway, and Switzerland).^[3] The risk of TBI varies greatly with age, being particularly high in early childhood and in the elderly, but the incidence also has a striking peak incidence in early adulthood—especially among males (Fig. 1). Traumatic brain injury is more frequent in males than in females; it is overall approximately1.4 times more common among males (Fig. 1).^[2]

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Figure 1.

Annual rate of traumatic brain injury by sex in the United States, 2002–2006.²

The consequences of TBI are significant, not least in terms of increase in mortality. Mortality following TBI remains low until 15 years of age, but from that age onward the mortality increases sharply (Fig. 2). There are marked sex differences, with mortality from TBI being 2.9 times more likely in males than in females (Fig. 2).^[2] Approximately 50,000 persons in the United States die annually from TBI-related injuries. Traumatic brain injury results from several causes, including falls and motor vehicle accidents (Fig. 3). The causes of injury relate closely to age—for example, TBI from motor vehicle accidents and assaults peak in adolescence and early adulthood, coinciding with the sharp rise in incidence and mortality (for males) associated with TBI in that age group (Fig. 3).^[2]

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Figure 2.

Rates of traumatic brain injury-related deaths by age group and sex in the United States, 2002–2006.²

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Figure 3.

Traumatic brain injury by external cause in the United States, 2002–2006.²

It is extremely difficult to estimate the costs of TBI and more difficult to compare these estimates across countries or even continents. However, it has been estimated that the total costs of TBI in the European Union (plus Iceland, Norway, and Switzerland) with a total population of 514 million, is more than 33 billion euros (equivalent to 37 billion US$ or 24 billion GBP£) this compares to the total cost of stroke of 64 billion euros (72 billion US$ or 47 billion GBP£ per year).^[3] It is currently unknown what additional part comorbid epilepsy plays in the economic cost of the consequences of TBI.