Though the disease may occur at any age, most cases occur before the age of
twenty, there being good reason to look for other causes (often syphilis)
in cases which occur after that age. Of 1,450 of Gowers' cases, 30 per cent
commenced before the age of ten; 75 per cent before twenty. In Starr's
2,000 cases, 68 per cent commenced before the patient was twenty-one.

According to Turner, the first epoch is from birth to the age of six,
during which 25 per cent of all cases commence, usually associated with
mental backwardness, and some due to organic brain trouble. The second
epoch is ten to twenty-two, the time of puberty and adolescence, during
which time no less than 54 per cent of all cases commence. This is, _par
excellence_, the age of onset of genuine epilepsy, the mean age of maximum
onset being fourteen in men and sixteen in women. The remaining 21 per cent
of cases occur after the age of twenty-two.

In 430 cases of epilepsy in children, Osler found that 230 were attacked
before they reached the age of five, 100 between five and ten, and 100
between ten and fifteen.

Epilepsy, then, is a disease of early youth, coming on when the development
and growth of the nervous and reproductive systems is taking place. During
this period, causes, insignificant for stable people, may light up the
disease in those of unstable, nervous constitution, a fact which explains
the importance of training the child.

Both sexes are attacked. If we consider only cases of true idiopathic
epilepsy female patients are probably in excess, but in epilepsy in adults,
from all causes, males predominate. In females, the menopause may arrest
the disease.