Epilepsy is a "functional" disease.

GRAND MAL ("_Great Evil_")

An unusual feeling called an _aura_ (Latin--vapour), sometimes warns a
patient of an impending fit, commonly lasting long enough to permit him to
sit or lie down. This is followed by giddiness, a roaring in the ears, or
some unusual sensation, and merciful unconsciousness. In many cases this
stage is instantaneous; in others it lasts some seconds--but an eternity to
the sufferer. This stage is all that victims can recall (and this only
after painful effort) of an attack.

As unconsciousness supervenes, the patient becomes pale, and gives a cry,
which varies from a low moan to a loud, inhuman shriek. The head and eyes
turn to one side, or up or down, the pupils of the eyes enlarge and become
fixed in a set stare, and the patient drops as if shot, making no effort to
guard his fall, being often slightly and sometimes severely injured.

The whole body then becomes stiff. The hands are clenched, with thumbs
inside the palms, the legs are extended, the arms stiffly bent, and the
head thrown back, or twisted to one side. The muscles of the chest and
heart are impeded in their action, breathing ceases, the heart is slowed,
and the face becomes pale, and then a livid, dusky blue.

The skin is cold and clammy, the eyebrows knit; the tongue may be
protruded, and bitten between the teeth. The eyeballs seem starting from
their sockets, the eyes are fixed or turned up, so that only the sclerotic
("whites") can be seen, and they may be touched or pressed without causing
blinking. The stomach, bladder, and bowels may involuntarily be emptied.